KVM: SVM: Inhibit APIC virtualization for X2APIC guest

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The AVIC does not support guest use of the x2APIC interface. Currently,
KVM simply chooses to squash the x2APIC feature in the guest's CPUID
If the AVIC is enabled. Doing so prevents KVM from running a guest
with greater than 255 vCPUs, as such a guest necessitates the use
of the x2APIC interface.

Instead, inhibit AVIC enablement on a per-VM basis whenever the x2APIC
feature is set in the guest's CPUID.

Signed-off-by: Oliver Upton <oupton@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

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Oliver Upton 2020-02-28 00:59:04 -08:00 • committed by Paolo Bonzini

parent 4d39576259

commit cc7f5577ad

2 changed files with 10 additions and 6 deletions

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1

arch/x86/include/asm/kvm_host.h

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15

arch/x86/kvm/svm.c

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