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Re: [Qemu-devel] [PATCH 1/7] target/openrisc: Fixes for memory debugging
From: |
Stafford Horne |
Subject: |
Re: [Qemu-devel] [PATCH 1/7] target/openrisc: Fixes for memory debugging |
Date: |
Tue, 18 Apr 2017 23:18:46 +0900 |
User-agent: |
Mutt/1.8.0 (2017-02-23) |
On Tue, Apr 18, 2017 at 12:47:30AM -0700, Richard Henderson wrote:
> On 04/16/2017 04:23 PM, Stafford Horne wrote:
> > When debugging in gdb you might want to inspect instructions in mapped
> > pages or in exception vectors like 0x800 etc. This was previously not
> > possible in qemu since the *get_phys_page_debug() routine only looked
> > into the data tlb.
> >
> > Change to fall back to look into instruction tlb and plain physical
> > pages.
> >
> > Signed-off-by: Stafford Horne <address@hidden>
>
> Oh the horrors of a software managed TLB.
>
> You might do well to architecturally define an SPR that holds the page table
> base, even if for real hardware that's only used by the software refill to
> load up the address.
>
> That would give qemu the option of performing a real page table walk. This
> would fix this debug hook properly (so that you can examine pages that
> aren't in the TLB at all). It would also optionally allow QEMU to skip the
> software refill, which *significantly* speeds up emulation.
Understood, I guess we would also need a way to represent which paging
model we are using (1 level, 2 level etc)?
> That said,
>
> Reviewed-by: Richard Henderson <address@hidden>
Thanks for the review.
-Stafford
>
> r~
[Qemu-devel] [PATCH 2/7] target/openrisc: add shutdown logic, Stafford Horne, 2017/04/16
- Re: [Qemu-devel] [PATCH 2/7] target/openrisc: add shutdown logic, Richard Henderson, 2017/04/18
- Re: [Qemu-devel] [PATCH 2/7] target/openrisc: add shutdown logic, Stafford Horne, 2017/04/18
- Re: [Qemu-devel] [PATCH 2/7] target/openrisc: add shutdown logic, Stafford Horne, 2017/04/22
- Re: [Qemu-devel] [PATCH 2/7] target/openrisc: add shutdown logic, Richard Henderson, 2017/04/22
- [Qemu-devel] [PATCH RFC] target/openrisc: Support non-busy idle state using PMR SPR, Stafford Horne, 2017/04/23
- Re: [Qemu-devel] [PATCH RFC] target/openrisc: Support non-busy idle state using PMR SPR, Richard Henderson, 2017/04/25
- [Qemu-devel] [PATCH RFC v2] target/openrisc: Support non-busy idle state using PMR SPR, Stafford Horne, 2017/04/25