Introduce a basic set of smoke tests using the XTF selftest image, and run
them on QEMU. Use the matrix keyword to create a different task for each
XTF flavor on each FreeBSD build.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Oleksii Kurochko<oleksii.kurochko@gmail.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
In preparation for adding some smoke tests that will consume those outputs.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
In preparation for using the XTF selftests to smoke test the FreeBSD based
Xen builds.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Move the current logic to use the matrix keyword to generate a task for
each version of FreeBSD we want to build Xen on. The matrix keyword
however cannot be used in YAML aliases, so it needs to be explicitly used
inside of each task, which creates a bit of duplication. At least abstract
the FreeBSD minor version numbers to avoid repetition of image names.
Note that the full build uses matrix over an env variable instead of using
it directly in image_family. This is so that the alias can also be set
based on the FreeBSD version, in preparation for adding further tasks that
will depend on the full build having finished.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Introduce an additional Kconfig check to only offer the option if the
compiler supports -fsanitize=undefined.
We no longer use Travis CI, so the original motivation for not enabling
UBSAN might no longer present. Regardless, the option won't be present in
the first place if the compiler doesn't support -fsanitize=undefined.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
The call to ioremap_wc() in video_init() will always fail, because
video_init() is called ahead of vm_init_type(), and so the underlying
__vmap() call will fail to allocate the linear address space.
Fix by reverting to the previous behavior and use __va() for the VGA text
buffer, as it's below the 1MB boundary, and thus always mapped in the
directmap.
Fixes: 81d195c6c0 ('x86: introduce ioremap_wc()')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
mkelf32 attempt to check that the program header defined NOTE segment falls
inside of the LOAD segment, as the build-id should be loaded for Xen at
runtime to check.
However the current code doesn't take into account the LOAD program header
segment offset when calculating overlap with the NOTE segment. This
results in incorrect detection, and the following build error:
arch/x86/boot/mkelf32 --notes xen-syms ./.xen.elf32 0x200000 \
`nm xen-syms | sed -ne 's/^\([^ ]*\) . __2M_rwdata_end$/0x\1/p'`
Expected .note section within .text section!
Offset 4244776 not within 2910364!
When xen-syms has the following program headers:
Program Header:
LOAD off 0x0000000000200000 vaddr 0xffff82d040200000 paddr 0x0000000000200000 align 2**21
filesz 0x00000000002c689c memsz 0x00000000003f7e20 flags rwx
NOTE off 0x000000000040c528 vaddr 0xffff82d04040c528 paddr 0x000000000040c528 align 2**2
filesz 0x0000000000000024 memsz 0x0000000000000024 flags r--
Account for the program header offset of the LOAD segment when checking
whether the NOTE segments is contained within. Also fix the logic to
ensure the NOTE segments is fully contained between the LOAD segment.
Fixes: a353cab905 ('build_id: Provide ld-embedded build-ids')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Clarify that trampoline_setup is only used for EFI when booted using the
multiboot2 entry point.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Instead use env to find the location of expect.
Additionally do not use the -f flag, as it's only meaningful when passing
arguments on the command line, which we never do for console.exp. From the
expect 5.45.4 man page:
> The -f flag prefaces a file from which to read commands from. The flag
> itself is optional as it is only useful when using the #! notation (see
> above), so that other arguments may be supplied on the command line.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
In case the build fails or gets stuck, store the Kconfig file ahead of
starting the build.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Such timestamps can still be disabled from the Web UI using a tick box.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
UBSAN complains with:
UBSAN: Undefined behaviour in arch/x86/mm/shadow/private.h:515:30
pointer operation overflowed ffff82e000000000 to ffff82dfffffffe0
[...]
Xen call trace:
[<ffff82d040303782>] R common/ubsan/ubsan.c#ubsan_epilogue+0xa/0xc0
[<ffff82d040304bc3>] F __ubsan_handle_pointer_overflow+0xcb/0x100
[<ffff82d040471b2d>] F arch/x86/mm/shadow/guest_2.c#sh_page_fault__guest_2+0x1e350
[<ffff82d0403b206b>] F svm_vmexit_handler+0xdf3/0x2450
[<ffff82d0402049c0>] F svm_stgi_label+0x5/0x15
Fix by moving the call to mfn_to_page() after the check of whether the
passed gmfn is valid. This avoid the call to mfn_to_page() with an
INVALID_MFN parameter.
While there make the page local variable const, it's not modified by the
function.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
UBSAN complains with:
UBSAN: Undefined behaviour in common/compat/memory.c:90:9
pointer operation overflowed ffff820080000000 to 0000020080000000
[...]
Xen call trace:
[<ffff82d040303782>] R common/ubsan/ubsan.c#ubsan_epilogue+0xa/0xc0
[<ffff82d040304bc3>] F __ubsan_handle_pointer_overflow+0xcb/0x100
[<ffff82d0402a6259>] F compat_memory_op+0xf1/0x4d20
[<ffff82d04041532d>] F hvm_memory_op+0x55/0xe0
[<ffff82d040416150>] F hvm_hypercall+0xae8/0x21b0
[<ffff82d0403b24ca>] F svm_vmexit_handler+0x1252/0x2450
[<ffff82d0402049c0>] F svm_stgi_label+0x5/0x15
Adjust the calculations in COMPAT_ARG_XLAT_VIRT_BASE to subtract from the
per-domain area to obtain the mirrored linear address in the 4th slot,
instead of overflowing the per-domain linear address.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
When enabling UBSAN with clang, the following error is triggered during the
build:
common/wait.c:154:9: error: symbol '.L_wq_resume' is already defined
154 | "push %%rbx; push %%rbp; push %%r12;"
| ^
<inline asm>:1:121: note: instantiated into assembly here
1 | push %rbx; push %rbp; push %r12;push %r13; push %r14; push %r15;sub %esp,%ecx;cmp $4096, %ecx;ja .L_skip;mov %rsp,%rsi;.L_wq_resume: rep movsb;mov %rsp,%rsi;.L_skip:pop %r15; pop %r14; pop %r13;pop %r12; pop %rbp; pop %rbx
| ^
common/wait.c:154:9: error: symbol '.L_skip' is already defined
154 | "push %%rbx; push %%rbp; push %%r12;"
| ^
<inline asm>:1:159: note: instantiated into assembly here
1 | push %rbx; push %rbp; push %r12;push %r13; push %r14; push %r15;sub %esp,%ecx;cmp $4096, %ecx;ja .L_skip;mov %rsp,%rsi;.L_wq_resume: rep movsb;mov %rsp,%rsi;.L_skip:pop %r15; pop %r14; pop %r13;pop %r12; pop %rbp; pop %rbx
| ^
2 errors generated.
The inline assembly block in __prepare_to_wait() is duplicated, thus
leading to multiple definitions of the otherwise unique labels inside the
assembly block. GCC extended-asm documentation notes the possibility of
duplicating asm blocks:
> Under certain circumstances, GCC may duplicate (or remove duplicates of)
> your assembly code when optimizing. This can lead to unexpected duplicate
> symbol errors during compilation if your asm code defines symbols or
> labels. Using ‘%=’ (see AssemblerTemplate) may help resolve this problem.
Workaround the issue by latching esp to a local variable, this prevents
clang duplicating the inline asm blocks.
Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
After 8e60d47cf0 writes from __setup_msi_irq() will no longer be
propagated to the MSI registers if the IOMMU IRTE was already allocated.
Given the purpose of __setup_msi_irq() is MSI initialization, always
propagate the write to the hardware, regardless of whether the IRTE was
already allocated.
No functional change expected, as the write should always be propagated in
__setup_msi_irq(), but make it explicit on the write_msi_msg() call.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Relax the limitation on MSI register writes, and only apply it when the
system is in active state. For example AMD IOMMU drivers rely on using
set_msi_affinity() to force an MSI register write on resume from
suspension.
The original patch intention was to reduce the number of MSI register
writes when the system is in active state. Leave the other states to
always perform the writes, as it's safer given the existing code, and it's
expected to not make a difference performance wise.
