[PATCH] KVM: PPC: bookehv: Allow duplicate calls of DO_KVM macro

[PATCH] KVM: PPC: bookehv: Allow duplicate calls of DO_KVM macro

[Mihai Caraman]

The current form of DO_KVM macro restricts its use to one call per input
parameter set. This is caused by kvmppc_resume_\intno\()_\srr1 symbol
definition.
Duplicate calls of DO_KVM are required by distinct implementations of
exeption handlers which are delegated at runtime. Use a rare label number
to avoid conflicts with the calling contexts.

Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
---
 arch/powerpc/include/asm/kvm_booke_hv_asm.h |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_booke_hv_asm.h b/arch/powerpc/include/asm/kvm_booke_hv_asm.h
index 30a600f..a37a12a 100644
--- a/arch/powerpc/include/asm/kvm_booke_hv_asm.h
+++ b/arch/powerpc/include/asm/kvm_booke_hv_asm.h
@@ -38,9 +38,9 @@
 #ifdef CONFIG_KVM_BOOKE_HV
 BEGIN_FTR_SECTION
 	mtocrf	0x80, r11	/* check MSR[GS] without clobbering reg */
-	bf	3, kvmppc_resume_\intno\()_\srr1
+	bf	3, 1975f
 	b	kvmppc_handler_\intno\()_\srr1
-kvmppc_resume_\intno\()_\srr1:
+1975:
 END_FTR_SECTION_IFSET(CPU_FTR_EMB_HV)
 #endif
 .endm
-- 
1.7.4.1

Re: [PATCH] KVM: PPC: bookehv: Allow duplicate calls of DO_KVM macro

[Alexander Graf]

On 12.09.2012, at 15:18, Mihai Caraman <mihai.caraman@freescale.com> wrote:

> The current form of DO_KVM macro restricts its use to one call per input
> parameter set. This is caused by kvmppc_resume_\intno\()_\srr1 symbol
> definition.
> Duplicate calls of DO_KVM are required by distinct implementations of
> exeption handlers which are delegated at runtime.

Not sure I understand what you're trying to achieve here. Please elaborate ;=
)

Alex

> Use a rare label number
> to avoid conflicts with the calling contexts.
>=20
> Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
> ---
> arch/powerpc/include/asm/kvm_booke_hv_asm.h |    4 ++--
> 1 files changed, 2 insertions(+), 2 deletions(-)
>=20
> diff --git a/arch/powerpc/include/asm/kvm_booke_hv_asm.h b/arch/powerpc/in=
clude/asm/kvm_booke_hv_asm.h
> index 30a600f..a37a12a 100644
> --- a/arch/powerpc/include/asm/kvm_booke_hv_asm.h
> +++ b/arch/powerpc/include/asm/kvm_booke_hv_asm.h
> @@ -38,9 +38,9 @@
> #ifdef CONFIG_KVM_BOOKE_HV
> BEGIN_FTR_SECTION
>    mtocrf    0x80, r11    /* check MSR[GS] without clobbering reg */
> -    bf    3, kvmppc_resume_\intno\()_\srr1
> +    bf    3, 1975f
>    b    kvmppc_handler_\intno\()_\srr1
> -kvmppc_resume_\intno\()_\srr1:
> +1975:
> END_FTR_SECTION_IFSET(CPU_FTR_EMB_HV)
> #endif
> .endm
> --=20
> 1.7.4.1
>=20
>=20
> --
> To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH] KVM: PPC: bookehv: Allow duplicate calls of DO_KVM macro

[Scott Wood]

On 09/12/2012 01:56 PM, Alexander Graf wrote:
> 
> 
> On 12.09.2012, at 15:18, Mihai Caraman <mihai.caraman@freescale.com> wrote:
> 
>> The current form of DO_KVM macro restricts its use to one call per input
>> parameter set. This is caused by kvmppc_resume_\intno\()_\srr1 symbol
>> definition.
>> Duplicate calls of DO_KVM are required by distinct implementations of
>> exeption handlers which are delegated at runtime.
> 
> Not sure I understand what you're trying to achieve here. Please elaborate ;)

On 64-bit book3e we compile multiple versions of the TLB miss handlers,
and choose from them at runtime.  Without this patch, we get duplicate
label errors if more than one variant of the same exception uses DO_KVM.

