Commit Graph
45025 Commits
Author SHA1 Message Date
Jan Beulich 5da8dd30b7 x86/idle: undo use of MONITOR/MWAIT mnemonics
While the change is fine on staging, where the toolchain baseline was
moved, we need to remain compatible with older gas on stable branches
for now.

Fixes: fa254938f0 ("x86/idle: Move monitor()/mwait() wrappers into cpu-idle.c")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
2025-07-09 12:21:28 +02:00
Andrew Cooper 14bcad6593 x86/spec-ctrl: Mitigate Transitive Scheduler Attacks
TSA affects AMD Fam19h CPUs (Zen3 and 4 microarchitectures).

Three new CPUID bits have been defined.  Two (TSA_SQ_NO and TSA_L1_NO)
indicate that the system is unaffected, and must be synthesised by Xen on
unaffected parts to date.

A third new bit indicates that VERW now has a flushing side effect.  Xen must
synthesise this bit on affected systems based on microcode version.  As with
other VERW-based flushing features, VERW_CLEAR needs OR-ing across a resource
pool, and guests which have seen it can safely migrate in.

This is part of XSA-471 / CVE-2024-36350 / CVE-2024-36357.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 578b34adb1)
2025-07-08 15:10:58 +01:00
Andrew Cooper 1fe13584d2 x86/idle: Rearrange VERW and MONITOR in mwait_idle_with_hints()
In order to mitigate TSA, Xen will need to issue VERW before going idle.

On AMD CPUs, the VERW scrubbing side effects cancel an active MONITOR, causing
the MWAIT to exit without entering an idle state.  Therefore the VERW must be
ahead of MONITOR.

Split spec_ctrl_enter_idle() in two and allow the VERW aspect to be handled
separately.  While adjusting, update a stale comment concerning MSBDS; more
issues have been mitigated using VERW since it was written.

By moving VERW earlier, it is ahead of the determination of whether to go
idle.  We can't move the check on softirq_pending (for correctness reasons),
but we can duplicate it earlier as a best effort attempt to skip the
speculative overhead.

This is part of XSA-471 / CVE-2024-36350 / CVE-2024-36357.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 01429bbb0a)
2025-07-08 15:10:58 +01:00
Andrew Cooper 7a7171a236 x86/ucode: Digests for TSA microcode
AMD are releasing microcode for TSA, so extend the known-provenance list with
their hashes.  These were produced before the remediation of the microcode
signature issues (the entrysign vulnerability), so can be OS-loaded on
out-of-date firmware.

Include an off-by-default check for the sorted-ness of patch_digests[].  It's
not worth running generally under SELF_TESTS, but is useful when editing the
digest list.

This is part of XSA-471 / CVE-2024-36350 / CVE-2024-36357.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit a8708ea8bd)
2025-07-08 15:10:58 +01:00
Andrew Cooper 77d74b0208 x86/cpu-policy: Infrastructure for CPUID leaf 0x80000021.ecx
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 6e3c3cea09)
2025-07-08 15:10:58 +01:00
Andrew Cooper 8a4ed23a10 x86/cpu-policy: Rearrange guest_common_*_feature_adjustments()
Turn the if()s into switch()es, as we're going to need AMD sections.

Move the RTM adjustments into the Intel section, where they ought to live.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 7c5025394d)
2025-07-08 15:10:58 +01:00
Andrew Cooper 1d0efc4b70 x86/xen-cpuid: Fix backports of new features
Xen 4.18 doesn't automatically generate feature names like Xen 4.19 does, and
these hunks were missed on prior security fixes.

