On 4/27/22 17:54, Sasha Levin wrote:
From: Paolo Bonzini pbonzini@redhat.com
[ Upstream commit d22a81b304a27fca6124174a8e842e826c193466 ]
Emulating writes to SELF_IPI with a write to ICR has an unwanted side effect: the value of ICR in vAPIC page gets changed. The lists SELF_IPI as write-only, with no associated MMIO offset, so any write should have no visible side effect in the vAPIC page.
Reported-by: Chao Gao chao.gao@intel.com Reviewed-by: Sean Christopherson seanjc@google.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org
arch/x86/kvm/lapic.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index de11149e28e0..e45ebf0870b6 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -2106,10 +2106,9 @@ int kvm_lapic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val) break; case APIC_SELF_IPI:
if (apic_x2apic_mode(apic)) {kvm_lapic_reg_write(apic, APIC_ICR,APIC_DEST_SELF | (val & APIC_VECTOR_MASK));} else
if (apic_x2apic_mode(apic))kvm_apic_send_ipi(apic, APIC_DEST_SELF | (val & APIC_VECTOR_MASK), 0);else ret = 1;
Acked-by: Paolo Bonzini pbonzini@redhat.com