Commit 73034e9e authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

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



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: default avatarPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 68f3f65b

include/exec/memory.h

+19 −9
Original line number Diff line number Diff line
@@ -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);



/**

memory.c

+15 −5
Original line number Diff line number Diff line
@@ -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,