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memory: allow memory_region_find() to run on non-root memory regions

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memory_region_find() is similar to registering a MemoryListener and
checking for the MemoryRegionSections that come from a particular
region.  There is no reason for this to be limited to a root memory
region.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2013-05-07 15:48:28 +02:00
parent 68f3f65b09
commit 73034e9e08
2 changed files with 34 additions and 14 deletions
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28
include/exec/memory.h
View file

@ -718,24 +718,34 @@ void memory_region_set_alias_offset(MemoryRegion *mr,
hwaddr offset);
/**
* memory_region_find: locate a MemoryRegion in an address space
* memory_region_find: translate an address/size relative to a
* MemoryRegion into a #MemoryRegionSection.
*
* Locates the first #MemoryRegion within an address space given by
* @address_space that overlaps the range given by @addr and @size.
* Locates the first #MemoryRegion within @mr that overlaps the range
* given by @addr and @size.
*
* Returns a #MemoryRegionSection that describes a contiguous overlap.
* It will have the following characteristics:
* .@offset_within_address_space >= @addr
* .@offset_within_address_space + .@size <= @addr + @size
* .@size = 0 iff no overlap was found
* .@mr is non-%NULL iff an overlap was found
*
* @address_space: a top-level (i.e. parentless) region that contains
* the region to be found
* @addr: start of the area within @address_space to be searched
* Remember that in the return value the @offset_within_region is
* relative to the returned region (in the .@mr field), not to the
* @mr argument.
*
* Similarly, the .@offset_within_address_space is relative to the
* address space that contains both regions, the passed and the
* returned one. However, in the special case where the @mr argument
* has no parent (and thus is the root of the address space), the
* following will hold:
* .@offset_within_address_space >= @addr
* .@offset_within_address_space + .@size <= @addr + @size
*
* @mr: a MemoryRegion within which @addr is a relative address
* @addr: start of the area within @as to be searched
* @size: size of the area to be searched
*/
MemoryRegionSection memory_region_find(MemoryRegion *address_space,
MemoryRegionSection memory_region_find(MemoryRegion *mr,
hwaddr addr, uint64_t size);
/**

20
memory.c
View file

@ -1451,15 +1451,24 @@ static FlatRange *address_space_lookup(AddressSpace *as, AddrRange addr)
sizeof(FlatRange), cmp_flatrange_addr);
}
MemoryRegionSection memory_region_find(MemoryRegion *address_space,
MemoryRegionSection memory_region_find(MemoryRegion *mr,
hwaddr addr, uint64_t size)
{
AddressSpace *as = memory_region_to_address_space(address_space);
AddrRange range = addrrange_make(int128_make64(addr),
int128_make64(size));
FlatRange *fr = address_space_lookup(as, range);
MemoryRegionSection ret = { .mr = NULL, .size = 0 };
MemoryRegion *root;
AddressSpace *as;
AddrRange range;
FlatRange *fr;
addr += mr->addr;
for (root = mr; root->parent; ) {
root = root->parent;
addr += root->addr;
}
as = memory_region_to_address_space(root);
range = addrrange_make(int128_make64(addr), int128_make64(size));
fr = address_space_lookup(as, range);
if (!fr) {
return ret;
}
@ -1470,6 +1479,7 @@ MemoryRegionSection memory_region_find(MemoryRegion *address_space,
}
ret.mr = fr->mr;
ret.address_space = as;
range = addrrange_intersection(range, fr->addr);
ret.offset_within_region = fr->offset_in_region;
ret.offset_within_region += int128_get64(int128_sub(range.start,