On Sat, 2023-01-07 at 01:10 +0000, Sean Christopherson wrote: > Mark APIC_DFR as being invalid/non-existent in x2APIC mode instead of > handling it as a one-off check in kvm_x2apic_msr_read(). This will allow > reusing "valid_reg_mask" to generate VMX's interception bitmaps for > x2APIC. Handling DFR in the common read path may also fix the Hyper-V > PV MSR interface, if that can coexist with x2APIC. > > Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx> > --- > arch/x86/kvm/lapic.c | 11 ++++------- > 1 file changed, 4 insertions(+), 7 deletions(-) > > diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c > index bf53e4752f30..c49b13418638 100644 > --- a/arch/x86/kvm/lapic.c > +++ b/arch/x86/kvm/lapic.c > @@ -1541,7 +1541,6 @@ static int kvm_lapic_reg_read(struct kvm_lapic *apic, u32 offset, int len, > APIC_REG_MASK(APIC_TASKPRI) | > APIC_REG_MASK(APIC_PROCPRI) | > APIC_REG_MASK(APIC_LDR) | > - APIC_REG_MASK(APIC_DFR) | > APIC_REG_MASK(APIC_SPIV) | > APIC_REGS_MASK(APIC_ISR, APIC_ISR_NR) | > APIC_REGS_MASK(APIC_TMR, APIC_ISR_NR) | > @@ -1562,12 +1561,13 @@ static int kvm_lapic_reg_read(struct kvm_lapic *apic, u32 offset, int len, > valid_reg_mask |= APIC_REG_MASK(APIC_LVTCMCI); > > /* > - * ARBPRI and ICR2 are not valid in x2APIC mode. WARN if KVM reads ICR > - * in x2APIC mode as it's an 8-byte register in x2APIC and needs to be > - * manually handled by the caller. > + * ARBPRI, DFR, and ICR2 are not valid in x2APIC mode. WARN if KVM > + * reads ICR in x2APIC mode as it's an 8-byte register in x2APIC and > + * needs to be manually handled by the caller. > */ > if (!apic_x2apic_mode(apic)) > valid_reg_mask |= APIC_REG_MASK(APIC_ARBPRI) | > + APIC_REG_MASK(APIC_DFR) | > APIC_REG_MASK(APIC_ICR2); > else > WARN_ON_ONCE(offset == APIC_ICR); > @@ -3141,9 +3141,6 @@ int kvm_x2apic_msr_read(struct kvm_vcpu *vcpu, u32 msr, u64 *data) > if (!lapic_in_kernel(vcpu) || !apic_x2apic_mode(apic)) > return 1; > > - if (reg == APIC_DFR) > - return 1; > - > return kvm_lapic_msr_read(apic, reg, data); > } > Reviewed-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx> Best regards, Maxim Levitsky