For such propagation to work even when the IRT index is not updated the MSI
message must be adjusted in all success cases for AMD IOMMU, not just when
the index has been newly allocated.
Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Fixes: 8e60d47cf0 ('x86/iommu: avoid MSI address and data writes if IRT index hasn't changed')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
This was reported by clang UBSAN as:
UBSAN: Undefined behaviour in arch/x86/mm.c:6297:40
applying zero offset to null pointer
[...]
Xen call trace:
[<ffff82d040303662>] R common/ubsan/ubsan.c#ubsan_epilogue+0xa/0xc0
[<ffff82d040304aa3>] F __ubsan_handle_pointer_overflow+0xcb/0x100
[<ffff82d0406ebbc0>] F ioremap_wc+0xc8/0xe0
[<ffff82d0406c3728>] F video_init+0xd0/0x180
[<ffff82d0406ab6f5>] F console_init_preirq+0x3d/0x220
[<ffff82d0406f1876>] F __start_xen+0x68e/0x5530
[<ffff82d04020482e>] F __high_start+0x8e/0x90
Fix bt_ioremap() and ioremap{,_wc}() to not add the offset if the returned
pointer from __vmap() is NULL.
Fixes: d0d4635d03 ('implement vmap()')
Fixes: f390941a92 ('x86/DMI: fix table mapping when one lives above 1Mb')
Fixes: 81d195c6c0 ('x86: introduce ioremap_wc()')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Add messages about operations against the NULL pointer, or that result in
a NULL pointer.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
When building Xen with GCC 12 with UBSAN and PVH_GUEST both enabled the
compiler emits the following errors:
arch/x86/setup.c: In function '__start_xen':
arch/x86/setup.c:1504:19: error: 'consider_modules' reading 40 bytes from a region of size 4 [-Werror=stringop-overread]
1504 | end = consider_modules(s, e, reloc_size + mask,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1505 | bi->mods, bi->nr_modules, -1);
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arch/x86/setup.c:1504:19: note: referencing argument 4 of type 'const struct boot_module[0]'
arch/x86/setup.c:686:24: note: in a call to function 'consider_modules'
686 | static uint64_t __init consider_modules(
| ^~~~~~~~~~~~~~~~
arch/x86/setup.c:1535:19: error: 'consider_modules' reading 40 bytes from a region of size 4 [-Werror=stringop-overread]
1535 | end = consider_modules(s, e, size, bi->mods,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1536 | bi->nr_modules + relocated, j);
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arch/x86/setup.c:1535:19: note: referencing argument 4 of type 'const struct boot_module[0]'
arch/x86/setup.c:686:24: note: in a call to function 'consider_modules'
686 | static uint64_t __init consider_modules(
| ^~~~~~~~~~~~~~~~
This seems to be the result of some function manipulation done by UBSAN
triggering GCC stringops related errors. Placate the errors by declaring
the function parameter as `const struct *boot_module` instead of `const
struct boot_module[]`.
Note that GCC 13 seems to be fixed, and doesn't trigger the error when
using `[]`.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
clang's -fsanitize=function relies on the presence of
__ubsan_handle_function_type_mismatch() to print the detection of indirect
calls of a function through a function pointer of the wrong type.
Implement the helper, inspired on the llvm ubsan lib implementation.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Attempt to reduce the MSI entry writes, and the associated checking whether
memory decoding and MSI-X is enabled for the PCI device, when the MSI data
hasn't changed.
When using Interrupt Remapping the MSI entry will contain an index into
the remapping table, and it's in such remapping table where the MSI vector
and destination CPU is stored. As such, when using interrupt remapping,
changes to the interrupt affinity shouldn't result in changes to the MSI
entry, and the MSI entry update can be avoided.
Signal from the IOMMU update_ire_from_msi hook whether the MSI data or
address fields have changed, and thus need writing to the device registers.
Such signaling is done by returning 1 from the function. Otherwise
returning 0 means no update of the MSI fields, and thus no write
required.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Consume the return code from hvm_pi_update_irte(), and propagate the error
back to the caller if hvm_pi_update_irte() fails.
Fixes: 35a1caf8b6 ('pass-through: update IRTE according to guest interrupt config changes')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
The current usage of msi_desc->msg in vmx_pi_update_irte() will make the
field contain a translated MSI message, instead of the expected
untranslated one. This breaks dump_msi(), that use the data in
msi_desc->msg to print the interrupt details.
Fix this by introducing a dummy local msi_msg, and use it with
iommu_update_ire_from_msi(). vmx_pi_update_irte() relies on the MSI
message not changing, so there's no need to propagate the resulting msi_msg
to the hardware, and the contents can be ignored.
Additionally add a comment to clarify that msi_desc->msg must always
contain the untranslated MSI message.
Fixes: a5e25908d1 ('VT-d: introduce new fields in msi_desc to track binding with guest interrupt')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
The MMIO_CONF_BASE reports the base of the MCFG range on AMD systems.
Linux pre-6.14 is unconditionally attempting to read the MSR without a
safe MSR accessor, and since Xen doesn't allow access to it Linux reports
the following error:
unchecked MSR access error: RDMSR from 0xc0010058 at rIP: 0xffffffff8101d19f (xen_do_read_msr+0x7f/0xa0)
Call Trace:
xen_read_msr+0x1e/0x30
amd_get_mmconfig_range+0x2b/0x80
quirk_amd_mmconfig_area+0x28/0x100
pnp_fixup_device+0x39/0x50
__pnp_add_device+0xf/0x150
pnp_add_device+0x3d/0x100
pnpacpi_add_device_handler+0x1f9/0x280
acpi_ns_get_device_callback+0x104/0x1c0
acpi_ns_walk_namespace+0x1d0/0x260
acpi_get_devices+0x8a/0xb0
pnpacpi_init+0x50/0x80
do_one_initcall+0x46/0x2e0
kernel_init_freeable+0x1da/0x2f0
kernel_init+0x16/0x1b0
ret_from_fork+0x30/0x50
ret_from_fork_asm+0x1b/0x30
Such access is conditional to the presence of a device with PnP ID
"PNP0c01", which triggers the execution of the quirk_amd_mmconfig_area()
function. Note that prior to commit 3fac3734c43a MSR accesses when running
as a PV guest would always use the safe variant, and thus silently handle
the #GP.
Fix by allowing access to the MSR on AMD systems for the hardware domain.
Write attempts to the MSR will still result in #GP for all domain types.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
All local APIC drivers use physical destination and fixed delivery modes,
remove the fields from the genapic struct and simplify the logic.
No functional change intended.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Xen currently prevents dom0 from creating CPU or IOMMU page-table mappings
into the interrupt address range [0xfee00000, 0xfeefffff]. This range has
two different purposes. For accesses from the CPU is contains the default
position of local APIC page at 0xfee00000. For accesses from devices
it's the MSI address range, so the address field in the MSI entries
(usually) point to an address on that range to trigger an interrupt.
There are reports of Lenovo Thinkpad devices placing what seems to be the
UCSI shared mailbox at address 0xfeec2000 in the interrupt address range.
