Commit Graph
100 Commits
Author SHA1 Message Date
Andrew Cooper c554ec124b scripts: Fix git-checkout.sh to work with branches other than master
Xen uses master for QEMU_UPSTREAM_REVISION, and has done for other trees too
in the path.  Apparently we've never specified a different branch, because the
git-clone rune only pulls in the master branch; it does not pull in diverging
branches.  Fix this by stating which branch/tag is wanted.

$TAG is really a committish, and git-clone's -b/--branch takes a committish
too.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2024-10-31 10:34:13 +00:00
Andrew Cooper fa2d831803 x86/cpu-policy: Extend the guest max policy max leaf/subleaves
We already have one migration case opencoded (feat.max_subleaf).  A more
recent discovery is that we advertise x2APIC to guests without ensuring that
we provide max_leaf >= 0xb.

In general, any leaf known to Xen can be safely configured by the toolstack if
it doesn't violate other constraints.

Therefore, introduce guest_common_{max,default}_leaves() to generalise the
special case we currently have for feat.max_subleaf, in preparation to be able
to provide x2APIC topology in leaf 0xb even on older hardware.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Alejandro Vallejo <alejandro.vallejo@cloud.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-10-30 17:34:32 +00:00
Andrew Cooper fa1463cecf x86/boot: Explain how discard_initial_images() works
discard_initial_images() only works because init_domheap_pages() with ps==pe
is a no-op.

In dom0_construct(), explaining the significance of setting the initrd length
to 0, and put an explicit check in discard_initial_images().

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Daniel P. Smith <dpsmith@apertussolutions.com>
2024-10-24 17:57:59 +01:00
Andrew Cooper 83892f6a12 x86/boot: Drop the mbi and mod pointers in __start_xen()
We can't drop them fully yet, but we can limit their scope to almost nothing,
which serves the same purpose.

This removes the ability to accidentally reintroduce buggy uses of
__va(mbi->mods_addr).

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Daniel P. Smith <dpsmith@apertussolutions.com>
2024-10-24 17:57:59 +01:00
Andrew Cooper 0ba5392e70 x86/boot: Introduce bootstrap_unmap()
We're about to introduce alternative mapping functions, and passing NULL was
always a slightly weird way to express unmap.  Make an explicit unmap
function, to avoid having two different valid ways of unmapping.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Daniel P. Smith <dpsmith@apertussolutions.com>
2024-10-24 17:57:59 +01:00
Andrew Cooper 2802b77abe x86/ucode: Explain what microcode_set_module() does
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Alejandro Vallejo <alejandro.vallejo@cloud.com>
2024-10-24 17:57:59 +01:00
Andrew Cooper 9cbf61445c xen/earlycpio: Drop nextoff parameter
This is imported from Linux, but the parameter being signed is dubious in the
first place and we're not plausibly going to gain a use for the functionality.
Linux has subsequently made it an optional parameter to avoid forcing callers
to pass a stack variable they don't care about using.

In the unlikely case that we gain a usecase, we can reintroduce it, but in the
meantime simplify the single caller.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-10-24 17:57:59 +01:00
Andrew Cooper a974725a87 x86/boot: Remove the mbi_p parameter from __start_xen()
The use of physical addresses in __start_xen() has proved to be fertile soure
of bugs.

The MB1/2 path stashes the MBI pointer in multiboot_ptr (a setup.c variable
even), then re-loads it immediately before calling __start_xen().  For this,
we can just drop the function parameter and read multiboot_ptr in the one
place where it's used.

The EFI path also passes this parameter into __start_xen().  Have the EFI path
set up multiboot_ptr too, and move the explanation of phyiscal-mode pointers.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Daniel P. Smith <dpsmith@apertussolutions.com>
2024-10-23 18:14:24 +01:00
Andrew Cooper 89f855d564 x86/boot: Add a temporary module_map pointer to boot_image
... in order to untangle parameter handling independently from other logic
changes.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Daniel P. Smith <dpsmith@apertussolutions.com>
2024-10-23 18:14:24 +01:00
Andrew Cooper 2c3294775e x86/boot: Simplify size calculations in move_memory()
While both src and dst are similar, src is mapped only accounting for src's
size, while dst is mapped based on the minimum of both.  This means that in
some cases, an overly large mapping is requested for src.

Rework the sz calcuation to be symmetric, and leave an explanation of how
logic works.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Daniel P. Smith <dpsmith@apertussolutions.com>
2024-10-23 10:27:36 +01:00
Andrew Cooper c960871c7c x86/boot: Simplify address calculations in move_memory()
Given that soffs is the offset into the 2M superpage,

  start = (src - soffs) >> PAGE_SIFT

is a complicated expression for the frame address of the containing superpage.
Except, start is converted straight back to a byte address to use, so the
shifting is unnecessary too.

The only thing done with the mapped pointer is to have soffs added back on for
the memmove() call.  bootstrap_map_addr() passes through the offset, so we can
pass src directly in and simplify the memmove() call too.  For the end mapping
address, this simplifies to just src + sz too.

The same reasoning holds for dst and doffs.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Daniel P. Smith <dpsmith@apertussolutions.com>
2024-10-23 10:27:36 +01:00
Andrew Cooper e33e18df05 x86/boot: Convert move_memory() to use bootstrap_map_addr()
move_memory() is very complicated, and buggy.  In order to fix the latter, we
have to address the former.

Given prior cleanup, bootstrap_map() is now implemented in terms of
bootstrap_map_addr(), meaning that it is counterproductive to plumb the
mapping through module_t.

Delete mod, and introduce two same-sized/named fields.  At this point in boot,
neither fields have their named purpose, so indicate the purpose in comments.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Daniel P. Smith <dpsmith@apertussolutions.com>
2024-10-23 10:27:36 +01:00
Andrew Cooper 0fe607b2a1 x86/boot: Fix PVH boot during boot_info transition period
multiboot_fill_boot_info() taking the physical address of the multiboot_info
structure leads to a subtle use-after-free on the PVH path, with rather less
subtle fallout.

The pointers used by __start_xen(), mbi and mod, are either:

 - MB:  Directmap pointers into the trampoline, or
 - PVH: Xen pointers into .initdata, or
 - EFI: Directmap pointers into Xen.

Critically, these either remain valid across move_xen() (MB, PVH), or rely on
move_xen() being inhibited (EFI).

The conversion to multiboot_fill_boot_info(), taking only mbi_p, makes the PVH
path use directmap pointers into Xen, as well as move_xen() which invalidates
said pointers.

Switch multiboot_fill_boot_info() to consume the same virtual addresses that
__start_xen() currently uses.  This keeps all the pointers valid for the
duration of __start_xen(), for all boot protocols.

