[v3,3/3] kvm: arm64: handle single-step of userspace mmio instructions

Message ID 20171116153921.21991-4-alex.bennee@linaro.org
State New
Headers show
Series
  • [v3,1/3] kvm: arm debug: introduce helper for single-step
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Commit Message

Alex Bennée Nov. 16, 2017, 3:39 p.m.
The system state of KVM when using userspace emulation is not complete
until we return into KVM_RUN. To handle mmio related updates we wait
until they have been committed and then schedule our KVM_EXIT_DEBUG.

The kvm_arm_handle_step_debug() helper tells us if we need to return
and sets up the exit_reason for us.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>


---
v2
  - call helper directly from kvm_arch_vcpu_ioctl_run
v3
  - return 0 (ioctl success) instead of 1
---
 virt/kvm/arm/arm.c | 3 +++
 1 file changed, 3 insertions(+)

-- 
2.15.0

Comments

Julien Thierry Nov. 16, 2017, 5:44 p.m. | #1
On 16/11/17 15:39, Alex Bennée wrote:
> The system state of KVM when using userspace emulation is not complete

> until we return into KVM_RUN. To handle mmio related updates we wait

> until they have been committed and then schedule our KVM_EXIT_DEBUG.

> 

> The kvm_arm_handle_step_debug() helper tells us if we need to return

> and sets up the exit_reason for us.

> 

> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

> 


Reviewed-by: Julien Thierry <julien.thierry@arm.com>


> ---

> v2

>    - call helper directly from kvm_arch_vcpu_ioctl_run

> v3

>    - return 0 (ioctl success) instead of 1

> ---

>   virt/kvm/arm/arm.c | 3 +++

>   1 file changed, 3 insertions(+)

> 

> diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c

> index 95cba0799828..b40440defca1 100644

> --- a/virt/kvm/arm/arm.c

> +++ b/virt/kvm/arm/arm.c

> @@ -625,6 +625,9 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)

>   		ret = kvm_handle_mmio_return(vcpu, vcpu->run);

>   		if (ret)

>   			return ret;

> +		if (kvm_arm_handle_step_debug(vcpu, vcpu->run))

> +			return 0;

> +

>   	}

>   

>   	if (run->immediate_exit)

> 


-- 
Julien Thierry

Patch

diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index 95cba0799828..b40440defca1 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -625,6 +625,9 @@  int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 		ret = kvm_handle_mmio_return(vcpu, vcpu->run);
 		if (ret)
 			return ret;
+		if (kvm_arm_handle_step_debug(vcpu, vcpu->run))
+			return 0;
+
 	}
 
 	if (run->immediate_exit)