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kvm/x86: Update SynIC timers on guest entry only

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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 <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Andrey Smetanin 2015-12-28 18:27:24 +03:00 committed by Paolo Bonzini
parent 7be58a6488
commit f3b138c5d8
2 changed files with 25 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

38
arch/x86/kvm/hyperv.c
View File

@ -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 (stimer->config & HV_STIMER_ENABLE)
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) &&
stimer->count)
stimer_start(stimer);
else
stimer_cleanup(stimer);

6
arch/x86/kvm/x86.c
View File

@ -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);
}