For KVM remote TLB flushes we need to check the KVM_REQ_TLB_FLUSH
request flag when the irqs are already disabled. Otherwise there is a
small window of time for a race condition where we may enter a guest
without doing a requested TLB flush.
Signed-off-by: Joerg Roedel <joerg.roedel@xxxxxxx>
---
arch/x86/kvm/x86.c | 5 +++--
1 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index b556b6a..301660a 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3108,8 +3108,6 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
kvm_write_guest_time(vcpu);
if (test_and_clear_bit(KVM_REQ_MMU_SYNC, &vcpu->requests))
kvm_mmu_sync_roots(vcpu);
- if (test_and_clear_bit(KVM_REQ_TLB_FLUSH, &vcpu->requests))
- kvm_x86_ops->tlb_flush(vcpu);
if (test_and_clear_bit(KVM_REQ_REPORT_TPR_ACCESS,
&vcpu->requests)) {
kvm_run->exit_reason = KVM_EXIT_TPR_ACCESS;
@@ -3133,6 +3131,9 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
local_irq_disable();
+ if (test_and_clear_bit(KVM_REQ_TLB_FLUSH, &vcpu->requests))
+ kvm_x86_ops->tlb_flush(vcpu);
+
if (vcpu->requests || need_resched() || signal_pending(current)) {
local_irq_enable();
preempt_enable();
--
1.5.6.4
--
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