diff options
authorZenghui Yu <yuzenghui@huawei.com>2019-10-29 15:19:19 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-12-13 08:52:45 +0100
commit66f8ca55eb8131fde0b63239d7462a0dbb5cb1d2 (patch)
parente8d9825d557367bdebc0f8d2c1aa27814ac7319f (diff)
KVM: arm/arm64: vgic: Don't rely on the wrong pending table
commit ca185b260951d3b55108c0b95e188682d8a507b7 upstream. It's possible that two LPIs locate in the same "byte_offset" but target two different vcpus, where their pending status are indicated by two different pending tables. In such a scenario, using last_byte_offset optimization will lead KVM relying on the wrong pending table entry. Let us use last_ptr instead, which can be treated as a byte index into a pending table and also, can be vcpu specific. Fixes: 280771252c1b ("KVM: arm64: vgic-v3: KVM_DEV_ARM_VGIC_SAVE_PENDING_TABLES") Cc: stable@vger.kernel.org Signed-off-by: Zenghui Yu <yuzenghui@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: Eric Auger <eric.auger@redhat.com> Link: https://lore.kernel.org/r/20191029071919.177-4-yuzenghui@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 files changed, 3 insertions, 3 deletions
diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
index 8b958ed05306..62a3a2f716bf 100644
--- a/virt/kvm/arm/vgic/vgic-v3.c
+++ b/virt/kvm/arm/vgic/vgic-v3.c
@@ -375,8 +375,8 @@ retry:
int vgic_v3_save_pending_tables(struct kvm *kvm)
struct vgic_dist *dist = &kvm->arch.vgic;
- int last_byte_offset = -1;
struct vgic_irq *irq;
+ gpa_t last_ptr = ~(gpa_t)0;
int ret;
u8 val;
@@ -396,11 +396,11 @@ int vgic_v3_save_pending_tables(struct kvm *kvm)
bit_nr = irq->intid % BITS_PER_BYTE;
ptr = pendbase + byte_offset;
- if (byte_offset != last_byte_offset) {
+ if (ptr != last_ptr) {
ret = kvm_read_guest_lock(kvm, ptr, &val, 1);
if (ret)
return ret;
- last_byte_offset = byte_offset;
+ last_ptr = ptr;
stored = val & (1U << bit_nr);