Re: [Qemu-devel] [PATCH 09/17] ppc: SPURR & PURR are HV writeable and privileged

[David Gibson]

On Mon, Mar 14, 2016 at 08:37:59PM +0100, Thomas Huth wrote:
> On 14.03.2016 17:56, Cédric Le Goater wrote:
> > From: Benjamin Herrenschmidt 
> > 
> > Those are HV writeable, so we provide a dummy write. We eventually need
> > to provide a better emulation but for now this will get us going.
> > 
> > We also make them non-user readable as per the architecture.
> > 
> > Signed-off-by: Benjamin Herrenschmidt 
> > ---
> >  target-ppc/translate_init.c | 25 +
> >  1 file changed, 17 insertions(+), 8 deletions(-)
> > 
> > diff --git a/target-ppc/translate_init.c b/target-ppc/translate_init.c
> > index 7a399b97bc6f..10f67136b609 100644
> > --- a/target-ppc/translate_init.c
> > +++ b/target-ppc/translate_init.c
> > @@ -293,6 +293,13 @@ static void spr_read_purr (DisasContext *ctx, int 
> > gprn, int sprn)
> >  {
> >  gen_helper_load_purr(cpu_gpr[gprn], cpu_env);
> >  }
> > +
> > +__attribute__ ((unused))
> > +static void spr_write_purr(DisasContext *ctx, int gprn, int sprn)
> > +{
> > +/* Temporary placeholder */
> > +}
> 
> What's the "__attribute__ ((unused))" needed here for? The function is
> referenced below, so it should be "used"?
> Or is this simply about handling the CONFIG_USER_ONLY case? Then I think
> it would be nicer to change the #ifdef in front of it to include
> "!defined(CONFIG_USER_ONLY)", too.

Ah, yes.  I second Thomas' comment.

> 
>  Thomas
> 
> >  #endif
> >  #endif
> >  
> > @@ -7828,14 +7835,16 @@ static void gen_spr_book3s_purr(CPUPPCState *env)
> >  {
> >  #if !defined(CONFIG_USER_ONLY)
> >  /* PURR & SPURR: Hack - treat these as aliases for the TB for now */
> > -spr_register_kvm(env, SPR_PURR,   "PURR",
> > - _read_purr, SPR_NOACCESS,
> > - _read_purr, SPR_NOACCESS,
> > - KVM_REG_PPC_PURR, 0x);
> > -spr_register_kvm(env, SPR_SPURR,   "SPURR",
> > - _read_purr, SPR_NOACCESS,
> > - _read_purr, SPR_NOACCESS,
> > - KVM_REG_PPC_SPURR, 0x);
> > +spr_register_kvm_hv(env, SPR_PURR,   "PURR",
> > +SPR_NOACCESS, SPR_NOACCESS,
> > +_read_purr, SPR_NOACCESS,
> > +_read_purr, _write_purr,
> > +KVM_REG_PPC_PURR, 0x);
> > +spr_register_kvm_hv(env, SPR_SPURR,   "SPURR",
> > +SPR_NOACCESS, SPR_NOACCESS,
> > +_read_purr, SPR_NOACCESS,
> > +_read_purr, _write_purr,
> > +KVM_REG_PPC_SPURR, 0x);
> >  #endif
> >  }
> >  
> > 
> 

-- 
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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Re: [Qemu-devel] [PATCH 09/17] ppc: SPURR & PURR are HV writeable and privileged

[David Gibson]

On Mon, Mar 14, 2016 at 05:56:32PM +0100, Cédric Le Goater wrote:
> From: Benjamin Herrenschmidt 
> 
> Those are HV writeable, so we provide a dummy write. We eventually need
> to provide a better emulation but for now this will get us going.
> 
> We also make them non-user readable as per the architecture.
> 
> Signed-off-by: Benjamin Herrenschmidt 

Reviewed-by: David Gibson 

But expecting it for 2.7, not 2.6.

> ---
>  target-ppc/translate_init.c | 25 +
>  1 file changed, 17 insertions(+), 8 deletions(-)
> 
> diff --git a/target-ppc/translate_init.c b/target-ppc/translate_init.c
> index 7a399b97bc6f..10f67136b609 100644
> --- a/target-ppc/translate_init.c
> +++ b/target-ppc/translate_init.c
> @@ -293,6 +293,13 @@ static void spr_read_purr (DisasContext *ctx, int gprn, 
> int sprn)
>  {
>  gen_helper_load_purr(cpu_gpr[gprn], cpu_env);
>  }
> +
> +__attribute__ ((unused))
> +static void spr_write_purr(DisasContext *ctx, int gprn, int sprn)
> +{
> +/* Temporary placeholder */
> +}
> +
>  #endif
>  #endif
>  
> @@ -7828,14 +7835,16 @@ static void gen_spr_book3s_purr(CPUPPCState *env)
>  {
>  #if !defined(CONFIG_USER_ONLY)
>  /* PURR & SPURR: Hack - treat these as aliases for the TB for now */
> -spr_register_kvm(env, SPR_PURR,   "PURR",
> - _read_purr, SPR_NOACCESS,
> - _read_purr, SPR_NOACCESS,
> - KVM_REG_PPC_PURR, 0x);
> -spr_register_kvm(env, SPR_SPURR,   "SPURR",
> - _read_purr, SPR_NOACCESS,
> - _read_purr, SPR_NOACCESS,
> - KVM_REG_PPC_SPURR, 0x);
> +spr_register_kvm_hv(env, SPR_PURR,   "PURR",
> +SPR_NOACCESS, SPR_NOACCESS,
> +_read_purr, SPR_NOACCESS,
> +_read_purr, _write_purr,
> +KVM_REG_PPC_PURR, 0x);
> +spr_register_kvm_hv(env, SPR_SPURR,   "SPURR",
> +SPR_NOACCESS, SPR_NOACCESS,
> +_read_purr, SPR_NOACCESS,
> +_read_purr, _write_purr,
> +KVM_REG_PPC_SPURR, 0x);
>  #endif
>  }
>  

