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authorWanpeng Li <wanpengli@tencent.com>2021-04-28 19:08:02 +0800
committerPaolo Bonzini <pbonzini@redhat.com>2021-05-03 11:25:35 -0400
commitd981dd15498b188636ec5a7d8ad485e650f63d8d (patch)
tree449a9fab29eefb9997130f34620e0ce0fd418698 /arch/x86/kvm/lapic.c
parent1699f65c8b658d434fe92563c906cd1a136c9cb6 (diff)
downloadlinux-d981dd15498b188636ec5a7d8ad485e650f63d8d.tar.bz2
KVM: LAPIC: Accurately guarantee busy wait for timer to expire when using hv_timer
Commit ee66e453db13d (KVM: lapic: Busy wait for timer to expire when using hv_timer) tries to set ktime->expired_tscdeadline by checking ktime->hv_timer_in_use since lapic timer oneshot/periodic modes which are emulated by vmx preemption timer also get advanced, they leverage the same vmx preemption timer logic with tsc-deadline mode. However, ktime->hv_timer_in_use is cleared before apic_timer_expired() handling, let's delay this clearing in preemption-disabled region. Fixes: ee66e453db13d ("KVM: lapic: Busy wait for timer to expire when using hv_timer") Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Message-Id: <1619608082-4187-1-git-send-email-wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/lapic.c')
-rw-r--r--arch/x86/kvm/lapic.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 152591f9243a..c0ebef560bd1 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1913,8 +1913,8 @@ void kvm_lapic_expired_hv_timer(struct kvm_vcpu *vcpu)
if (!apic->lapic_timer.hv_timer_in_use)
goto out;
WARN_ON(rcuwait_active(&vcpu->wait));
- cancel_hv_timer(apic);
apic_timer_expired(apic, false);
+ cancel_hv_timer(apic);
if (apic_lvtt_period(apic) && apic->lapic_timer.period) {
advance_periodic_target_expiration(apic);