It can be safely untangled once multiboot_fill_boot_info() takes a full copy
the multiboot info data, and __start_xen() has been moved over to using the
new boot_info consistently.

Right now, bi->{loader,cmdline,mods} are problematic.  Nothing uses
bi->mods[], and nothing uses bi->cmdline after move_xen().

bi->loader is used after move_xen(), although only for cmdline_cook() of
dom0's cmdline, where it happens to be benign because PVH boot skips the
inspection of the bootloader name.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
2024-10-22 16:16:43 +01:00
Andrew Cooper b837d02163 CI: Add {adl,zen3p}-pvshim-* tests
GitlabCI has no testing of Xen's PVH entrypoint.  Fix this.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
2024-10-22 16:16:43 +01:00
Andrew Cooper 3be3ae0770 CI: Rework domU_config generation in qubes-x86-64.sh
Right now, various blocks rewrite domU_config= as a whole, even though it is
largely the same.

 * dom0pvh-hvm does nothing but change the domain type to hvm
 * *-pci sets the domain type, clears vif=[], appends earlyprintk=xen to the
   cmdline, and adds some PCI config.

Refactor this to be domU_type (defaults to pvh), domU_vif (defaults to
xenbr0), and domU_extra_config (defaults to empty) and use these variables to
build domU_config= once.

Of note, the default domU_config= now sets cmdline=, and extra= is intended
for inclusion via domU_extra_config as necessary.

No practical change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
2024-10-22 16:16:43 +01:00
Andrew Cooper 6685a129c7 CI: Minor cleanup to qubes-x86-64.sh
* List all the test_variants and summerise what's going on
 * Use case rather than an if/else chain for $test_variant
 * Adjust indentation inside the case block

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
2024-10-22 16:16:43 +01:00
Andrew Cooper 73785a4c77 x86/boot: Fix PVH boot following the start of the MBI->BI conversion
pvh_init() sets up the mbi pointer, but leaves mbi_p at 0.  This isn't
compatbile with multiboot_fill_boot_info() starting from the physical address,
in order to remove the use of the mbi pointer.

Fixes: 038826b61e ("x86/boot: move x86 boot module counting into a new boot_info struct")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Daniel P. Smith <dpsmith@apertussolutions.com>
2024-10-19 19:25:36 +01:00
Andrew Cooper 4c21b6affb x86/boot: Further simplify CR4 handling in dom0_construct_pv()
The logic would be more robust disabling SMAP based on its precense in CR4,
rather than SMAP's accociation with a synthetic feature.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
2024-10-18 11:30:34 +01:00
Andrew Cooper 6e085825cb CI: Refresh and upgrade the Fedora container
Fedora 29 is long out of date.  Move forward 5 years to Fedora 40.

Include all the usual improvements.  Rework the container to be non-root, use
heredocs for legibility, and switch to the new naming scheme.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Javi Merino <javi.merino@cloud.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
2024-10-18 10:56:41 +01:00
Andrew Cooper 572010c552 x86/boot: split bootstrap_map_addr() out of bootstrap_map()
Using an interface based on addresses directly, not modules.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Daniel P. Smith <dpsmith@apertussolutions.com>
Reviewed-by: Jason Andryuk <jason.andryuk@amd.com>
2024-10-18 01:32:32 +01:00
Andrew Cooper 542ac112fc xen/spinlock: Fix UBSAN "load of address with insufficient space" in lock_prof_init()
UBSAN complains:

  (XEN) ================================================================================
  (XEN) UBSAN: Undefined behaviour in common/spinlock.c:794:10
  (XEN) load of address ffff82d040ae24c8 with insufficient space
  (XEN) for an object of type 'struct lock_profile *'
  (XEN) ----[ Xen-4.20-unstable  x86_64  debug=y ubsan=y  Tainted:   C    ]----

This shows up with GCC-14, but not with GCC-12.  I have not bisected further.

Either way, the types for __lock_profile_{start,end} are incorrect.

They are an array of struct lock_profile pointers.  Correct the extern's
types, and adjust the loop to match.

No practical change.

Reported-by: Andreas Glashauser <ag@andreasglashauser.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
2024-10-14 16:14:26 +01:00
Andrew Cooper e305256e69 CI: Stop building QEMU in general
We spend an awful lot of CI time building QEMU, even though most changes don't
touch the subset of tools/libs/ used by QEMU.  Some numbers taken at a time
when CI was otherwise quiet:

                       With     Without
  Alpine:              13m38s   6m04s
  Debian 12:           10m05s   8m10s
  OpenSUSE Tumbleweed: 11m40s   7m54s
  Ubuntu 24.04:        14m56s   8m06s

which is a >50% improvement in wallclock time in some cases.

The only build we have that needs QEMU is alpine-3.18-gcc-debug.  This is the
build deployed and used by the QubesOS ADL-* and Zen3p-* jobs.

Xilinx-x86_64 deploys it too, but is PVH-only and doesn't use QEMU.

QEMU is also built by CirrusCI for FreeBSD (fully Clang/LLVM toolchain).

This should help quite a lot with Gitlab CI capacity.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2024-10-09 15:14:14 +01:00
Andrew Cooper c1035b0463 CI: Drop bin86/dev86 from archlinux container
These packages have moved out of main to AUR, and are not easily accessible
any more.  Drop them, because they're only needed for RomBIOS which is very
legacy these days.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
2024-10-08 11:15:08 +01:00
Andrew Cooper 1223375d8b CI: Fix builds following qemu-xen update
A recent update to qemu-xen has bumped the build requirements, with Python 3.8
being the new baseline but also needing the 'ensurepip' and 'tomllib/tomli'
packages.

 * Ubuntu/Debian package 'ensurepip' separately, but it can be obtained by
   installing the python3-venv package.

 * 'tomllib' was added to the python standard library in Python 3.11, but
   previously it was a separate package named 'tomli'.

In terms of changes required to build QEMU:

 * Ubuntu 24.04 (Noble) has Python 3.12 so only needs python3-venv

 * Ubuntu 22.04 (Jammy) has Python 3.10 but does have a python3-tomli package
   that QEMU is happy with.

 * FreeBSD has Python 3.9, but Python 3.11 is available.

In terms of exclusions:

 * Ubuntu 20.04 (Focal) has Python 3.8, but lacks any kind of tomli package.

 * Fedora 29 (Python 3.7), OpenSUSE Leap 15.6 (Python 3.6), and Ubuntu
   18.04/Bionic (Python 3.6) are now too old.

Detecting tomllib/tomli is more than can fit in build's one-liner, so break it
out into a proper script.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
2024-10-04 19:27:40 +01:00
Andrew Cooper 1eeb7c3379 x86: Introduce X86_ET_* constants in x86-defns.h
The FRED spec architecturalises the Event Type encoding, previously exposed
only in VMCB/VMCS fields.

