Commit Graph
47437 Commits
Author SHA1 Message Date
Roger Pau Monné 3c2b6175a1 x86/msr: expose MSR_FAM10H_MMIO_CONF_BASE on AMD
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>
master commit: b4071d28c5
master date: 2025-03-12 13:32:30 +0100
2025-03-20 13:18:46 +01:00
Andrew Cooper da239140a4 x86/vlapic: Fix handling of writes to APIC_ESR
Xen currently presents APIC_ESR to guests as a simple read/write register.

This is incorrect.  The SDM states:

  The ESR is a write/read register. Before attempt to read from the ESR,
  software should first write to it. (The value written does not affect the
  values read subsequently; only zero may be written in x2APIC mode.) This
  write clears any previously logged errors and updates the ESR with any
  errors detected since the last write to the ESR.

Introduce a new pending_esr field in hvm_hw_lapic.

Update vlapic_error() to accumulate errors here, and extend vlapic_reg_write()
to discard the written value and transfer pending_esr into APIC_ESR.  Reads
are still as before.

Importantly, this means that guests no longer destroys the ESR value it's
looking for in the LVTERR handler when following the SDM instructions.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: b28b590d4a
master date: 2025-03-07 14:34:08 +0000
2025-03-20 13:18:23 +01:00
Juergen Gross 7c767b7093 tools/xl: fix channel configuration setting
Channels work differently than other device types: their devid should
be -1 initially in order to distinguish them from the primary console
which has the devid of 0.

So when parsing the channel configuration, use
ARRAY_EXTEND_INIT_NODEVID() in order to avoid overwriting the devid
set by libxl_device_channel_init().

Fixes: 3a66796347 ("libxl: set channel devid when not provided by application")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
master commit: e1ccced4af
master date: 2025-03-05 16:37:37 +0100
2025-03-20 13:17:41 +01:00
Roger Pau Monné e665204eb3 x86/dom0: be less restrictive with the Interrupt Address Range
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>
master commit: 381caa3885
master date: 2025-03-05 10:26:46 +0100
2025-03-20 13:17:17 +01:00
Roger Pau Monné 74e860e45e x86/iommu: account for IOMEM caps when populating dom0 IOMMU page-tables
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>
master commit: 62f3fc5296
master date: 2025-03-05 10:26:46 +0100
2025-03-20 13:16:56 +01:00
Roger Pau Monné eaa79d83b6 x86/dom0: correctly set the maximum ->iomem_caps bound for PVH
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>
master commit: a00e08799c
master date: 2025-03-05 10:26:46 +0100
2025-03-20 13:16:37 +01:00
Roger Pau Monné 2f47f9df89 x86/dom0: attempt to fixup p2m page-faults for PVH dom0
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>
master commit: 104591f5dd
master date: 2025-03-05 10:26:46 +0100
2025-03-20 13:16:14 +01:00
Roger Pau Monné c6366b64dd x86/emul: dump unhandled memory accesses for PVH dom0
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>
master commit: 43d8a80a0c
master date: 2025-03-05 10:26:46 +0100
2025-03-20 13:15:48 +01:00
Andrew Cooper b067751570 x86/svm: Separate STI and VMRUN instructions in svm_asm_do_resume()
There is a corner case in the VMRUN instruction where its INTR_SHADOW state
leaks into guest state if a VMExit occurs before the VMRUN is complete.  An
example of this could be taking #NPF due to event injection.

Xen can safely execute STI anywhere between CLGI and VMRUN, as CLGI blocks
external interrupts too.  However, an exception (while fatal) will appear to
be in an irqs-on region (as GIF isn't considered), so position the STI after
the speculation actions but prior to the GPR pops.

Link: https://lore.kernel.org/all/CADH9ctBs1YPmE4aCfGPNBwA10cA8RuAk2gO7542DjMZgs4uzJQ@mail.gmail.com/
Fixes: 66b245d9ea ("SVM: limit GIF=0 region")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: c989ff614f
master date: 2025-02-19 12:45:48 +0000
2025-03-20 13:14:51 +01:00
Oleksandr Tyshchenko 93027a991a xen/memory: Make resource_max_frames() to return 0 on unknown type
This is actually what the caller acquire_resource() expects on any kind
of error (the comment on top of resource_max_frames() also suggests that).
Otherwise, the caller will treat -errno as a valid value and propagate incorrect
nr_frames to the VM. As a possible consequence, a VM trying to query a resource
size of an unknown type will get the success result from the hypercall and obtain
nr_frames 4294967201.

Also, add an ASSERT_UNREACHABLE() in the default case of _acquire_resource(),
normally we won't get to this point, as an unknown type will always be rejected
earlier in resource_max_frames().

Also, update test-resource app to verify that Xen can deal with invalid
(unknown) resource type properly.

