svm/avic: Fix invalidate logical APIC id entry

Only clear the valid bit when invalidate logical APIC id entry.
The current logic clear the valid bit, but also set the rest of
the bits (including reserved bits) to 1.

Fixes: 98d90582be2e ('svm: Fix AVIC DFR and LDR handling')
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index d7b14c9..933f19d 100644 (file)
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -262,6 +262,7 @@ struct amd_svm_iommu_ir {
 };
 
 #define AVIC_LOGICAL_ID_ENTRY_GUEST_PHYSICAL_ID_MASK   (0xFF)
+#define AVIC_LOGICAL_ID_ENTRY_VALID_BIT                        31
 #define AVIC_LOGICAL_ID_ENTRY_VALID_MASK               (1 << 31)
 
 #define AVIC_PHYSICAL_ID_ENTRY_HOST_PHYSICAL_ID_MASK   (0xFFULL)
@@ -4607,7 +4608,7 @@ static void avic_invalidate_logical_id_entry(struct kvm_vcpu *vcpu)
        u32 *entry = avic_get_logical_id_entry(vcpu, svm->ldr_reg, flat);
 
        if (entry)
-               WRITE_ONCE(*entry, (u32) ~AVIC_LOGICAL_ID_ENTRY_VALID_MASK);
+               clear_bit(AVIC_LOGICAL_ID_ENTRY_VALID_BIT, (unsigned long *)entry);
 }
 
 static int avic_handle_ldr_update(struct kvm_vcpu *vcpu)