diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index d5a33b6be7d5..535fd566a3a2 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -2180,9 +2180,6 @@ void kvm_apic_write_nodecode(struct kvm_vcpu *vcpu, u32 offset) { u32 val = 0; - /* hw has done the conditional check and inst decode */ - offset &= 0xff0; - kvm_lapic_reg_read(vcpu->arch.apic, offset, 4, &val); /* TODO: optimize to just emulate side effect w/o one more write */ diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 3d7fe9de045a..b325f99b2177 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -5314,9 +5314,16 @@ static int handle_apic_eoi_induced(struct kvm_vcpu *vcpu) static int handle_apic_write(struct kvm_vcpu *vcpu) { unsigned long exit_qualification = vmx_get_exit_qual(vcpu); - u32 offset = exit_qualification & 0xfff; - /* APIC-write VM exit is trap-like and thus no need to adjust IP */ + /* + * APIC-write VM-Exit is trap-like, KVM doesn't need to advance RIP and + * hardware has done any necessary aliasing, offset adjustments, etc... + * for the access. I.e. the correct value has already been written to + * the vAPIC page for the correct 16-byte chunk. KVM needs only to + * retrieve the register value and emulate the access. + */ + u32 offset = exit_qualification & 0xff0; + kvm_apic_write_nodecode(vcpu, offset); return 1; }