On Mon, Jul 06, 2015 at 02:49:55PM +0200, Eric Auger wrote:
> The kvm_vcpu_arch pause field is renamed into power_off to prepare
> for the introduction of a new pause field.
>
> Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>
>
> v4 -> v5:
> - fix compilation issue on arm64 (add power_off field in kvm_host.h)
> ---
> arch/arm/include/asm/kvm_host.h | 4 ++--
> arch/arm/kvm/arm.c | 10 +++++-----
> arch/arm/kvm/psci.c | 10 +++++-----
> arch/arm64/include/asm/kvm_host.h | 4 ++--
> 4 files changed, 14 insertions(+), 14 deletions(-)
>
> diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
> index e896d2c..304004d 100644
> --- a/arch/arm/include/asm/kvm_host.h
> +++ b/arch/arm/include/asm/kvm_host.h
> @@ -129,8 +129,8 @@ struct kvm_vcpu_arch {
> * here.
> */
>
> - /* Don't run the guest on this vcpu */
> - bool pause;
> + /* vcpu power-off state */
> + bool power_off;
>
> /* IO related fields */
> struct kvm_decode mmio_decode;
> diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
> index bcdf799..7537e68 100644
> --- a/arch/arm/kvm/arm.c
> +++ b/arch/arm/kvm/arm.c
> @@ -475,7 +475,7 @@ static void vcpu_pause(struct kvm_vcpu *vcpu)
> {
> wait_queue_head_t *wq = kvm_arch_vcpu_wq(vcpu);
>
> - wait_event_interruptible(*wq, !vcpu->arch.pause);
> + wait_event_interruptible(*wq, !vcpu->arch.power_off);
would there be any benefit to simply calling kvm_vcpu_block() instead of
vcpu_pause, and rewrite kvm_arch_vcpu_runnable to:
int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
{
▸ return !vcpu->arch.power_off &&
(!!v->arch.irq_lines || kvm_vgic_vcpu_pending_irq(v));
}
Not sure really, certainly the runnable function does not become more
readable.
> }
>
> static int kvm_vcpu_initialized(struct kvm_vcpu *vcpu)
> @@ -525,7 +525,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
>
> update_vttbr(vcpu->kvm);
>
> - if (vcpu->arch.pause)
> + if (vcpu->arch.power_off)
> vcpu_pause(vcpu);
looking back over this code, how does this actually guarantee that we
don't run a powered-off cpu?
vcpu_pause() just does a wait_event_interruptible(), so if we get
scheduled again, we'll just proceed running. Is there any case where we
could get scheduled without signal_pending() being true and therefore
inadvertedly run the vcpu?
if so, we should change the line below like this:
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index bc738d2..98f31e6 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -542,7 +542,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
run->exit_reason = KVM_EXIT_INTR;
}
- if (ret <= 0 || need_new_vmid_gen(vcpu->kvm)) {
+ if (ret <= 0 || need_new_vmid_gen(vcpu->kvm) ||
+ vcpu->arch.power_off) {
local_irq_enable();
preempt_enable();
kvm_timer_sync_hwstate(vcpu);
Sorry for polluting your patch with these questions, I'm otherwise fine
with the rename.
Thanks,
-Christoffer
>
> /*
> @@ -766,12 +766,12 @@ static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu,
> vcpu_reset_hcr(vcpu);
>
> /*
> - * Handle the "start in power-off" case by marking the VCPU as paused.
> + * Handle the "start in power-off" case.
> */
> if (test_bit(KVM_ARM_VCPU_POWER_OFF, vcpu->arch.features))
> - vcpu->arch.pause = true;
> + vcpu->arch.power_off = true;
> else
> - vcpu->arch.pause = false;
> + vcpu->arch.power_off = false;
>
> return 0;
> }
> diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c
> index 4b94b51..134971a 100644
> --- a/arch/arm/kvm/psci.c
> +++ b/arch/arm/kvm/psci.c
> @@ -63,7 +63,7 @@ static unsigned long kvm_psci_vcpu_suspend(struct kvm_vcpu *vcpu)
>
> static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu)
> {
> - vcpu->arch.pause = true;
> + vcpu->arch.power_off = true;
> }
>
> static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
> @@ -87,7 +87,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
> */
> if (!vcpu)
> return PSCI_RET_INVALID_PARAMS;
> - if (!vcpu->arch.pause) {
> + if (!vcpu->arch.power_off) {
> if (kvm_psci_version(source_vcpu) != KVM_ARM_PSCI_0_1)
> return PSCI_RET_ALREADY_ON;
> else
> @@ -115,7 +115,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
> * the general puspose registers are undefined upon CPU_ON.
> */
> *vcpu_reg(vcpu, 0) = context_id;
> - vcpu->arch.pause = false;
> + vcpu->arch.power_off = false;
> smp_mb(); /* Make sure the above is visible */
>
> wq = kvm_arch_vcpu_wq(vcpu);
> @@ -152,7 +152,7 @@ static unsigned long kvm_psci_vcpu_affinity_info(struct kvm_vcpu *vcpu)
> kvm_for_each_vcpu(i, tmp, kvm) {
> mpidr = kvm_vcpu_get_mpidr_aff(tmp);
> if (((mpidr & target_affinity_mask) == target_affinity) &&
> - !tmp->arch.pause) {
> + !tmp->arch.power_off) {
> return PSCI_0_2_AFFINITY_LEVEL_ON;
> }
> }
> @@ -175,7 +175,7 @@ static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type)
> * re-initialized.
> */
> kvm_for_each_vcpu(i, tmp, vcpu->kvm) {
> - tmp->arch.pause = true;
> + tmp->arch.power_off = true;
> kvm_vcpu_kick(tmp);
> }
>
> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
> index 2709db2..009da6b 100644
> --- a/arch/arm64/include/asm/kvm_host.h
> +++ b/arch/arm64/include/asm/kvm_host.h
> @@ -122,8 +122,8 @@ struct kvm_vcpu_arch {
> * here.
> */
>
> - /* Don't run the guest */
> - bool pause;
> + /* vcpu power-off state */
> + bool power_off;
>
> /* IO related fields */
> struct kvm_decode mmio_decode;
> --
> 1.9.1
>
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