Attempting to use that device with a Linux PV dom0 leads to an error when
Linux kernel maps 0xfeec2000:
RIP: e030:xen_mc_flush+0x1e8/0x2b0
xen_leave_lazy_mmu+0x15/0x60
vmap_range_noflush+0x408/0x6f0
__ioremap_caller+0x20d/0x350
acpi_os_map_iomem+0x1a3/0x1c0
acpi_ex_system_memory_space_handler+0x229/0x3f0
acpi_ev_address_space_dispatch+0x17e/0x4c0
acpi_ex_access_region+0x28a/0x510
acpi_ex_field_datum_io+0x95/0x5c0
acpi_ex_extract_from_field+0x36b/0x4e0
acpi_ex_read_data_from_field+0xcb/0x430
acpi_ex_resolve_node_to_value+0x2e0/0x530
acpi_ex_resolve_to_value+0x1e7/0x550
acpi_ds_evaluate_name_path+0x107/0x170
acpi_ds_exec_end_op+0x392/0x860
acpi_ps_parse_loop+0x268/0xa30
acpi_ps_parse_aml+0x221/0x5e0
acpi_ps_execute_method+0x171/0x3e0
acpi_ns_evaluate+0x174/0x5d0
acpi_evaluate_object+0x167/0x440
acpi_evaluate_dsm+0xb6/0x130
ucsi_acpi_dsm+0x53/0x80
ucsi_acpi_read+0x2e/0x60
ucsi_register+0x24/0xa0
ucsi_acpi_probe+0x162/0x1e3
platform_probe+0x48/0x90
really_probe+0xde/0x340
__driver_probe_device+0x78/0x110
driver_probe_device+0x1f/0x90
__driver_attach+0xd2/0x1c0
bus_for_each_dev+0x77/0xc0
bus_add_driver+0x112/0x1f0
driver_register+0x72/0xd0
do_one_initcall+0x48/0x300
do_init_module+0x60/0x220
__do_sys_init_module+0x17f/0x1b0
do_syscall_64+0x82/0x170
Remove the restrictions to create mappings in the interrupt address range
for dom0. Note that the restriction to map the local APIC page is enforced
separately, and that continues to be present. Additionally make sure the
emulated local APIC page is also not mapped, in case dom0 is using it.
Note that even if the interrupt address range entries are populated in the
IOMMU page-tables no device access will reach those pages. Device accesses
to the Interrupt Address Range will always be converted into Interrupt
Messages and are not subject to DMA remapping.
There's also the following restriction noted in Intel VT-d:
> Software must not program paging-structure entries to remap any address to
> the interrupt address range. Untranslated requests and translation requests
> that result in an address in the interrupt range will be blocked with
> condition code LGN.4 or SGN.8. Translated requests with an address in the
> interrupt address range are treated as Unsupported Request (UR).
Similarly for AMD-Vi:
> Accesses to the interrupt address range (Table 3) are defined to go through
> the interrupt remapping portion of the IOMMU and not through address
> translation processing. Therefore, when a transaction is being processed as
> an interrupt remapping operation, the transaction attribute of
> pretranslated or untranslated is ignored.
>
> Software Note: The IOMMU should
> not be configured such that an address translation results in a special
> address such as the interrupt address range.
However those restrictions don't apply to the identity mappings possibly
created for dom0, since the interrupt address range is never subject to DMA
remapping, and hence there's no output address after translation that
belongs to the interrupt address range.
Reported-by: Jürgen Groß <jgross@suse.com>
Link: https://lore.kernel.org/xen-devel/baade0a7-e204-4743-bda1-282df74e5f89@suse.com/
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
The current code in arch_iommu_hwdom_init() kind of open-codes the same
MMIO permission ranges that are added to the hardware domain ->iomem_caps.
Avoid this duplication and use ->iomem_caps in arch_iommu_hwdom_init() to
filter which memory regions should be added to the dom0 IOMMU page-tables.
Note the IO-APIC and MCFG page(s) must be set as not accessible for a PVH
dom0, otherwise the internal Xen emulation for those ranges won't work.
This requires adjustments in dom0_setup_permissions().
The call to pvh_setup_mmcfg() in dom0_construct_pvh() must now strictly be
done ahead of setting up dom0 permissions, so take the opportunity to also
put it inside the existing is_hardware_domain() region.
Also the special casing of E820_UNUSABLE regions no longer needs to be done
in arch_iommu_hwdom_init(), as those regions are already blocked in
->iomem_caps and thus would be removed from the rangeset as part of
->iomem_caps processing in arch_iommu_hwdom_init(). The E820_UNUSABLE
regions below 1Mb are not removed from ->iomem_caps, that's a slight
difference for the IOMMU created page-tables, but the aim is to allow
access to the same memory either from the CPU or the IOMMU page-tables.
Since ->iomem_caps already takes into account the domain max paddr, there's
no need to remove any regions past the last address addressable by the
domain, as applying ->iomem_caps would have already taken care of that.
Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
The logic in dom0_setup_permissions() sets the maximum bound in
->iomem_caps unconditionally using paddr_bits, which is not correct for HVM
based domains. Instead use domain_max_paddr_bits() to get the correct
maximum paddr bits for each possible domain type.
Switch to using PFN_DOWN() instead of PAGE_SHIFT, as that's shorter.
Fixes: 53de839fb4 ('x86: constrain MFN range Dom0 may access')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
When building a PVH dom0 Xen attempts to map all (relevant) MMIO regions
into the p2m for dom0 access. However the information Xen has about the
host memory map is limited. Xen doesn't have access to any resources
described in ACPI dynamic tables, and hence the p2m mappings provided might
not be complete.
PV doesn't suffer from this issue because a PV dom0 is capable of mapping
into it's page-tables any address not explicitly banned in d->iomem_caps.
Introduce a new command line options that allows Xen to attempt to fixup
the p2m page-faults, by creating p2m identity maps in response to p2m
page-faults.
This is aimed as a workaround to small ACPI regions Xen doesn't know about.
Note that missing large MMIO regions mapped in this way will lead to
slowness due to the VM exit processing, plus the mappings will always use
small pages.
The ultimate aim is to attempt to bring better parity with a classic PV
dom0.
Note such fixup rely on the CPU doing the access to the unpopulated
address. If the access is attempted from a device instead there's no
possible way to fixup, as IOMMU page-fault are asynchronous.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
---
Only slightly tested on my local PVH dom0 deployment.
---
Changes since v1:
- Make the fixup function static.
- Print message in case mapping already exists.
A PV dom0 can map any host memory as long as it's allowed by the IO
capability range in d->iomem_caps. On the other hand, a PVH dom0 has no
way to populate MMIO region onto it's p2m, so it's limited to what Xen
initially populates on the p2m based on the host memory map and the enabled
device BARs.
Introduce a new debug build only printk that reports attempts by dom0 to
access addresses not populated on the p2m, and not handled by any emulator.
This is for information purposes only, but might allow getting an idea of
what MMIO ranges might be missing on the p2m.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Add a new hook to inhibit interrupt generation by the IOMMU(s). Note the
hook is currently only implemented for x86 IOMMUs. The purpose is to
disable interrupt generation at shutdown so any kexec chained image finds
the IOMMU(s) in a quiesced state.
It would also prevent "Receive accept error" being raised as a result of
non-disabled interrupts targeting offline CPUs.
Note that the iommu_quiesce() call in nmi_shootdown_cpus() is still
required even when there's a preceding iommu_crash_shutdown() call; the
later can become a no-op depending on the setting of the "crash-disable"
command line option.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Release-Acked-by: Oleksii Kurochko<oleksii.kurochko@gmail.com>
Attempt to disable MSI(-X) capabilities on all PCI devices know by Xen at
shutdown. Doing such disabling should facilitate kexec chained kernel from
booting more reliably, as device MSI(-X) interrupt generation should be
quiesced.
Only attempt to disable MSI(-X) on all devices in the crash context if the
PCI lock is not taken, otherwise the PCI device list could be in an
inconsistent state. This requires introducing a new pcidevs_trylock()
helper to check whether the lock is currently taken.
Disabling MSI(-X) should prevent "Receive accept error" being raised as a
result of non-disabled interrupts targeting offline CPUs.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Release-Acked-by: Oleksii Kurochko<oleksii.kurochko@gmail.com>
Move the disabling of interrupt sources so it's done ahead of the offlining
of APs. This is to prevent AMD systems triggering "Receive accept error"
when interrupts target CPUs that are no longer online.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Release-Acked-by: Oleksii Kurochko<oleksii.kurochko@gmail.com>
The solely remaining caller always passes the same globally available
parameters. Drop the parameters and modify fixup_irqs() to use
cpu_online_map in place of the input mask parameter, and always be verbose
in its output printing.
While there remove some of the checks given the single context where
fixup_irqs() is now called, which should always be in the CPU offline path,
after the CPU going offline has been removed from cpu_online_map.
