Re: [Qemu-devel] efi var store migration assert (bdrv_co_do_pwritev: Assertion `!(bs->open_flags & 0x0800)' failed.)

[Paolo Bonzini]

On 01/04/2016 19:58, Dr. David Alan Gilbert wrote:
> In the continuing journeys of trying to migrate a q35 guest with ovmf,
> I've just hit this assert:
> 
> qemu-system-x86_64: /root/git/qemu/block/io.c:1297: bdrv_co_do_pwritev: 
> Assertion `!(bs->open_flags & 0x0800)' failed.
> 
> This is just ahead of rc0 - 1458317c8ada834cf39287f6d11a8cb8a37360d6 from 
> yesterday.

Try this...

Paolo

diff --git a/hw/block/pflash_cfi01.c b/hw/block/pflash_cfi01.c
index c475c2a..e96a7b0 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 +946,24 @@ 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;
 }