Re: [PATCH] x86: properly handle KVM emulation of hyperv

From: Paolo Bonzini
Date: Fri Jul 19 2013 - 17:00:47 EST


Il 19/07/2013 22:59, H. Peter Anvin ha scritto:
>>> >> - cpuid(KVM_CPUID_SIGNATURE, &eax, &ebx, &ecx, &edx);
>>> >> - memcpy(signature + 0, &ebx, 4);
>>> >> - memcpy(signature + 4, &ecx, 4);
>>> >> - memcpy(signature + 8, &edx, 4);
>>> >> - signature[12] = 0;
>>> >> -
>>> >> - if (strcmp(signature, "KVMKVMKVM") == 0)
>>> >> + if (kvm_para_available_function(KVM_CPUID_SIGNATURE) ||
>>> >> + kvm_para_available_function(KVM_CPUID_SIGNATURE_NEXT))
>>> >> return true;
>>> >> }
>> >
>> > Nice catch. Just one small thing, you should loop until 0x40010000, as
>> > done in arch/x86/include/asm/xen/hypervisor.h, in case one day a third
>> > hypervisor implements three extensions (Hyper-V, KVM and its own set).
>> >
> Any way we can centralize this stuff?

I guess a function cpuid_hypervisor_base("KVMKVMKVM") that does the scan?

Paolo
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