No functional change intended.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Release-Acked-by: Oleksii Kurochko<oleksii.kurochko@gmail.com>
The current shutdown logic in smp_send_stop() will disable the APs while
having interrupts enabled on the BSP or possibly other APs. On AMD systems
this can lead to local APIC errors:
APIC error on CPU0: 00(08), Receive accept error
Such error message can be printed in a loop, thus blocking the system from
rebooting. I assume this loop is created by the error being triggered by
the console interrupt, which is further stirred by the ESR handler
printing to the console.
Intel SDM states:
"Receive Accept Error.
Set when the local APIC detects that the message it received was not
accepted by any APIC on the APIC bus, including itself. Used only on P6
family and Pentium processors."
So the error shouldn't trigger on any Intel CPU supported by Xen.
However AMD doesn't make such claims, and indeed the error is broadcast to
all local APICs when an interrupt targets a CPU that's already offline.
To prevent the error from stalling the shutdown process perform the
disabling of APs and the BSP local APIC with interrupts disabled on all
CPUs in the system, so that by the time interrupts are unmasked on the BSP
the local APIC is already disabled. This can still lead to a spurious:
APIC error on CPU0: 00(00)
As a result of an LVT Error getting injected while interrupts are masked on
the CPU, and the vector only handled after the local APIC is already
disabled. ESR reports 0 because as part of disable_local_APIC() the ESR
register is cleared.
Note the NMI crash path doesn't have such issue, because disabling of APs
and the caller local APIC is already done in the same contiguous region
with interrupts disabled. There's a possible window on the NMI crash path
(nmi_shootdown_cpus()) where some APs might be disabled (and thus
interrupts targeting them raising "Receive accept error") before others APs
have interrupts disabled. However the shutdown NMI will be handled,
regardless of whether the AP is processing a local APIC error, and hence
such interrupts will not cause the shutdown process to get stuck.
Remove the call to fixup_irqs() in smp_send_stop(): it doesn't achieve the
intended goal of moving all interrupts to the BSP anyway. The logic in
fixup_irqs() will move interrupts whose affinity doesn't overlap with the
passed mask, but the movement of interrupts is done to any CPU set in
cpu_online_map. As in the shutdown path fixup_irqs() is called before APs
are cleared from cpu_online_map this leads to interrupts being shuffled
around, but not assigned to the BSP exclusively.
The Fixes tag is more of a guess than a certainty; it's possible the
previous sleep window in fixup_irqs() allowed any in-flight interrupt to be
delivered before APs went offline. However fixup_irqs() was still
incorrectly used, as it didn't (and still doesn't) move all interrupts to
target the provided cpu mask.
Fixes: e2bb28d621 ('x86/irq: forward pending interrupts to new destination in fixup_irqs()')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Release-Acked-by: Oleksii Kurochko<oleksii.kurochko@gmail.com>
Either when using a 32bit Interrupt Remapping Entry or a 128bit one update
the entry atomically, by using cmpxchg unconditionally as IOMMU depends on
it. No longer disable the entry by setting RemapEn = 0 ahead of updating
it. As a consequence of not toggling RemapEn ahead of the update the
Interrupt Remapping Table needs to be flushed after the entry update.
This avoids a window where the IRTE has RemapEn = 0, which can lead to
IO_PAGE_FAULT if the underlying interrupt source is not masked.
There's no guidance in AMD-Vi specification about how IRTE update should be
performed as opposed to DTE updating which has specific guidance. However
DTE updating claims that reads will always be at least 128bits in size, and
hence for the purposes here assume that reads and caching of the IRTE
entries in either 32 or 128 bit format will be done atomically from
the IOMMU.
Note that as part of introducing a new raw128 field in the IRTE struct, the
current raw field is renamed to raw64 to explicitly contain the size in the
field name.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Add a new randconfig job for each FreeBSD version. This requires some
rework of the template so common parts can be shared between the full and
the randconfig builds. Such randconfig builds are relevant because FreeBSD
is the only tested system that has a full non-GNU toolchain.
While there replace the usage of the python311 package with python3, which is
already using 3.11, and remove the install of the plain python package for full
builds.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-Acked-by: Oleksii Kurochko<oleksii.kurochko@gmail.com>
If randconfig enables coverage support the build times out due to GNU LD
taking too long. For the time being prevent coverage from being enabled in
clang randconfig job.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Release-Acked-by: Oleksii Kurochko<oleksii.kurochko@gmail.com>
The EFI_GET_TIME implementation is well known to be broken for many firmware
implementations, for Xen the result on such implementations are:
----[ Xen-4.19-unstable x86_64 debug=y Tainted: C ]----
CPU: 0
RIP: e008:[<0000000062ccfa70>] 0000000062ccfa70
[...]
Xen call trace:
[<0000000062ccfa70>] R 0000000062ccfa70
[<00000000732e9a3f>] S 00000000732e9a3f
[<ffff82d04034f34f>] F arch/x86/time.c#get_cmos_time+0x1b3/0x26e
[<ffff82d04045926f>] F init_xen_time+0x28/0xa4
[<ffff82d040454bc4>] F __start_xen+0x1ee7/0x2578
[<ffff82d040203334>] F __high_start+0x94/0xa0
Pagetable walk from 0000000062ccfa70:
L4[0x000] = 000000207ef1c063 ffffffffffffffff
L3[0x001] = 000000005d6c0063 ffffffffffffffff
L2[0x116] = 8000000062c001e3 ffffffffffffffff (PSE)
****************************************
Panic on CPU 0:
FATAL PAGE FAULT
[error_code=0011]
Faulting linear address: 0000000062ccfa70
****************************************
Swap the preference to default to CMOS first, and EFI later, in an attempt to
use EFI_GET_TIME as a last resort option only. Note that Linux for example
doesn't allow calling the get_time method, and instead provides a dummy handler
that unconditionally returns EFI_UNSUPPORTED on x86-64.
Such change in the preferences requires some re-arranging of the function
logic, so that panic messages with workaround suggestions are suitably printed.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Acked-By: Oleksii Kurochko<oleksii.kurochko@gmail.com>
Release-Acked-by: Oleksii Kurochko<oleksii.kurochko@gmail.com>
Allow setting the used wallclock from the command line. When the option is set
to a value different than `auto` the probing is bypassed and the selected
implementation is used (as long as it's available).
The `xen` and `efi` options require being booted as a Xen guest (with Xen guest
supported built-in) or from UEFI firmware respectively.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Release-Acked-by: Oleksii Kurochko<oleksii.kurochko@gmail.com>
Avoid exiting early from the loop when a pin that could be connected to the
i8259 is found, as such early exit would leave the EOI handler translation
array only partially allocated and/or initialized.
Otherwise on systems with multiple IO-APICs and an unmasked ExtINT pin on
any IO-APIC that's no the last one the following NULL pointer dereference
triggers:
(XEN) Enabling APIC mode. Using 2 I/O APICs
(XEN) ----[ Xen-4.20-unstable x86_64 debug=y Not tainted ]----
(XEN) CPU: 0
(XEN) RIP: e008:[<ffff82d040328046>] __ioapic_write_entry+0x83/0x95
[...]