Fixes: 9244528955 ("xen/memory: Fix acquire_resource size semantics")
Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: 9b87082900
master date: 2025-02-18 14:47:34 +0000
2025-03-20 13:14:27 +01:00
Andrew Cooper 330ecfc7c1 xen/console: Fix truncation of panic() messages
The panic() function uses a static buffer to format its arguments into, simply
to emit the result via printk("%s", buf).  This buffer is not large enough for
some existing users in Xen.  e.g.:

  (XEN) ****************************************
  (XEN) Panic on CPU 0:
  (XEN) Invalid device tree blob at physical address 0x46a00000.
  (XEN) The DTB must be 8-byte aligned and must not exceed 2 MB in size.
  (XEN)
  (XEN) Plea****************************************

The remainder of this particular message is 'e check your bootloader.', but
has been inherited by RISC-V from ARM.

It is also pointless double buffering.  Implement vprintk() beside printk(),
and use it directly rather than rendering into a local buffer, removing it as
one source of message limitation.

This marginally simplifies panic(), and drops a global used-once buffer.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: 81f8b1dd94
master date: 2025-02-18 14:15:58 +0000
2025-03-20 13:13:44 +01:00
Jan Beulich f2c5b4b1aa IOMMU/x86: the bus-to-bridge lock needs to be acquired IRQ-safe
The function's use from set_msi_source_id() is guaranteed to be in an
IRQs-off region. While the invocation of that function could be moved
ahead in msi_msg_to_remap_entry() (doesn't need to be in the IOMMU-
intremap-locked region), the call tree from map_domain_pirq() holds an
IRQ descriptor lock. Hence all use sites of the lock need become IRQ-
safe ones.

In find_upstream_bridge() do a tiny bit of tidying in adjacent code:
Change a variable's type to unsigned and merge a redundant assignment
into another variable's initializer.

This is XSA-467 / CVE-2025-1713.

Fixes: 476bbccc81 ("VT-d: fix MSI source-id of interrupt remapping")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
(cherry picked from commit 39bc6af3ba)
2025-02-27 12:59:57 +00:00
Roger Pau Monné 93302bb888 x86/iommu: disable interrupts at shutdown
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>
master commit: 819c3cb186
master date: 2025-02-12 15:56:07 +0100
2025-02-17 13:24:23 +01:00
Roger Pau Monné eae35da8f4 x86/pci: disable MSI(-X) on all devices at shutdown
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>
master commit: 7ab6951981
master date: 2025-02-12 15:56:07 +0100
2025-02-17 13:24:03 +01:00
Roger Pau Monné 30aadc8dbc x86/smp: perform disabling on interrupts ahead of AP shutdown
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>
master commit: db6daa9bf4
master date: 2025-02-12 15:56:07 +0100
2025-02-17 13:23:50 +01:00
Roger Pau Monné e801a86d5e x86/shutdown: offline APs with interrupts disabled on all CPUs
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>
master commit: 1191ce954f
master date: 2025-02-12 15:56:07 +0100
2025-02-17 13:23:27 +01:00
Jan Beulich 46e3e9d739 radix-tree: introduce RADIX_TREE{,_INIT}()
... now that static initialization is possible. Use RADIX_TREE() for
pci_segments and ivrs_maps.

This then fixes an ordering issue on x86: With the call to
radix_tree_init(), acpi_mmcfg_init()'s invocation of pci_segments_init()
will zap the possible earlier introduction of segment 0 by
amd_iommu_detect_one_acpi()'s call to pci_ro_device(), and thus the
write-protection of the PCI devices representing AMD IOMMUs.

Fixes: 3950f2485b ("x86/x2APIC: defer probe until after IOMMU ACPI table parsing")
Requested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: 26fe09e345
master date: 2025-02-07 10:00:04 +0100
2025-02-17 13:23:00 +01:00
Jan Beulich ebc8b4a450 radix-tree: purge node allocation override hooks
These were needed by TMEM only, which is long gone. The Linux original
doesn't have such either. This effectively reverts one of the "Other
changes" from 8dc6738dbb ("Update radix-tree.[ch] from upstream Linux
to gain RCU awareness").

Positive side effect: Two cf_check go away.

While there also convert xmalloc()+memset() to xzalloc().

Requested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: 1275093a96
master date: 2025-02-07 09:59:11 +0100
2025-02-17 13:22:24 +01:00
Andrew Cooper c4d4fc58b6 x86/intel: Fix PERF_GLOBAL fixup when virtualised
Logic using performance counters needs to look at
MSR_MISC_ENABLE.PERF_AVAILABLE before touching any other resources.

When virtualised under ESX, Xen dies with a #GP fault trying to read
MSR_CORE_PERF_GLOBAL_CTRL.

