Commit 047be4ed authored by Stefan Hajnoczi's avatar Stefan Hajnoczi Committed by Peter Maydell
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memory: add memory_region_flush_rom_device() 



ROM devices go via MemoryRegionOps->write() callbacks for write
operations and do not dirty/invalidate that memory.  Device emulation
must be able to mark memory ranges that have been modified internally
(e.g. using memory_region_get_ram_ptr()).

Introduce the memory_region_flush_rom_device() API for this purpose.

Signed-off-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190123212234.32068-2-stefanha@redhat.com
Reviewed-by: default avatarPeter Maydell <peter.maydell@linaro.org>
[PMM: fix block comment style]
Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
parent bf8d0969

exec.c

+13 −0
Original line number Diff line number Diff line
@@ -3162,6 +3162,19 @@ static void invalidate_and_set_dirty(MemoryRegion *mr, hwaddr addr, 
    cpu_physical_memory_set_dirty_range(addr, length, dirty_log_mask);

}



void memory_region_flush_rom_device(MemoryRegion *mr, hwaddr addr, hwaddr size)

{

    /*

     * In principle this function would work on other memory region types too,

     * but the ROM device use case is the only one where this operation is

     * necessary.  Other memory regions should use the

     * address_space_read/write() APIs.

     */

    assert(memory_region_is_romd(mr));



    invalidate_and_set_dirty(mr, addr, size);

}



static int memory_access_size(MemoryRegion *mr, unsigned l, hwaddr addr)

{

    unsigned access_size_max = mr->ops->valid.max_access_size;

include/exec/memory.h

+18 −0
Original line number Diff line number Diff line
@@ -1344,6 +1344,24 @@ bool memory_region_snapshot_get_dirty(MemoryRegion *mr, 
void memory_region_reset_dirty(MemoryRegion *mr, hwaddr addr,

                               hwaddr size, unsigned client);



/**

 * memory_region_flush_rom_device: Mark a range of pages dirty and invalidate

 *                                 TBs (for self-modifying code).

 *

 * The MemoryRegionOps->write() callback of a ROM device must use this function

 * to mark byte ranges that have been modified internally, such as by directly

 * accessing the memory returned by memory_region_get_ram_ptr().

 *

 * This function marks the range dirty and invalidates TBs so that TCG can

 * detect self-modifying code.

 *

 * @mr: the region being flushed.

 * @addr: the start, relative to the start of the region, of the range being

 *        flushed.

 * @size: the size, in bytes, of the range being flushed.

 */

void memory_region_flush_rom_device(MemoryRegion *mr, hwaddr addr, hwaddr size);



/**

 * memory_region_set_readonly: Turn a memory region read-only (or read-write)

 *