On Sat, 2022-10-01 at 00:59 +0000, Sean Christopherson wrote:
> Update the vCPU's local (virtual) APIC on LDR writes even if the write
> "fails". The APIC needs to recalc the optimized logical map even if the
> LDR is invalid or zero, e.g. if the guest clears its LDR, the optimized
> map will be left as is and the vCPU will receive interrupts using its
> old LDR.
>
> Fixes: 18f40c53e10f ("svm: Add VMEXIT handlers for AVIC")
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> ---
> arch/x86/kvm/svm/avic.c | 11 ++++-------
> 1 file changed, 4 insertions(+), 7 deletions(-)
>
> diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c
> index 27d5abc15a91..2b640c73f447 100644
> --- a/arch/x86/kvm/svm/avic.c
> +++ b/arch/x86/kvm/svm/avic.c
> @@ -573,7 +573,7 @@ static void avic_invalidate_logical_id_entry(struct kvm_vcpu *vcpu)
> clear_bit(AVIC_LOGICAL_ID_ENTRY_VALID_BIT, (unsigned long *)entry);
> }
>
> -static int avic_handle_ldr_update(struct kvm_vcpu *vcpu)
> +static void avic_handle_ldr_update(struct kvm_vcpu *vcpu)
> {
> int ret = 0;
> struct vcpu_svm *svm = to_svm(vcpu);
> @@ -582,10 +582,10 @@ static int avic_handle_ldr_update(struct kvm_vcpu *vcpu)
>
> /* AVIC does not support LDR update for x2APIC */
> if (apic_x2apic_mode(vcpu->arch.apic))
> - return 0;
> + return;
>
> if (ldr == svm->ldr_reg)
> - return 0;
> + return;
>
> avic_invalidate_logical_id_entry(vcpu);
>
> @@ -594,8 +594,6 @@ static int avic_handle_ldr_update(struct kvm_vcpu *vcpu)
>
> if (!ret)
> svm->ldr_reg = ldr;
> -
> - return ret;
> }
>
> static void avic_handle_dfr_update(struct kvm_vcpu *vcpu)
> @@ -617,8 +615,7 @@ static int avic_unaccel_trap_write(struct kvm_vcpu *vcpu)
>
> switch (offset) {
> case APIC_LDR:
> - if (avic_handle_ldr_update(vcpu))
> - return 0;
> + avic_handle_ldr_update(vcpu);
> break;
> case APIC_DFR:
> avic_handle_dfr_update(vcpu);
Reviewed-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
Best regards,
Maxim Levitsky