Factor this logic out into a separate function (it's already too squashed to
the RHS), and insert a check of MSR_MISC_ENABLE.PERF_AVAILABLE.

This also avoids setting X86_FEATURE_ARCH_PERFMON if MSR_MISC_ENABLE says that
PERF is unavailable, although oprofile (the only consumer of this flag)
cross-checks too.

Fixes: 6bdb965178 ("x86/intel: ensure Global Performance Counter Control is setup correctly")
Reported-by: Jonathan Katz <jonathan.katz@aptar.com>
Link: https://xcp-ng.org/forum/topic/10286/nesting-xcp-ng-on-esx-8
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Tested-by: Jonathan Katz <jonathan.katz@aptar.com>
master commit: dd05d265b8
master date: 2025-01-28 11:19:45 +0000
2025-02-17 13:21:50 +01:00
Jan Beulich 125270d49d x86/PV: further harden guest memory accesses against speculative abuse
The original implementation has two issues: For one it doesn't preserve
non-canonical-ness of inputs in the range 0x8000000000000000 through
0x80007fffffffffff. Bogus guest pointers in that range would not cause a
(#GP) fault upon access, when they should.

And then there is an AMD-specific aspect, where only the low 48 bits of
an address are used for speculative execution; the architecturally
mandated #GP for non-canonical addresses would be raised at a later
execution stage. Therefore to prevent Xen controlled data to make it
into any of the caches in a guest controllable manner, we need to
additionally ensure that for non-canonical inputs bit 47 would be clear.

See the code comment for how addressing both is being achieved.

Fixes: 4dc1815991 ("x86/PV: harden guest memory accesses against speculative abuse")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
master commit: 8306d773b0
master date: 2025-01-27 15:23:59 +0100
2025-02-17 13:21:30 +01:00
Jan Beulich b7b0ce5e11 x86emul: further correct 64-bit mode zero count repeated string insn handling
In an entirely different context I came across Linux commit 428e3d08574b
("KVM: x86: Fix zero iterations REP-string"), which points out that
we're still doing things wrong: For one, there's no zero-extension at
all on AMD. And then while RCX is zero-extended from 32 bits uniformly
for all string instructions on newer hardware, RSI/RDI are only for MOVS
and STOS on the systems I have access to. (On an old family 0xf system
I've further found that for REP LODS even RCX is not zero-extended.)

While touching the lines anyway, replace two casts in get_rep_prefix().

Fixes: 79e996a89f ("x86emul: correct 64-bit mode repeated string insn handling with zero count")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
master commit: 5310a042c4
master date: 2025-01-27 15:23:19 +0100
2025-02-17 13:21:00 +01:00
Roger Pau Monné 457b9e11fa iommu/amd: atomically update IRTE
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>
master commit: b953a99da9
master date: 2025-01-27 13:05:11 +0100
2025-02-17 13:20:38 +01:00
Teddy Astie 49c3324f37 x86/iommu: check for CMPXCHG16B when enabling IOMMU
All hardware with VT-d/AMD-Vi has CMPXCHG16B support. Check this at
initialisation time, and otherwise refuse to use the IOMMU.

If the local APICs support x2APIC mode the IOMMU support for interrupt
remapping will be checked earlier using a specific helper.  If no support
for CX16 is detected by that earlier hook disable the IOMMU at that point
and prevent further poking for CX16 later in the boot process, which would
also fail.

There's a possible corner case when running virtualized, and the underlying
hypervisor exposing an IOMMU but no CMPXCHG16B support.  In which case
ignoring the IOMMU is fine, albeit the most natural would be for the
underlying hypervisor to also expose CMPXCHG16B support if an IOMMU is
available to the VM.

Note this change only introduces the checks, but doesn't remove the now
stale checks for CX16 support sprinkled in the IOMMU code.  Further changes
will take care of that.

Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Teddy Astie <teddy.astie@vates.tech>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: 2636fcdc15
master date: 2025-01-27 13:05:11 +0100
2025-02-17 13:20:14 +01:00
Jan Beulich e990bf3de5 x86/HVM: correct read/write split at page boundaries
The MMIO cache is intended to have one entry used per independent memory
access that an insn does. This, in particular, is supposed to be
ignoring any page boundary crossing. Therefore when looking up a cache
entry, the access'es starting (linear) address is relevant, not the one
possibly advanced past a page boundary.

In order for the same offset-into-buffer variable to be usable in
hvmemul_phys_mmio_access() for both the caller's buffer and the cache
entry's it is further necessary to have the un-adjusted caller buffer
passed into there.

Fixes: 2d527ba310 ("x86/hvm: split all linear reads and writes at page boundary")
Reported-by: Manuel Andreas <manuel.andreas@tum.de>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
master commit: 672894a11f
master date: 2025-01-24 10:15:56 +0100
2025-02-17 13:19:51 +01:00
Jan Beulich dcac022fd9 x86/HVM: allocate emulation cache entries dynamically
Both caches may need higher capacity, and the upper bound will need to
be determined dynamically based on CPUID policy (for AMX'es TILELOAD /
TILESTORE at least).

