Commit a014ed07 authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

memory: accept mismatching sizes in memory_region_access_valid 



The memory API is able to use smaller/wider accesses than requested,
match that in memory_region_access_valid.  Of course, the accepts
callback is still free to reject those accesses.

Reviewed-by: default avatarRichard Henderson <rth@twiddle.net>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 51644ab7

memory.c

+20 −9
Original line number Diff line number Diff line
@@ -856,24 +856,35 @@ bool memory_region_access_valid(MemoryRegion *mr, 
                                unsigned size,

                                bool is_write)

{

    if (mr->ops->valid.accepts

        && !mr->ops->valid.accepts(mr->opaque, addr, size, is_write)) {

        return false;

    }

    int access_size_min, access_size_max;

    int access_size, i;



    if (!mr->ops->valid.unaligned && (addr & (size - 1))) {

        return false;

    }



    /* Treat zero as compatibility all valid */

    if (!mr->ops->valid.max_access_size) {

    if (!mr->ops->valid.accepts) {

        return true;

    }



    if (size > mr->ops->valid.max_access_size

        || size < mr->ops->valid.min_access_size) {

    access_size_min = mr->ops->valid.min_access_size;

    if (!mr->ops->valid.min_access_size) {

        access_size_min = 1;

    }



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

    if (!mr->ops->valid.max_access_size) {

        access_size_max = 4;

    }



    access_size = MAX(MIN(size, access_size_max), access_size_min);

    for (i = 0; i < size; i += access_size) {

        if (!mr->ops->valid.accepts(mr->opaque, addr + i, access_size,

                                    is_write)) {

            return false;

        }

    }



    return true;

}