Commit 9488cacd authored by Sean Christopherson's avatar Sean Christopherson Committed by Greg Kroah-Hartman

KVM: lapic: Busy wait for timer to expire when using hv_timer

commit ee66e453 upstream.

...now that VMX's preemption timer, i.e. the hv_timer, also adjusts its
programmed time based on lapic_timer_advance_ns.  Without the delay, a
guest can see a timer interrupt arrive before the requested time when
KVM is using the hv_timer to emulate the guest's interrupt.

Fixes: c5ce8235 ("KVM: VMX: Optimize tscdeadline timer latency")
Cc: <stable@vger.kernel.org>
Cc: Wanpeng Li <wanpengli@tencent.com>
Reviewed-by: default avatarLiran Alon <liran.alon@oracle.com>
Signed-off-by: default avatarSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 971a62fb
...@@ -1454,7 +1454,7 @@ static void apic_timer_expired(struct kvm_lapic *apic) ...@@ -1454,7 +1454,7 @@ static void apic_timer_expired(struct kvm_lapic *apic)
if (swait_active(q)) if (swait_active(q))
swake_up_one(q); swake_up_one(q);
if (apic_lvtt_tscdeadline(apic)) if (apic_lvtt_tscdeadline(apic) || ktimer->hv_timer_in_use)
ktimer->expired_tscdeadline = ktimer->tscdeadline; ktimer->expired_tscdeadline = ktimer->tscdeadline;
} }
......
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