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
master commit: 23d60dbb04
master date: 2025-01-24 10:15:29 +0100
2025-02-17 13:19:04 +01:00
Jan Beulich 15f83e2744 x86/HVM: correct MMIO emulation cache bounds check
To avoid overrunning the internal buffer we need to take the offset into
the buffer into account.

Fixes: d95da91fb4 ("x86/HVM: grow MMIO cache data size to 64 bytes")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
master commit: e5339bb689
master date: 2025-01-23 11:14:48 +0100
2025-02-17 13:18:15 +01:00
Jan Beulich 41d38d270e x86/HVM: reduce recursion in linear_{read,write}()
Let's make explicit what the compiler may or may not do on our behalf:
The 2nd of the recursive invocations each can fall through rather than
re-invoking the function. This will save us from adding yet another
parameter (or more) to the function, just for the recursive invocations.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: 18053054b7
master date: 2024-09-09 13:40:47 +0200
2025-02-17 13:17:45 +01:00
Juergen Gross 4803a3c5b5 xen/events: fix race with set_global_virq_handler()
There is a possible race scenario between set_global_virq_handler()
and clear_global_virq_handlers() targeting the same domain, which
might result in that domain ending as a zombie domain.

In case set_global_virq_handler() is being called for a domain which
is just dying, it might happen that clear_global_virq_handlers() is
running first, resulting in set_global_virq_handler() taking a new
reference for that domain and entering in the global_virq_handlers[]
array afterwards. The reference will never be dropped, thus the domain
will never be freed completely.

This can be fixed by checking the is_dying state of the domain inside
the region guarded by global_virq_handlers_lock. In case the domain is
dying, handle it as if the domain wouldn't exist, which will be the
case in near future anyway.

Fixes: 87521589aa ("xen: allow global VIRQ handlers to be delegated to other domains")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: 4d8acc9c1c
master date: 2025-01-09 17:34:01 +0100
2025-01-21 09:21:01 +01:00
Michal Orzel e7f96aa3f3 xen/flask: Wire up XEN_DOMCTL_dt_overlay
Addition of FLASK permission for this hypercall was overlooked in the
original patch. Fix it. The only dt overlay operation is attaching that can
happen only after the domain is created. Dom0 can attach overlay to itself
as well.

Fixes: 4c733873b5 ("xen/arm: Add XEN_DOMCTL_dt_overlay and device attachment to domains")
Signed-off-by: Michal Orzel <michal.orzel@amd.com>
Acked-by: Daniel P. Smith <dpsmith@apertussolutions.com>
master commit: 7fa1411676
master date: 2025-01-08 13:05:50 +0100
2025-01-21 09:20:51 +01:00
Michal Orzel 30a8d910ca xen/flask: Wire up XEN_DOMCTL_vuart_op
Addition of FLASK permission for this hypercall was overlooked in the
original patch. Fix it. The only VUART operation is initialization that
can occur only during domain creation.

Fixes: 86039f2e8c ("xen/arm: vpl011: Add a new domctl API to initialize vpl011")
Signed-off-by: Michal Orzel <michal.orzel@amd.com>
Acked-by: Daniel P. Smith <dpsmith@apertussolutions.com>
master commit: 29daa72e40
master date: 2025-01-08 13:05:38 +0100
2025-01-21 09:20:42 +01:00
Jan Beulich 4df28706ad x86emul: correct put_fpu()'s segment selector handling
All selector fields under ctxt->regs are (normally) poisoned in the HVM
case, and the four ones besides CS and SS are potentially stale for PV.
Avoid using them in the hypervisor incarnation of the emulator, when
trying to cover for a missing ->read_segment() hook.

To make sure there's always a valid ->read_segment() handler for all HVM
cases, add a respective function to shadow code, even if it is not
expected for FPU insns to be used to update page tables.

Fixes: 0711b59b85 ("x86emul: correct FPU code/data pointers and opcode handling")
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: 645b8d48c7
master date: 2025-01-08 11:02:16 +0100
2025-01-21 09:19:56 +01:00
Jan Beulich 4abf7f1d61 x86emul: VCVT{,U}DQ2PD ignores embedded rounding
IOW we shouldn't raise #UD in that case. Be on the safe side though and
only encode fully legitimate forms into the stub to be executed.

Things weren't quite right for VCVT{,U}SI2SD either, in the attempt to
be on the safe side: Clearing EVEX.L'L isn't useful; it's EVEX.b which
primarily needs clearing. Also reflect the somewhat improved doc
situation in the comment there.