Fixes: 8bced9a15c ("x86/spec-ctrl: Support for SRSO_U/S_NO and SRSO_MSR_FIX")
Fixes: f132c82fa6 ("x86/spec-ctrl: Synthesise ITS_NO to guests on unaffected hardware")
Fixes: dba0556612 ("x86/spec-ctrl: Support Intel's new PB-OPT")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
[For 4.17, PB-OPT wasn't backported]
(cherry picked from commit cd46db24e5)
2025-07-08 15:10:42 +01:00
Andrew Cooper 0ecbb2fa92 x86/idle: Fix buggy "x86/mwait-idle: enable interrupts before C1 on Xeons"
The check of this_softirq_pending must be performed with irqs disabled, but
this property was broken by an attempt to optimise entry/exit latency.

Commit c227233ad64c in Linux (which we copied into Xen) was fixed up by
edc8fc01f608 in Linux, which we have so far missed.

Going to sleep without waking on interrupts is nonsensical outside of
play_dead(), so overload this to select between two possible MWAITs, the
second using the STI shadow to cover MWAIT for exactly the same reason as we
do in safe_halt().

Fixes: b17e0ec72e ("x86/mwait-idle: enable interrupts before C1 on Xeons")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 9b0f0f6e23)
2025-07-07 22:52:06 +01:00
Andrew Cooper d6223a09fb x86/idle: Implement a new MWAIT IPI-elision algorithm
In order elide IPIs, we must be able to identify whether a target CPU is in
MWAIT at the point it is woken up.  i.e. the store to wake it up must also
identify the state.

Create a new in_mwait variable beside __softirq_pending, so we can use a
CMPXCHG to set the softirq while also observing the status safely.  Implement
an x86 version of arch_pend_softirq() which does this.

In mwait_idle_with_hints(), advertise in_mwait, with an explanation of
precisely what it means.  X86_BUG_MONITOR can be accounted for simply by not
advertising in_mwait.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
(cherry picked from commit 3e0bc4b503)
2025-07-07 22:52:06 +01:00
Andrew Cooper b73528f624 xen/softirq: Rework arch_skip_send_event_check() into arch_set_softirq()
x86 is the only architecture wanting an optimisation here, but the
test_and_set_bit() is a store into the monitored line (i.e. will wake up the
target) and, prior to the removal of the broken IPI-elision algorithm, was
racy, causing unnecessary IPIs to be sent.

To do this in a race-free way, the store to the monited line needs to also
sample the status of the target in one atomic action.  Implement a new arch
helper with different semantics; to make the softirq pending and decide about
IPIs together.  For now, implement the default helper.  It will be overridden
by x86 in a subsequent change.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
(cherry picked from commit b473e5e212)
2025-07-07 22:52:06 +01:00
Andrew Cooper 1bd4c2bc55 x86/idle: Convert force_mwait_ipi_wakeup to X86_BUG_MONITOR
We're going to want alternative-patch based on it.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
(cherry picked from commit b0ca0f93f4)
2025-07-07 22:52:06 +01:00
Andrew Cooper c865cbf2a2 x86/idle: Drop incorrect smp_mb() in mwait_idle_with_hints()
With the recent simplifications, it becomes obvious that smp_mb() isn't the
right barrier.  Strictly speaking, MONITOR is ordered as a load, but smp_rmb()
isn't correct either, as this only pertains to local ordering.  All we need is
a compiler barrier().

Merge the barier() into the monitor() itself, along with an explantion.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
(cherry picked from commit e7710dd843)
2025-07-07 22:52:06 +01:00
Andrew Cooper bf9027375e x86/idle: Remove broken MWAIT implementation
cpuidle_wakeup_mwait() is a TOCTOU race.  The cpumask_and() sampling
cpuidle_mwait_flags can take a arbitrary period of time, and there's no
guarantee that the target CPUs are still in MWAIT when writing into
mwait_wakeup(cpu).

The consequence of the race is that we'll fail to IPI certain targets.  Also,
there's no guarantee that mwait_idle_with_hints() will raise a TIMER_SOFTIRQ
on it's way out.

The fundamental bug is that the "in_mwait" variable needs to be in the
monitored line, and not in a separate cpuidle_mwait_flags variable, in order
to do this in a race-free way.

