2021-09-01 21:16:33

by Raghavendra Rao Ananta

Subject: [PATCH v3 03/12] KVM: arm64: selftests: Add support for cpu_relax

Implement the guest helper routine, cpu_relax(), to yield
the processor to other tasks.

The function was derived from
arch/arm64/include/asm/vdso/processor.h.

Signed-off-by: Raghavendra Rao Ananta <[email protected]>
---
tools/testing/selftests/kvm/include/aarch64/processor.h | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/tools/testing/selftests/kvm/include/aarch64/processor.h b/tools/testing/selftests/kvm/include/aarch64/processor.h
index 082cc97ad8d3..78df059dc974 100644
--- a/tools/testing/selftests/kvm/include/aarch64/processor.h
+++ b/tools/testing/selftests/kvm/include/aarch64/processor.h
@@ -191,6 +191,11 @@ asm(
val; \
})

+static inline void cpu_relax(void)
+{
+ asm volatile("yield" ::: "memory");
+}
+
#define isb() asm volatile("isb" : : : "memory")
#define dsb(opt) asm volatile("dsb " #opt : : : "memory")
#define dmb(opt) asm volatile("dmb " #opt : : : "memory")
--
2.33.0.153.gba50c8fa24-goog

2021-09-01 22:46:51

by Oliver Upton

Subject: Re: [PATCH v3 03/12] KVM: arm64: selftests: Add support for cpu_relax

On Wed, Sep 01, 2021 at 09:14:03PM +0000, Raghavendra Rao Ananta wrote:
> Implement the guest helper routine, cpu_relax(), to yield
> the processor to other tasks.
>
> The function was derived from
> arch/arm64/include/asm/vdso/processor.h.
>
> Signed-off-by: Raghavendra Rao Ananta <[email protected]>

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

> ---
> tools/testing/selftests/kvm/include/aarch64/processor.h | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/tools/testing/selftests/kvm/include/aarch64/processor.h b/tools/testing/selftests/kvm/include/aarch64/processor.h
> index 082cc97ad8d3..78df059dc974 100644
> --- a/tools/testing/selftests/kvm/include/aarch64/processor.h
> +++ b/tools/testing/selftests/kvm/include/aarch64/processor.h
> @@ -191,6 +191,11 @@ asm(
> val; \
> })
>
> +static inline void cpu_relax(void)
> +{
> + asm volatile("yield" ::: "memory");
> +}
> +
> #define isb() asm volatile("isb" : : : "memory")
> #define dsb(opt) asm volatile("dsb " #opt : : : "memory")
> #define dmb(opt) asm volatile("dmb " #opt : : : "memory")
> --
> 2.33.0.153.gba50c8fa24-goog
>

2021-09-01 22:47:50

by Oliver Upton

Subject: Re: [PATCH v3 03/12] KVM: arm64: selftests: Add support for cpu_relax

On Wed, Sep 01, 2021 at 09:14:03PM +0000, Raghavendra Rao Ananta wrote:
> Implement the guest helper routine, cpu_relax(), to yield
> the processor to other tasks.
>
> The function was derived from
> arch/arm64/include/asm/vdso/processor.h.
>
> Signed-off-by: Raghavendra Rao Ananta <[email protected]>

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

> ---
> tools/testing/selftests/kvm/include/aarch64/processor.h | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/tools/testing/selftests/kvm/include/aarch64/processor.h b/tools/testing/selftests/kvm/include/aarch64/processor.h
> index 082cc97ad8d3..78df059dc974 100644
> --- a/tools/testing/selftests/kvm/include/aarch64/processor.h
> +++ b/tools/testing/selftests/kvm/include/aarch64/processor.h
> @@ -191,6 +191,11 @@ asm(
> val; \
> })
>
> +static inline void cpu_relax(void)
> +{
> + asm volatile("yield" ::: "memory");
> +}
> +
> #define isb() asm volatile("isb" : : : "memory")
> #define dsb(opt) asm volatile("dsb " #opt : : : "memory")
> #define dmb(opt) asm volatile("dmb " #opt : : : "memory")
> --
> 2.33.0.153.gba50c8fa24-goog
>

2021-09-02 13:54:36

by Andrew Jones

Subject: Re: [PATCH v3 03/12] KVM: arm64: selftests: Add support for cpu_relax

On Wed, Sep 01, 2021 at 09:14:03PM +0000, Raghavendra Rao Ananta wrote:
> Implement the guest helper routine, cpu_relax(), to yield
> the processor to other tasks.
>
> The function was derived from
> arch/arm64/include/asm/vdso/processor.h.
>
> Signed-off-by: Raghavendra Rao Ananta <[email protected]>
> ---
> tools/testing/selftests/kvm/include/aarch64/processor.h | 5 +++++
> 1 file changed, 5 insertions(+)
>

Reviewed-by: Andrew Jones <[email protected]>