diff options
| author | Linus Walleij <[email protected]> | 2021-11-27 00:54:16 +0100 |
|---|---|---|
| committer | Linus Walleij <[email protected]> | 2021-11-27 00:54:16 +0100 |
| commit | 2448eab44034d9603c97ca17760a53d4d6e4b60c (patch) | |
| tree | 7f323cea55258e94e0c7c70b63d02c9effb00c1f /arch/x86/kernel/cpu/mshyperv.c | |
| parent | deee705a1c9cce9c7eb699d529f1c0b3c80d339d (diff) | |
| parent | 136057256686de39cc3a07c2e39ef6bc43003ff6 (diff) | |
Merge tag 'v5.16-rc2' into devel
Linux 5.16-rc2 is needed because nonurgent fixes headed
for next are strongly textually dependent on a fix that
was applied for rc2.
Signed-off-by: Linus Walleij <[email protected]>
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) |