[PATCH v5 03/13] KVM: arm64: Track vCPU power state using MP state values
Reiji Watanabe
reijiw at google.com
Wed Apr 13 22:26:24 PDT 2022
Hi Oliver,
On Sat, Apr 9, 2022 at 11:46 AM Oliver Upton <oupton at google.com> wrote:
>
> 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 at google.com>
> ---
> 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;
Nit: It might be a bit odd that KVM_MP_STATE_STOPPED case only copies
the 'mp_state' field of kvm_mp_state from userspace (that's not a 'copy'
operation though), while KVM_MP_STATE_RUNNABLE case copies entire
kvm_mp_state from user space.
('mp_state' is the only field of kvm_mp_state though)
Reviewed-by: Reiji Watanabe <reijiw at google.com>
Thanks,
Reiji
> 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 cdc0609c1135..f2f45a3cbe86 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));
> --
> 2.35.1.1178.g4f1659d476-goog
>
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