-- 
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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Re: [Qemu-devel] [PATCH 09/17] ppc: SPURR & PURR are HV writeable and privileged

[Thomas Huth]

On 14.03.2016 17:56, Cédric Le Goater wrote:
> From: Benjamin Herrenschmidt 
> 
> Those are HV writeable, so we provide a dummy write. We eventually need
> to provide a better emulation but for now this will get us going.
> 
> We also make them non-user readable as per the architecture.
> 
> Signed-off-by: Benjamin Herrenschmidt 
> ---
>  target-ppc/translate_init.c | 25 +
>  1 file changed, 17 insertions(+), 8 deletions(-)
> 
> diff --git a/target-ppc/translate_init.c b/target-ppc/translate_init.c
> index 7a399b97bc6f..10f67136b609 100644
> --- a/target-ppc/translate_init.c
> +++ b/target-ppc/translate_init.c
> @@ -293,6 +293,13 @@ static void spr_read_purr (DisasContext *ctx, int gprn, 
> int sprn)
>  {
>  gen_helper_load_purr(cpu_gpr[gprn], cpu_env);
>  }
> +
> +__attribute__ ((unused))
> +static void spr_write_purr(DisasContext *ctx, int gprn, int sprn)
> +{
> +/* Temporary placeholder */
> +}

What's the "__attribute__ ((unused))" needed here for? The function is
referenced below, so it should be "used"?
Or is this simply about handling the CONFIG_USER_ONLY case? Then I think
it would be nicer to change the #ifdef in front of it to include
"!defined(CONFIG_USER_ONLY)", too.

 Thomas

>  #endif
>  #endif
>  
> @@ -7828,14 +7835,16 @@ static void gen_spr_book3s_purr(CPUPPCState *env)
>  {
>  #if !defined(CONFIG_USER_ONLY)
>  /* PURR & SPURR: Hack - treat these as aliases for the TB for now */
> -spr_register_kvm(env, SPR_PURR,   "PURR",
> - _read_purr, SPR_NOACCESS,
> - _read_purr, SPR_NOACCESS,
> - KVM_REG_PPC_PURR, 0x);
> -spr_register_kvm(env, SPR_SPURR,   "SPURR",
> - _read_purr, SPR_NOACCESS,
> - _read_purr, SPR_NOACCESS,
> - KVM_REG_PPC_SPURR, 0x);
> +spr_register_kvm_hv(env, SPR_PURR,   "PURR",
> +SPR_NOACCESS, SPR_NOACCESS,
> +_read_purr, SPR_NOACCESS,
> +_read_purr, _write_purr,
> +KVM_REG_PPC_PURR, 0x);
> +spr_register_kvm_hv(env, SPR_SPURR,   "SPURR",
> +SPR_NOACCESS, SPR_NOACCESS,
> +_read_purr, SPR_NOACCESS,
> +_read_purr, _write_purr,
> +KVM_REG_PPC_SPURR, 0x);
>  #endif
>  }
>  
> 

[Qemu-devel] [PATCH 09/17] ppc: SPURR & PURR are HV writeable and privileged

[Cédric Le Goater]

From: Benjamin Herrenschmidt 

Those are HV writeable, so we provide a dummy write. We eventually need
to provide a better emulation but for now this will get us going.

We also make them non-user readable as per the architecture.

Signed-off-by: Benjamin Herrenschmidt 
---
 target-ppc/translate_init.c | 25 +
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/target-ppc/translate_init.c b/target-ppc/translate_init.c
index 7a399b97bc6f..10f67136b609 100644
--- a/target-ppc/translate_init.c
+++ b/target-ppc/translate_init.c
@@ -293,6 +293,13 @@ static void spr_read_purr (DisasContext *ctx, int gprn, 
int sprn)
 {
 gen_helper_load_purr(cpu_gpr[gprn], cpu_env);
 }
+
+__attribute__ ((unused))
+static void spr_write_purr(DisasContext *ctx, int gprn, int sprn)
+{
+/* Temporary placeholder */
+}
+
 #endif
 #endif
 
@@ -7828,14 +7835,16 @@ static void gen_spr_book3s_purr(CPUPPCState *env)
 {
 #if !defined(CONFIG_USER_ONLY)
 /* PURR & SPURR: Hack - treat these as aliases for the TB for now */
-spr_register_kvm(env, SPR_PURR,   "PURR",
- _read_purr, SPR_NOACCESS,
- _read_purr, SPR_NOACCESS,
- KVM_REG_PPC_PURR, 0x);
-spr_register_kvm(env, SPR_SPURR,   "SPURR",
- _read_purr, SPR_NOACCESS,
- _read_purr, SPR_NOACCESS,
- KVM_REG_PPC_SPURR, 0x);
+spr_register_kvm_hv(env, SPR_PURR,   "PURR",
+SPR_NOACCESS, SPR_NOACCESS,
+_read_purr, SPR_NOACCESS,
+_read_purr, _write_purr,
+KVM_REG_PPC_PURR, 0x);
+spr_register_kvm_hv(env, SPR_SPURR,   "SPURR",
+SPR_NOACCESS, SPR_NOACCESS,
+_read_purr, SPR_NOACCESS,
+_read_purr, _write_purr,
+KVM_REG_PPC_SPURR, 0x);
 #endif
 }
 
-- 
2.1.4