Fixes: ed806f3737 ("x86emul: support AVX512F legacy-equivalent packed int/FP conversion insns")
Fixes: baf4a376f5 ("x86emul: support AVX512F legacy-equivalent scalar int/FP conversion insns")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: d3709d1324
master date: 2025-01-08 11:01:17 +0100
2025-01-21 09:19:39 +01:00
Andrew Cooper 71d626f2f7 x86/amd: Misc setup for Fam1Ah processors
Fam1Ah is similar to Fam19h in these regards.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
master commit: f29cc14de1
master date: 2025-01-06 18:01:32 +0000
2025-01-21 09:19:14 +01:00
Andrew Cooper 1b88dc9afc x86/traps: Rework LER initialisation and support Zen5/Diamond Rapids
AMD have always used the architectural MSRs for LER.  As the first processor
to support LER was the K7 (which was 32bit), we can assume it's presence
unconditionally in 64bit mode.

Intel are about to run out of space in Family 6 and start using 19.  It is
only the Pentium 4 which uses non-architectural LER MSRs.

percpu_traps_init(), which runs on every CPU, contains a lot of code which
should be init-only, and is the only reason why opt_ler can't be in initdata.

Write a brand new init_ler() which expects all future Intel and AMD CPUs to
continue using the architectural MSRs, and does all setup together.  Call it
from trap_init(), and remove the setup logic percpu_traps_init() except for
the single path configuring MSR_IA32_DEBUGCTLMSR.

Leave behind a warning if the user asked for LER and Xen couldn't enable it.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: 555866cb56
master date: 2025-01-06 12:24:05 +0000
2025-01-21 09:18:42 +01:00
Andrew Cooper 816235e311 x86/spec-ctrl: Support for SRSO_U/S_NO and SRSO_MSR_FIX
AMD have updated the SRSO whitepaper[1] with further information.  These
features exist on AMD Zen5 CPUs and are necessary for Xen to use.

The two features are in principle unrelated:

 * SRSO_U/S_NO is an enumeration saying that SRSO attacks can't cross the
   User(CPL3) / Supervisor(CPL<3) boundary.  i.e. Xen don't need to use
   IBPB-on-entry for PV64.  PV32 guests are explicitly unsupported for
   speculative issues, and excluded from consideration for simplicity.

 * SRSO_MSR_FIX is an enumeration identifying that the BP_SPEC_REDUCE bit is
   available in MSR_BP_CFG.  When set, SRSO attacks can't cross the host/guest
   boundary.  i.e. Xen don't need to use IBPB-on-entry for HVM.

Extend ibpb_calculations() to account for these when calculating
opt_ibpb_entry_{pv,hvm} defaults.  Add a `bp-spec-reduce=<bool>` option to
control the use of BP_SPEC_REDUCE, with it active by default.

Because MSR_BP_CFG is core-scoped with a race condition updating it, repurpose
amd_check_erratum_1485() into amd_check_bp_cfg() and calculate all updates at
once.

Xen also needs to to advertise SRSO_U/S_NO to guests to allow the guest kernel
to skip SRSO mitigations too:

 * This is trivial for HVM guests.  It is also is accurate for PV32 guests
   too, but we have already excluded them from consideration, and do so again
   here to simplify the policy logic.

 * As written, SRSO_U/S_NO does not help for the PV64 user->kernel boundary.
   However, after discussing with AMD, an implementation detail of having
   BP_SPEC_REDUCE active causes the PV64 user->kernel boundary to have the
   property described by SRSO_U/S_NO, so we can advertise SRSO_U/S_NO to
   guests when the BP_SPEC_REDUCE precondition is met.

Finally, fix a typo in the SRSO_NO's comment.

[1] https://www.amd.com/content/dam/amd/en/documents/corporate/cr/speculative-return-stack-overflow-whitepaper.pdf
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
master commit: a1746cd443
master date: 2025-01-02 18:44:49 +0000
2025-01-21 09:18:08 +01:00
Maximilian Engelhardt d260f79784 xen/arch/x86: make objdump output user locale agnostic
The objdump output is fed to grep, so make sure it doesn't change with
different user locales and break the grep parsing.
This problem was identified while updating xen in Debian and the fix is
needed for generating reproducible builds in varying environments.

