exec: Change RAMBlockIterFunc definition

Currently, qemu_ram_foreach_* calls RAMBlockIterFunc with many
block-specific arguments. But often iter func needs RAMBlock*.
This refactoring is needed for fast access to RAMBlock flags from
qemu_ram_foreach_block's callback. The only way to achieve this now
is to call qemu_ram_block_from_host (which also enumerates blocks).

So, this patch reduces complexity of
qemu_ram_foreach_block() -> cb() -> qemu_ram_block_from_host()
from O(n^2) to O(n).

Fix RAMBlockIterFunc definition and add some functions to read
RAMBlock* fields witch were passed.

Signed-off-by: Yury Kotov <yury-kotov@yandex-team.ru>
Message-Id: <20190215174548.2630-2-yury-kotov@yandex-team.ru>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/util/vfio-helpers.c b/util/vfio-helpers.c
index 342d4a2285..2367fe8f7f 100644
--- a/util/vfio-helpers.c
+++ b/util/vfio-helpers.c
@@ -391,10 +391,10 @@ static void qemu_vfio_ram_block_removed(RAMBlockNotifier *n,
     }
 }
 
-static int qemu_vfio_init_ramblock(const char *block_name, void *host_addr,
-                                   ram_addr_t offset, ram_addr_t length,
-                                   void *opaque)
+static int qemu_vfio_init_ramblock(RAMBlock *rb, void *opaque)
 {
+    void *host_addr = qemu_ram_get_host_addr(rb);
+    ram_addr_t length = qemu_ram_get_used_length(rb);
     int ret;
     QEMUVFIOState *s = opaque;