From f3b138c5d89a1f74a2b46adaa1067aea9a7e3cbb Mon Sep 17 00:00:00 2001 From: Andrey Smetanin Date: Mon, 28 Dec 2015 18:27:24 +0300 Subject: [PATCH] kvm/x86: Update SynIC timers on guest entry only Consolidate updating the Hyper-V SynIC timers in a single place: on guest entry in processing KVM_REQ_HV_STIMER request. This simplifies the overall logic, and makes sure the most current state of msrs and guest clock is used for arming the timers (to achieve that, KVM_REQ_HV_STIMER has to be processed after KVM_REQ_CLOCK_UPDATE). Signed-off-by: Andrey Smetanin Reviewed-by: Roman Kagan CC: Gleb Natapov CC: Paolo Bonzini CC: Roman Kagan CC: Denis V. Lunev CC: qemu-devel@nongnu.org Signed-off-by: Paolo Bonzini --- arch/x86/kvm/hyperv.c | 38 +++++++++++++++++++------------------- arch/x86/kvm/x86.c | 6 ++++++ 2 files changed, 25 insertions(+), 19 deletions(-) diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index ddae13eed075..101c2e4a0255 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -389,7 +389,7 @@ static u64 get_time_ref_counter(struct kvm *kvm) return div_u64(get_kernel_ns() + kvm->arch.kvmclock_offset, 100); } -static void stimer_mark_expired(struct kvm_vcpu_hv_stimer *stimer, +static void stimer_mark_pending(struct kvm_vcpu_hv_stimer *stimer, bool vcpu_kick) { struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer); @@ -417,7 +417,7 @@ static enum hrtimer_restart stimer_timer_callback(struct hrtimer *timer) struct kvm_vcpu_hv_stimer *stimer; stimer = container_of(timer, struct kvm_vcpu_hv_stimer, timer); - stimer_mark_expired(stimer, true); + stimer_mark_pending(stimer, true); return HRTIMER_NORESTART; } @@ -462,7 +462,7 @@ static int stimer_start(struct kvm_vcpu_hv_stimer *stimer) * "If a one shot is enabled and the specified count is in * the past, it will expire immediately." */ - stimer_mark_expired(stimer, false); + stimer_mark_pending(stimer, false); return 0; } @@ -475,30 +475,24 @@ static int stimer_start(struct kvm_vcpu_hv_stimer *stimer) static int stimer_set_config(struct kvm_vcpu_hv_stimer *stimer, u64 config, bool host) { + stimer_cleanup(stimer); if ((stimer->config & HV_STIMER_ENABLE) && HV_STIMER_SINT(config) == 0) config &= ~HV_STIMER_ENABLE; stimer->config = config; - stimer_cleanup(stimer); - if (stimer->config & HV_STIMER_ENABLE) - if (stimer_start(stimer)) - return 1; + stimer_mark_pending(stimer, false); return 0; } static int stimer_set_count(struct kvm_vcpu_hv_stimer *stimer, u64 count, bool host) { - stimer->count = count; - stimer_cleanup(stimer); + stimer->count = count; if (stimer->count == 0) stimer->config &= ~HV_STIMER_ENABLE; - else if (stimer->config & HV_STIMER_AUTOENABLE) { + else if (stimer->config & HV_STIMER_AUTOENABLE) stimer->config |= HV_STIMER_ENABLE; - if (stimer_start(stimer)) - return 1; - } - + stimer_mark_pending(stimer, false); return 0; } @@ -582,18 +576,24 @@ void kvm_hv_process_stimers(struct kvm_vcpu *vcpu) { struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu); struct kvm_vcpu_hv_stimer *stimer; - u64 time_now; + u64 time_now, exp_time; int i; for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++) if (test_and_clear_bit(i, hv_vcpu->stimer_pending_bitmap)) { stimer = &hv_vcpu->stimer[i]; if (stimer->config & HV_STIMER_ENABLE) { - time_now = get_time_ref_counter(vcpu->kvm); - if (time_now >= stimer->exp_time) - stimer_expiration(stimer); + exp_time = stimer->exp_time; + + if (exp_time) { + time_now = + get_time_ref_counter(vcpu->kvm); + if (time_now >= exp_time) + stimer_expiration(stimer); + } - if (stimer->config & HV_STIMER_ENABLE) + if ((stimer->config & HV_STIMER_ENABLE) && + stimer->count) stimer_start(stimer); else stimer_cleanup(stimer); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 107ceaf8cbd0..fad1d096919e 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6508,6 +6508,12 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) r = 0; goto out; } + + /* + * KVM_REQ_HV_STIMER has to be processed after + * KVM_REQ_CLOCK_UPDATE, because Hyper-V SynIC timers + * depend on the guest clock being up-to-date + */ if (kvm_check_request(KVM_REQ_HV_STIMER, vcpu)) kvm_hv_process_stimers(vcpu); } -- 2.30.2