Signed-off-by: Maximilian Engelhardt <maxi@daemonizer.de>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: 0d729221ab
master date: 2024-12-30 21:40:37 +0000
2025-01-21 09:17:58 +01:00
Marek Marczykowski-Górecki 0a14438052 tools/xg: increase LZMA_BLOCK_SIZE for uncompressing the kernel
Linux 6.12-rc2 fails to decompress with the current 128MiB, contrary to
the code comment. It results in a failure like this:

    domainbuilder: detail: xc_dom_kernel_file: filename="/var/lib/qubes/vm-kernels/6.12-rc2-1.1.fc37/vmlinuz"
    domainbuilder: detail: xc_dom_malloc_filemap    : 12104 kB
    domainbuilder: detail: xc_dom_module_file: filename="/var/lib/qubes/vm-kernels/6.12-rc2-1.1.fc37/initramfs"
    domainbuilder: detail: xc_dom_malloc_filemap    : 7711 kB
    domainbuilder: detail: xc_dom_boot_xen_init: ver 4.19, caps xen-3.0-x86_64 hvm-3.0-x86_32 hvm-3.0-x86_32p hvm-3.0-x86_64
    domainbuilder: detail: xc_dom_parse_image: called
    domainbuilder: detail: xc_dom_find_loader: trying multiboot-binary loader ...
    domainbuilder: detail: loader probe failed
    domainbuilder: detail: xc_dom_find_loader: trying HVM-generic loader ...
    domainbuilder: detail: loader probe failed
    domainbuilder: detail: xc_dom_find_loader: trying Linux bzImage loader ...
    domainbuilder: detail: _xc_try_lzma_decode: XZ decompression error: Memory usage limit reached
    xc: error: panic: xg_dom_bzimageloader.c:761: xc_dom_probe_bzimage_kernel unable to XZ decompress kernel: Invalid kernel
    domainbuilder: detail: loader probe failed
    domainbuilder: detail: xc_dom_find_loader: trying ELF-generic loader ...
    domainbuilder: detail: loader probe failed
    xc: error: panic: xg_dom_core.c:689: xc_dom_find_loader: no loader found: Invalid kernel
    libxl: error: libxl_dom.c:566:libxl__build_dom: xc_dom_parse_image failed

The important part: XZ decompression error: Memory usage limit reached

This looks to be related to the following change in Linux:
8653c909922743bceb4800e5cc26087208c9e0e6 ("xz: use 128 MiB dictionary and force single-threaded mode")

Fix this by increasing the block size to 256MiB. And remove the
misleading comment (from lack of better ideas).

Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Anthony PERARD <anthony.perard@vates.tech>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: e6472d4668
master date: 2024-12-19 17:33:54 +0000
2025-01-21 09:17:44 +01:00
Andrew Cooper 8dd897e691 MISRA: Unmark Rules 1.1 and 2.1 as clean following Eclair upgrade
Updating the Eclair runner has had knock-on effects with previously-clean
rules now flagging violations:

 - x86:   Rule 1.1, 1940 violations
 - ARM64: Rule 1.1, 725 violations, Rule 2.1, 255 violations

Fixes: 631f535a3d ("xen: update ECLAIR service identifiers from MC3R1 to MC3A2.")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
(cherry picked from commit 171cb318de)
2024-12-17 22:01:58 +00:00
Alessandro Zucchelli 8b584c97f8 xen: update ECLAIR service identifiers from MC3R1 to MC3A2.
Rename all instances of ECLAIR MISRA C:2012 service identifiers,
identified by the prefix MC3R1, to use the prefix MC3A2, which
refers to MISRA C:2012 Amendment 2 guidelines.

This update is motivated by the need to upgrade ECLAIR GitLab runners
that use the new naming scheme for MISRA C:2012 Amendment 2 guidelines.

Changes to the docs/misra directory are needed in order to keep
comment-based deviation up to date.

Signed-off-by: Alessandro Zucchelli <alessandro.zucchelli@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
(cherry picked from commit 631f535a3d)
2024-12-17 13:09:58 +00:00
Roger Pau Monné c41c22bf8e x86/io-apic: prevent early exit from i8259 loop detection
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>
master commit: f38fd27c4c
master date: 2024-12-17 11:15:30 +0100
2024-12-17 12:46:29 +01:00
Andrii Sultanov fbe3ec72dc tools/ocaml: Specify rpath correctly for ocamlmklib
ocamlmklib has special handling for C-like '-Wl,-rpath' option, but does
not know how to handle '-Wl,-rpath-link', as evidenced by warnings like:
"Unknown option
-Wl,-rpath-link=$HOME/xen/tools/ocaml/libs/eventchn/../../../../tools/libs/toollog"
Pass this option directly to the compiler with -ccopt instead.

Also pass -L directly to the linker with -ldopt. This prevents embedding absolute
paths from buildtime into binary's RPATH.

Fixes: f7b4e4558b ("tools/ocaml: Fix OCaml libs rules")
Reported-by: Fernando Rodrigues <alpha@sigmasquadron.net>
Tested-by: Fernando Rodrigues <alpha@sigmasquadron.net>
Signed-off-by: Andrii Sultanov <andrii.sultanov@cloud.com>
Acked-by: Christian Lindig <christian.lindig@cloud.com>
master commit: bf8a209915
master date: 2024-12-11 10:45:08 +0000
2024-12-16 13:33:17 +01:00
Andrew Cooper 60573721c5 libs/guest: Fix migration compatibility with a security-patched Xen 4.13
xc_cpuid_apply_policy() provides compatibility for migration of a pre-4.14 VM
where no CPUID data was provided in the stream.

