On Fri, Jan 6, 2023 at 5:10 PM Sean Christopherson <seanjc@xxxxxxxxxx> wrote: > > Don't clear the "read" bits for x2APIC registers above SELF_IPI (APIC regs Odd use of quotation marks in the shortlog and here. > 0x400 - 0xff0, MSRs 0x840 - 0x8ff). KVM doesn't emulate registers in that > space (there are a smattering of AMD-only extensions) and so should > intercept reads in order to inject #GP. When APICv is fully enabled, > Intel hardware doesn't validate the registers on RDMSR and instead blindly > retrieves data from the vAPIC page, i.e. it's software's responsibility to > intercept reads to non-existent MSRs. > > Fixes: 8d14695f9542 ("x86, apicv: add virtual x2apic support") > Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx> Reviewed-by: Jim Mattson <jmattson@xxxxxxxxxx>