diff mbox

[RFC,08/17] kvm: arm/arm64: implement kvm_arm_[halt,resume]_guest

Message ID 1435843047-6327-9-git-send-email-eric.auger@linaro.org (mailing list archive)
State New, archived
Headers show

Commit Message

Eric Auger July 2, 2015, 1:17 p.m. UTC
On halt, the guest is forced to exit and prevented from being
re-entered. This is synchronous.

Those two operations will be needed for IRQ forwarding setting.

Signed-off-by: Eric Auger <eric.auger@linaro.org>

---

RFC:
- rename the function and this latter becomes static
- remove __KVM_HAVE_ARCH_HALT_GUEST

v4 -> v5: add arm64 support
- also defines __KVM_HAVE_ARCH_HALT_GUEST for arm64
- add pause field
---
 arch/arm/include/asm/kvm_host.h   |  3 +++
 arch/arm/kvm/arm.c                | 32 +++++++++++++++++++++++++++++---
 arch/arm64/include/asm/kvm_host.h |  3 +++
 3 files changed, 35 insertions(+), 3 deletions(-)

Comments

Eric Auger July 3, 2015, 11:55 a.m. UTC | #1
Christoffer, Marc,
On 07/02/2015 03:17 PM, Eric Auger wrote:
> On halt, the guest is forced to exit and prevented from being
> re-entered. This is synchronous.
> 
> Those two operations will be needed for IRQ forwarding setting.
> 
> Signed-off-by: Eric Auger <eric.auger@linaro.org>
would you agree to handle this ARM functionality separately from the
forwarding series?

This includes 2 patch files, that one +
https://lkml.org/lkml/2015/7/2/288. This functionality is needed for
forwarding control since when changing the forwarding state we need to
"freeze" the state of the physical/virtual IRQ to undertake proper
actions. Stopping the guest makes sure it won't deactivate the virtual
IRQ while we are doing state change actions.

The forwarding series is quite heterogeneous (VFIO platform driver,
vgic, irq bypass manager) and I think it would simplify the review process.

Please let me know if you agree. If yes, I will post a separate series.

Best Regards

Eric
> 
> ---
> 
> RFC:
> - rename the function and this latter becomes static
> - remove __KVM_HAVE_ARCH_HALT_GUEST
> 
> v4 -> v5: add arm64 support
> - also defines __KVM_HAVE_ARCH_HALT_GUEST for arm64
> - add pause field
> ---
>  arch/arm/include/asm/kvm_host.h   |  3 +++
>  arch/arm/kvm/arm.c                | 32 +++++++++++++++++++++++++++++---
>  arch/arm64/include/asm/kvm_host.h |  3 +++
>  3 files changed, 35 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
> index 304004d..899ae27 100644
> --- a/arch/arm/include/asm/kvm_host.h
> +++ b/arch/arm/include/asm/kvm_host.h
> @@ -132,6 +132,9 @@ struct kvm_vcpu_arch {
>  	/* vcpu power-off state */
>  	bool power_off;
>  
> +	/* Don't run the guest */
> +	bool pause;
> +
>  	/* IO related fields */
>  	struct kvm_decode mmio_decode;
>  
> diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
> index 7537e68..4be6715 100644
> --- a/arch/arm/kvm/arm.c
> +++ b/arch/arm/kvm/arm.c
> @@ -471,11 +471,36 @@ bool kvm_arch_intc_initialized(struct kvm *kvm)
>  	return vgic_initialized(kvm);
>  }
>  
> +static void kvm_arm_halt_guest(struct kvm *kvm)
> +{
> +	int i;
> +	struct kvm_vcpu *vcpu;
> +
> +	kvm_for_each_vcpu(i, vcpu, kvm)
> +		vcpu->arch.pause = true;
> +	force_vm_exit(cpu_all_mask);
> +}
> +
> +static void kvm_arm_resume_guest(struct kvm *kvm)
> +{
> +	int i;
> +	struct kvm_vcpu *vcpu;
> +
> +	kvm_for_each_vcpu(i, vcpu, kvm) {
> +		wait_queue_head_t *wq = kvm_arch_vcpu_wq(vcpu);
> +
> +		vcpu->arch.pause = false;
> +		wake_up_interruptible(wq);
> +	}
> +}
> +
> +
>  static void vcpu_pause(struct kvm_vcpu *vcpu)
>  {
>  	wait_queue_head_t *wq = kvm_arch_vcpu_wq(vcpu);
>  
> -	wait_event_interruptible(*wq, !vcpu->arch.power_off);
> +	wait_event_interruptible(*wq, ((!vcpu->arch.power_off) &&
> +				       (!vcpu->arch.pause)));
>  }
>  
>  static int kvm_vcpu_initialized(struct kvm_vcpu *vcpu)
> @@ -525,7 +550,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
>  
>  		update_vttbr(vcpu->kvm);
>  
> -		if (vcpu->arch.power_off)
> +		if (vcpu->arch.power_off || vcpu->arch.pause)
>  			vcpu_pause(vcpu);
>  
>  		/*
> @@ -551,7 +576,8 @@ 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.pause) {
>  			local_irq_enable();
>  			preempt_enable();
>  			kvm_vgic_sync_hwstate(vcpu);
> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
> index 009da6b..69e3785 100644
> --- a/arch/arm64/include/asm/kvm_host.h
> +++ b/arch/arm64/include/asm/kvm_host.h
> @@ -125,6 +125,9 @@ struct kvm_vcpu_arch {
>  	/* vcpu power-off state */
>  	bool power_off;
>  
> +	/* Don't run the guest */
> +	bool pause;
> +
>  	/* IO related fields */
>  	struct kvm_decode mmio_decode;
>  
>
Marc Zyngier July 3, 2015, 12:14 p.m. UTC | #2
On 03/07/15 12:55, Eric Auger wrote:
> Christoffer, Marc,
> On 07/02/2015 03:17 PM, Eric Auger wrote:
>> On halt, the guest is forced to exit and prevented from being
>> re-entered. This is synchronous.
>>
>> Those two operations will be needed for IRQ forwarding setting.
>>
>> Signed-off-by: Eric Auger <eric.auger@linaro.org>
> would you agree to handle this ARM functionality separately from the
> forwarding series?
> 
> This includes 2 patch files, that one +
> https://lkml.org/lkml/2015/7/2/288. This functionality is needed for
> forwarding control since when changing the forwarding state we need to
> "freeze" the state of the physical/virtual IRQ to undertake proper
> actions. Stopping the guest makes sure it won't deactivate the virtual
> IRQ while we are doing state change actions.
> 
> The forwarding series is quite heterogeneous (VFIO platform driver,
> vgic, irq bypass manager) and I think it would simplify the review process.
> 
> Please let me know if you agree. If yes, I will post a separate series.

