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Re: [Qemu-devel] [PATCH 03/14] target-ppc: use separate indices for vari
From: |
Richard Henderson |
Subject: |
Re: [Qemu-devel] [PATCH 03/14] target-ppc: use separate indices for various translation modes |
Date: |
Tue, 16 Sep 2014 15:23:51 -0700 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.1.0 |
On 09/16/2014 11:41 AM, Richard Henderson wrote:
>> In practice, only 3 to 7 are---hence my original attempt at using some
>> kind of FIFO caching:
>>
>> user mode, translation enabled
>> kernel mode, paging disabled
>> kernel mode, paging enabled
>> supervisor mode, paging disabled
>> supervisor mode, paging enabled
>>
>> Plus perhaps kernel and supervisor mode with only data paging enabled.
>>
>> You could lump together the IR!=0, DR!=0 cases, and flush that one TLB
>> index if the IR/DR pair changes with respect to the last time. This
>> would use 6 indices.
>
> I think I would prefer a solution that uses 6 indicies, as will not cause env
> to overflow 64k, and not require that any tcg backends be updated.
... alternately ...
What if instead of having a "mmu_index" for the mmu arrays, we have a pointer
to the "mmu context". This does imply an extra memory load on the fast path,
but probably not an extra instruction.
With this, we can suddenly afford to have a relatively large number of mmu
contexts, with which we could implement address space numbers for relevant
targets.
It is, of course, a much larger change, but perhaps it's of larger benefit.
r~
- [Qemu-devel] [PATCH 04/14] ppc: introduce ppc_get_cr and ppc_set_cr, (continued)
- [Qemu-devel] [PATCH 04/14] ppc: introduce ppc_get_cr and ppc_set_cr, Paolo Bonzini, 2014/09/15
- [Qemu-devel] [PATCH 01/14] ppc: do not look at the MMU index to detect PR/HV mode, Paolo Bonzini, 2014/09/15
- [Qemu-devel] [PATCH 02/14] softmmu: support up to 12 MMU modes, Paolo Bonzini, 2014/09/15
- [Qemu-devel] [PATCH 05/14] ppc: use CRF_* in fpu_helper.c, Paolo Bonzini, 2014/09/15
- [Qemu-devel] [PATCH 03/14] target-ppc: use separate indices for various translation modes, Paolo Bonzini, 2014/09/15
- Re: [Qemu-devel] [PATCH 03/14] target-ppc: use separate indices for various translation modes, Tom Musta, 2014/09/16
- Re: [Qemu-devel] [PATCH 03/14] target-ppc: use separate indices for various translation modes, Richard Henderson, 2014/09/16
- Re: [Qemu-devel] [PATCH 03/14] target-ppc: use separate indices for various translation modes, Paolo Bonzini, 2014/09/16
- Re: [Qemu-devel] [PATCH 03/14] target-ppc: use separate indices for various translation modes, Richard Henderson, 2014/09/16
- Re: [Qemu-devel] [PATCH 03/14] target-ppc: use separate indices for various translation modes,
Richard Henderson <=
- Re: [Qemu-devel] [PATCH 03/14] target-ppc: use separate indices for various translation modes, Paolo Bonzini, 2014/09/17
- Re: [Qemu-devel] [PATCH 03/14] target-ppc: use separate indices for various translation modes, Paolo Bonzini, 2014/09/17
- Re: [Qemu-devel] [PATCH 03/14] target-ppc: use separate indices for various translation modes, Richard Henderson, 2014/09/17
- Re: [Qemu-devel] [PATCH 03/14] target-ppc: use separate indices for various translation modes, Paolo Bonzini, 2014/09/17
- Re: [Qemu-devel] [PATCH 03/14] target-ppc: use separate indices for various translation modes, Richard Henderson, 2014/09/17
- Re: [Qemu-devel] [PATCH 03/14] target-ppc: use separate indices for various translation modes, Peter Maydell, 2014/09/16
- Re: [Qemu-devel] [PATCH 03/14] target-ppc: use separate indices for various translation modes, Richard Henderson, 2014/09/16
[Qemu-devel] [PATCH 06/14] ppc: introduce helpers for mfocrf/mtocrf, Paolo Bonzini, 2014/09/15