Arranging to fix this while keeping the old implementation is prohibitive, so
strip the current one out in order to implement the new one cleanly.  In the
interim, this causes IPIs to be used unconditionally which is safe albeit
suboptimal.

Fixes: 3d521e933e ("cpuidle: mwait on softirq_pending & remove wakeup ipis")
Fixes: 1adb34ea84 ("CPUIDLE: re-implement mwait wakeup process")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
(cherry picked from commit 3faf0866a3)
2025-07-07 22:52:06 +01:00
Andrew Cooper bdca9c89ad x86/cpu-policy: Fix handling of leaf 0x80000021
When support was originally introduced, ebx, ecx and edx were reserved and
should have been zeroed in recalculate_misc() to avoid leaking into guests.

Since then, fields have been added into ebx.  Guests can't load microcode, so
shouldn't see ucode_size, and while in principle we do want to support larger
RAP sizes in guests, virtualising this for guests depends on AMD procuding any
official documentation for ERAPS, which is long overdue and with no ETA.

This patch will cause a difference in guests on Zen5 CPUs, but as the main
ERAPS feature is hidden, guests should be ignoring the rap_size field too.

Fixes: e9b4fe2636 ("x86/cpuid: support LFENCE always serialising CPUID bit")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 10dc35c516)
2025-07-07 22:52:06 +01:00
Andrew Cooper 63b21de0c6 x86/cpu-policy: Simplify logic in guest_common_default_feature_adjustments()
For features which are unconditionally set in the max policies, making the
default policy to match the host can be done with a conditional clear.

This is simpler than the unconditional clear, conditional set currently
performed.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 30f8fed68f)
2025-07-07 22:52:06 +01:00
Andrew Cooper df9770b0fc Revert part of "x86/mwait-idle: disable IBRS during long idle"
Most of the patch (handling of CPUIDLE_FLAG_IBRS) is fine, but the
adjustements to mwait_idle() are not; spec_ctrl_enter_idle() does more than
just alter MSR_SPEC_CTRL.IBRS.

The only reason this doesn't need an XSA is because the unconditional
spec_ctrl_{enter,exit}_idle() in mwait_idle_with_hints() were left unaltered,
and thus the MWAIT remained properly protected.

There (would have been) two problems.  In the ibrs_disable (== deep C) case:

 * On entry, VERW and RSB-stuffing are architecturally skipped.
 * On exit, there's a branch crossing the WRMSR which reinstates the
   speculative safety for indirect branches.

All this change did was double up the expensive operations in the deep C case,
and fail to optimise the intended case.

I have an idea of how to plumb this more nicely, but it requires larger
changes to legacy IBRS handling to not make spec_ctrl_enter_idle() vulnerable
in other ways.  In the short term, simply take out the perf hit.

Fixes: 08acdf9a26 ("x86/mwait-idle: disable IBRS during long idle")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 07d7163334)
2025-07-07 22:52:06 +01:00
Andrew Cooper 27dad0c0e0 x86/idle: Remove MFENCEs for CLFLUSH_MONITOR
Commit 48d32458bc ("x86, idle: add barriers to CLFLUSH workaround") was
inherited from Linux and added MFENCEs around the AAI65 errata fix.

The SDM now states:

  Executions of the CLFLUSH instruction are ordered with respect to each
  other and with respect to writes, locked read-modify-write instructions,
  and fence instructions[1].

with footnote 1 reading:

  Earlier versions of this manual specified that executions of the CLFLUSH
  instruction were ordered only by the MFENCE instruction.  All processors
  implementing the CLFLUSH instruction also order it relative to the other
  operations enumerated above.

I.e. the MFENCEs came about because of an incorrect statement in the SDM.

The Spec Update (no longer available on Intel's website) simply says "issue a
CLFLUSH", with no mention of MFENCEs.

As this erratum is specific to Intel, it's fine to remove the the MFENCEs; AMD
CPUs of a similar vintage do sport otherwise-unordered CLFLUSHs.