(XEN) Xen call trace:
(XEN) [<ffff82d040328046>] R __ioapic_write_entry+0x83/0x95
(XEN) [<ffff82d04027464b>] F amd_iommu_ioapic_update_ire+0x1ea/0x273
(XEN) [<ffff82d0402755a1>] F iommu_update_ire_from_apic+0xa/0xc
(XEN) [<ffff82d040328056>] F __ioapic_write_entry+0x93/0x95
(XEN) [<ffff82d0403283c1>] F arch/x86/io_apic.c#clear_IO_APIC_pin+0x7c/0x10e
(XEN) [<ffff82d040328480>] F arch/x86/io_apic.c#clear_IO_APIC+0x2d/0x61
(XEN) [<ffff82d0404448b7>] F enable_IO_APIC+0x2e3/0x34f
(XEN) [<ffff82d04044c9b0>] F smp_prepare_cpus+0x254/0x27a
(XEN) [<ffff82d04044bec2>] F __start_xen+0x1ce1/0x23ae
(XEN) [<ffff82d0402033ae>] F __high_start+0x8e/0x90
(XEN)
(XEN) Pagetable walk from 0000000000000000:
(XEN) L4[0x000] = 000000007dbfd063 ffffffffffffffff
(XEN) L3[0x000] = 000000007dbfa063 ffffffffffffffff
(XEN) L2[0x000] = 000000007dbcc063 ffffffffffffffff
(XEN) L1[0x000] = 0000000000000000 ffffffffffffffff
(XEN)
(XEN) ****************************************
(XEN) Panic on CPU 0:
(XEN) FATAL PAGE FAULT
(XEN) [error_code=0002]
(XEN) Faulting linear address: 0000000000000000
(XEN) ****************************************
(XEN)
(XEN) Reboot in five seconds...
Reported-by: Sergii Dmytruk <sergii.dmytruk@3mdeb.com>
Fixes: 86001b3970 ('x86/io-apic: fix directed EOI when using AMD-Vi interrupt remapping')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
The tools infrastructure used to build livepatches for Xen
(livepatch-build-tools) consumes some DWARF debug information present in
xen-syms to generate a livepatch (see livepatch-build script usage of readelf
-wi).
The current Kconfig defaults however will enable LIVEPATCH without DEBUG_INFO
on release builds, thus providing a default Kconfig selection that's not
suitable for livepatch-build-tools even when LIVEPATCH support is enabled,
because it's missing the DWARF debug section.
Fix by defaulting DEBUG_INFO to enabled when LIVEPATCH is.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
The current code in pv_domain_initialise() populates the L3 slot used for the
GDT/LDT, however that's not needed, since the create_perdomain_mapping() in
pv_create_gdt_ldt_l1tab() will already take care of allocating an L2 and
populating the L3 entry if not present.
No functional change intended.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Do not return early in the PVH/HVM case, so that the number of pIRQs is also
printed. While PVH dom0 doesn't have access to the hypercalls to manage pIRQs
itself, nor the knowledge to do so, pIRQs are still used by Xen to map and
bind interrupts to a PVH dom0 behind its back. Hence the pIRQ limit is still
relevant for a PVH dom0.
Fixes: 17f6d398f7 ('cmdline: document and enforce "extra_guest_irqs" upper bounds')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
The current calculation of PV dom0 pIRQs uses:
n = min(fls(num_present_cpus()), dom0_max_vcpus());
The usage of fls() is wrong, as num_present_cpus() already returns the number
of present CPUs, not the bitmap mask of CPUs.
Fix by removing the usage of fls().
Fixes: 7e73a6e7f1 ('have architectures specify the number of PIRQs a hardware domain gets')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Adjust the macros to parenthesize their arguments. Use
MASK_EXTR()/MASK_INSR() where appropriate.
No functional change intended.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
While not strictly needed to guarantee operator precedence is as expected, add
the parentheses to comply with Misra Rule 20.7.
No functional change intended.
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Fixes: 5b52e1b043 ('x86/mm: skip super-page alignment checks for non-present entries')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
While the alignment of the mfn is not relevant for non-present entries, the
alignment of the linear address is. Commit 5b52e1b043 introduced a
regression by not checking the alignment of the linear address when the new
entry was a non-present one.
Fix by always checking the alignment of the linear address, non-present entries
must just skip the alignment check of the physical address.
Fixes: 5b52e1b043 ('x86/mm: skip super-page alignment checks for non-present entries')
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
The current logic in modify_xen_mappings() allows for fully empty L2 tables to
not be freed and unhooked from the parent L3 if the last L2 slot is not
populated.
Ensure that even when an L2 slot is empty the logic to check whether the whole
L2 can be removed is not skipped.
Fixes: 4376c05c31 ('x86-64: use 1GB pages in 1:1 mapping if available')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
INVALID_MFN is ~0, so by it having all bits as 1s it doesn't fulfill the
super-page address alignment checks for L3 and L2 entries. Skip the alignment
checks if the new entry is a non-present one.
This fixes a regression introduced by 0b6b51a69f, where the switch from 0 to
INVALID_MFN caused all super-pages to be shattered when attempting to remove
mappings by passing INVALID_MFN instead of 0.
Fixes: 0b6b51a69f ('xen/mm: Switch map_pages_to_xen to use MFN typesafe')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Split the code that detects whether the physical and linear address of a
mapping request are suitable to be used in an L3 or L2 slot.
No functional change intended.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
GNU assembly that supports such feature will unconditionally add a
.note.gnu.property section to object files. The content of that section can
change depending on the generated instructions. The current logic in
livepatch-build-tools doesn't know how to deal with such section changing
as a result of applying a patch and rebuilding.
Since .note.gnu.property is not consumed by the Xen build, suppress its
addition when livepatch support is enabled.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Clang 19 complains with the following error when building libxl:
libxl_utils.c:48:15: error: variable length array folded to constant array as an extension [-Werror,-Wgnu-folding-constant]
48 | char path[strlen("/local/domain") + 12];
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
Replace the usage of strlen() with sizeof, which allows the literal
string length to be known at build time. Note sizeof accounts for the
NUL terminator while strlen() didn't, hence subtract 1 from the total
size calculation.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Frediano Ziglio <frediano.ziglio@cloud.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Anthony PERARD <anthony.perard@vates.tech>
When using AMD-Vi interrupt remapping the vector field in the IO-APIC RTE is
repurposed to contain part of the offset into the remapping table. Previous to
2ca9fbd739 Xen had logic so that the offset into the interrupt remapping
table would match the vector. Such logic was mandatory for end of interrupt to
work, since the vector field (even when not containing a vector) is used by the
IO-APIC to find for which pin the EOI must be performed.
A simple solution wold be to read the IO-APIC RTE each time an EOI is to be
performed, so the raw value of the vector field can be obtained. However
that's likely to perform poorly. Instead introduce a cache to store the
EOI handles when using interrupt remapping, so that the IO-APIC driver can
translate pins into EOI handles without having to read the IO-APIC RTE entry.
Note that to simplify the logic such cache is used unconditionally when
interrupt remapping is enabled, even if strictly it would only be required
for AMD-Vi.
Reported-by: Willi Junga <xenproject@ymy.be>
Suggested-by: David Woodhouse <dwmw@amazon.co.uk>
Fixes: 2ca9fbd739 ('AMD IOMMU: allocate IRTE entries instead of using a static mapping')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
The current logic in modify_xen_mappings() allows for fully empty L2 tables to
not be freed and unhooked from the parent L3 if the last L2 slot is not
populated.
Ensure that even when an L2 slot is empty the logic to check whether the whole
L2 can be removed is not skipped.
Fixes: 4376c05c31 ('x86-64: use 1GB pages in 1:1 mapping if available')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
BUG_ON() itself already contains an unlikely() wrapping the bug condition.
No functional change.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
IVMD table contains restrictions about memory which must be mandatory assigned
to devices (and which permissions it should use), or memory that should be
never accessible to devices.
Some hardware however contains ranges in IVMD that reference devices outside of
the IVHD tables (in other words, devices not behind any IOMMU). Such mismatch
will cause Xen to fail in register_range_for_device(), ultimately leading to
the IOMMU being disabled, and Xen crashing as x2APIC support might be already
enabled and relying on the IOMMU functionality.
Relax IVMD parsing: allow IVMD blocks to reference devices not assigned to any
IOMMU. It's impossible for Xen to fulfill the requirement in the IVMD block if
the device is not behind any IOMMU, but it's no worse than booting without
IOMMU support, and thus not parsing ACPI IVRS in the first place.
Reported-by: Willi Junga <xenproject@ymy.be>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Some error paths in the MSR state loading logic don't contain error messages,
which makes debugging them quite hard without adding extra patches to print the
information.
Add two new log messages to the MSR state load path that print information
about the entry that failed to load, for both PV and HVM.
