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    SubjectRe: [PATCH 03/43] KVM: SVM: Require exact CPUID.0x1 match when stuffing EDX at INIT
    On Fri, Apr 23, 2021 at 5:47 PM Sean Christopherson <seanjc@google.com> wrote:
    >
    > Do not allow an inexact CPUID "match" when querying the guest's CPUID.0x1
    > to stuff EDX during INIT. In the common case, where the guest CPU model
    > is an AMD variant, allowing an inexact match is a nop since KVM doesn't
    > emulate Intel's goofy "out-of-range" logic for AMD and Hygon. If the
    > vCPU model happens to be an Intel variant, an inexact match is possible
    > if and only if the max CPUID leaf is precisely '0'. Aside from the fact
    > that there's probably no CPU in existence with a single CPUID leaf, if
    > the max CPUID leaf is '0', that means that CPUID.0.EAX is '0', and thus
    > an inexact match for CPUID.0x1.EAX will also yield '0'.
    >
    > So, with lots of twisty logic, no functional change intended.
    >
    > Signed-off-by: Sean Christopherson <seanjc@google.com>

    Reviewed-by: Reiji Watanabe <reijiw@google.com>

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