[PATCH v6 03/12] KVM: arm64: Track vCPU power state using MP state values

From: Oliver Upton
Date: Tue May 03 2022 - 23:25:13 EST


A subsequent change to KVM will add support for additional power states.
Store the MP state by value rather than keeping track of it as a
boolean.

No functional change intended.

Signed-off-by: Oliver Upton <oupton@xxxxxxxxxx>
Reviewed-by: Reiji Watanabe <reijiw@xxxxxxxxxx>
---
arch/arm64/include/asm/kvm_host.h | 5 +++--
arch/arm64/kvm/arm.c | 22 ++++++++++++----------
arch/arm64/kvm/psci.c | 12 ++++++------
3 files changed, 21 insertions(+), 18 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 490cd7f3a905..f3f93d48e21a 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -365,8 +365,8 @@ struct kvm_vcpu_arch {
u32 mdscr_el1;
} guest_debug_preserved;

- /* vcpu power-off state */
- bool power_off;
+ /* vcpu power state */
+ struct kvm_mp_state mp_state;

/* Don't run the guest (internal implementation need) */
bool pause;
@@ -842,5 +842,6 @@ static inline void kvm_hyp_reserve(void) { }
#endif

void kvm_arm_vcpu_power_off(struct kvm_vcpu *vcpu);
+bool kvm_arm_vcpu_stopped(struct kvm_vcpu *vcpu);

#endif /* __ARM64_KVM_HOST_H__ */
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 28c83c6ddbae..29e107457c4d 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -434,18 +434,20 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)

void kvm_arm_vcpu_power_off(struct kvm_vcpu *vcpu)
{
- vcpu->arch.power_off = true;
+ vcpu->arch.mp_state.mp_state = KVM_MP_STATE_STOPPED;
kvm_make_request(KVM_REQ_SLEEP, vcpu);
kvm_vcpu_kick(vcpu);
}

+bool kvm_arm_vcpu_stopped(struct kvm_vcpu *vcpu)
+{
+ return vcpu->arch.mp_state.mp_state == KVM_MP_STATE_STOPPED;
+}
+
int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
struct kvm_mp_state *mp_state)
{
- if (vcpu->arch.power_off)
- mp_state->mp_state = KVM_MP_STATE_STOPPED;
- else
- mp_state->mp_state = KVM_MP_STATE_RUNNABLE;
+ *mp_state = vcpu->arch.mp_state;

return 0;
}
@@ -457,7 +459,7 @@ int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,

switch (mp_state->mp_state) {
case KVM_MP_STATE_RUNNABLE:
- vcpu->arch.power_off = false;
+ vcpu->arch.mp_state = *mp_state;
break;
case KVM_MP_STATE_STOPPED:
kvm_arm_vcpu_power_off(vcpu);
@@ -480,7 +482,7 @@ int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
{
bool irq_lines = *vcpu_hcr(v) & (HCR_VI | HCR_VF);
return ((irq_lines || kvm_vgic_vcpu_pending_irq(v))
- && !v->arch.power_off && !v->arch.pause);
+ && !kvm_arm_vcpu_stopped(v) && !v->arch.pause);
}

bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu)
@@ -597,10 +599,10 @@ static void vcpu_req_sleep(struct kvm_vcpu *vcpu)
struct rcuwait *wait = kvm_arch_vcpu_get_wait(vcpu);

rcuwait_wait_event(wait,
- (!vcpu->arch.power_off) &&(!vcpu->arch.pause),
+ (!kvm_arm_vcpu_stopped(vcpu)) && (!vcpu->arch.pause),
TASK_INTERRUPTIBLE);

- if (vcpu->arch.power_off || vcpu->arch.pause) {
+ if (kvm_arm_vcpu_stopped(vcpu) || vcpu->arch.pause) {
/* Awaken to handle a signal, request we sleep again later. */
kvm_make_request(KVM_REQ_SLEEP, vcpu);
}
@@ -1126,7 +1128,7 @@ static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu,
if (test_bit(KVM_ARM_VCPU_POWER_OFF, vcpu->arch.features))
kvm_arm_vcpu_power_off(vcpu);
else
- vcpu->arch.power_off = false;
+ vcpu->arch.mp_state.mp_state = KVM_MP_STATE_RUNNABLE;

return 0;
}
diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c
index 9b1f3acae155..2e6f060214a7 100644
--- a/arch/arm64/kvm/psci.c
+++ b/arch/arm64/kvm/psci.c
@@ -76,7 +76,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
*/
if (!vcpu)
return PSCI_RET_INVALID_PARAMS;
- if (!vcpu->arch.power_off) {
+ if (!kvm_arm_vcpu_stopped(vcpu)) {
if (kvm_psci_version(source_vcpu) != KVM_ARM_PSCI_0_1)
return PSCI_RET_ALREADY_ON;
else
@@ -100,12 +100,12 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
kvm_make_request(KVM_REQ_VCPU_RESET, vcpu);

/*
- * Make sure the reset request is observed if the change to
- * power_off is observed.
+ * Make sure the reset request is observed if the RUNNABLE mp_state is
+ * observed.
*/
smp_wmb();

- vcpu->arch.power_off = false;
+ vcpu->arch.mp_state.mp_state = KVM_MP_STATE_RUNNABLE;
kvm_vcpu_wake_up(vcpu);

return PSCI_RET_SUCCESS;
@@ -143,7 +143,7 @@ static unsigned long kvm_psci_vcpu_affinity_info(struct kvm_vcpu *vcpu)
mpidr = kvm_vcpu_get_mpidr_aff(tmp);
if ((mpidr & target_affinity_mask) == target_affinity) {
matching_cpus++;
- if (!tmp->arch.power_off)
+ if (!kvm_arm_vcpu_stopped(tmp))
return PSCI_0_2_AFFINITY_LEVEL_ON;
}
}
@@ -169,7 +169,7 @@ static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type, u64 flags)
* re-initialized.
*/
kvm_for_each_vcpu(i, tmp, vcpu->kvm)
- tmp->arch.power_off = true;
+ tmp->arch.mp_state.mp_state = KVM_MP_STATE_STOPPED;
kvm_make_all_cpus_request(vcpu->kvm, KVM_REQ_SLEEP);

memset(&vcpu->run->system_event, 0, sizeof(vcpu->run->system_event));
--
2.36.0.464.gb9c8b46e94-goog