[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH 03/16] tlb_set_page_with_attrs: Take argument sp
From: |
Edgar E. Iglesias |
Subject: |
Re: [Qemu-devel] [PATCH 03/16] tlb_set_page_with_attrs: Take argument specifying AddressSpace to use |
Date: |
Fri, 6 Nov 2015 14:49:05 +0100 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
On Fri, Nov 06, 2015 at 01:41:54PM +0000, Peter Maydell wrote:
> On 6 November 2015 at 13:27, Edgar E. Iglesias <address@hidden> wrote:
> > On Thu, Nov 05, 2015 at 06:15:45PM +0000, Peter Maydell wrote:
> >> Add an argument to tlb_set_page_with_attrs which allows the target CPU code
> >> to tell the core code which AddressSpace to use.
> >>
> >> The AddressSpace is specified by the index into the array of ASes which
> >> were registered with cpu_address_space_init().
>
> >> --- a/exec.c
> >> +++ b/exec.c
> >> @@ -445,12 +445,13 @@ MemoryRegion *address_space_translate(AddressSpace
> >> *as, hwaddr addr,
> >>
> >> /* Called from RCU critical section */
> >> MemoryRegionSection *
> >> -address_space_translate_for_iotlb(CPUState *cpu, hwaddr addr,
> >> +address_space_translate_for_iotlb(CPUState *cpu, int asidx, hwaddr addr,
> >> hwaddr *xlat, hwaddr *plen)
> >
> > Does it make sense to replace the CPUState argument with an AddressSpace *
> > and have the callers do the cpu->cpu_ases[asidx]?
> > It would be more consistent and eventually maybe eliminate the need for
> > address_space_translate_for_iotlb in favor of calling
> > address_space_translate
> > directly?
>
> We can't accept an arbitrary AddressSpace, it has to be one which is
> embedded in a CPUAddressSpace and which we can thus find the
> memory_dispatch for. So you could pass a CPUAddressSpace*, but not
> an AddressSpace*. But to pass a CPUAddressSpace we would have to
> expose the currently-private-to-exec.c layout of the CPUAddressSpace
> struct. I chose not to do that (and you can see the results elsewhere
> in the patch series, like the function that's basically just "do
> the cs_ases array lookup for me"); there's an argument for making
> the structure more widely available to avoid some of that.
Aha, I see.. Thanks for clarifying.
Cheers,
Edgar
[Qemu-devel] [PATCH 14/16] hw/arm/virt: Wire up memory region to CPUs explicitly, Peter Maydell, 2015/11/05
[Qemu-devel] [PATCH 11/16] memory: Add address_space_init_shareable(), Peter Maydell, 2015/11/05