[PATCH] KVM: PPC: Book3S HV: HFSCR[PREFIX] does not exist

[PATCH] KVM: PPC: Book3S HV: HFSCR[PREFIX] does not exist

[Nicholas Piggin]

This facility is controlled by FSCR only. Reserved bits should not be
set in the HFSCR register (although it's likely harmless as this
position would not be re-used, and the L0 is forgiving here too).

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/reg.h | 1 -
 arch/powerpc/kvm/book3s_hv.c   | 2 +-
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index 2835f6363228..1e14324c5190 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -417,7 +417,6 @@
 #define   FSCR_DSCR	__MASK(FSCR_DSCR_LG)
 #define   FSCR_INTR_CAUSE (ASM_CONST(0xFF) << 56)	/* interrupt cause */
 #define SPRN_HFSCR	0xbe	/* HV=1 Facility Status & Control Register */
-#define   HFSCR_PREFIX	__MASK(FSCR_PREFIX_LG)
 #define   HFSCR_MSGP	__MASK(FSCR_MSGP_LG)
 #define   HFSCR_TAR	__MASK(FSCR_TAR_LG)
 #define   HFSCR_EBB	__MASK(FSCR_EBB_LG)
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 84c89f08ae9a..be8914c3dde9 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -2830,7 +2830,7 @@ static int kvmppc_core_vcpu_create_hv(struct kvm_vcpu *vcpu)
 	 * to trap and then we emulate them.
 	 */
 	vcpu->arch.hfscr = HFSCR_TAR | HFSCR_EBB | HFSCR_PM | HFSCR_BHRB |
-		HFSCR_DSCR | HFSCR_VECVSX | HFSCR_FP | HFSCR_PREFIX;
+		HFSCR_DSCR | HFSCR_VECVSX | HFSCR_FP;
 	if (cpu_has_feature(CPU_FTR_HVMODE)) {
 		vcpu->arch.hfscr &= mfspr(SPRN_HFSCR);
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-- 
2.23.0

Re: [PATCH] KVM: PPC: Book3S HV: HFSCR[PREFIX] does not exist

[Fabiano Rosas]

Nicholas Piggin <npiggin@gmail.com> writes:

> This facility is controlled by FSCR only. Reserved bits should not be
> set in the HFSCR register (although it's likely harmless as this
> position would not be re-used, and the L0 is forgiving here too).
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>

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

> ---
>  arch/powerpc/include/asm/reg.h | 1 -
>  arch/powerpc/kvm/book3s_hv.c   | 2 +-
>  2 files changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
> index 2835f6363228..1e14324c5190 100644
> --- a/arch/powerpc/include/asm/reg.h
> +++ b/arch/powerpc/include/asm/reg.h
> @@ -417,7 +417,6 @@
>  #define   FSCR_DSCR	__MASK(FSCR_DSCR_LG)
>  #define   FSCR_INTR_CAUSE (ASM_CONST(0xFF) << 56)	/* interrupt cause */
>  #define SPRN_HFSCR	0xbe	/* HV=1 Facility Status & Control Register */
> -#define   HFSCR_PREFIX	__MASK(FSCR_PREFIX_LG)
>  #define   HFSCR_MSGP	__MASK(FSCR_MSGP_LG)
>  #define   HFSCR_TAR	__MASK(FSCR_TAR_LG)
>  #define   HFSCR_EBB	__MASK(FSCR_EBB_LG)
> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
> index 84c89f08ae9a..be8914c3dde9 100644
> --- a/arch/powerpc/kvm/book3s_hv.c
> +++ b/arch/powerpc/kvm/book3s_hv.c
> @@ -2830,7 +2830,7 @@ static int kvmppc_core_vcpu_create_hv(struct kvm_vcpu *vcpu)
>  	 * to trap and then we emulate them.
>  	 */
>  	vcpu->arch.hfscr = HFSCR_TAR | HFSCR_EBB | HFSCR_PM | HFSCR_BHRB |
> -		HFSCR_DSCR | HFSCR_VECVSX | HFSCR_FP | HFSCR_PREFIX;
> +		HFSCR_DSCR | HFSCR_VECVSX | HFSCR_FP;
>  	if (cpu_has_feature(CPU_FTR_HVMODE)) {
>  		vcpu->arch.hfscr &= mfspr(SPRN_HFSCR);
>  #ifdef CONFIG_PPC_TRANSACTIONAL_MEM

Re: [PATCH] KVM: PPC: Book3S HV: HFSCR[PREFIX] does not exist

[Michael Ellerman]

On Sat, 22 Jan 2022 20:56:39 +1000, Nicholas Piggin wrote:
> This facility is controlled by FSCR only. Reserved bits should not be
> set in the HFSCR register (although it's likely harmless as this
> position would not be re-used, and the L0 is forgiving here too).
> 
> 

Applied to powerpc/topic/ppc-kvm.

[1/1] KVM: PPC: Book3S HV: HFSCR[PREFIX] does not exist
      https://git.kernel.org/powerpc/c/861604614a94a7aabc111e4a18aaf5d56d270e8a

cheers