On 04/15/16 13:41, Dr. David Alan Gilbert (git) wrote:
> From: "Dr. David Alan Gilbert" <dgilb...@redhat.com>
>
> Pflash migration (e.g. q35 + EFI variable storage) fails
> with the assert:
>
> bdrv_co_do_pwritev: Assertion `!(bs->open_flags & 0x0800)' failed.
>
> This avoids the problem by delaying the pflash update until after
> the device loads complete.
>
> Tested by:
> Migrating Q35/EFI vm.
> Changing efi variable content (with efiboot in the guest)
> md5sum'ing the variable file before migration and after.
>
> This is a fix that Paolo posted in the message
> 570244b3.4070...@redhat.com
>
> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
> Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
> ---
> hw/block/pflash_cfi01.c | 18 ++++++++++++++++--
> 1 file changed, 16 insertions(+), 2 deletions(-)
>
> diff --git a/hw/block/pflash_cfi01.c b/hw/block/pflash_cfi01.c
> index c475c2a..106a775 100644
> --- a/hw/block/pflash_cfi01.c
> +++ b/hw/block/pflash_cfi01.c
> @@ -46,6 +46,7 @@
> #include "exec/address-spaces.h"
> #include "qemu/host-utils.h"
> #include "hw/sysbus.h"
> +#include "sysemu/sysemu.h"
>
> #define PFLASH_BUG(fmt, ...) \
> do { \
> @@ -97,6 +98,7 @@ struct pflash_t {
> MemoryRegion mem;
> char *name;
> void *storage;
> + VMChangeStateEntry *vmstate;
> };
>
> static int pflash_post_load(void *opaque, int version_id);
> @@ -944,13 +946,25 @@ MemoryRegion *pflash_cfi01_get_memory(pflash_t *fl)
> return &fl->mem;
> }
>
> +static void postload_update_cb(void *opaque, int running, RunState state)
> +{
> + pflash_t *pfl = opaque;
> +
> + /* This is called after bdrv_invalidate_cache_all. */
> + qemu_del_vm_change_state_handler(pfl->vmstate);
> + pfl->vmstate = NULL;
> +
> + DPRINTF("%s: updating bdrv for %s\n", __func__, pfl->name);
> + pflash_update(pfl, 0, pfl->sector_len * pfl->nb_blocs);
> +}
> +
> static int pflash_post_load(void *opaque, int version_id)
> {
> pflash_t *pfl = opaque;
>
> if (!pfl->ro) {
> - DPRINTF("%s: updating bdrv for %s\n", __func__, pfl->name);
> - pflash_update(pfl, 0, pfl->sector_len * pfl->nb_blocs);
> + pfl->vmstate = qemu_add_vm_change_state_handler(postload_update_cb,
> + pfl);
> }
> return 0;
> }
>
I can't offer an in-depth review (I don't know migration internals /
vmstate changes well enough, sorry), but I agree with the fix (and am
thankful for it), and both the patch and the testing look good to me.
Perhaps some assert()s could be added to postload_update_cb(), about
"running" and "state", but I'm not certain.
Acked-by: Laszlo Ersek <ler...@redhat.com>