While there also adjust XEN_DOMCTL_set_vcpu_msrs to return -ENXIO in case the
MSR is unhandled or can't be loaded, so it matches the error code used by HVM
MSR loading (and it's less ambiguous than -EINVAL).
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Since the addition of the MSR_AMD64_DR{1-4}_ADDRESS_MASK MSRs to the
msrs_to_send array, the calculations for the maximum number of MSRs that
the hypercall can handle is off by 4.
Remove the addition of 4 to the maximum number of MSRs that
XEN_DOMCTL_{set,get}_vcpu_msrs supports, as those are already part of the
array.
A further adjustment could be to subtract 4 from the maximum size if the DBEXT
CPUID feature is not exposed to the guest, but guest_{rd,wr}msr() will already
perform that check when fetching or loading the MSRs. The maximum array is
used to indicate the caller of the buffer it needs to allocate in the get case,
and as an early input sanitation in the set case, using a buffer size slightly
lager than required is not an issue.
Fixes: 86d47adcd3 ('x86/msr: Handle MSR_AMD64_DR{0-3}_ADDRESS_MASK in the new MSR infrastructure')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
The current dpci logic relies on a softirq being executed as a side effect of
the cpu_notifier_call_chain() call in the code path that offlines the target
CPU. However the call to cpu_notifier_call_chain() won't trigger any softirq
processing, and even if it did, such processing should be done after all
interrupts have been migrated off the current CPU, otherwise new pending dpci
interrupts could still appear.
Currently the ASSERT() in the cpu callback notifier is fairly easy to trigger
by doing CPU offline from a PVH dom0.
Solve this by instead moving out any dpci interrupts pending processing once
the CPU is dead. This might introduce more latency than attempting to drain
before the CPU is put offline, but it's less complex, and CPU online/offline is
not a common action. Any extra introduced latency should be tolerable.
Fixes: f6dd295381 ('dpci: replace tasklet with softirq')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
The only functions to modify the list, amd_iommu_detect_one_acpi() and
amd_iommu_init_cleanup(), are already init.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Ensure at build time the feature(s) used for the alternative blocks are in
range of the featureset.
No functional change intended, as all current usages are correct.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
alternatives is used both at boot time, and when loading livepatch payloads.
While for the former it makes sense to panic, it's not useful for the later, as
for livepatches it's possible to fail to load the livepatch if alternatives
cannot be resolved and continue operating normally.
Relax the BUGs in _apply_alternatives() to instead return an error code. The
caller will figure out whether the failures are fatal and panic.
Print an error message to provide some user-readable information about what
went wrong.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
The check against the expected Xen build ID should be done ahead of attempting
to apply the alternatives contained in the livepatch.
If the CPUID in the alternatives patching data is out of the scope of the
running Xen featureset the BUG() in _apply_alternatives() will trigger thus
bringing the system down. Note the layout of struct alt_instr could also
change between versions. It's also possible for struct exception_table_entry
to have changed format, hence leading to other kind of errors if parsing of the
payload is done ahead of checking if the Xen build-id matches.
Move the Xen build ID check as early as possible. To do so introduce a new
check_xen_buildid() function that parses and checks the Xen build-id before
moving the payload. Since the expected Xen build-id is used early to
detect whether the livepatch payload could be loaded, there's no reason to
store it in the payload struct, as a non-matching Xen build-id won't get the
payload populated in the first place.
Note printing the expected Xen build ID has part of dumping the payload
information is no longer done: all loaded payloads would have Xen build IDs
matching the running Xen, otherwise they would have failed to load.
Fixes: 879615f5db ('livepatch: Always check hypervisor build ID upon livepatch upload')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
The following sections: .note.gnu.build-id, .livepatch.xen_depends and
.livepatch.depends are mandatory and ensured to be present by
check_special_sections() before prepare_payload() is called.
Simplify the logic in prepare_payload() by introducing a generic function to
parse the sections that contain a buildid. Note the function assumes the
buildid related section to always be present.
No functional change intended.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
The Elf loading logic will initially use the `data` section field to stash a
pointer to the temporary loaded data (from the buffer allocated in
livepatch_upload(), which is later relocated and the new pointer stashed in
`load_addr`.
Remove this dual field usage and use an `addr` uniformly. Initially data will
point to the temporary buffer, until relocation happens, at which point the
pointer will be updated to the relocated address.
This avoids leaving a dangling pointer in the `data` field once the temporary
buffer is freed by livepatch_upload().
Note the `addr` field cannot retain the const attribute from the previous
`data`field, as there's logic that performs manipulations against the loaded
sections, like applying relocations or sorting the exception table.
No functional change intended.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Michal Orzel <michal.orzel@amd.com>
The current check for duplicated sections in a payload is not effective. Such
check is done inside a loop that iterates over the sections names, it's
logically impossible for the bitmap to be set more than once.
The usage of a bitmap in check_patching_sections() has been replaced with a
boolean, since the function just cares that at least one of the special
sections is present.
No functional change intended, as the check was useless.
Fixes: 29f4ab0b0a ('xsplice: Implement support for applying/reverting/replacing patches.')
Fixes: 76b3d4098a ('livepatch: Do not enforce ELF_LIVEPATCH_FUNC section presence')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Current blkif implementations (both backends and frontends) have all slight
differences about how they handle the 'sector-size' xenstore node, and how
other fields are derived from this value or hardcoded to be expressed in units
of 512 bytes.
To give some context, this is an excerpt of how different implementations use
the value in 'sector-size' as the base unit for to other fields rather than
just to set the logical sector size of the block device:
│ sectors xenbus node │ requests sector_number │ requests {first,last}_sect
────────────────────────┼─────────────────────┼────────────────────────┼───────────────────────────
FreeBSD blk{front,back} │ sector-size │ sector-size │ 512
────────────────────────┼─────────────────────┼────────────────────────┼───────────────────────────
Linux blk{front,back} │ 512 │ 512 │ 512
────────────────────────┼─────────────────────┼────────────────────────┼───────────────────────────
QEMU blkback │ sector-size │ sector-size │ sector-size
────────────────────────┼─────────────────────┼────────────────────────┼───────────────────────────
Windows blkfront │ sector-size │ sector-size │ sector-size
────────────────────────┼─────────────────────┼────────────────────────┼───────────────────────────
MiniOS │ sector-size │ 512 │ 512
An attempt was made by 67e1c050e3 in order to change the base units of the
request fields and the xenstore 'sectors' node. That however only lead to more
confusion, as the specification now clearly diverged from the reference
implementation in Linux. Such change was only implemented for QEMU Qdisk
and Windows PV blkfront.
Partially revert to the state before 67e1c050e3 while adjusting the
documentation for 'sectors' to match what it used to be previous to
2fa701e534:
* Declare 'feature-large-sector-size' deprecated. Frontends should not expose
the node, backends should not make decisions based on its presence.
* Clarify that 'sectors' xenstore node and the requests fields are always in
512-byte units, like it was previous to 2fa701e534 and 67e1c050e3.
All base units for the fields used in the protocol are 512-byte based, the
xenbus 'sector-size' field is only used to signal the logic block size. When
'sector-size' is greater than 512, blkfront implementations must make sure that
the offsets and sizes (despite being expressed in 512-byte units) are aligned
to the logical block size specified in 'sector-size', otherwise the backend
will fail to process the requests.
This will require changes to some of the frontends and backends in order to
properly support 'sector-size' nodes greater than 512.
Fixes: 2fa701e534 ('blkif.h: Provide more complete documentation of the blkif interface')
Fixes: 67e1c050e3 ('public/io/blkif.h: try to fix the semantics of sector based quantities')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
Adding such probing allows to clearly separate init vs runtime code, and to
place the probing logic into the init section for the CMOS case. Note both
the Xen shared_info page wallclock, and the EFI wallclock don't really have any
probing-specific logic. The shared_info wallclock will always be there if
booted as a Xen guest, while the EFI_GET_TIME method probing relies on checking
if it returns a value different than 0.