Introduce the constants in x86-defns.h, making them a bit more concise, and
retire enum x86_event_type.

Take the opportunity to introduce X86_ET_OTHER.  It's absence appears to be a
bug in Introspection's Monitor Trap Flag support, when considering VECTORING
events during another VMExit.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-10-04 12:13:32 +01:00
Andrew Cooper 7fd80df2bf x86/boot: Convert remaining uses of the legacy ALIGN
There are only two remaining standalone uses the legacy ALIGN macro.

Drop these by switching the .incbin's over to using FUNC()/END() which has
alignment handled internally.  While the incbin's aren't technically one
single function, they behave as if they are.

Finally, expand ALIGN inside the legacy ENTRY() macro in order to remove ALIGN
itself.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-10-04 12:13:32 +01:00
Andrew Cooper 163338e6fb x86/boot: Don't use INC to set defaults
__efi64_mb2_start() makes some bold assumptions about the efi_platform and
skip_realmode booleans.  Set them to 1 explicitly, which is more robust.

Make the comment a little more concise.

No practical change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Frediano Ziglio <frediano.ziglio@cloud.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
2024-10-03 18:07:36 +01:00
Andrew Cooper 444cb9350f stubdom: Fix newlib build with GCC-14
Based on a fix from OpenSUSE, but adjusted to be Clang-compatible too.  Pass
-Wno-implicit-function-declaration library-wide rather than using local GCC
pragmas.

Fix of copy_past_newline() to avoid triggering -Wstrict-prototypes.

Link: https://build.opensuse.org/request/show/1178775
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
2024-10-03 10:07:25 +01:00
Andrew Cooper 41190d2ceb x86/kexec: Separate code and data into different cache lines
No functional change, but it performs a bit better.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-10-02 19:08:27 +01:00
Andrew Cooper 633ee8b2df x86/pv: Rename pv.iobmp_limit to iobmp_nr and clarify behaviour
Ever since it's introduction in commit 013351bd7a ("Define new event-channel
and physdev hypercalls") in 2006, the public interface was named nr_ports
while the internal field was called iobmp_limit.

Rename the internal field to iobmp_nr to match the public interface, and
clarify that, when nonzero, Xen will read 2 bytes.

There isn't a perfect parallel with a real TSS, but iobmp_nr being 0 is the
paravirt "no IOPB" case, and it is important that no read occurs in this case.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-10-01 14:58:18 +01:00
Andrew Cooper 8a6c495d72 x86/pv: Handle #PF correctly when reading the IO permission bitmap
The switch statement in guest_io_okay() is a very expensive way of
pre-initialising x with ~0, and performing a partial read into it.

However, the logic isn't correct either.

In a real TSS, the CPU always reads two bytes (like here), and any TSS limit
violation turns silently into no-access.  But, in-limit accesses trigger #PF
as usual.  AMD document this property explicitly, and while Intel don't (so
far as I can tell), they do behave consistently with AMD.

Switch from __copy_from_guest_offset() to __copy_from_guest_pv(), like
everything else in this file.  This removes code generation setting up
copy_from_user_hvm() (in the likely path even), and safety LFENCEs from
evaluate_nospec().

Change the logic to raise #PF if __copy_from_guest_pv() fails, rather than
disallowing the IO port access.  This brings the behaviour better in line with
normal x86.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-10-01 14:58:18 +01:00
Andrew Cooper 7429e1cc07 x86/pv: Rework guest_io_okay() to return X86EMUL_*
In order to fix a bug with guest_io_okay() (subsequent patch), rework
guest_io_okay() to take in an emulation context, and return X86EMUL_* rather
than a boolean.

For the failing case, take the opportunity to inject #GP explicitly, rather
than returning X86EMUL_UNHANDLEABLE.  There is a logical difference between
"we know what this is, and it's #GP", vs "we don't know what this is".

There is no change in practice as emulation is the final step on general #GP
resolution, but returning X86EMUL_UNHANDLEABLE would be a latent bug if a
subsequent action were to appear.

No practical change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-10-01 14:58:18 +01:00
Andrew Cooper 0416f1f66a xen/ucode: Improve commentary for parsing AMD containers
Despite writing this code, it's not the easiest logic to follow.

Shorten the UCODE_EQUIV_TYPE name, and provide more of an explanation of
what's going on.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
2024-09-24 18:57:38 +01:00
Andrew Cooper 6a039b0500 x86/cpufeature: Reposition cpu_has_{lfence_dispatch,nscb}
LFENCE_DISPATCH used to be a synthetic feature, but was given a real CPUID bit
by AMD.  The define wasn't moved when this was changed.

NSCB has always been a real CPUID bit, and was misplaced when introduced in
the synthetic block alongside LFENCE_DISPATCH.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-09-24 10:49:59 +01:00
Andrew Cooper 95c3ae591c tools/libxs: Style consistency improvements
This is mostly Linux style.  Make the file self-consistent.  Drop trailing
whitespace, and use tabs consistently.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
2024-09-24 10:47:14 +01:00
Andrew Cooper e1c8a3dc8a x86/boot: Drop stale comment about zeroing the stack
This used to be true, but was altered by commit 37786b23b0 ("x86/cet: Remove
writeable mapping of the BSPs shadow stack") which moved cpu0_stack into
.init.bss.stack_aligned.

Fixes: 37786b23b0 ("x86/cet: Remove writeable mapping of the BSPs shadow stack")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
2024-09-23 15:46:58 +01:00
Andrew Cooper 4e23c86bd8 xen/keyhandler: Move key_table[] into __ro_after_init
All registration is done at boot.  Almost...

iommu_dump_page_tables() is registered in iommu_hwdom_init(), which is called
twice when LATE_HWDOM is in use.

register_irq_keyhandler() has an ASSERT() guarding againt multiple
registration attempts, and the absence of bug reports hints at how many
configurations use LATE_HWDOM in practice.

Move the registration into iommu_setup() just after printing the overall
status of the IOMMU.  For starters, the hardware domain is specifically
excluded by iommu_dump_page_tables().

ept_dump_p2m_table is registered in setup_ept_dump() which is non-__init, but
whose sole caller, start_vmx(), is __init.  Move setup_ept_dump() to match.

With these two tweeks, all keyhandler reigstration is from __init functions,
so register_{,irq_}keyhandler() can move, and key_table[] can become
__ro_after_init.

