2022-11-17 00:31:50

by Sean Christopherson

Subject: [PATCH 1/2] KVM: arm64: selftests: Disable single-step with correct KVM define

Disable single-step by setting debug.control to KVM_GUESTDBG_ENABLE,
not to SINGLE_STEP_DISABLE. The latter is an arbitrary test enum that
just happens to have the same value as KVM_GUESTDBG_ENABLE, and so
effectively disables single-step debug.

No functional change intended.

Cc: Reiji Watanabe <[email protected]>
Fixes: b18e4d4aebdd ("KVM: arm64: selftests: Add a test case for KVM_GUESTDBG_SINGLESTEP")
Signed-off-by: Sean Christopherson <[email protected]>
---
tools/testing/selftests/kvm/aarch64/debug-exceptions.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/kvm/aarch64/debug-exceptions.c b/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
index 947bd201435c..91f55b45dfc7 100644
--- a/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
+++ b/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
@@ -369,7 +369,7 @@ void test_single_step_from_userspace(int test_cnt)
KVM_GUESTDBG_SINGLESTEP;
ss_enable = true;
} else {
- debug.control = SINGLE_STEP_DISABLE;
+ debug.control = KVM_GUESTDBG_ENABLE;
ss_enable = false;
}

--
2.38.1.431.g37b22c650d-goog

2022-11-17 01:23:23

by Oliver Upton

Subject: Re: [PATCH 1/2] KVM: arm64: selftests: Disable single-step with correct KVM define

On Thu, Nov 17, 2022 at 12:23:49AM +0000, Sean Christopherson wrote:
> Disable single-step by setting debug.control to KVM_GUESTDBG_ENABLE,
> not to SINGLE_STEP_DISABLE. The latter is an arbitrary test enum that
> just happens to have the same value as KVM_GUESTDBG_ENABLE, and so
> effectively disables single-step debug.
>
> No functional change intended.
>
> Cc: Reiji Watanabe <[email protected]>
> Fixes: b18e4d4aebdd ("KVM: arm64: selftests: Add a test case for KVM_GUESTDBG_SINGLESTEP")
> Signed-off-by: Sean Christopherson <[email protected]>

Reviewed-by: Oliver Upton <[email protected]>

--
Thanks,
Oliver

2022-11-17 04:01:32

by Reiji Watanabe

Subject: Re: [PATCH 1/2] KVM: arm64: selftests: Disable single-step with correct KVM define

On Wed, Nov 16, 2022 at 4:24 PM Sean Christopherson <[email protected]> wrote:
>
> Disable single-step by setting debug.control to KVM_GUESTDBG_ENABLE,
> not to SINGLE_STEP_DISABLE. The latter is an arbitrary test enum that
> just happens to have the same value as KVM_GUESTDBG_ENABLE, and so
> effectively disables single-step debug.
>
> No functional change intended.
>
> Cc: Reiji Watanabe <[email protected]>
> Fixes: b18e4d4aebdd ("KVM: arm64: selftests: Add a test case for KVM_GUESTDBG_SINGLESTEP")
> Signed-off-by: Sean Christopherson <[email protected]>
> ---
> tools/testing/selftests/kvm/aarch64/debug-exceptions.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/kvm/aarch64/debug-exceptions.c b/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
> index 947bd201435c..91f55b45dfc7 100644
> --- a/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
> +++ b/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
> @@ -369,7 +369,7 @@ void test_single_step_from_userspace(int test_cnt)
> KVM_GUESTDBG_SINGLESTEP;
> ss_enable = true;
> } else {
> - debug.control = SINGLE_STEP_DISABLE;
> + debug.control = KVM_GUESTDBG_ENABLE;

Reviewed-by: Reiji Watanabe <[email protected]>

Maybe I originally wanted to set it to 0:)
There is no issue with KVM_GUESTDBG_ENABLE at all,
as KVM_GUESTDBG_SINGLESTEP is cleared with that.

Thank you for fixing this!

Thanks,
Reiji


> ss_enable = false;
> }
>
> --
> 2.38.1.431.g37b22c650d-goog
>