The panic message printed when Xen is unable to find a viable wallclock source
has been adjusted slightly, I believe the printed guidance still provides the
same amount of information to the user.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Rename cmos_rtc_probe to opt_cmos_rtc_probe in order to better describe it
being a command line option, and rename cmos_probe() function to
cmos_rtc_probe().
Also move opt_cmos_rtc_probe to being a static global variable in preparation
for further changes that will require the variable being global to the file.
No functional change intended.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
The current logic to probe for the CMOS RTC is open-coded in get_cmos_time(),
move it to a separate function that both serves the purpose of testing for the
CMOS RTC existence and returning its value.
The goal is to be able to split the probing and the reading logic into separate
helpers, and putting the current logic in a separate function helps simplifying
further changes.
A transient *rtc_p variable is introduced as a parameter to the function, that
will be removed by further changes. Also note that due to the code movement,
now cmos_rtc_probe will only get cleared on a second call to get_cmos_time(),
as the newly introduced cmos_probe() function doesn't modify the variable
anymore.
No functional change intended.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Move the logic that ensures the CMOS RTC data is read just after it's been
updated into the __get_cmos_time() function that does the register reads. This
requires returning a boolean from __get_cmos_time() to signal whether the read
has been successfully performed after an update.
Note that while __get_cmos_time() can be used without waiting for the update
edge, so far the only caller does wait for it, hence move the code inside of
the function.
The goal, albeit not accomplished by this patch, is to be able to split the
probing and the reading of the CMOS RTC data into two separate functions.
No functional change intended.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Move the current code in get_wallclock_time() to fetch the Xen wallclock
information from the shared page when running as a guest into a separate
helper.
No functional change intended.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Making opt_allow_unsafe read only after init requires changes to the logic in
init_amd(), otherwise the following #PF happens on CPU hotplug:
----[ Xen-4.20.0-1-d x86_64 debug=y Tainted: H ]----
CPU: 1
RIP: e008:[<ffff82d040291081>] arch/x86/cpu/amd.c#init_amd+0x37f/0x993
[...]
Xen call trace:
[<ffff82d040291081>] R arch/x86/cpu/amd.c#init_amd+0x37f/0x993
[<ffff82d040291fbe>] F identify_cpu+0x2d4/0x4db
[<ffff82d04032eeaa>] F start_secondary+0x22e/0x3cf
[<ffff82d040203327>] F __high_start+0x87/0xa0
Pagetable walk from ffff82d0404011ea:
L4[0x105] = 000000006fc2e063 ffffffffffffffff
L3[0x141] = 000000006fc2b063 ffffffffffffffff
L2[0x002] = 000000807c7ca063 ffffffffffffffff
L1[0x001] = 800000006f801121 ffffffffffffffff
****************************************
Panic on CPU 1:
FATAL PAGE FAULT
[error_code=0003]
Faulting linear address: ffff82d0404011ea
****************************************
For the time being revert opt_allow_unsafe to be __read_mostly.
Fixes: bfcb0abb19 ('types: replace remaining uses of s8')
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Move the logic that disables SMAP so it's only performed when building a PV
dom0, PVH dom0 builder doesn't require disabling SMAP.
The fixes tag is to account for the wrong usage of cpu_has_smap in
create_dom0(), it should instead have used
boot_cpu_has(X86_FEATURE_XEN_SMAP). Fix while moving the logic to apply to PV
only.
While there also make cr4_pv32_mask __ro_after_init.
Fixes: 493ab190e5 ('xen/sm{e, a}p: allow disabling sm{e, a}p for Xen itself')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
XPTI being a speculation mitigation feels better to be initialized in
spec_ctrl_init_domain().
No functional change intended, although the call to spec_ctrl_init_domain() in
arch_domain_create() needs to be moved ahead of pv_domain_initialise() for
d->->arch.pv.xpti to be correctly set.
Move it ahead of most of the initialization functions, since
spec_ctrl_init_domain() doesn't depend on any member in the struct domain being
set.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Delay setting X86_CR4_SMAP on the BSP until the domain building is done, so
that there's no need to disable SMAP. Note however that SMAP is enabled for
the APs on bringup, as domain builder code strictly run on the BSP. Delaying
the setting for the APs would mean having to do a callfunc IPI later in order
to set it on all the APs.
The fixes tag is to account for the wrong usage of cpu_has_smap in
create_dom0(), it should instead have used
boot_cpu_has(X86_FEATURE_XEN_SMAP).
While there also make cr4_pv32_mask __ro_after_init.
Fixes: 493ab190e5 ('xen/sm{e, a}p: allow disabling sm{e, a}p for Xen itself')
Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
The current logic to chose the preferred reboot method is based on the mode Xen
has been booted into, so if the box is booted from UEFI, the preferred reboot
method will be to use the ResetSystem() run time service call.
However, that method seems to be widely untested, and quite often leads to a
result similar to:
Hardware Dom0 shutdown: rebooting machine
----[ Xen-4.18-unstable x86_64 debug=y Tainted: C ]----
CPU: 0
RIP: e008:[<0000000000000017>] 0000000000000017
RFLAGS: 0000000000010202 CONTEXT: hypervisor
[...]
Xen call trace:
[<0000000000000017>] R 0000000000000017
[<ffff83207eff7b50>] S ffff83207eff7b50
[<ffff82d0403525aa>] F machine_restart+0x1da/0x261
[<ffff82d04035263c>] F apic_wait_icr_idle+0/0x37
[<ffff82d040233689>] F smp_call_function_interrupt+0xc7/0xcb
[<ffff82d040352f05>] F call_function_interrupt+0x20/0x34
[<ffff82d04033b0d5>] F do_IRQ+0x150/0x6f3
[<ffff82d0402018c2>] F common_interrupt+0x132/0x140
[<ffff82d040283d33>] F arch/x86/acpi/cpu_idle.c#acpi_idle_do_entry+0x113/0x129
[<ffff82d04028436c>] F arch/x86/acpi/cpu_idle.c#acpi_processor_idle+0x3eb/0x5f7
[<ffff82d04032a549>] F arch/x86/domain.c#idle_loop+0xec/0xee
****************************************
Panic on CPU 0:
FATAL TRAP: vector = 6 (invalid opcode)
****************************************
Which in most cases does lead to a reboot, however that's unreliable.
Change the default reboot preference to prefer ACPI over UEFI if available and
not in reduced hardware mode.
This is in line to what Linux does, so it's unlikely to cause issues on current
and future hardware, since there's a much higher chance of vendors testing
hardware with Linux rather than Xen.
Add a special case for one Acer model that does require being rebooted using
ResetSystem(). See Linux commit 0082517fa4bce for rationale.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Acked-By: Oleksii Kurochko <oleksii.kurochko@gmail.com>
The current code in ALT_CALL_ARG() won't successfully workaround the clang
code-generation issue if the arg parameter has a size that's not a power of 2.
While there are no such sized parameters at the moment, improve the workaround
to also be effective when such sizes are used.
Instead of using a union with a long use an unsigned long that's first
initialized to 0 and afterwards set to the argument value.
Reported-by: Alejandro Vallejo <alejandro.vallejo@cloud.com>
Suggested-by: Alejandro Vallejo <alejandro.vallejo@cloud.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
One of the error paths in the PV dom0 builder section that runs on the guest
page-tables wasn't restoring the Xen value of %cr3, neither removing the
mapcache override.
Fixes: 079ff2d32c ('libelf-loader: introduce elf_load_image')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
This reduces the repeated accessing of v->domain.
No functional change intended.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
There are no callers outside the translation unit where it's defined, so make
the function static.
No functional change intended.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
There's no l{1,2,3,4}e_read() implementation, so drop the _atomic suffix from
the read helpers. This allows unifying the naming with the write helpers,
which are also atomic but don't have the suffix already: l{1,2,3,4}e_write().
