lkml.org 
[lkml]   [2017]   [Oct]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH v1 2/2] kvm: arm64: handle single-step of userspace mmio instructions
From
Date


On 06/10/17 12:39, 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.
>
> I've introduced a new function kvm_arm_maybe_return_debug() to wrap up
> the differences between arm/arm64 which is currently null for arm.
>
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> ---
> arch/arm/include/asm/kvm_host.h | 2 ++
> arch/arm64/include/asm/kvm_host.h | 1 +
> arch/arm64/kvm/debug.c | 21 +++++++++++++++++++++
> arch/arm64/kvm/handle_exit.c | 9 +++------
> virt/kvm/arm/arm.c | 2 +-
> virt/kvm/arm/mmio.c | 3 ++-
> 6 files changed, 30 insertions(+), 8 deletions(-)
>
> diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
> index 4a879f6ff13b..aec943f6d123 100644
> --- a/arch/arm/include/asm/kvm_host.h
> +++ b/arch/arm/include/asm/kvm_host.h
> @@ -285,6 +285,8 @@ static inline void kvm_arm_init_debug(void) {}
> static inline void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) {}
> static inline void kvm_arm_clear_debug(struct kvm_vcpu *vcpu) {}
> static inline void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu) {}
> +static inline int kvm_arm_maybe_return_debug(struct kvm_vcpu *vcpu,
> + struct kvm_run *run) {}
>

This function should return 1.

> int kvm_arm_vcpu_arch_set_attr(struct kvm_vcpu *vcpu,
> struct kvm_device_attr *attr);
> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
> index e923b58606e2..fa67d21662f6 100644
> --- a/arch/arm64/include/asm/kvm_host.h
> +++ b/arch/arm64/include/asm/kvm_host.h
> @@ -369,6 +369,7 @@ void kvm_arm_init_debug(void);
> void kvm_arm_setup_debug(struct kvm_vcpu *vcpu);
> void kvm_arm_clear_debug(struct kvm_vcpu *vcpu);
> void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu);
> +int kvm_arm_maybe_return_debug(struct kvm_vcpu *vcpu, struct kvm_run *run);

I feel the name could be a little bit more explicit:

kvm_arm_trap_need_step_debug, kvm_arm_trap_step_return_debug,
kvm_arm_trap_need_return_debug.

At least, I think it would be nice that the name reflect that this check
is meant for emulated instructions.

Otherwise:

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

Thanks,

--
Julien Thierry

\
 
 \ /
  Last update: 2017-10-06 15:13    [W:0.082 / U:0.336 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site