No practical change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
2024-09-12 17:28:52 +01:00
Andrew Cooper 08ffd8705d x86/hvm: Simplify stdvga_mem_accept() further
stdvga_mem_accept() is called on almost all IO emulations, and the
overwhelming likely answer is to reject the ioreq.  Simply rearranging the
expression yields an improvement:

  add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-57 (-57)
  Function                                     old     new   delta
  stdvga_mem_accept                            109      52     -57

which is best explained looking at the disassembly:

  Before:                                                    After:
  f3 0f 1e fa           endbr64                              f3 0f 1e fa           endbr64
  0f b6 4e 1e           movzbl 0x1e(%rsi),%ecx            |  0f b6 46 1e           movzbl 0x1e(%rsi),%eax
  48 8b 16              mov    (%rsi),%rdx                |  31 d2                 xor    %edx,%edx
  f6 c1 40              test   $0x40,%cl                  |  a8 30                 test   $0x30,%al
  75 38                 jne    <stdvga_mem_accept+0x48>   |  75 23                 jne    <stdvga_mem_accept+0x31>
  31 c0                 xor    %eax,%eax                  <
  48 81 fa ff ff 09 00  cmp    $0x9ffff,%rdx              <
  76 26                 jbe    <stdvga_mem_accept+0x41>   <
  8b 46 14              mov    0x14(%rsi),%eax            <
  8b 7e 10              mov    0x10(%rsi),%edi            <
  48 0f af c7           imul   %rdi,%rax                  <
  48 8d 54 02 ff        lea    -0x1(%rdx,%rax,1),%rdx     <
  31 c0                 xor    %eax,%eax                  <
  48 81 fa ff ff 0b 00  cmp    $0xbffff,%rdx              <
  77 0c                 ja     <stdvga_mem_accept+0x41>   <
  83 e1 30              and    $0x30,%ecx                 <
  75 07                 jne    <stdvga_mem_accept+0x41>   <
  83 7e 10 01           cmpl   $0x1,0x10(%rsi)               83 7e 10 01           cmpl   $0x1,0x10(%rsi)
  0f 94 c0              sete   %al                        |  75 1d                 jne    <stdvga_mem_accept+0x31>
  c3                    ret                               |  48 8b 0e              mov    (%rsi),%rcx
  66 0f 1f 44 00 00     nopw   0x0(%rax,%rax,1)           |  48 81 f9 ff ff 09 00  cmp    $0x9ffff,%rcx
  8b 46 10              mov    0x10(%rsi),%eax            |  76 11                 jbe    <stdvga_mem_accept+0x31>
  8b 7e 14              mov    0x14(%rsi),%edi            |  8b 46 14              mov    0x14(%rsi),%eax
  49 89 d0              mov    %rdx,%r8                   |  48 8d 44 01 ff        lea    -0x1(%rcx,%rax,1),%rax
  48 83 e8 01           sub    $0x1,%rax                  |  48 3d ff ff 0b 00     cmp    $0xbffff,%rax
  48 8d 54 3a ff        lea    -0x1(%rdx,%rdi,1),%rdx     |  0f 96 c2              setbe  %dl
  48 0f af c7           imul   %rdi,%rax                  |  89 d0                 mov    %edx,%eax
  49 29 c0              sub    %rax,%r8                   <
  31 c0                 xor    %eax,%eax                  <
  49 81 f8 ff ff 09 00  cmp    $0x9ffff,%r8               <
  77 be                 ja     <stdvga_mem_accept+0x2a>   <
  c3                    ret                                  c3                    ret

By moving the "p->count != 1" check ahead of the
ioreq_mmio_{first,last}_byte() calls, both multiplies disappear along with a
lot of surrounding logic.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-09-12 17:28:52 +01:00
Andrew Cooper 42968684e5 ARM/cache: Drop legacy __read_mostly/__ro_after_init definitions
These are no longer needed.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Julien Grall <jgrall@amazon.com>
2024-09-12 17:28:52 +01:00
Andrew Cooper afc8d7dd30 x86/cache: Drop legacy __read_mostly/__ro_after_init definitions
Lots of files were picking these up transitively, including lib.h

However, lib.h needs __read_mostly for printk_once() and this has the side
effect of kicking the transitive can down the road.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
2024-09-09 14:59:05 +01:00
Andrew Cooper 41556be010 x86/build: Swap cache.h includes for xen/sections.h
These include {xen/asm}/cache.h but only want xen/sections.h.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
2024-09-09 14:59:05 +01:00
Andrew Cooper a4194782da xen/build: Drop unused includes of xen/cache.h
None of these are used, not even transitively.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
2024-09-09 14:59:05 +01:00
Andrew Cooper e58d41e9f0 x86/build: Rework includes in genapic/probe.c
probe.c includes a large number of headers which are unused, and not from
churn so far as I can see in history.  Strip back to a reasonable set.

One complication is that genapic.h has to include xen/cpumask.h because
there's no way to forward declare a cpumask_t.

Also strip trailing whitespace while adjusting the file.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
2024-09-09 14:59:05 +01:00
Andrew Cooper 0a15b7695b tools/ocaml: Rationalise .gitignore
The root .gitignore is quite stale from recent (and less recent) removals, but
also fails to work for the forthcoming dynamic plugin work.

Strip all Ocaml content out of the root .gitignore, and provide a more local
.gitignore's with up-to-date patterns.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@cloud.com>
2024-09-09 14:59:05 +01:00
Andrew Cooper 6978602334 x86/bitops: Use the POPCNT instruction when available
It has existed in x86 CPUs since 2008, so we're only 16 years late adding
support.  With all the other scafolding in place, implement arch_hweightl()
for x86.

The only complication is that the call to arch_generic_hweightl() is behind
the compilers back.  Address this by writing it in ASM and ensure that it
preserves all registers.

Copy the code generation from generic_hweightl().  It's not a complicated
algorithm, and is easy to regenerate if needs be, but cover it with the same
unit tests as test_generic_hweightl() just for piece of mind.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
2024-09-09 14:59:05 +01:00
Andrew Cooper d177793f70 xen/bitops: Implement hweight64() in terms of hweight{l,32}()
... and drop generic_hweight{32,64}().

This is identical on all architectures except ARM32.  Add one extra SELF_TEST
to check that hweight64() works when the input is split in half.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
2024-09-09 14:59:05 +01:00
Andrew Cooper f20504e1cf xen/bitops: Implement hweight32() in terms of hweightl()
... and drop generic_hweight32().

As noted previously, the only two users of hweight32() are in __init paths.

The int-optimised form of generic_hweight() is only two instructions shorter
than the long-optimised form, and even then only on architectures which lack
fast multiplication, so there's no point providing an int-optimised form.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
2024-09-09 14:59:05 +01:00
Andrew Cooper e8f0cc77dc xen/bitops: Drop the remnants of hweight{8,16}()
They are no more.  No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
2024-09-09 14:59:05 +01:00
Andrew Cooper f7dc086294 xen/bitops: Reinstate the please tidy message
Recent additions have undone prior tidying at the top of the file.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
2024-09-09 14:59:05 +01:00
Andrew Cooper 65e4bc585c x86/trampoline: Move the trampoline declarations out of <asm/config.h>
asm/config.h is included in every translation unit (via xen/config.h), while
only a handful of functions actually interact with the trampoline.