-Scott

Re: [PATCH] KVM: PPC: bookehv: Allow duplicate calls of DO_KVM macro

[Alexander Graf]

On 12.09.2012, at 23:38, Scott Wood <scottwood@freescale.com> wrote:

> On 09/12/2012 01:56 PM, Alexander Graf wrote:
>>=20
>>=20
>> On 12.09.2012, at 15:18, Mihai Caraman <mihai.caraman@freescale.com> wrot=
e:
>>=20
>>> The current form of DO_KVM macro restricts its use to one call per input=

>>> parameter set. This is caused by kvmppc_resume_\intno\()_\srr1 symbol
>>> definition.
>>> Duplicate calls of DO_KVM are required by distinct implementations of
>>> exeption handlers which are delegated at runtime.
>>=20
>> Not sure I understand what you're trying to achieve here. Please elaborat=
e ;)
>=20
> On 64-bit book3e we compile multiple versions of the TLB miss handlers,
> and choose from them at runtime. =20

Why?

> Without this patch, we get duplicate
> label errors if more than one variant of the same exception uses DO_KVM.

Makes sense. The proposed solution also looks good. Just quickly walk me thr=
ough the reasoning for the runtime check again please.


Alex

>=20
> -Scott
>=20
>=20
> --
> To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH] KVM: PPC: bookehv: Allow duplicate calls of DO_KVM macro

[Scott Wood]

On 09/12/2012 04:45 PM, Alexander Graf wrote:
> 
> 
> On 12.09.2012, at 23:38, Scott Wood <scottwood@freescale.com> wrote:
> 
>> On 09/12/2012 01:56 PM, Alexander Graf wrote:
>>>
>>>
>>> On 12.09.2012, at 15:18, Mihai Caraman <mihai.caraman@freescale.com> wrote:
>>>
>>>> The current form of DO_KVM macro restricts its use to one call per input
>>>> parameter set. This is caused by kvmppc_resume_\intno\()_\srr1 symbol
>>>> definition.
>>>> Duplicate calls of DO_KVM are required by distinct implementations of
>>>> exeption handlers which are delegated at runtime.
>>>
>>> Not sure I understand what you're trying to achieve here. Please elaborate ;)
>>
>> On 64-bit book3e we compile multiple versions of the TLB miss handlers,
>> and choose from them at runtime.  
> 
> Why?

Because one size does not fit all, and we try to not force a separate
kernel build based on what sort of TLB miss handler a piece of hardware
wants.  Some of the differences are too large to be sanely handled by
feature fixups.

>> Without this patch, we get duplicate
>> label errors if more than one variant of the same exception uses DO_KVM.
> 
> Makes sense. The proposed solution also looks good. Just quickly walk me through the reasoning for the runtime check again please.

To start with, you have a TLB miss handler for when partial hardware
tablewalk is used (only the final page table level is looked up in
hardware, so we still need a TLB miss handler to load indirect entries),
and one where that feature is not available.  Then you have the "bolted"
variant used by e5500, which is faster than the generic version because
it doesn't have to deal with recursive faults.  So far the bolted
version is the only one with DO_KVM.

I posted a patch to add another variant, for e6500-style hardware
tablewalk, which shares the bolted prolog/epilog (besides prolog/epilog
performance, e6500 is incompatible with the IBM tablewalk code for
various reasons).  That caused us to have two DO_KVMs for the same
exception type.

-Scott

RE: [PATCH] KVM: PPC: bookehv: Allow duplicate calls of DO_KVM macro

[Caraman Mihai Claudiu-B02008]
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Re: [PATCH] KVM: PPC: bookehv: Allow duplicate calls of DO_KVM macro

[Alexander Graf]

On 09/12/2012 03:18 PM, Mihai Caraman wrote:
> The current form of DO_KVM macro restricts its use to one call per input
> parameter set. This is caused by kvmppc_resume_\intno\()_\srr1 symbol
> definition.
> Duplicate calls of DO_KVM are required by distinct implementations of
> exeption handlers which are delegated at runtime. Use a rare label number
> to avoid conflicts with the calling contexts.
>
> Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>

Thanks, applied to kvm-ppc-next.


Alex