[PATCH kernel v2] KVM: PPC: Use arch_get_random_seed_long instead of powernv variant

[PATCH kernel v2] KVM: PPC: Use arch_get_random_seed_long instead of powernv variant

[Alexey Kardashevskiy]

The powernv_get_random_long() does not work in nested KVM (which is
pseries) and produces a crash when accessing in_be64(rng->regs) in
powernv_get_random_long().

This replaces powernv_get_random_long with the ppc_md machine hook
wrapper.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---

Changes:
v2:
* replaces [PATCH kernel] powerpc/powernv: Check if powernv_rng is initialized

---
 arch/powerpc/kvm/book3s_hv.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index be0cde26f156..ecfd133e0ca8 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -1165,7 +1165,7 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
 		break;
 #endif
 	case H_RANDOM:
-		if (!powernv_get_random_long(&vcpu->arch.regs.gpr[4]))
+		if (!arch_get_random_seed_long(&vcpu->arch.regs.gpr[4]))
 			ret = H_HARDWARE;
 		break;
 	case H_RPT_INVALIDATE:
-- 
2.30.2

Re: [PATCH kernel v2] KVM: PPC: Use arch_get_random_seed_long instead of powernv variant

[Fabiano Rosas]

Alexey Kardashevskiy <aik@ozlabs.ru> writes:

> The powernv_get_random_long() does not work in nested KVM (which is
> pseries) and produces a crash when accessing in_be64(rng->regs) in
> powernv_get_random_long().
>
> This replaces powernv_get_random_long with the ppc_md machine hook
> wrapper.
>
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>

> ---
>
> Changes:
> v2:
> * replaces [PATCH kernel] powerpc/powernv: Check if powernv_rng is initialized
>
> ---
>  arch/powerpc/kvm/book3s_hv.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
> index be0cde26f156..ecfd133e0ca8 100644
> --- a/arch/powerpc/kvm/book3s_hv.c
> +++ b/arch/powerpc/kvm/book3s_hv.c
> @@ -1165,7 +1165,7 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
>  		break;
>  #endif
>  	case H_RANDOM:
> -		if (!powernv_get_random_long(&vcpu->arch.regs.gpr[4]))
> +		if (!arch_get_random_seed_long(&vcpu->arch.regs.gpr[4]))
>  			ret = H_HARDWARE;
>  		break;
>  	case H_RPT_INVALIDATE:

Re: [PATCH kernel v2] KVM: PPC: Use arch_get_random_seed_long instead of powernv variant

[Michael Ellerman]

On Thu, 5 Aug 2021 17:56:49 +1000, Alexey Kardashevskiy wrote:
> The powernv_get_random_long() does not work in nested KVM (which is
> pseries) and produces a crash when accessing in_be64(rng->regs) in
> powernv_get_random_long().
> 
> This replaces powernv_get_random_long with the ppc_md machine hook
> wrapper.

Applied to powerpc/next.

[1/1] KVM: PPC: Use arch_get_random_seed_long instead of powernv variant
      https://git.kernel.org/powerpc/c/2ac78e0c00184a9ba53d507be7549c69a3f566b6

cheers