| Message ID | 20211009021236.4122790-20-seanjc@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: Halt-polling and x86 APICv overhaul | expand |
On 09/10/21 04:12, Sean Christopherson wrote: > diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c > index 7e8396f74010..addd53b6eba6 100644 > --- a/arch/arm64/kvm/arch_timer.c > +++ b/arch/arm64/kvm/arch_timer.c > @@ -649,7 +649,6 @@ void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu) > { > struct arch_timer_cpu *timer = vcpu_timer(vcpu); > struct timer_map map; > - struct rcuwait *wait = kvm_arch_vcpu_get_wait(vcpu); > > if (unlikely(!timer->enabled)) > return; > @@ -672,7 +671,7 @@ void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu) > if (map.emul_ptimer) > soft_timer_cancel(&map.emul_ptimer->hrtimer); > > - if (rcuwait_active(wait)) > + if (kvm_vcpu_is_blocking(vcpu)) > kvm_timer_blocking(vcpu); > > /* So this trick is what you're applying to x86 too instead of using vmx_pre_block, I see. Paolo
On Fri, 2021-10-08 at 19:12 -0700, Sean Christopherson wrote: > Add helpers to wake and query a blocking vCPU. In addition to providing > nice names, the helpers reduce the probability of KVM neglecting to use > kvm_arch_vcpu_get_wait(). > > No functional change intended. > > Signed-off-by: Sean Christopherson <seanjc@google.com> > --- > arch/arm64/kvm/arch_timer.c | 3 +-- > arch/arm64/kvm/arm.c | 2 +- > arch/x86/kvm/lapic.c | 2 +- > include/linux/kvm_host.h | 14 ++++++++++++++ > virt/kvm/async_pf.c | 2 +- > virt/kvm/kvm_main.c | 8 ++------ > 6 files changed, 20 insertions(+), 11 deletions(-) > > diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c > index 7e8396f74010..addd53b6eba6 100644 > --- a/arch/arm64/kvm/arch_timer.c > +++ b/arch/arm64/kvm/arch_timer.c > @@ -649,7 +649,6 @@ void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu) > { > struct arch_timer_cpu *timer = vcpu_timer(vcpu); > struct timer_map map; > - struct rcuwait *wait = kvm_arch_vcpu_get_wait(vcpu); > > if (unlikely(!timer->enabled)) > return; > @@ -672,7 +671,7 @@ void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu) > if (map.emul_ptimer) > soft_timer_cancel(&map.emul_ptimer->hrtimer); > > - if (rcuwait_active(wait)) > + if (kvm_vcpu_is_blocking(vcpu)) > kvm_timer_blocking(vcpu); > > /* > diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c > index 268b1e7bf700..9ff0e85a9f16 100644 > --- a/arch/arm64/kvm/arm.c > +++ b/arch/arm64/kvm/arm.c > @@ -622,7 +622,7 @@ void kvm_arm_resume_guest(struct kvm *kvm) > > kvm_for_each_vcpu(i, vcpu, kvm) { > vcpu->arch.pause = false; > - rcuwait_wake_up(kvm_arch_vcpu_get_wait(vcpu)); > + __kvm_vcpu_wake_up(vcpu); > } > } > > diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c > index 76fb00921203..0cd7ed21b205 100644 > --- a/arch/x86/kvm/lapic.c > +++ b/arch/x86/kvm/lapic.c > @@ -1931,7 +1931,7 @@ void kvm_lapic_expired_hv_timer(struct kvm_vcpu *vcpu) > /* If the preempt notifier has already run, it also called apic_timer_expired */ > if (!apic->lapic_timer.hv_timer_in_use) > goto out; > - WARN_ON(rcuwait_active(&vcpu->wait)); > + WARN_ON(kvm_vcpu_is_blocking(vcpu)); > apic_timer_expired(apic, false); > cancel_hv_timer(apic); > > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h > index bdaa0e70b060..1fa38dc00b87 100644 > --- a/include/linux/kvm_host.h > +++ b/include/linux/kvm_host.h > @@ -1151,6 +1151,20 @@ static inline struct rcuwait *kvm_arch_vcpu_get_wait(struct kvm_vcpu *vcpu) > #endif > } > > +/* > + * Wake a vCPU if necessary, but don't do any stats/metadata updates. Returns > + * true if the vCPU was blocking and was awakened, false otherwise. > + */ > +static inline bool __kvm_vcpu_wake_up(struct kvm_vcpu *vcpu) > +{ > + return !!rcuwait_wake_up(kvm_arch_vcpu_get_wait(vcpu)); > +} > + > +static inline bool kvm_vcpu_is_blocking(struct kvm_vcpu *vcpu) > +{ > + return rcuwait_active(kvm_arch_vcpu_get_wait(vcpu)); > +} > + > #ifdef __KVM_HAVE_ARCH_INTC_INITIALIZED > /* > * returns true if the virtual interrupt controller is initialized and > diff --git a/virt/kvm/async_pf.c b/virt/kvm/async_pf.c > index ccb35c22785e..9bfe1d6f6529 100644 > --- a/virt/kvm/async_pf.c > +++ b/virt/kvm/async_pf.c > @@ -85,7 +85,7 @@ static void async_pf_execute(struct work_struct *work) > > trace_kvm_async_pf_completed(addr, cr2_or_gpa); > > - rcuwait_wake_up(kvm_arch_vcpu_get_wait(vcpu)); > + __kvm_vcpu_wake_up(vcpu); > > mmput(mm); > kvm_put_kvm(vcpu->kvm); > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index 481e8178b43d..c870cae7e776 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -3332,10 +3332,7 @@ EXPORT_SYMBOL_GPL(kvm_vcpu_halt); > > bool