[Qemu-ppc] [RFC PATCH 15/17] KVM: PPC64: bookehv: Add support for interrupt handling

[Alexander Graf]

On 04.07.2012, at 17:37, Caraman Mihai Claudiu-B02008 wrote:

>> -----Original Message-----
>> From: kvm-ppc-owner at vger.kernel.org [mailto:kvm-ppc-
>> owner at vger.kernel.org] On Behalf Of Alexander Graf
>> Sent: Wednesday, July 04, 2012 6:14 PM
>> To: Caraman Mihai Claudiu-B02008
>> Cc: kvm-ppc at vger.kernel.org; kvm at vger.kernel.org; linuxppc-
>> dev at lists.ozlabs.org; qemu-ppc at nongnu.org
>> Subject: Re: [Qemu-ppc] [RFC PATCH 15/17] KVM: PPC64: bookehv: Add
>> support for interrupt handling
>> 
>> 
>> On 25.06.2012, at 14:26, Mihai Caraman wrote:
>> 
>>> Add bookehv interrupt handling support for 64-bit hosts. Change common
>> stack
>>> layout to refer PPC_LR_STKOFF kernel constant. Dispatch the 64-bit
>> execution
>>> flow to the existing kvm_handler_common asm macro. Update input
>> register
>>> values documentation.
>>> Only the bolted version of TLB miss exception handlers is supported
>> now.
>>> 
>>> Signed-off-by: Mihai Caraman <mihai.caraman at freescale.com>
>>> ---
>>> arch/powerpc/include/asm/kvm_booke_hv_asm.h |   12 +++-
>>> arch/powerpc/kvm/bookehv_interrupts.S       |  120
>> +++++++++++++++++++++++++--
>>> 2 files changed, 122 insertions(+), 10 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..8be6f87 100644
>>> --- a/arch/powerpc/include/asm/kvm_booke_hv_asm.h
>>> +++ b/arch/powerpc/include/asm/kvm_booke_hv_asm.h
>>> @@ -1,5 +1,5 @@
>>> /*
>>> - * Copyright 2010-2011 Freescale Semiconductor, Inc.
>>> + * Copyright 2010-2012 Freescale Semiconductor, Inc.
>>> *
>>> * This program is free software; you can redistribute it and/or modify
>>> * it under the terms of the GNU General Public License, version 2, as
>>> @@ -17,6 +17,7 @@
>>> * there are no exceptions for which we fall through directly to
>>> * the normal host handler.
>>> *
>>> + * 32-bit host
>>> * Expected inputs (normal exceptions):
>>> *   SCRATCH0 = saved r10
>>> *   r10 = thread struct
>>> @@ -33,6 +34,15 @@
>>> *   *(r8 + GPR9) = saved r9
>>> *   *(r8 + GPR10) = saved r10 (r10 not yet clobbered)
>>> *   *(r8 + GPR11) = saved r11
>>> + *
>>> + * 64-bit host
>>> + * Expected inputs (exception types GEN/DBG/CRIT/MC):
>>> + *  r13 = PACA_POINTER
>>> + *  r10 = saved CR
>>> + *  SPRN_SPRG_##type##_SCRATCH = saved r13
>>> + *  *(r13 + PACA_EX##type + EX_R10) = saved r10
>>> + *  *(r13 + PACA_EX##type + EX_R11) = saved r11
>>> + * Only the bolted version of TLB miss exception handlers is supported
>> now.
>>> */
>>> .macro DO_KVM intno srr1
>>> #ifdef CONFIG_KVM_BOOKE_HV
>>> diff --git a/arch/powerpc/kvm/bookehv_interrupts.S
>> b/arch/powerpc/kvm/bookehv_interrupts.S
>>> index dff8ed4..04097de 100644
>>> --- a/arch/powerpc/kvm/bookehv_interrupts.S
>>> +++ b/arch/powerpc/kvm/bookehv_interrupts.S
>>> @@ -12,10 +12,11 @@
>>> * along with this program; if not, write to the Free Software
>>> * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
>> USA.
>>> *
>>> - * Copyright (C) 2010-2011 Freescale Semiconductor, Inc.
>>> + * Copyright (C) 2010-2012 Freescale Semiconductor, Inc.
>>> *
>>> * Author: Varun Sethi <varun.sethi at freescale.com>
>>> * Author: Scott Wood <scotwood at freescale.com>
>>> + * Author: Mihai Caraman <mihai.caraman at freescale.com>
>>> *
>>> * This file is derived from arch/powerpc/kvm/booke_interrupts.S
>>> */
>>> @@ -30,7 +31,11 @@
>>> #include <asm/bitsperlong.h>
>>> #include <asm/thread_info.h>
>>> 
>>> +#ifdef CONFIG_64BIT
>>> +#include <asm/exception-64e.h>
>>> +#else
>>> #include "../kernel/head_booke.h" /* for THREAD_NORMSAVE() */
>>> +#endif
>>> 
>>> 
>>> +#ifdef CONFIG_64BIT
>>> +/*
>>> + * For input register values, see
>> arch/powerpc/include/asm/kvm_booke_hv_asm.h
>>> + */
>>> +.macro kvm_handler intno scratch, paca_ex, ex_r10, ex_r11, srr0, srr1,
>> flags
>>> + _GLOBAL(kvmppc_handler_\intno\()_\srr1)
>> 
>> Is this code so vastly different from the 32bit variant that they can't
>> be the same with a few simple ifdef's here and there?
> 
> As you can see from input register values things are quite different. I strived
> to keep the code common, the only divergence is in the kvm_handler definitions.

What a shame :(. A lot of it looks very very similar.


Alex