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@xxxxxxxxxxxxx>
Reviewed-by: Roman Kagan <rkagan@xxxxxxxxxxxxx>
CC: Gleb Natapov <gleb@xxxxxxxxxx>
CC: Paolo Bonzini <pbonzini@xxxxxxxxxx>
CC: Roman Kagan <rkagan@xxxxxxxxxxxxx>
CC: Denis V. Lunev <den@xxxxxxxxxx>
CC: qemu-devel@xxxxxxxxxx
---
arch/x86/kvm/hyperv.c | 35 +++++++++++++++++------------------
arch/x86/kvm/x86.c | 6 ++++++
2 files changed, 23 insertions(+), 18 deletions(-)
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index d7e6651..7857329 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;
}
@@ -460,7 +460,7 @@ 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;
}
@@ -473,30 +473,24 @@ 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;
}
@@ -580,16 +574,21 @@ 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)
stimer_start(stimer);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index b6102c1..795c14c 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6492,6 +6492,12 @@ 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);
}
--
2.4.3
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