It guesses the various max-leaf limits, based on what was true at the time of
writing, but this was not correctly adapted when speculative security issues
forced the advertisement of new feature bits.  Of note are:

 * LFENCE-DISPATCH, in leaf 0x80000021.eax
 * BHI-CTRL, in leaf 0x7[2].edx

In both cases, a VM booted on a security-patched Xen 4.13, and then migrated
on to any newer version of Xen on the same or compatible hardware would have
these features stripped back because Xen is still editing the cpu-policy for
sanity behind the back of the toolstack.

For VMs using BHI_DIS_S to mitigate Native-BHI, this resulted in a failure to
restore the guests MSR_SPEC_CTRL setting:

  (XEN) HVM d7v0 load MSR 0x48 with value 0x401 failed
  (XEN) HVM7 restore: failed to load entry 20/0 rc -6

Fixes: e9b4fe2636 ("x86/cpuid: support LFENCE always serialising CPUID bit")
Fixes: f3709b15fc ("x86/cpuid: Infrastructure for cpuid word 7:2.edx")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: 28301682f4
master date: 2024-12-03 12:20:41 +0000
2024-12-16 13:33:07 +01:00
Roger Pau Monné 475511a467 xen/Kconfig: livepatch-build-tools requires debug information
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>
master commit: 126b0a6e53
master date: 2024-12-02 15:22:05 +0100
2024-12-16 13:32:43 +01:00
Jan Beulich 3a9e5a93e6 x86emul: MOVBE requires a memory operand
The reg-reg forms should cause #UD; they come into existence only with
APX, where MOVBE also extends BSWAP (for the latter not being "eligible"
to a REX2 prefix).

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: 4c5d9a01f8
master date: 2024-12-02 09:50:14 +0100
2024-12-16 13:32:19 +01:00
Jan Beulich 5d61bc0585 update Xen version to 4.19.2-pre 2024-12-16 13:31:51 +01:00
Luca Fancellu 6f7af8383f xen/device-tree: Allow region overlapping with /memreserve/ ranges
There are some cases where the device tree exposes a memory range
in both /memreserve/ and reserved-memory node, in this case the
current code will stop Xen to boot since it will find that the
latter range is clashing with the already recorded /memreserve/
ranges.

Furthermore, u-boot lists boot modules ranges, such as ramdisk,
in the /memreserve/ part and even in this case this will prevent
Xen to boot since it will see that the module memory range that
it is going to add in 'add_boot_module' clashes with a /memreserve/
range.

When Xen populate the data structure that tracks the memory ranges,
it also adds a memory type described in 'enum membank_type', so
in order to fix this behavior, allow overlapping with the /memreserve/
ranges in the 'check_reserved_regions_overlap' function when a flag
is set.

In order to implement this solution, there is a distinction between
the 'struct membanks *' handled by meminfo_overlap_check(...) that
needs to be done, because the static shared memory banks doesn't have
a usable bank[].type field and so it can't be accessed, hence now
the 'struct membanks_hdr' have a 'enum region_type type' field in order
to be able to identify static shared memory banks in meminfo_overlap_check(...).

While there, set a type for the memory recorded using meminfo_add_bank()
from efi-boot.h.

Fixes: 53dc37829c ("xen/arm: Add DT reserve map regions to bootinfo.reserved_mem")
Reported-by: Shawn Anastasio <sanastasio@raptorengineering.com>
Reported-by: Grygorii Strashko <grygorii_strashko@epam.com>
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Tested-by: Grygorii Strashko <grygorii_strashko@epam.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>

bootfdt: Add missing trailing commas in BOOTINFO_{ACPI,SHMEM}_INIT

Commit a14593e399 extended BOOTINFO_{ACPI,SHMEM}_INIT initializers
list with a new 'type' member but forgot to add trailing commas (they
were present before). This results in a build failure when building
with CONFIG_ACPI=y and CONFIG_STATIC_SHM=y:
./include/xen/bootfdt.h:155:5: error: request for member 'shmem' in something not a structure or union
  155 |     .shmem.common.max_banks = NR_SHMEM_BANKS,       \
      |     ^
./include/xen/bootfdt.h:168:5: note: in expansion of macro 'BOOTINFO_SHMEM_INIT'
  168 |     BOOTINFO_SHMEM_INIT                             \
      |     ^~~~~~~~~~~~~~~~~~~
common/device-tree/bootinfo.c:22:39: note: in expansion of macro 'BOOTINFO_INIT'
   22 | struct bootinfo __initdata bootinfo = BOOTINFO_INIT;