kvm_vcpu_wake_up(struct kvm_vcpu *vcpu) > { > - struct rcuwait *waitp; > - > - waitp = kvm_arch_vcpu_get_wait(vcpu); > - if (rcuwait_wake_up(waitp)) { > + if (__kvm_vcpu_wake_up(vcpu)) { > WRITE_ONCE(vcpu->ready, true); > ++vcpu->stat.generic.halt_wakeup; > return true; > @@ -3490,8 +3487,7 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool yield_to_kernel_mode) > continue; > if (vcpu == me) > continue; > - if (rcuwait_active(kvm_arch_vcpu_get_wait(vcpu)) && > - !vcpu_dy_runnable(vcpu)) > + if (kvm_vcpu_is_blocking(vcpu) && !vcpu_dy_runnable(vcpu)) > continue; > if (READ_ONCE(vcpu->preempted) && yield_to_kernel_mode && > !kvm_arch_dy_has_pending_interrupt(vcpu) && Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c index 7e8396f74010..addd53b6eba6 100644 --- a/arch/arm64/kvm/arch_timer.c +++ b/arch/arm64/kvm/arch_timer.c @@ -649,7 +649,6 @@ void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu) { struct arch_timer_cpu *timer = vcpu_timer(vcpu); struct timer_map map; - struct rcuwait *wait = kvm_arch_vcpu_get_wait(vcpu); if (unlikely(!timer->enabled)) return; @@ -672,7 +671,7 @@ void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu) if (map.emul_ptimer) soft_timer_cancel(&map.emul_ptimer->hrtimer); - if (rcuwait_active(wait)) + if (kvm_vcpu_is_blocking(vcpu)) kvm_timer_blocking(vcpu); /* diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 268b1e7bf700..9ff0e85a9f16 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -622,7 +622,7 @@ void kvm_arm_resume_guest(struct kvm *kvm) kvm_for_each_vcpu(i, vcpu, kvm) { vcpu->arch.pause = false; - rcuwait_wake_up(kvm_arch_vcpu_get_wait(vcpu)); + __kvm_vcpu_wake_up(vcpu); } } diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 76fb00921203..0cd7ed21b205 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -1931,7 +1931,7 @@ void kvm_lapic_expired_hv_timer(struct kvm_vcpu *vcpu) /* If the preempt notifier has already run, it also called apic_timer_expired */ if (!apic->lapic_timer.hv_timer_in_use) goto out; - WARN_ON(rcuwait_active(&vcpu->wait)); + WARN_ON(kvm_vcpu_is_blocking(vcpu)); apic_timer_expired(apic, false); cancel_hv_timer(apic); diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index bdaa0e70b060..1fa38dc00b87 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -1151,6 +1151,20 @@ static inline struct rcuwait *kvm_arch_vcpu_get_wait(struct kvm_vcpu *vcpu) #endif } +/* + * Wake a vCPU if necessary, but don't do any stats/metadata updates. Returns + * true if the vCPU was blocking and was awakened, false otherwise. + */ +static inline bool __kvm_vcpu_wake_up(struct kvm_vcpu *vcpu) +{ + return !!rcuwait_wake_up(kvm_arch_vcpu_get_wait(vcpu)); +} + +static inline bool kvm_vcpu_is_blocking(struct kvm_vcpu *vcpu) +{ + return rcuwait_active(kvm_arch_vcpu_get_wait(vcpu)); +} + #ifdef __KVM_HAVE_ARCH_INTC_INITIALIZED /* * returns true if the virtual interrupt controller is initialized and diff --git a/virt/kvm/async_pf.c b/virt/kvm/async_pf.c index ccb35c22785e..9bfe1d6f6529 100644 --- a/virt/kvm/async_pf.c +++ b/virt/kvm/async_pf.c @@ -85,7 +85,7 @@ static void async_pf_execute(struct work_struct *work) trace_kvm_async_pf_completed(addr, cr2_or_gpa); - rcuwait_wake_up(kvm_arch_vcpu_get_wait(vcpu)); + __kvm_vcpu_wake_up(vcpu); mmput(mm); kvm_put_kvm(vcpu->kvm); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 481e8178b43d..c870cae7e776 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -3332,10 +3332,7 @@ EXPORT_SYMBOL_GPL(kvm_vcpu_halt); bool kvm_vcpu_wake_up(struct kvm_vcpu *vcpu) { - struct rcuwait *waitp; - - waitp = kvm_arch_vcpu_get_wait(vcpu); - if (rcuwait_wake_up(waitp)) { + if (__kvm_vcpu_wake_up(vcpu)) { WRITE_ONCE(vcpu->ready, true); ++vcpu->stat.generic.halt_wakeup; return true; @@ -3490,8 +3487,7 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool yield_to_kernel_mode) continue; if (vcpu == me) continue; - if (rcuwait_active(kvm_arch_vcpu_get_wait(vcpu)) && - !vcpu_dy_runnable(vcpu)) + if (kvm_vcpu_is_blocking(vcpu) && !vcpu_dy_runnable(vcpu)) continue; if (READ_ONCE(vcpu->preempted) && yield_to_kernel_mode && !kvm_arch_dy_has_pending_interrupt(vcpu) &&
Add helpers to wake and query a blocking vCPU. In addition to providing nice names, the helpers reduce the probability of KVM neglecting to use kvm_arch_vcpu_get_wait(). No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> --- arch/arm64/kvm/arch_timer.c | 3 +-- arch/arm64/kvm/arm.c | 2 +- arch/x86/kvm/lapic.c | 2 +- include/linux/kvm_host.h | 14 ++++++++++++++ virt/kvm/async_pf.c | 2 +- virt/kvm/kvm_main.c | 8 ++------ 6 files changed, 20 insertions(+), 11 deletions(-)