> -----Original Message----- > From: Paolo Bonzini [mailto:paolo.bonzini@xxxxxxxxx] On Behalf Of Paolo > Bonzini > Sent: Friday, October 2, 2015 2:27 AM > To: linux-kernel@xxxxxxxxxxxxxxx > Cc: KY Srinivasan <kys@xxxxxxxxxxxxx>; Haiyang Zhang > <haiyangz@xxxxxxxxxxxxx>; x86@xxxxxxxxxx; devel@xxxxxxxxxxxxxxxxxxxxxx; > alex.williamson@xxxxxxxxxx > Subject: [PATCH] x86: guest: rely on leaf 0x40000001 to detect Hyper-V > > The specification says that "Microsoft Hv" is actually a vendor ID field > that is only used for reporting and diagnostic purposes. The actual > field that you need to check is the interface ID that you get in eax > when querying the HYPERV_CPUID_INTERFACE. > > Change ms_hyperv_platform to actually do what the specification suggests. > This roughy matches what Windows looks for, though Windows actually > ignores HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS completely. > > Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> Thanks Paolo. Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx> > --- > arch/x86/kernel/cpu/mshyperv.c | 14 ++++++-------- > 1 file changed, 6 insertions(+), 8 deletions(-) > > diff --git a/arch/x86/kernel/cpu/mshyperv.c > b/arch/x86/kernel/cpu/mshyperv.c > index 381c8b9b3a33..7910e7fd705b 100644 > --- a/arch/x86/kernel/cpu/mshyperv.c > +++ b/arch/x86/kernel/cpu/mshyperv.c > @@ -116,18 +116,16 @@ static void hv_machine_crash_shutdown(struct > pt_regs *regs) > static uint32_t __init ms_hyperv_platform(void) > { > u32 eax; > - u32 hyp_signature[3]; > > if (!boot_cpu_has(X86_FEATURE_HYPERVISOR)) > return 0; > > - 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; > + eax = > cpuid_eax(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS); > + if (eax >= HYPERV_CPUID_MIN && eax <= HYPERV_CPUID_MAX) { > + eax = cpuid_eax(HYPERV_CPUID_INTERFACE); > + if (!memcmp(&eax, "Hv#1", sizeof(eax))) > + return > HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS; > + } > > return 0; > } > -- > 2.5.0 _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