Fixes: a14593e399 ("xen/device-tree: Allow region overlapping with /memreserve/ ranges")
Signed-off-by: Michal Orzel <michal.orzel@amd.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
Reviewed-by: Luca Fancellu <luca.fancellu@arm.com>
master commit: a14593e399
master date: 2024-11-28 18:57:21 +0000
master commit: 5a455a52ea
master date: 2024-12-03 12:20:41 +0000
2024-12-16 13:31:23 +01:00
Jan Beulich ccf4008467 update Xen version to 4.19.1 RELEASE-4.19.1 2024-12-04 08:52:37 +01:00
Stewart Hildebrand 5d4a29158d x86/msi: fix locking for SR-IOV devices
In commit 4f78438b45 ("vpci: use per-domain PCI lock to protect vpci
structure") a lock was moved from allocate_and_map_msi_pirq() to the
caller and changed from pcidevs_lock() to read_lock(&d->pci_lock).
However, one call path wasn't updated to reflect the change, leading to
a failed assertion observed under the following conditions:

* PV dom0
* Debug build (CONFIG_DEBUG=y) of Xen
* There is an SR-IOV device in the system with one or more VFs enabled
* Dom0 has loaded the driver for the VF and enabled MSI-X

(XEN) Assertion 'd || pcidevs_locked()' failed at drivers/passthrough/pci.c:535
(XEN) ----[ Xen-4.20-unstable  x86_64  debug=y  Not tainted ]----
...
(XEN) Xen call trace:
(XEN)    [<ffff82d040284da8>] R pci_get_pdev+0x4c/0xab
(XEN)    [<ffff82d040344f5c>] F arch/x86/msi.c#read_pci_mem_bar+0x58/0x272
(XEN)    [<ffff82d04034530e>] F arch/x86/msi.c#msix_capability_init+0x198/0x755
(XEN)    [<ffff82d040345dad>] F arch/x86/msi.c#__pci_enable_msix+0x82/0xe8
(XEN)    [<ffff82d0403463e5>] F pci_enable_msi+0x3f/0x78
(XEN)    [<ffff82d04034be2b>] F map_domain_pirq+0x2a4/0x6dc
(XEN)    [<ffff82d04034d4d5>] F allocate_and_map_msi_pirq+0x103/0x262
(XEN)    [<ffff82d04035da5d>] F physdev_map_pirq+0x210/0x259
(XEN)    [<ffff82d04035e798>] F do_physdev_op+0x9c3/0x1454
(XEN)    [<ffff82d040329475>] F pv_hypercall+0x5ac/0x6af
(XEN)    [<ffff82d0402012d3>] F lstar_enter+0x143/0x150

In read_pci_mem_bar(), the VF obtains the struct pci_dev pointer for its
associated PF to access the vf_rlen array. This array is initialized in
pci_add_device() and is only populated in the associated PF's struct
pci_dev.

Access the vf_rlen array via the link to the PF, and remove the
troublesome call to pci_get_pdev().

Fixes: 4f78438b45 ("vpci: use per-domain PCI lock to protect vpci structure")
Reported-by: Teddy Astie <teddy.astie@vates.tech>
Signed-off-by: Stewart Hildebrand <stewart.hildebrand@amd.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: 931eaa21cd
master date: 2024-11-26 11:23:19 +0100
2024-11-27 12:21:04 +01:00
Stewart Hildebrand f67d770d86 xen/pci: introduce PF<->VF links
Add links between a VF's struct pci_dev and its associated PF struct
pci_dev.

The hardware domain is expected to remove the associated VFs before
removing the PF. If removal happens out of order, print a warning and
return an error. This means that VFs can only exist with an associated
PF.

Additionally, if the hardware domain attempts to remove a PF with VFs
still present, mark the PF and VFs broken, because Linux Dom0 has been
observed to not respect the error returned.

Move the calls to pci_get_pdev() and pci_add_device() down to avoid
dropping and re-acquiring the pcidevs_lock().

Check !pdev->pf_pdev before adding the VF to the list to guard against
adding it multiple times.

Signed-off-by: Stewart Hildebrand <stewart.hildebrand@amd.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: 4e18a39056
master date: 2024-11-26 11:22:26 +0100
2024-11-27 12:20:46 +01:00
Andrew Cooper 54452a3df9 build: Remove -fno-stack-protector-all from EMBEDDED_EXTRA_CFLAGS
This seems to have been introduced in commit f8beb54e24 ("Disable PIE/SSP
features when building Xen, if GCC supports them.") in 2004.

However, neither GCC nor Clang appear to have ever supported taking the
negated form of -fstack-protector-all, meaning this been useless since its
introduction.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: b661fe107d
master date: 2024-11-25 13:44:56 +0000
2024-11-27 12:20:32 +01:00