[Qemu-devel] [PATCH 1/2] ppc: Properly tag the translation cache based on MMU mode

[Qemu-devel] [PATCH 1/2] ppc: Properly tag the translation cache based on MMU mode

[Benjamin Herrenschmidt]

We used to always flush the TLB when changing relocation mode in
MSR:IR and MSR:DR (ie. MMU on/off for Instructions and Data).

We don't anymore since we have split mmu_idx for instruction and data.

However, since we hard code the mmu_idx in the translated code, we
now need to also make sure MSR:IR and MSR:DR are part of the hflags
used to tag translated code, so that we use different translated
code for different MMU settings.

Darwin gets hurt by this problem.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
 target-ppc/helper_regs.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/target-ppc/helper_regs.h b/target-ppc/helper_regs.h
index 12af61c..104b690 100644
--- a/target-ppc/helper_regs.h
+++ b/target-ppc/helper_regs.h
@@ -95,7 +95,7 @@ static inline void hreg_compute_hflags(CPUPPCState *env)
     /* We 'forget' FE0 & FE1: we'll never generate imprecise exceptions */
     hflags_mask = (1 << MSR_VR) | (1 << MSR_AP) | (1 << MSR_SA) |
         (1 << MSR_PR) | (1 << MSR_FP) | (1 << MSR_SE) | (1 << MSR_BE) |
-        (1 << MSR_LE) | (1 << MSR_VSX);
+        (1 << MSR_LE) | (1 << MSR_VSX) | (1 << MSR_IR) | (1 << MSR_DR);
     hflags_mask |= (1ULL << MSR_CM) | (1ULL << MSR_SF) | MSR_HVB;
     hreg_compute_mem_idx(env);
     env->hflags = env->msr & hflags_mask;

Re: [Qemu-devel] [PATCH 1/2] ppc: Properly tag the translation cache based on MMU mode

[Cédric Le Goater]

On 06/06/2016 11:52 AM, Benjamin Herrenschmidt wrote:
> We used to always flush the TLB when changing relocation mode in
> MSR:IR and MSR:DR (ie. MMU on/off for Instructions and Data).
> 
> We don't anymore since we have split mmu_idx for instruction and data.
> 
> However, since we hard code the mmu_idx in the translated code, we
> now need to also make sure MSR:IR and MSR:DR are part of the hflags
> used to tag translated code, so that we use different translated
> code for different MMU settings.
> 
> Darwin gets hurt by this problem.
> 
> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Looks good on G3 and G4 running macosx10.2 and macosx10.4. 

Tested-by: Cédric Le Goater <clg@kaod.org>

> ---
>  target-ppc/helper_regs.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/target-ppc/helper_regs.h b/target-ppc/helper_regs.h
> index 12af61c..104b690 100644
> --- a/target-ppc/helper_regs.h
> +++ b/target-ppc/helper_regs.h
> @@ -95,7 +95,7 @@ static inline void hreg_compute_hflags(CPUPPCState *env)
>      /* We 'forget' FE0 & FE1: we'll never generate imprecise exceptions */
>      hflags_mask = (1 << MSR_VR) | (1 << MSR_AP) | (1 << MSR_SA) |
>          (1 << MSR_PR) | (1 << MSR_FP) | (1 << MSR_SE) | (1 << MSR_BE) |
> -        (1 << MSR_LE) | (1 << MSR_VSX);
> +        (1 << MSR_LE) | (1 << MSR_VSX) | (1 << MSR_IR) | (1 << MSR_DR);
>      hflags_mask |= (1ULL << MSR_CM) | (1ULL << MSR_SF) | MSR_HVB;
>      hreg_compute_mem_idx(env);
>      env->hflags = env->msr & hflags_mask;
> 
> 

Re: [Qemu-devel] [PATCH 1/2] ppc: Properly tag the translation cache based on MMU mode

[Mark Cave-Ayland]