Move the infrastructure into its own header, and take the opportunity to
document everything.

Change trampoline_realmode_entry() and wakeup_start() to be nocall functions,
rather than char arrays.  Also switch to fixed width integers which are less
likely to diverge from the asm declaration.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-09-06 18:04:48 +01:00
Andrew Cooper b34d5e3de9 x86/acpi: Drop acpi_video_flags and use bootsym(video_flags) directly
This removes a level of indirection, as well as removing a somewhat misleading
name; the variable is really "S3 video quirks".

More importantly however it makes it very clear that, right now, parsing the
cmdline and quirks depends on having already placed the trampoline; a
dependency which is going to be gnarly to untangle.

That said, fixing the quirk is easy.  The Toshiba Satellite 4030CDT has an
Intel Celeron 300Mhz CPU (Pentium 2 era) from 1998 when MMX was the headline
feature, sporting 64M of RAM.  Being a 32-bit processor, it hasn't been able
to run Xen for about a decade now, so drop the quirk entirely.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Alejandro Vallejo <alejandro.vallejo@cloud.com>
2024-09-06 18:04:41 +01:00
Andrew Cooper 8c3ab4ffa9 xen/ppc: Adjust ppc64_defconfig
All of CONFIG_SCHED_*, and CONFIG_HYPFS build fine.

Add a stub for share_xen_page_with_guest(), which is all that is necessary to
make CONFIG_TRACEBUFFER build.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
2024-09-06 14:42:18 +01:00
Andrew Cooper 6471badeee RISCV/shutdown: Implement machine_{halt,restart}()
SBI has an API for shutdown so wire it up.  However, the spec does allow the
call not to be implemented, so we have to cope with sbi_shutdown() returning.

There is a reboot-capable SBI extention, but in the short term route
machine_restart() into machine_halt().

Then, use use machine_halt() rather than an infinite loop at the end of
start_xen().  This avoids the Qemu smoke test needing to wait for the full
timeout in order to succeed.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
2024-09-04 11:27:50 +01:00
Andrew Cooper 57c8f93fc1 xen/bitops: Drop hweight_long() and use hweightl()
No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-09-03 20:22:18 +01:00
Andrew Cooper 6bb2a4ff2d xen/bitops: Introduce generic_hweightl() and hweightl()
There are 6 remaining callers in Xen:

  * The two hweight32() calls, _domain_struct_bits() and efi_find_gop_mode(),
    are __init only.
  * The two hweight_long() calls are both in bitmap_weight().
  * The two hweight64() calls are hv_vpset_nr_banks() and x86_emulate().

Only bitmap_weight() and possibly hv_vpset_nr_banks() can be considered fast
paths, and they're all of GPR-width form.

Furthermore, the differences between a generic int and generic long form is
only an ADD and SHIFT, and only in !CONFIG_HAS_FAST_MULTIPLY builds.

Therefore, it is definitely not worth having both generic implemenations.

Implement generic_hweightl() based on the current generic_hweight64(),
adjusted to be compatible with ARM32, along with standard SELF_TESTS.

Implement hweightl() with usual constant-folding and arch opt-in support.  PPC
is the only architecture that devates from generic, and it simply uses the
builtin.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-09-03 20:22:18 +01:00
Andrew Cooper d35fb45d3c xen/bitops: Convert 'hweight(x) > 1' to new multiple_bits_set()
Using hweight() is an especially expensive way of determining simply if
multiple bits are set in a value.  Worse, 4 of the 10 hweight() calls in Xen
are of this form.

Switch to the new multiple_bits_set() helper.  This is far more efficient than
the longhand hweight() algorithm and, owing to its simplicity, likely more
efficient than even a dedicated instruction on a superscalar processor.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-09-03 20:22:18 +01:00
Andrew Cooper bd1664db7b xen/bitops: Introduce a multiple_bits_set() helper
This will be used to simplify real logic in the following patch.  Add compile
and boot time testing as with other bitops.

Because the expression is so simple, implement it as a function-like macro
which is generic on the type of it's argument, rather than having multiple
variants.

Testing function-like macros needs a minor adjustments to the infrastructure
in xen/self-tests.h to avoid bracketing the fn parameter.  The utility of this
outweighs the associated risks.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-09-03 20:22:18 +01:00
Andrew Cooper 11aa8f5ff8 xen/bitops: Switch from __pure to attr_const
All of the ffs()/fls() infrastructure is in fact (attr) const, because it
doesn't even read global state.  This allows the compiler even more
flexibility to optimise.

No functional change.

Reported-by: Jan Beulich <JBeulich@suse.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-09-03 20:22:18 +01:00
Andrew Cooper 3cbd5f0c18 xen/compiler: Rename __attribute_const__ to attr_const
There's no need for the name to be so verbose.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-09-03 20:22:18 +01:00
Andrew Cooper e9c703f85e ARM/vgic: Use for_each_set_bit() in gic_find_unused_lr()
There are no bits set in lr_mask beyond nr_lrs, so when substituting
bitmap_for_each() for for_each_set_bit(), we don't need to worry about the
upper bound.

However, the type of lr_mask does matter, so switch it to be uint64_t * and
move unsigned long * override until the find_next_zero_bit() call.

Move lr_val into a narrower scope and drop used_lr as it's declared by
for_each_set_bit() itself.

Drop the nr_lrs variable and use gic_get_nr_lrs() in the one location its now
used.  It hides a triple pointer dereference, and while it may not be needed
in the PRISTINE case, it certainly doesn't need to be live across the rest of
the function.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
2024-09-03 15:51:44 +01:00
Andrew Cooper bad717f845 ARM/vgic: Correct the expression for lr_all_full()
The current expression hits UB with 31 LRs (shifting into the sign bit), and
malfunctions with 32 LRs (shifting beyond the range of int).  Swapping 1 for
1ULL fixes some of these, but still malfunctions at 64 LRs which is the
architectural limit.

Instead, shift -1ULL right in order to create the mask.