Move the feature bit into the BUG range (rather than FEATURE), and move the
workaround into monitor() itself.

The erratum check itself must use setup_force_cpu_cap().  It needs activating
if any CPU needs it, not if all of them need it.

Fixes: 48d32458bc ("x86, idle: add barriers to CLFLUSH workaround")
Fixes: 96d1b237ae ("x86/Intel: work around Xeon 7400 series erratum AAI65")
Link: https://web.archive.org/web/20090219054841/http://download.intel.com/design/xeon/specupdt/32033601.pdf
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit f77ef34435)
2025-07-07 22:52:06 +01:00
Andrew Cooper d09cad49f5 x86/idle: Move monitor()/mwait() wrappers into cpu-idle.c
They're not used by any other translation unit, so shouldn't live in
asm/processor.h, which is included almost everywhere.

Our new toolchain baseline knows the MONITOR/MWAIT instructions, so use them
directly rather than using raw hex.

Change the hint/extention parameters from long to int.  They're specified to
remain 32bit operands even 64-bit mode.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 61e10fc28c)
2025-07-07 22:52:06 +01:00
Andrew Cooper 1b989d65d7 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>
(cherry picked from commit 6a039b0500)
2025-07-07 22:52:06 +01:00
Roger Pau Monne 0596a69f7a x86/intel: workaround several MONITOR/MWAIT errata
There are several errata on Intel regarding the usage of the MONITOR/MWAIT
instructions, all having in common that stores to the monitored region
might not wake up the CPU.

Fix them by forcing the sending of an IPI for the affected models.

The Ice Lake issue has been reproduced internally on XenServer hardware,
and the fix does seem to prevent it.  The symptom was APs getting stuck in
the idle loop immediately after bring up, which in turn prevented the BSP
from making progress.  This would happen before the watchdog was
initialized, and hence the whole system would get stuck.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
(cherry picked from commit 4aae4452ef)
2025-07-07 22:52:06 +01:00
Andrew Cooper 90b79a5f7b x86/emul: Fix extable registration in invoke_stub()
For exception recovery in the stubs, the registered address for fixup is the
return address of the CALL entering the stub.

In invoke_stub(), the '.Lret%=:' label is the wrong side of the 'post'
parameter.  The 'post' parameter is non-empty in cases where the arithmetic
flags of the operation need recovering.

Split the line to separate 'pre' and 'post', making it more obvious that the
return address label was in the wrong position.

However, in the case that an exception did occur, we want to skip 'post' as
it's logically part of the operation which had already failed.  Therefore, add
a new skip label and use that for the exception recovery path.

This is XSA-470 / CVE-2025-27465

Fixes: 79903e50db ("x86emul: catch exceptions occurring in stubs")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit b9f8311975)
2025-07-01 12:58:35 +01:00
Andrew Cooper 015a7e3ab2 x86/spec-ctrl: Synthesise ITS_NO to guests on unaffected hardware
It is easier to express feature word 17 in terms of word 16 + [32, 64) as
that's how the layout is given in documentation.

This is part of XSA-469 / CVE-2024-28956

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
(cherry picked from commit f6042f38e6)
2025-05-12 17:32:24 +01:00
Jan Beulich 3c31a87bcb x86/thunk: Build Xen with Return Thunks
The Indirect Target Selection speculative vulnerability means that indirect
branches (including RETs) are unsafe when in the first half of a cacheline.

In order to mitigate this, build with return thunks and arrange for
__x86_return_thunk to be (mis)aligned in the same manner as
__x86_indirect_thunk_* so the RET instruction is placed in a safe location.

place_ret() needs to conditionally emit JMP __x86_return_thunk instead of RET.

This is part of XSA-469 / CVE-2024-28956

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
(cherry picked from commit afcb4a06c7)
2025-05-12 17:32:24 +01:00
Andrew Cooper ddc5c1e0aa x86/stubs: Introduce place_ret() to abstract away raw 0xc3's
The Indirect Target Selection speculative vulnerability means that indirect
branches (including RETs) are unsafe when in the first half of a cacheline.
This means it's not safe for logic using the stubs to write raw 0xc3's.

