Resurrect a patch[*] from over a year ago to avoid RDMSR in a fairly hot path in KVM's posted interrupt support. Note, in my response to that patch, I suggested checking x2apic_supported() as well as x2apic_mode. I have no idea why I suggested that; unless I'm missing something, x2apic_mode can never be set if x2apic_supported() is false. [*] https://lkml.kernel.org/r/20190723130608.26528-1-luferry@xxxxxxx/ Sean Christopherson (2): x86/apic: Export x2apic_mode for use by KVM in "warm" path KVM: VMX: Use x2apic_mode to avoid RDMSR when querying PI state arch/x86/kernel/apic/apic.c | 1 + arch/x86/kvm/vmx/posted_intr.c | 6 +++--- 2 files changed, 4 insertions(+), 3 deletions(-) -- 2.30.0.284.gd98b1dd5eaa7-goog
