Re: [Qemu-devel] [PATCH] TCG: Fix TB invalidation after breakpoint insertion/deletion

[Avi Kivity <avi@redhat.com>]

On 05/24/2012 05:11 PM, Max Filippov wrote:
>>
>> Not in breakpoint_invalidate as the missing offset was compensated
>> before your commit (well, starting with c2f07f81a2 in fact).
> 
> I'd say that compensation that you mention
> 
>     ram_addr = (memory_region_get_ram_addr(section.mr)
>                 + section.offset_within_region) & TARGET_PAGE_MASK;
> this >>>>    ram_addr |= (pc & ~TARGET_PAGE_MASK);
>     tb_invalidate_phys_page_range(ram_addr, ram_addr + 1, 0);
> 
> was removed by f3705d53296d, not by 1e7855a558


Indeed.  Note how the |= cleverly accommodates both truncating and
non-truncating cpu_get_phys_page_debug().

> 
>> But it looks like cpu_get_phys_page_debug was broken for quite a while.
>> Let's fix those archs to return more than page-aligned addresses.
> 
> You mean make them all return full physical address?
> I'd propose to rename the function then as well.
> 

Agree to both.  cpu_translate_virtual_address() or similar would be more
explanatory IMO.

btw, how does the thing work for soft-tlb cpus?  It looks like this
thing should trigger on tlb loads, not when the breakpoint is set.  This
is true for hardware page tables as well, as the mapping can change,
though it's less likely.
-- 
error compiling committee.c: too many arguments to function