Introduce place_ret() which, for now, writes a raw 0xc3 but will contain
additional logic when return thunks are in use.

stub_selftest() doesn't strictly need to be converted as they only run on
boot, but doing so gets us a partial test of place_ret() too.

No functional change.

This is part of XSA-469 / CVE-2024-28956

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
(cherry picked from commit 2eb1132f79)
2025-05-12 17:32:24 +01:00
Andrew Cooper 1d4361b041 x86/thunk: (Mis)align the RETs in clear_bhb_loops() to mitigate ITS
The Indirect Target Selection speculative vulnerability means that indirect
branches (including RETs) are unsafe when in the first half of a cacheline.

clear_bhb_loops() has a precise layout of branches.  The alignment for
performance cause the RETs to always be in an unsafe position, and converting
those to return thunks changes the branching pattern.  While such a conversion
is believed to be safe, clear_bhb_loops() is also a performance-relevant
fastpath, so (mis)align the RETs to be in a safe position.

No functional change.

This is part of XSA-469 / CVE-2024-28956

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
(cherry picked from commit c0db07031a)
2025-05-12 17:32:24 +01:00
Jan Beulich ebf61f7699 x86/thunk: (Mis)align __x86_indirect_thunk_* to mitigate ITS
The Indirect Target Selection speculative vulnerability means that indirect
branches (including RETs) are unsafe when in the first half of a cacheline.

Arrange for __x86_indirect_thunk_* to always be in the second half.

This is part of XSA-469 / CVE-2024-28956

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit d293cc9da9)
2025-05-12 17:32:24 +01:00
Andrew Cooper 15bb4cccf5 x86/guest: Remove use of the Xen hypercall_page
In order to protect against ITS, Xen needs to start using return thunks.
Therefore the advice in XSA-466 becomes relevant, and the hypercall_page needs
to be removed.

Implement early_hypercall(), with infrastructure to figure out the correct
instruction on first use.  Use ALTERNATIVE()s to result in inline hypercalls,
including the ALT_NOT() form so we only need a single synthetic feature bit.

No overall change.

This is part of XSA-469 / CVE-2024-28956

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
(cherry picked from commit ef30ffe0a0)
2025-05-12 17:32:24 +01:00
Andrew Cooper 2aa9922c89 x86/alternative: Support replacements when a feature is not present
Use the top bit of a->cpuid to express inverted polarity.  This requires
stripping the top bit back out when performing the sanity checks.

Despite only being used once, create a replace boolean to express the decision
more clearly in _apply_alternatives().

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 328ed39c59)
2025-05-12 17:32:24 +01:00
Andrew Cooper d109962a2a x86/ucode: Extend AMD digest checks to cover Zen5 CPUs
AMD have updated the SB-7033 advisory to include Zen5 CPUs.  Extend the digest
check to cover Zen5 too.

In practice, cover everything until further notice.

Observant readers may be wondering where the update to the digest list is.  At
the time of writing, no Zen5 patches are available via a verifiable channel.

Link: https://www.amd.com/en/resources/product-security/bulletin/amd-sb-7033.html
Fixes: 630e8875ab ("x86/ucode: Perform extra SHA2 checks on AMD Fam17h/19h microcode")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
(cherry picked from commit b63951467e)

x86/ucode: Extend warning about disabling digest check too

This was missed by accident.

Fixes: b63951467e ("x86/ucode: Extend AMD digest checks to cover Zen5 CPUs")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
(cherry picked from commit 59bb316ea8)
2025-04-11 17:34:28 +01:00
Andrew Cooper d6654c63e7 x86/ucode: Perform extra SHA2 checks on AMD Fam17h/19h microcode
Collisions have been found in the microcode signing algorithm used by AMD
Fam17h/19h CPUs, and now anyone can sign their own.

