On 4/3/20 12:18 PM, Shameer Kolothum wrote:
> From: David Hildenbrand <david@redhat.com>
>
> Summarizing the issue:
> 1. Memory regions contain ram blocks with a different size, if the
> size is not properly aligned. While memory regions can have an
> unaligned size, ram blocks can't. This is true when creating
> resizable memory region with an unaligned size.
> 2. When resizing a ram block/memory region, the size of the memory
> region is set to the aligned size. The callback is called with
> the aligned size. The unaligned piece is lost.
>
> Because of the above, if ACPI blob length modifications happens
> after the initial virt_acpi_build() call, and the changed blob
> length is within the PAGE size boundary, then the revised size
> is not seen by the firmware on Guest reboot.
>
> Hence make sure callback is called if memory region size is changed,
> irrespective of aligned or not.
>
> Signed-off-by: David Hildenbrand <david@redhat.com>
> [Shameer: added commit log]
> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
> Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
> Please find previous discussion here,
> https://patchwork.kernel.org/patch/11432375/#23216751
> ---
> exec.c | 16 ++++++++++++++--
> 1 file changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/exec.c b/exec.c
> index de9d949902..2874bb5088 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -2074,11 +2074,23 @@ static int memory_try_enable_merging(void *addr, size_t len)
> */
> int qemu_ram_resize(RAMBlock *block, ram_addr_t newsize, Error **errp)
> {
> + const ram_addr_t unaligned_size = newsize;
> +
> assert(block);
>
> newsize = HOST_PAGE_ALIGN(newsize);
>
> if (block->used_length == newsize) {
> + /*
> + * We don't have to resize the ram block (which only knows aligned
> + * sizes), however, we have to notify if the unaligned size changed.
> + */
> + if (unaligned_size != memory_region_size(block->mr)) {
> + memory_region_set_size(block->mr, unaligned_size);
> + if (block->resized) {
> + block->resized(block->idstr, unaligned_size, block->host);
> + }
> + }
> return 0;
> }
>
> @@ -2102,9 +2114,9 @@ int qemu_ram_resize(RAMBlock *block, ram_addr_t newsize, Error **errp)
> block->used_length = newsize;
> cpu_physical_memory_set_dirty_range(block->offset, block->used_length,
> DIRTY_CLIENTS_ALL);
> - memory_region_set_size(block->mr, newsize);
> + memory_region_set_size(block->mr, unaligned_size);
> if (block->resized) {
> - block->resized(block->idstr, newsize, block->host);
> + block->resized(block->idstr, unaligned_size, block->host);
> }
> return 0;
> }
>