No functional change intended.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
The l{1,2,3,4}e_write_atomic() and non _atomic suffixed helpers share the same
implementation, so it seems pointless and possibly confusing to have both.
x86 32bit mode used to have a non-atomic PTE write that would split the write
in two halves, but with Xen only supporting x86 64bit that's no longer
present.
Remove the l{1,2,3,4}e_write_atomic() helpers and switch it's user to
l{1,2,3,4}e_write(), as that's also atomic. While there also remove
pte_write{,_atomic}() and just use write_atomic() in the wrappers.
No functional change intended.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Yet another clang code generation issue when using altcalls.
The issue this time is with using loop constructs around alternative_{,v}call
instances using parameter types smaller than the register size.
Given the following example code:
static void bar(bool b)
{
unsigned int i;
for ( i = 0; i < 10; i++ )
{
int ret_;
register union {
bool e;
unsigned long r;
} di asm("rdi") = { .e = b };
register unsigned long si asm("rsi");
register unsigned long dx asm("rdx");
register unsigned long cx asm("rcx");
register unsigned long r8 asm("r8");
register unsigned long r9 asm("r9");
register unsigned long r10 asm("r10");
register unsigned long r11 asm("r11");
asm volatile ( "call %c[addr]"
: "+r" (di), "=r" (si), "=r" (dx),
"=r" (cx), "=r" (r8), "=r" (r9),
"=r" (r10), "=r" (r11), "=a" (ret_)
: [addr] "i" (&(func)), "g" (func)
: "memory" );
}
}
See: https://godbolt.org/z/qvxMGd84q
Clang will generate machine code that only resets the low 8 bits of %rdi
between loop calls, leaving the rest of the register possibly containing
garbage from the use of %rdi inside the called function. Note also that clang
doesn't truncate the input parameters at the callee, thus breaking the psABI.
Fix this by turning the `e` element in the anonymous union into an array that
consumes the same space as an unsigned long, as this forces clang to reset the
whole %rdi register instead of just the low 8 bits.
Fixes: 2ce562b2a4 ('x86/altcall: use a union as register type for function parameters on clang')
Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
fixup_irqs() is used to evacuate interrupts from to be offlined CPUs. Given
the CPU is to become offline, the normal migration logic used by Xen where the
vector in the previous target(s) is left configured until the interrupt is
received on the new destination is not suitable.
Instead attempt to do as much as possible in order to prevent loosing
interrupts. If fixup_irqs() is called from the CPU to be offlined (as is
currently the case for CPU hot unplug) attempt to forward pending vectors when
interrupts that target the current CPU are migrated to a different destination.
Additionally, for interrupts that have already been moved from the current CPU
prior to the call to fixup_irqs() but that haven't been delivered to the new
destination (iow: interrupts with move_in_progress set and the current CPU set
in ->arch.old_cpu_mask) also check whether the previous vector is pending and
forward it to the new destination.
This allows us to remove the window with interrupts enabled at the bottom of
fixup_irqs(). Such window wasn't safe anyway: references to the CPU to become
offline are removed from interrupts masks, but the per-CPU vector_irq[] array
is not updated to reflect those changes (as the CPU is going offline anyway).
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Currently there's logic in fixup_irqs() that attempts to prevent
_assign_irq_vector() from failing, as fixup_irqs() is required to evacuate all
interrupts from the CPUs not present in the input mask. The current logic in
fixup_irqs() is incomplete, as it doesn't deal with interrupts that have
move_cleanup_count > 0 and a non-empty ->arch.old_cpu_mask field.
Instead of attempting to fixup the interrupt descriptor in fixup_irqs() so that
_assign_irq_vector() cannot fail, introduce logic in _assign_irq_vector()
to deal with interrupts that have either move_{in_progress,cleanup_count} set
and no remaining online CPUs in ->arch.cpu_mask.
If _assign_irq_vector() is requested to move an interrupt in the state
described above, first attempt to see if ->arch.old_cpu_mask contains any valid
CPUs that could be used as fallback, and if that's the case do move the
interrupt back to the previous destination. Note this is easier because the
vector hasn't been released yet, so there's no need to allocate and setup a new
vector on the destination.
Due to the logic in fixup_irqs() that clears offline CPUs from
->arch.old_cpu_mask (and releases the old vector if the mask becomes empty) it
shouldn't be possible to get into _assign_irq_vector() with
->arch.move_{in_progress,cleanup_count} set but no online CPUs in
->arch.old_cpu_mask.
However if ->arch.move_{in_progress,cleanup_count} is set and the interrupt has
also changed affinity, it's possible the members of ->arch.old_cpu_mask are no
longer part of the affinity set, move the interrupt to a different CPU part of
the provided mask and keep the current ->arch.old_{cpu_mask,vector} for the
pending interrupt movement to be completed.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Given the current logic it's possible for ->arch.old_cpu_mask to get out of
sync: if a CPU set in old_cpu_mask is offlined and then onlined
again without old_cpu_mask having been updated the data in the mask will no
longer be accurate, as when brought back online the CPU will no longer have
old_vector configured to handle the old interrupt source.
If there's an interrupt movement in progress, and the to be offlined CPU (which
is the call context) is in the old_cpu_mask, clear it and update the mask, so
it doesn't contain stale data.
Note that when the system is going down fixup_irqs() will be called by
smp_send_stop() from CPU 0 with a mask with only CPU 0 on it, effectively
asking to move all interrupts to the current caller (CPU 0) which is the only
CPU to remain online. In that case we don't care to migrate interrupts that
are in the process of being moved, as it's likely we won't be able to move all
interrupts to CPU 0 due to vector shortage anyway.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
The current check used in fixup_irqs() to decide whether to move around
interrupts is based on the affinity mask, but such mask can have all bits set,
and hence is unlikely to be a subset of the input mask. For example if an
interrupt has an affinity mask of all 1s, any input to fixup_irqs() that's not
an all set CPU mask would cause that interrupt to be shuffled around
unconditionally.
What fixup_irqs() care about is evacuating interrupts from CPUs not set on the
input CPU mask, and for that purpose it should check whether the interrupt is
assigned to a CPU not present in the input mask. Assume that ->arch.cpu_mask
is a subset of the ->affinity mask, and keep the current logic that resets the
->affinity mask if the interrupt has to be shuffled around.
Doing the affinity movement based on ->arch.cpu_mask requires removing the
special handling to ->arch.cpu_mask done for high priority vectors, otherwise
the adjustment done to cpu_mask makes them always skip the CPU interrupt
movement.
While there also adjust the comment as to the purpose of fixup_irqs().
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Release-Acked-By: Oleksii Kurochko <oleksii.kurochko@gmail.com>
The logic to move interrupts across CPUs is complex, attempt to provide a
comment that describes the expected behavior so users of the interrupt system
have more context about the usage of the arch_irq_desc structure fields.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Due to the current rwlock logic, if the CPU calling get_cpu_maps() does
so from a cpu_hotplug_{begin,done}() region the function will still
return success, because a CPU taking the rwlock in read mode after
having taken it in write mode is allowed. Such corner case makes using
get_cpu_maps() alone not enough to prevent using the shorthand in CPU
hotplug regions.
Introduce a new helper to detect whether the current caller is between a
cpu_hotplug_{begin,done}() region and use it in send_IPI_mask() to restrict
shorthand usage.
Fixes: 5500d265a2 ('x86/smp: use APIC ALLBUT destination shorthand when possible')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
PVH dom0 is functionally very similar to PVH domU except for the domain
builder and the added set of hypercalls available to it.
The main concern with declaring it "Supported" is the lack of some features
when compared to classic PV dom0, hence switch it's status to supported with
caveats. List the known missing features, there might be more features missing
or not working as expected apart from the ones listed.
Note there's some (limited) PVH dom0 testing on both osstest and gitlab.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
When adjusting move_cleanup_count to account for CPUs that are offline also
adjust old_cpu_mask, otherwise further calls to fixup_irqs() could subtract
those again and create an imbalance in move_cleanup_count.
Fixes: 472e0b74c5 ('x86/IRQ: deal with move cleanup count state in fixup_irqs()')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Roger Pau Monne