On 06/06/16 10:52, Benjamin Herrenschmidt wrote:

> We used to always flush the TLB when changing relocation mode in
> MSR:IR and MSR:DR (ie. MMU on/off for Instructions and Data).
> 
> We don't anymore since we have split mmu_idx for instruction and data.
> 
> However, since we hard code the mmu_idx in the translated code, we
> now need to also make sure MSR:IR and MSR:DR are part of the hflags
> used to tag translated code, so that we use different translated
> code for different MMU settings.
> 
> Darwin gets hurt by this problem.
> 
> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> ---
>  target-ppc/helper_regs.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/target-ppc/helper_regs.h b/target-ppc/helper_regs.h
> index 12af61c..104b690 100644
> --- a/target-ppc/helper_regs.h
> +++ b/target-ppc/helper_regs.h
> @@ -95,7 +95,7 @@ static inline void hreg_compute_hflags(CPUPPCState *env)
>      /* We 'forget' FE0 & FE1: we'll never generate imprecise exceptions */
>      hflags_mask = (1 << MSR_VR) | (1 << MSR_AP) | (1 << MSR_SA) |
>          (1 << MSR_PR) | (1 << MSR_FP) | (1 << MSR_SE) | (1 << MSR_BE) |
> -        (1 << MSR_LE) | (1 << MSR_VSX);
> +        (1 << MSR_LE) | (1 << MSR_VSX) | (1 << MSR_IR) | (1 << MSR_DR);
>      hflags_mask |= (1ULL << MSR_CM) | (1ULL << MSR_SF) | MSR_HVB;
>      hreg_compute_mem_idx(env);
>      env->hflags = env->msr & hflags_mask;
> 
> 
> 

I've run through my complete set of OpenBIOS boot tests with both this
and patch 2 applied on top of Cédric's recent fixes and I no longer see
any regressions with g3beige/mac99 under TCG:

Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>


ATB,

Mark.

Re: [Qemu-devel] [PATCH 1/2] ppc: Properly tag the translation cache based on MMU mode

[David Gibson]

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On Mon, Jun 06, 2016 at 07:52:44PM +1000, Benjamin Herrenschmidt wrote:
> We used to always flush the TLB when changing relocation mode in
> MSR:IR and MSR:DR (ie. MMU on/off for Instructions and Data).
> 
> We don't anymore since we have split mmu_idx for instruction and data.
> 
> However, since we hard code the mmu_idx in the translated code, we
> now need to also make sure MSR:IR and MSR:DR are part of the hflags
> used to tag translated code, so that we use different translated
> code for different MMU settings.
> 
> Darwin gets hurt by this problem.
> 
> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Bizarrely, patch complained about a malformed diff on this one for
reasons I couldn't figure out.  I recreated manually and applied to
ppc-for-2.7.

> ---
>  target-ppc/helper_regs.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/target-ppc/helper_regs.h b/target-ppc/helper_regs.h
> index 12af61c..104b690 100644
> --- a/target-ppc/helper_regs.h
> +++ b/target-ppc/helper_regs.h
> @@ -95,7 +95,7 @@ static inline void hreg_compute_hflags(CPUPPCState *env)
>      /* We 'forget' FE0 & FE1: we'll never generate imprecise exceptions */
>      hflags_mask = (1 << MSR_VR) | (1 << MSR_AP) | (1 << MSR_SA) |
>          (1 << MSR_PR) | (1 << MSR_FP) | (1 << MSR_SE) | (1 << MSR_BE) |
> -        (1 << MSR_LE) | (1 << MSR_VSX);
> +        (1 << MSR_LE) | (1 << MSR_VSX) | (1 << MSR_IR) | (1 << MSR_DR);
>      hflags_mask |= (1ULL << MSR_CM) | (1ULL << MSR_SF) | MSR_HVB;
>      hreg_compute_mem_idx(env);
>      env->hflags = env->msr & hflags_mask;
> 
> 

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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