Fixes: 596f885a32 ("xen/arm: set GICH_HCR_UIE if all the LRs are in use")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
2024-09-03 15:51:44 +01:00
Andrew Cooper 2eb32c6c2d ARM/div: Drop __div64_fls()
Following the improvements to Xen's bitops, fls() does constant propagation in
all cases.  Use it, and drop the local opencoded helper.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
2024-09-03 15:51:44 +01:00
Andrew Cooper ad783c71f7 x86/boot: Use <xen/compiler.h>
... rather than opencoding locally.  With this, defs.h is empty so delete it.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-09-03 15:51:44 +01:00
Andrew Cooper 62da0b364a x86/boot: Use fastcall for 32bit code
This is marginally more efficient, but is mostly to get rid of the use of
stdcall in cmdline.c and reloc.c

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-09-03 15:51:44 +01:00
Andrew Cooper a268cdc05a x86/boot: Use <xen/macros.h>
... rather than opencoding locally.

This involve collecting various macros scattered around Xen (min()/max()
macros from kernel.h, and _p() from lib.h) and moving them into macros.h

In reloc.c, replace ALIGN_UP() with ROUNDUP().

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-09-03 15:51:44 +01:00
Andrew Cooper 43d4c10dfa x86/boot: Use <xen/types.h>
... rather than opencoding locally.  This also covers NULL and *_MAX.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-09-03 15:51:44 +01:00
Andrew Cooper 5f36fab240 x86/boot: Fix include paths for 32bit objects
Most of Xen is build using -nostdinc and a fully specified include path.
However, the makefile line:

  $(head-bin-objs): XEN_CFLAGS := $(CFLAGS_x86_32) -fpic

discards XEN_CFLAGS and replaces them with CFLAGS_x86_32.

Reinstate -nostdinc, and copy the -include and all -I arguments from
XEN_CFLAGS.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
2024-09-03 15:51:14 +01:00
Andrew Cooper 7ab0f83e60 x86/pv: Make cr4_pv32_mask be PV32-only
The user of cr4_pv32_mask (the cr4_pv32_restore() function) only exists in a
CONFIG_PV32 build, but right now the variable is unconditionally set up.

To start with, move the setup into set_in_cr4() and remove it from it's
somewhat ad-hoc position in __start_xen().  This means the variable will be
set up in two steps for a CONFIG_PV32=y build, but it's cleaner and more
robust logic overall.

With that, there's no good reason for the variable to stay in setup.c.  Move
it to x86/pv/domain.c (beside opt_pv32, for want of any better place to live),
and move the declaration to beside set_in_cr4() and mmu_cr4_features which is
a better position than setup.h.

Guard the reference with CONFIG_PV32, and fix up a recent typo in an adjacent
comment while at it.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
2024-08-30 18:08:48 +01:00
Andrew Cooper 8d336fcb6e tools/ocaml: Factor out compatiblity handling
... rather than having each library implement its own subset.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@cloud.com>
2024-08-30 18:08:48 +01:00
Andrew Cooper 75c64db372 xen/evtchn: Use bitmap_for_each() in evtchn_check_pollers()
It is a preprocessor-identical opencoding.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-08-28 10:49:26 +01:00
Andrew Cooper 73fa03573e ARM/vgic: Fix variable shadowing in vgic_to_sgi()
for_each_set_bit() allocates its own variable intentionally as loop-scope
only.  Unfortunately, this causes the inner 'i' to shadow the outer 'i', and
violates MISRA Rule 5.3.

Drop the outermost 'i' and 'vcpuid' variables, moving them into a more narrow
scope and correcting them to be unsigned which they should have been all
along.  Update the printk() formatting of vcpuid to match.

Fixes: 9429f1a6c4 ("ARM/vgic: Use for_each_set_bit() in vgic_to_sgi()")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
2024-08-28 10:49:26 +01:00
Andrew Cooper 9429f1a6c4 ARM/vgic: Use for_each_set_bit() in vgic_to_sgi()
The existing expression is just a very complicated way of expressing a loop
over all bits of target->list.  Simplify the expression.

While here, fix the two gprintk()'s.  Because of a quotes vs line continuation
issue, there's a line of spaces in the middle of the format string.

  $ strings xen-syms-arm32 | grep -e VGIC -e GICD_SGIR
  <G><1>%pv VGIC: write r=%08x                         target->list=%hx, wrong CPUTargetList
  <G><1>%pv vGICD:unhandled GICD_SGIR write %08x                  with wrong mode

not to mention trailing whitespace too.

Rewrite them to be more concise and useful.  Use 0x prefixes for hex, rather
than being ambiguous, and identify the problem target vCPU / mode, rather than
simply saying something was wrong.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
2024-08-27 18:08:19 +01:00
Andrew Cooper 8d820e3581 ARM/vgic: Use for_each_set_bit() in vgic_check_inflight_irqs_pending()
... which is better optimised for scalar values, rather than using the
arbitrary-sized bitmap helpers.

Additionally, unlike other vgic helpers, this takes both a domain and vcpu
pointer.  The domain parameter isn't used, and the callers pass v->domain.

Strip out the domain pointer.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
2024-08-27 18:08:19 +01:00
Andrew Cooper 20885a36ce x86/xstate: Switch back to for_each_set_bit()
In all 3 examples, we're iterating over a scaler.  They have an upper bound of
63 which is to exclude the top bit; the COMPRESSED bit.

recalculate_xstate() calculates xstates directly and doesn't set the
COMPRESSED bit.  Both xstate_{un,}compressed_size() take architectural
register values, neither of which permit the COMPRESSED bit either.

xstate_uncompressed_size() has an ASSERT() covering this properly; add a
equivelent ASSERT() to xstate_compressed_size() too.

This alone produces:

  add/remove: 0/0 grow/shrink: 0/4 up/down: 0/-161 (-161)
  Function                                     old     new   delta
  compress_xsave_states                         66      58      -8
  xstate_uncompressed_size                     119      71     -48
  xstate_compressed_size                       124      76     -48
  recalculate_xstate                           347     290     -57

where xstate_{un,}compressed_size() have practically halved in size despite
being small before.

The change in compress_xsave_states() is unexpected.  The function is almost
entirely dead code, and within what remains there's a smaller stack frame.  I
suspect it's leftovers that the optimiser couldn't fully discard.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-08-23 21:50:57 +01:00
Andrew Cooper 2387c460eb ARM/vgic: Use for_each_set_bit() in vgic_set_irqs_pending()
... which is better optimised for scalar values, rather than using the
arbitrary-sized bitmap helpers.

For ARM32:

  add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-16 (-16)
  Function                                     old     new   delta
  vgic_set_irqs_pending                        284     268     -16

including removing calls to _find_{first,next}_bit_le(), and two stack-spilled
words too.

For ARM64:

  add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-40 (-40)
  Function                                     old     new   delta
  vgic_set_irqs_pending                        268     228     -40

including removing three calls to find_next_bit().

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
2024-08-23 21:50:57 +01:00
Andrew Cooper ed26376f20 xen/bitops: Introduce for_each_set_bit()
The prior version (renamed to bitmap_for_each()) was inefficeint when used
over a scalar, but this is the more common usage even before accounting for
the many opencoded forms.