I don't mind, I trust you to do what's best for these series to be
easily reviewed (if that is at all possible).

The only thing is that this patch implements a feature that will
otherwise be unused, so annotating the functions with __maybe_unused
would avoid warnings.

Thanks,

	M.
diff mbox

Patch

diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 304004d..899ae27 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -132,6 +132,9 @@  struct kvm_vcpu_arch {
 	/* vcpu power-off state */
 	bool power_off;
 
+	/* Don't run the guest */
+	bool pause;
+
 	/* IO related fields */
 	struct kvm_decode mmio_decode;
 
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 7537e68..4be6715 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -471,11 +471,36 @@  bool kvm_arch_intc_initialized(struct kvm *kvm)
 	return vgic_initialized(kvm);
 }
 
+static void kvm_arm_halt_guest(struct kvm *kvm)
+{
+	int i;
+	struct kvm_vcpu *vcpu;
+
+	kvm_for_each_vcpu(i, vcpu, kvm)
+		vcpu->arch.pause = true;
+	force_vm_exit(cpu_all_mask);
+}
+
+static void kvm_arm_resume_guest(struct kvm *kvm)
+{
+	int i;
+	struct kvm_vcpu *vcpu;
+
+	kvm_for_each_vcpu(i, vcpu, kvm) {
+		wait_queue_head_t *wq = kvm_arch_vcpu_wq(vcpu);
+
+		vcpu->arch.pause = false;
+		wake_up_interruptible(wq);
+	}
+}
+
+
 static void vcpu_pause(struct kvm_vcpu *vcpu)
 {
 	wait_queue_head_t *wq = kvm_arch_vcpu_wq(vcpu);
 
-	wait_event_interruptible(*wq, !vcpu->arch.power_off);
+	wait_event_interruptible(*wq, ((!vcpu->arch.power_off) &&
+				       (!vcpu->arch.pause)));
 }
 
 static int kvm_vcpu_initialized(struct kvm_vcpu *vcpu)
@@ -525,7 +550,7 @@  int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 
 		update_vttbr(vcpu->kvm);
 
-		if (vcpu->arch.power_off)
+		if (vcpu->arch.power_off || vcpu->arch.pause)
 			vcpu_pause(vcpu);
 
 		/*
@@ -551,7 +576,8 @@  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.pause) {
 			local_irq_enable();
 			preempt_enable();
 			kvm_vgic_sync_hwstate(vcpu);
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 009da6b..69e3785 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -125,6 +125,9 @@  struct kvm_vcpu_arch {
 	/* vcpu power-off state */
 	bool power_off;
 
+	/* Don't run the guest */
+	bool pause;
+
 	/* IO related fields */
 	struct kvm_decode mmio_decode;