For more details, see:
  https://bughunters.google.com/blog/5424842357473280/zen-and-the-art-of-microcode-hacking
  https://www.amd.com/en/resources/product-security/bulletin/amd-sb-7033.html

As a stopgap mitigation, check the digest of patches against a table of blobs
with known provenance.  These are all Fam17h and Fam19h blobs included in
linux-firwmare at the time of writing, specifically:

  https://git.kernel.org/firmware/linux-firmware/c/48bb90cceb882cab8e9ab692bc5779d3bf3a13b8

This checks can be opted out of by booting with ucode=no-digest-check, but
doing so is not recommended.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
(cherry picked from commit 630e8875ab)

Xen: CI fix from XSN-2

 * Add cf_check annotation to cmp_patch_id() used by bsearch().

Fixes: 630e8875ab ("x86/ucode: Perform extra SHA2 checks on AMD Fam17h/19h microcode")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
(cherry picked from commit 15fe2eb5f1)
2025-04-11 17:34:28 +01:00
Andrew Cooper b6eb7932a1 xen/lib: Introduce SHA2-256
A future change will need to calculate SHA2-256 digests.  Introduce an
implementation in lib/, derived from Trenchboot which itself is derived from
Linux.

In order to be useful to other architectures, it is careful with endianness
and misaligned accesses as well as being more MISRA friendly, but is only
wired up for x86 in the short term.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
(cherry picked from commit 372af52441)

Xen: CI fix from XSN-2

 * Add U suffix to the K[] table to fix MISRA Rule 7.2 violations.

Fixes: 372af52441 ("xen/lib: Introduce SHA2-256")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
(cherry picked from commit 15fe2eb5f1)
2025-04-11 17:34:28 +01:00
Andrew Cooper f370d37cfa CI: Resync .cirrus.yml for FreeBSD testing
Includes:
  commit 5395cd7b89 ("automation/cirrus-ci: update FreeBSD to 13.5")
  commit 850a263b78 ("automation/cirrus-ci: update FreeBSD to 13.4")
  commit 0cc8845fb9 ("CI: Update to FreeBSD 14.2")

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
2025-04-11 17:34:28 +01:00
Roger Pau Monne 2f5d4a0685 tools/libxl: remove usage of VLA arrays
Clang 19 complains with the following error when building libxl:

libxl_utils.c:48:15: error: variable length array folded to constant array as an extension [-Werror,-Wgnu-folding-constant]
   48 |     char path[strlen("/local/domain") + 12];
      |               ^~~~~~~~~~~~~~~~~~~~~~~~~~~~

Replace the usage of strlen() with sizeof, which allows the literal
string length to be known at build time.  Note sizeof accounts for the
NUL terminator while strlen() didn't, hence subtract 1 from the total
size calculation.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Frediano Ziglio <frediano.ziglio@cloud.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Anthony PERARD <anthony.perard@vates.tech>
(cherry picked from commit a7c7c3f642)
2025-04-11 17:34:28 +01:00
Jan Beulich 574e42e3fb 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 13:00:04 +00:00
Jason Andryuk a4e5191dc0 libxl: Use zero-ed memory for PVH acpi tables
xl/libxl memory is leaking into a PVH guest through uninitialized
portions of the ACPI tables.

Use libxl_zalloc() to obtain zero-ed memory to avoid this issue.

This is XSA-464 / CVE-2024-45819.

Signed-off-by: Jason Andryuk <jason.andryuk@amd.com>
Fixes: 14c0d328da ("libxl/acpi: Build ACPI tables for HVMlite guests")
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: 0bfe567b58
master date: 2024-11-12 13:32:45 +0100
2024-11-12 14:09:34 +01:00
Jan Beulich 1db4f1a3b7 x86/HVM: drop stdvga's "lock" struct member
No state is left to protect. It being the last field, drop the struct
itself as well. Similarly for then ending up empty, drop the .complete
handler.

