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| author |   Ingo Molnar <mingo@kernel.org> | 2021-12-13 10:48:46 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2021-12-13 10:48:46 +0100 |
| commit | 6773cc31a9bb5122fd5c288f73ca006ad20a6c17 (patch) | |
| tree | 730ec8bcc0a5ddd5030268bb3ffd4945d34728c1 /arch/x86/kernel/cpu/mshyperv.c | |
| parent | futex: Fix additional regressions (diff) | |
| parent | Linux 5.16-rc5 (diff) | |
| download | linux-dev-6773cc31a9bb5122fd5c288f73ca006ad20a6c17.tar.xz linux-dev-6773cc31a9bb5122fd5c288f73ca006ad20a6c17.zip | |
Merge tag 'v5.16-rc5' into locking/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/cpu/mshyperv.c')
| -rw-r--r-- | arch/x86/kernel/cpu/mshyperv.c | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index 4794b716ec79..ff55df60228f 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -163,12 +163,22 @@ static uint32_t __init ms_hyperv_platform(void) cpuid(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS, &eax, &hyp_signature[0], &hyp_signature[1], &hyp_signature[2]); - if (eax >= HYPERV_CPUID_MIN && - eax <= HYPERV_CPUID_MAX && - !memcmp("Microsoft Hv", hyp_signature, 12)) - return HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS; + if (eax < HYPERV_CPUID_MIN || eax > HYPERV_CPUID_MAX || + memcmp("Microsoft Hv", hyp_signature, 12)) + return 0; - return 0; + /* HYPERCALL and VP_INDEX MSRs are mandatory for all features. */ + eax = cpuid_eax(HYPERV_CPUID_FEATURES); + if (!(eax & HV_MSR_HYPERCALL_AVAILABLE)) { + pr_warn("x86/hyperv: HYPERCALL MSR not available.\n"); + return 0; + } + if (!(eax & HV_MSR_VP_INDEX_AVAILABLE)) { + pr_warn("x86/hyperv: VP_INDEX MSR not available.\n"); + return 0; + } + + return HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS; } static unsigned char hv_get_nmi_reason(void) |