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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-09-27 08:44:12 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-09-27 08:44:12 -0700 |
| commit | efb44d93a620c294c049db37c810c8ab7ee1122d (patch) | |
| tree | 095d326e3948f0fc217652bfb3545702831c8f49 /arch/x86/coco | |
| parent | 673dab7eac1618b6622bbee9eb2aaa47817631e3 (diff) | |
| parent | b8d1d5b63a8ef532038eebd9d97d406860385668 (diff) | |
| download | linux-stable-efb44d93a620c294c049db37c810c8ab7ee1122d.tar.gz linux-stable-efb44d93a620c294c049db37c810c8ab7ee1122d.zip | |
Merge tag 'x86-urgent-2026-09-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
- Fix preemption bugs in the SVSM vTPM guest implementation
(Melody Wang)
- Fix MCE-triggered hardware debug register corruption on
task migration (Masami Hiramatsu)
* tag 'x86-urgent-2026-09-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mce: Fix hardware debug register corruption on task migration
x86/sev: Make vTPM SVSM calls preemption-safe
Diffstat (limited to 'arch/x86/coco')
| -rw-r--r-- | arch/x86/coco/sev/svsm.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/arch/x86/coco/sev/svsm.c b/arch/x86/coco/sev/svsm.c index 916d62cd1..2d493d55f 100644 --- a/arch/x86/coco/sev/svsm.c +++ b/arch/x86/coco/sev/svsm.c @@ -74,6 +74,14 @@ int svsm_perform_call_protocol(struct svsm_call *call) flags = native_local_irq_save(); + /* + * 'caa' is a per-CPU variable. To avoid using a stale or incorrect + * 'caa' if the task is preempted or migrated to another CPU after it + * is fetched, always fetch 'caa' and then issue the SVSM call with + * interrupts disabled. This ensures the correct 'caa' is used. + */ + call->caa = svsm_get_caa(); + ghcb = __sev_get_ghcb(&state); do { @@ -321,7 +329,6 @@ int snp_svsm_vtpm_send_command(u8 *buffer) { struct svsm_call call = {}; - call.caa = svsm_get_caa(); call.rax = SVSM_VTPM_CALL(SVSM_VTPM_CMD); call.rcx = __pa(buffer); @@ -345,7 +352,6 @@ bool snp_svsm_vtpm_probe(void) if (!snp_vmpl) return false; - call.caa = svsm_get_caa(); call.rax = SVSM_VTPM_CALL(SVSM_VTPM_QUERY); if (svsm_perform_call_protocol(&call)) |