This is part of XSA-463 / CVE-2024-45818

Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
(cherry picked from commit b180a50326)
2024-11-12 14:09:10 +01:00
Jan Beulich 9629661904 x86/HVM: drop stdvga's "vram_page[]" struct member
No uses are left, hence its setup, teardown, and the field itself can
also go away. stdvga_deinit() is then empty and can be dropped as well.

This is part of XSA-463 / CVE-2024-45818

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
(cherry picked from commit 3beb4baf2a)
2024-11-12 14:08:53 +01:00
Jan Beulich f65f18ec68 x86/HVM: drop stdvga's "{g,s}r_index" struct members
No consumers are left, hence the producer and the fields themselves can
also go away. stdvga_outb() is then useless, rendering stdvga_out()
useless as well. Hence the entire I/O port intercept can go away.

This is part of XSA-463 / CVE-2024-45818

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
(cherry picked from commit 86c03372e1)
2024-11-12 14:08:44 +01:00
Jan Beulich 9a6bd1e704 x86/HVM: drop stdvga's "sr[]" struct member
No consumers are left, hence the producer and the array itself can also
go away. The static sr_mask[] is then orphaned and hence needs dropping,
too.

This is part of XSA-463 / CVE-2024-45818

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
(cherry picked from commit 7aba44bdd7)
2024-11-12 14:08:24 +01:00
Jan Beulich 72064cfd1b x86/HVM: drop stdvga's "gr[]" struct member
No consumers are left, hence the producer and the array itself can also
go away. The static gr_mask[] is then orphaned and hence needs dropping,
too.

This is part of XSA-463 / CVE-2024-45818

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
(cherry picked from commit b16c0966a1)
2024-11-12 14:08:07 +01:00
Jan Beulich 4ae329d1d1 x86/HVM: remove unused MMIO handling code
All read accesses are rejected by the ->accept handler, while writes
bypass the bulk of the function body. Drop the dead code, leaving an
assertion in the read handler.

A number of other static items (and a macro) are then unreferenced and
hence also need (want) dropping. The same applies to the "latch" field
of the state structure.

This is part of XSA-463 / CVE-2024-45818

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
(cherry picked from commit 89108547af)
2024-11-12 14:07:49 +01:00
Jan Beulich 06044960ea x86/HVM: drop stdvga's "stdvga" struct member
Two of its consumers are dead (in compile-time constant conditionals)
and the only remaining ones are merely controlling debug logging. Hence
the field is now pointless to set, which in particular allows to get rid
of the questionable conditional from which the field's value was
established (afaict 551ceee975 ["x86, hvm: stdvga cache always on"]
had dropped too much of the earlier extra check that was there, and
quite likely further checks were missing).

This is part of XSA-463 / CVE-2024-45818

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
(cherry picked from commit b740a9369e)
2024-11-12 14:07:12 +01:00
Jan Beulich d9606f9622 x86/HVM: properly reject "indirect" VRAM writes
While ->count will only be different from 1 for "indirect" (data in
guest memory) accesses, it being 1 does not exclude the request being an
"indirect" one. Check both to be on the safe side, and bring the ->count
part also in line with what ioreq_send_buffered() actually refuses to
handle.

This is part of XSA-463 / CVE-2024-45818

Fixes: 3bbaaec09b ("x86/hvm: unify stdvga mmio intercept with standard mmio intercept")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
(cherry picked from commit eb7cd0593d)
2024-11-12 14:06:53 +01:00
Jan Beulich 8d13862efa x86/HVM: drop stdvga's "cache" struct member
Since 68e1183411 ("libxc: introduce a xc_dom_arch for hvm-3.0-x86_32
guests"), HVM guests are built using XEN_DOMCTL_sethvmcontext, which
ends up disabling stdvga caching because of arch_hvm_load() being
involved in the processing of the request. With that the field is
useless, and can be dropped. Drop the helper functions manipulating /
checking as well right away, but leave the use sites of
stdvga_cache_is_enabled() with the hard-coded result the function would
have produced, to aid validation of subsequent dropping of further code.