Introduce a new version which operates on scalars only and does so without
spilling them to memory.  This in turn requires the addition of a type-generic
form of ffs().

Add testing for the new construct alongside the ffs/fls testing.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-08-23 21:50:57 +01:00
Andrew Cooper 1b30ac1281 xen/macros: Introduce BUILD_ERROR()
... and use it in self-tests.h.

This is intended to replace constructs such as __bitop_bad_size().  It
produces a better diagnostic, and is MISRA-friendly.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-08-23 21:50:57 +01:00
Andrew Cooper fbad385982 xen/bitops: Rename for_each_set_bit() to bitmap_for_each()
The current implementation wants to take an in-memory bitmap.  However, all
ARM callers and all-but-1 x86 callers spill a scalar to the stack in order to
use the "generic arbitrary bitmap" helpers under the hood.

This works, but is far from ideal.

Rename the construct and move it into bitmap.h, because having an iterator for
an arbitrary bitmap is a useful thing.

This will allow us to re-implement for_each_set_bit() to be more appropriate
for scalar values.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Michal Orzel <michal.orzel@amd.com>
2024-08-23 21:50:57 +01:00
Andrew Cooper 1965e9a930 tools/ocaml: Fix the version embedded in META files
Xen 4.1 is more than a decade stale now.  Use the same mechanism as elsewhere
in the tree to get the current version number.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@cloud.com>
Reviewed-by: Edwin Török <edwin.torok@cloud.com>
2024-08-23 15:02:27 +01:00
Andrew Cooper 5246924acf tools/ocaml: Drop the o= variable
This hides a shell redirection which is quite rude.  It also opencodes
$(move-if-changed) without the benefit of short-circuiting dependent logic
when the content hasn't changed.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@cloud.com>
Reviewed-by: Edwin Török <edwin.torok@cloud.com>
2024-08-23 15:02:27 +01:00
Andrew Cooper 126293eae6 tools/ocaml: Drop the OCAMLOPTFLAG_G invocation
These days, `ocamlopt -h` asks you whether you meant --help instead, meaning
that the $(shell ) invocation here isn't going end up containing '-g'.

Make it unconditional, like it is in OCAMLCFLAGS already.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@cloud.com>
Reviewed-by: Edwin Török <edwin.torok@cloud.com>
2024-08-23 15:02:27 +01:00
Andrew Cooper 6d41a9d8a1 x86/pv: Address Coverity complaint in check_guest_io_breakpoint()
Commit 08aacc392d ("x86/emul: Fix misaligned IO breakpoint behaviour in PV
guests") caused a Coverity INTEGER_OVERFLOW complaint based on the reasoning
that width could be 0.

It can't, but digging into the code generation, GCC 8 and later (bisected on
godbolt) choose to emit a CSWITCH lookup table, and because the range (bottom
2 bits clear), it's a 16-entry lookup table.

So Coverity is understandable, given that GCC did emit a (dead) logic path
where width stayed 0.

Rewrite the logic.  Introduce x86_bp_width() which compiles to a single basic
block, which replaces the switch() statement.  Take the opportunity to also
make start and width be loop-scope variables.

No practical change, but it should compile better and placate Coverity.

Fixes: 08aacc392d ("x86/emul: Fix misaligned IO breakpoint behaviour in PV guests")
Coverity-ID: 1616152
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-08-21 23:59:19 +01:00
Andrew Cooper db39fa4b27 x86/pv: Fix merging of new status bits into %dr6
All #DB exceptions result in an update of %dr6, but this isn't captured in
Xen's handling, and is buggy just about everywhere.

To begin resolving this issue, add a new pending_dbg field to x86_event
(unioned with cr2 to avoid taking any extra space, adjusting users to avoid
old-GCC bugs with anonymous unions), and introduce pv_inject_DB() to replace
the current callers using pv_inject_hw_exception().

Push the adjustment of v->arch.dr6 into pv_inject_event(), and use the new
x86_merge_dr6() rather than the current incorrect logic.

A key property is that pending_dbg is taken with positive polarity to deal
with RTM/BLD sensibly.  Most callers pass in a constant, but callers passing
in a hardware %dr6 value need to XOR the value with X86_DR6_DEFAULT to flip to
positive polarity.

This fixes the behaviour of the breakpoint status bits; that any left pending
are generally discarded when a new #DB is raised.  In principle it would fix
RTM/BLD too, except PV guests can't turn these capabilities on to start with.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-08-21 23:59:19 +01:00
Andrew Cooper 54ef601a66 x86/pv: Introduce x86_merge_dr6() and fix do_debug()
Pretty much everywhere in Xen the logic to update %dr6 when injecting #DB is
buggy.  Introduce a new x86_merge_dr6() helper, and start fixing the mess by
adjusting the dr6 merge in do_debug().  Also correct the comment.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-08-21 23:59:19 +01:00
Andrew Cooper 36f75d39b3 x86/domain: Fix domlist_insert() updating the domain hash
A last minute review request was to dedup the expression calculating the
domain hash bucket.

While the code reads correctly, it is buggy because rcu_assign_pointer() is a
deeply misleading API assigning by name not value, and - contrary to it's name
- does not hide an indirection.

Therefore, rcu_assign_pointer(bucket, d); updates the local bucket variable on
the stack, not domain_hash[], causing all subsequent domid lookups to fail.

Rework the logic to use pd in the same way that domlist_remove() does.

Fixes: 19995bc70c ("xen/domain: Factor domlist_{insert,remove}() out of domain_{create,destroy}()")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2024-07-31 23:19:42 +01:00
Andrew Cooper 19995bc70c xen/domain: Factor domlist_{insert,remove}() out of domain_{create,destroy}()
These are opencoded linked list and hashtable manipulations.  Factor them out
into static inline helpers, and discuss the consequence for the domain.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-07-31 15:28:43 +01:00
Andrew Cooper a5b8e72e9e arch/domain: Clean up the idle domain remnants in arch_domain_create()
With arch_domain_create() no longer being called with the idle domain, drop
the last remaining logic.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2024-07-31 11:14:50 +01:00
Andrew Cooper a259a658f2 xen/domain: Simpliy domain_create() now the idle domain is complete earlier
With x86 implementing arch_init_idle_domain(), there is no longer any need to
call arch_domain_create() with the idle domain.

Have the idle domain exit early with all other system domains.  Move the
static-analysis ASSERT() earlier.  Then, remove the !is_idle_domain()
protections around the majority of domain_create() and remove one level of
indentation.

No practical change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2024-07-31 11:14:50 +01:00
Andrew Cooper fdb4d76ff3 x86/domain: Implement arch_init_idle_domain()
The idle domain needs d->arch.ctxt_switch initialised on x86.  Implement the
new arch_init_idle_domain() in order to do this.

