Re: [PATCH 5/5] kvm: Replace vcpu->swait with rcuwait

From: Paolo Bonzini
Date: Sat Apr 25 2020 - 06:24:42 EST


I'm squashing this in to keep the changes compared to the current code minimal,
and queuing the series.

Thanks,

Paolo

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index bbefa2a7f950..feca3118b17f 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -230,10 +230,10 @@ static bool kvmppc_ipi_thread(int cpu)
static void kvmppc_fast_vcpu_kick_hv(struct kvm_vcpu *vcpu)
{
int cpu;
- struct rcuwait *wait;
+ struct rcuwait *waitp;

- wait = kvm_arch_vcpu_get_wait(vcpu);
- if (rcuwait_wake_up(wait))
+ waitp = kvm_arch_vcpu_get_wait(vcpu);
+ if (rcuwait_wake_up(waitp))
++vcpu->stat.halt_wakeup;

cpu = READ_ONCE(vcpu->arch.thread_cpu);
@@ -3814,7 +3814,10 @@ static void kvmppc_vcore_blocked(struct kvmppc_vcore *vc)
}
}

+ prepare_to_rcuwait(&vc->wait);
+ set_current_state(TASK_INTERRUPTIBLE);
if (kvmppc_vcore_check_block(vc)) {
+ finish_rcuwait(&vc->wait);
do_sleep = 0;
/* If we polled, count this as a successful poll */
if (vc->halt_poll_ns)
@@ -3827,8 +3830,8 @@ static void kvmppc_vcore_blocked(struct kvmppc_vcore *vc)
vc->vcore_state = VCORE_SLEEPING;
trace_kvmppc_vcore_blocked(vc, 0);
spin_unlock(&vc->lock);
- rcuwait_wait_event(&vc->wait,
- kvmppc_vcore_check_block(vc), TASK_INTERRUPTIBLE);
+ schedule();
+ finish_rcuwait(&vc->wait);
spin_lock(&vc->lock);
vc->vcore_state = VCORE_INACTIVE;
trace_kvmppc_vcore_blocked(vc, 1);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 7c2d18c12d87..c671de51a753 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2737,10 +2737,10 @@ EXPORT_SYMBOL_GPL(kvm_vcpu_block);

bool kvm_vcpu_wake_up(struct kvm_vcpu *vcpu)
{
- struct rcuwait *wait;
+ struct rcuwait *waitp;

- wait = kvm_arch_vcpu_get_wait(vcpu);
- if (rcuwait_wake_up(wait)) {
+ waitp = kvm_arch_vcpu_get_wait(vcpu);
+ if (rcuwait_wake_up(waitp)) {
WRITE_ONCE(vcpu->ready, true);
++vcpu->stat.halt_wakeup;
return true;