This is part of XSA-463 / CVE-2024-45818

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
(cherry picked from commit 53b7246bdf)
2024-11-12 14:06:31 +01:00
Andrew Cooper f27787545c 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>
(cherry picked from commit e305256e69)
2024-11-12 11:20:45 +00:00
Andrew Cooper 9cf7d9c4ca CI: Resync .cirrus.yml for FreeBSD testing
Includes:
  commit ebb7c6b2fa ("cirrus-ci: update to FreeBSD 14.1 image")

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
2024-11-12 11:20:45 +00:00
Andrew Cooper 78b984d1a8 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>
master commit: 444cb9350f
master date: 2024-10-03 10:07:25 +0100
2024-11-11 14:54:42 +00:00
Olaf Hering 8d75f6a4a1 stubdom: fix errors in newlib:makedoc
rpm post-build-checks found a few code bugs in newlib, and marks them as
errors. Add another newlib patch and apply it during stubdom build.

[  227s] ../../../../newlib-1.16.0/newlib/doc/makedoc.c: In function 'lookup_word':
[  227s] ../../../../newlib-1.16.0/newlib/doc/makedoc.c:1147:10: warning: implicit declaration of function 'strcmp' [-Wimplicit-function-declaration]
[  227s]       if (strcmp(ptr->word, word) == 0) return ptr;
[  227s]           ^

[  460s] I: Program is using implicit definitions of special functions.
[  460s]    these functions need to use their correct prototypes to allow
[  460s]    the lightweight buffer overflow checking to work.
[  460s]      - Implicit memory/string functions need #include <string.h>.
[  460s]      - Implicit *printf functions need #include <stdio.h>.
[  460s]      - Implicit *printf functions need #include <stdio.h>.
[  460s]      - Implicit *read* functions need #include <unistd.h>.
[  460s]      - Implicit *recv* functions need #include <sys/socket.h>.
[  460s] E: xen implicit-fortify-decl ../../../../newlib-1.16.0/newlib/doc/makedoc.c:1147

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
(cherry picked from commit dde20f7dc1)
2024-11-11 14:54:42 +00:00
Olaf Hering 0824ba957b stubdom: fix errors in newlib:cygmon-gmon.c
rpm post-build-checks found a few code bugs in newlib, and marks them as
errors. Add another newlib patch and apply it during stubdom build.

I: A function uses a 'return;' statement, but has actually a value
   to return, like an integer ('return 42;') or similar.
W: xen voidreturn ../../../../newlib-1.16.0/libgloss/i386/cygmon-gmon.c:117, 125, 146, 157, 330

I: Program is using implicit definitions of special functions.
   these functions need to use their correct prototypes to allow
   the lightweight buffer overflow checking to work.
     - Implicit memory/string functions need #include <string.h>.
     - Implicit *printf functions need #include <stdio.h>.
     - Implicit *printf functions need #include <stdio.h>.
     - Implicit *read* functions need #include <unistd.h>.
     - Implicit *recv* functions need #include <sys/socket.h>.
E: xen implicit-fortify-decl ../../../../newlib-1.16.0/libgloss/i386/cygmon-gmon.c:119

I: Program returns random data in a function
E: xen no-return-in-nonvoid-function ../../../../newlib-1.16.0/libgloss/i386/cygmon-gmon.c:362

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
(cherry picked from commit 860fb990bd)
2024-11-11 14:54:42 +00:00
Andrew Cooper 8ca06b7fd2 CI: Mark Archlinux/x86 as allowing failures
Archlinux is a rolling distro.  As a consequence, rebuilding the container
periodically changes the toolchain, and this affects all stable branches in
one go.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
Release-Acked-By: Oleksii Kurochko <oleksii.kurochko@gmail.com>
(cherry picked from commit 5e1773dc86)
2024-11-11 14:54:42 +00:00