Intentionally remove cpu_policy's initialisation to ZERO_BLOCK_PTR.  It has
never tripped since it's introduction, and is weird to have in isolation
without a similar approach on other pointers.

No practical change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-07-31 11:14:50 +01:00
Andrew Cooper 694ce812e7 xen/domain: Introduce arch_init_idle_domain()
The idle domain causes a large amount of complexity in domain_create() because
of x86's need to initialise d->arch.ctxt_switch in arch_domain_create().

In order to address this, introduce an optional hook to perform extra
initialisation of the idle domain.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2024-07-31 11:14:50 +01:00
Andrew Cooper ee32b9b29a XSM/domctl: Fix permission checks on XEN_DOMCTL_createdomain
The XSM checks for XEN_DOMCTL_createdomain are problematic.  There's a split
between xsm_domctl() called early, and flask_domain_create() called quite late
during domain construction.

All XSM implementations except Flask have a simple IS_PRIV check in
xsm_domctl(), and operate as expected when an unprivileged domain tries to
make a hypercall.

Flask however foregoes any action in xsm_domctl() and defers everything,
including the simple "is the caller permitted to create a domain" check, to
flask_domain_create().

As a consequence, when XSM Flask is active, and irrespective of the policy
loaded, all domains irrespective of privilege can:

 * Mutate the global 'rover' variable, used to track the next free domid.
   Therefore, all domains can cause a domid wraparound, and combined with a
   voluntary reboot, choose their own domid.

 * Cause a reasonable amount of a domain to be constructed before ultimately
   failing for permission reasons, including the use of settings outside of
   supported limits.

In order to remediate this, pass the ssidref into xsm_domctl() and at least
check that the calling domain privileged enough to create domains.

Take the opportunity to also fix the sign of the cmd parameter to be unsigned.

This issue has not been assigned an XSA, because Flask is experimental and not
security supported.

Reported-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Daniel P. Smith <dpsmith@apertussolutions.com>
2024-07-30 17:42:17 +01:00
Andrew Cooper cb2cd59d45 x86/APIC: Drop APIC_BASE and use fix_to_virt()
Right now the apic_mem_*() helpers only compile because sizeof(void *) ==
sizeof(long long).  Switch to using fix_to_virt() which is a void *type.

Also adjust the two places where the APIC/IO-APIC virtual address is rendered
in a printk().

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-07-30 17:36:51 +01:00
Andrew Cooper ef0c3e7483 tools/examples: Remove more obsolete content
xeninfo.pl was introduced in commit 1b0a8bb57e ("Added xeninfo.pl, a script
for collecting statistics from Xen hosts using the Xen-API") and has been
touched exactly twice since to remove hardcoded IP addresses and paths.

The configuration files in vnc/* date from when we had a vendered version of
Qemu living in the tree.

These have never (AFAICT) been wired into the `make install` rule.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
2024-07-30 17:36:51 +01:00
Andrew Cooper 90a8f4c7ea Revert "x86/pvh: Allow (un)map_pirq when dom0 is PVH"
This reverts commit e42d107d0d.

The Gitlab CI {adl,zen3p}-pci-hvm-x86-64-gcc-debug tests says this breaks PCI
Passthrough to HVM guests, with -EOPNOTSUPP.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
2024-07-30 17:36:51 +01:00
Andrew Cooper b25b28ede1 hvmloader: Use fastcall everywhere
HVMLoader is a single freestanding 32bit program with no external
dependencies.  Use the fastcall calling convetion (up to 3 parameters in
registers) globally, which is more efficient than passing all parameters on
the stack.

Some bloat-o-meter highlights are:

  add/remove: 0/0 grow/shrink: 3/118 up/down: 8/-3004 (-2996)
  Function                                     old     new   delta
  ...
  hvmloader_acpi_build_tables                 1125     961    -164
  acpi_build_tables                           1277    1081    -196
  pci_setup                                   4756    4516    -240
  construct_secondary_tables                  1689    1447    -242

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-07-24 18:24:56 +01:00
Andrew Cooper 5795a0bf54 x86/APIC: Rewrite apic_isr_read() to match apic_{tmr,irr}_read()
This allows for marginally better code generation including the use of BT
rather than SHR/TEST.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-07-24 12:18:44 +01:00
Andrew Cooper c29f6ee94d x86/APIC: Change APIC reg types to unsigned int
They're all within a 12 bit range of their respective bases, and this prevents
all the x2APIC MSR addresses being calculated in %rcx.

Also swap two u32's for uint32_t.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-07-24 12:18:44 +01:00
Andrew Cooper 90ac0e4f2f x86/IO-APIC: Improve APIC_TMR accesses
XenServer's instance of Coverity complains of OVERFLOW_BEFORE_WIDEN in
mask_and_ack_level_ioapic_irq(), which is ultimately because of v being
unsigned long, and (1U << ...) being 32 bits.

The reasoning isn't correct.  (1U << (x & 0x1f)) can't overflow, but the
complaint is really about having to expand the RHS.  While this can be fixed
by changing v to be unsigned int, take the opportunity to do better still.

Introduce a apic_tmr_read() helper like we already have for ISR and IRR, and
use it to remove the opencoded logic.  Introduce an is_level boolean to
improve the legibility of the surrounding logic.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2024-07-24 12:18:44 +01:00
Andrew Cooper a17b6db9b0 tools/libxs: Stop playing with SIGPIPE
It's very rude for a library to play with signals behind the back of the
application, no matter ones views on the default behaviour of SIGPIPE under
POSIX.  Even if the application doesn't care about the xenstored socket, it my
care about others.

This logic has existed since xenstore/xenstored was originally added in commit
29c9e570b1 ("Add xenstore daemon and library") in 2005.

It's also unnecessary.  Pass MSG_NOSIGNAL when talking to xenstored over a
pipe (to avoid sucumbing to SIGPIPE if xenstored has crashed), and forgo any
playing with the signal disposition.

This has a side benefit of saving 2 syscalls per xenstore request.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jason.andryuk@amd.com>
2024-07-23 15:11:27 +01:00
Andrew Cooper ebaeb0c64a tools/libxs: Use writev()/sendmsg() instead of write()
With the input data now conveniently arranged, use writev()/sendmsg() instead
of decomposing it into write() calls.

This causes all requests to be submitted with a single system call, rather
than at least two.  While in principle short writes can occur, the chances of
it happening are slim given that most xenbus comms are only a handful of
bytes.

Nevertheless, provide {writev,sendmsg}_exact() wrappers which take care of
resubmitting on EINTR or short write.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jason.andryuk@amd.com>
2024-07-23 15:11:27 +01:00