Il 06/11/2013 15:37, Gerd Hoffmann ha scritto:
>
>>> - vga ram by default is not aligned in a page number multiple of
>>> 64,
>>>
>>> it could be optimized. Kraxel? It syncs the kvm bitmap at least
>>> 1 a second or so? bitmap is only 2048 pages (16MB by default). We
>>> need to change the ram_addr only
> It is created using memory_region_init_ram(), in vga_common_init().
> Nothing special is done to avoid/force any alignment. Dunno why it
> ends up on a odd page number.
Because some random option ROM is loaded before the RAM region is
created, and thus the ram_addr_t's become misaligned. Keeping the
ram_addr_t's aligned in find_ram_offset is easy:
diff --git a/exec.c b/exec.c
index 79610ce..1b82e81 100644
--- a/exec.c
+++ b/exec.c
@@ -1002,7 +1002,7 @@ static ram_addr_t find_ram_offset(ram_addr_t size)
QTAILQ_FOREACH(block, &ram_list.blocks, next) {
ram_addr_t end, next = RAM_ADDR_MAX;
- end = block->offset + block->length;
+ end = ROUND_UP(block->offset + block->length, TARGET_PAGE_SIZE * 64);
QTAILQ_FOREACH(next_block, &ram_list.blocks, next) {
if (next_block->offset >= end) {
but I'm not sure if we're allowed to change the ram_addr_t's. On one hand they
are not part of guest ABI, on the other hand RDMA migration uses them
in the protocol.
Michael, can you check if RDMA migration works from a QEMU *without*
this patch to one *with*:
diff --git a/exec.c b/exec.c
index 79610ce..21b8b96 100644
--- a/exec.c
+++ b/exec.c
@@ -997,7 +997,7 @@ static ram_addr_t find_ram_offset(ram_addr_t size)
assert(size != 0); /* it would hand out same offset multiple times */
if (QTAILQ_EMPTY(&ram_list.blocks))
- return 0;
+ return TARGET_PAGE_SIZE * 100;
QTAILQ_FOREACH(block, &ram_list.blocks, next) {
ram_addr_t end, next = RAM_ADDR_MAX;
I suspect it doesn't. But perhaps we still have time before RDMA
becomes non-experimental.
Paolo
