From: Wanpeng Li wanpengli@tencent.com
mainline inclusion from mainline-v5.13-rc6 commit e898da784aed0ea65f7672d941c01dc9b79e6299 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I4NP0K CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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According to the SDM 10.5.4.1:
A write of 0 to the initial-count register effectively stops the local APIC timer, in both one-shot and periodic mode.
However, the lapic timer oneshot/periodic mode which is emulated by vmx-preemption timer doesn't stop by writing 0 to TMICT since vmx->hv_deadline_tsc is still programmed and the guest will receive the spurious timer interrupt later. This patch fixes it by also cancelling the vmx-preemption timer when writing 0 to the initial-count register.
Reviewed-by: Sean Christopherson seanjc@google.com Signed-off-by: Wanpeng Li wanpengli@tencent.com Message-Id: 1623050385-100988-1-git-send-email-wanpengli@tencent.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Jingyi Wang wangjingyi11@huawei.com Reviewed-by: Zenghui Yu yuzenghui@huawei.com Reviewed-by: Wei Li liwei391@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- arch/x86/kvm/lapic.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 677d21082454..94e75c941b47 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -1492,6 +1492,15 @@ static void limit_periodic_timer_frequency(struct kvm_lapic *apic)
static void cancel_hv_timer(struct kvm_lapic *apic);
+static void cancel_apic_timer(struct kvm_lapic *apic) +{ + hrtimer_cancel(&apic->lapic_timer.timer); + preempt_disable(); + if (apic->lapic_timer.hv_timer_in_use) + cancel_hv_timer(apic); + preempt_enable(); +} + static void apic_update_lvtt(struct kvm_lapic *apic) { u32 timer_mode = kvm_lapic_get_reg(apic, APIC_LVTT) & @@ -1500,11 +1509,7 @@ static void apic_update_lvtt(struct kvm_lapic *apic) if (apic->lapic_timer.timer_mode != timer_mode) { if (apic_lvtt_tscdeadline(apic) != (timer_mode == APIC_LVT_TIMER_TSCDEADLINE)) { - hrtimer_cancel(&apic->lapic_timer.timer); - preempt_disable(); - if (apic->lapic_timer.hv_timer_in_use) - cancel_hv_timer(apic); - preempt_enable(); + cancel_apic_timer(apic); kvm_lapic_set_reg(apic, APIC_TMICT, 0); apic->lapic_timer.period = 0; apic->lapic_timer.tscdeadline = 0; @@ -2082,7 +2087,7 @@ int kvm_lapic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val) if (apic_lvtt_tscdeadline(apic)) break;
- hrtimer_cancel(&apic->lapic_timer.timer); + cancel_apic_timer(apic); kvm_lapic_set_reg(apic, APIC_TMICT, val); start_apic_timer(apic); break;