update submodule and patches to 7.1.0

Notable changes:
* The only big change is the switch to using a custom QIOChannel for
  savevm-async, because the previously used QEMUFileOps was dropped.

  Changes to the current implementation:

  * Switch to vector based methods as required for an IO channel. For
    short reads the passed-in IO vector is stuffed with zeroes at the
    end, just to be sure.

  * For reading: The documentation in include/io/channel.h states that
    at least one byte should be read, so also error out when whe are
    at the very end instead of returning 0.

  * For reading: Fix off-by-one error when request goes beyond end.

    The wrong code piece was:
    if ((pos + size) > maxlen) {
        size = maxlen - pos - 1;
    }

    Previously, the last byte would not be read. It's actually
    possible to get a snapshot .raw file that has content all the way
    up the final 512 byte (= BDRV_SECTOR_SIZE) boundary without any
    trailing zero bytes (I wrote a script to do it).

    Luckily, it didn't cause a real issue, because qemu_loadvm_state()
    is not interested in the final (i.e. QEMU_VM_VMDESCRIPTION)
    section. The buffer for reading it is simply freed up afterwards
    and the function will assume that it read the whole section, even
    if that's not the case.

  * For writing: Make use of the generated blk_pwritev() wrapper
    instead of manually wrapping the coroutine to simplify and save a
    few lines.

* Adapt to changed interfaces for blk_{pread,pwrite}:
  * a9262f551e ("block: Change blk_{pread,pwrite}() param order")
  * 3b35d4542c ("block: Add a 'flags' param to blk_pread()")
  * bf5b16fa40 ("block: Make blk_{pread,pwrite}() return 0 on success")
  Those changes especially affected the qemu-img dd patches, because
  the context also changed, but also some of our block drivers used
  the functions.

* Drop qemu-common.h include: it got renamed after essentially
  everything was moved to other headers. The only remaining user I
  could find for things dropped from the header between 7.0 and 7.1
  was qemu_get_vm_name() in the iscsi-initiatorname patch, but it
  already includes the header to which the function was moved.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>

debian/patches/pve/0053-Revert-block-rbd-workaround-for-ceph-issue-53784.patch

@@ -1,80 +0,0 @@
-From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
-From: Fabian Ebner <f.ebner@proxmox.com>
-Date: Thu, 23 Jun 2022 14:00:05 +0200
-Subject: [PATCH] Revert "block/rbd: workaround for ceph issue #53784"
-
-This reverts commit fc176116cdea816ceb8dd969080b2b95f58edbc0 in
-preparation to revert 0347a8fd4c3faaedf119be04c197804be40a384b.
-
-Signed-off-by: Fabian Ebner <f.ebner@proxmox.com>
----
- block/rbd.c | 42 ++----------------------------------------
- 1 file changed, 2 insertions(+), 40 deletions(-)
-
-diff --git a/block/rbd.c b/block/rbd.c
-index 0cec24c86d..0a9b97aa5e 100644
---- a/block/rbd.c
-+++ b/block/rbd.c
-@@ -1324,7 +1324,6 @@ static int coroutine_fn qemu_rbd_co_block_status(BlockDriverState *bs,
-     int status, r;
-     RBDDiffIterateReq req = { .offs = offset };
-     uint64_t features, flags;
--    uint64_t head = 0;
- 
-     assert(offset + bytes <= s->image_size);
- 
-@@ -1352,43 +1351,7 @@ static int coroutine_fn qemu_rbd_co_block_status(BlockDriverState *bs,
-         return status;
-     }
- 
--#if LIBRBD_VERSION_CODE < LIBRBD_VERSION(1, 17, 0)
--    /*
--     * librbd had a bug until early 2022 that affected all versions of ceph that
--     * supported fast-diff. This bug results in reporting of incorrect offsets
--     * if the offset parameter to rbd_diff_iterate2 is not object aligned.
--     * Work around this bug by rounding down the offset to object boundaries.
--     * This is OK because we call rbd_diff_iterate2 with whole_object = true.
--     * However, this workaround only works for non cloned images with default
--     * striping.
--     *
--     * See: https://tracker.ceph.com/issues/53784
--     */
--
--    /* check if RBD image has non-default striping enabled */
--    if (features & RBD_FEATURE_STRIPINGV2) {
--        return status;
--    }
--
--#pragma GCC diagnostic push
--#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
--    /*
--     * check if RBD image is a clone (= has a parent).
--     *
--     * rbd_get_parent_info is deprecated from Nautilus onwards, but the
--     * replacement rbd_get_parent is not present in Luminous and Mimic.
--     */
--    if (rbd_get_parent_info(s->image, NULL, 0, NULL, 0, NULL, 0) != -ENOENT) {
--        return status;
--    }
--#pragma GCC diagnostic pop
--
--    head = req.offs & (s->object_size - 1);
--    req.offs -= head;
--    bytes += head;
--#endif
--
--    r = rbd_diff_iterate2(s->image, NULL, req.offs, bytes, true, true,
-+    r = rbd_diff_iterate2(s->image, NULL, offset, bytes, true, true,
-                           qemu_rbd_diff_iterate_cb, &req);
-     if (r < 0 && r != QEMU_RBD_EXIT_DIFF_ITERATE2) {
-         return status;
-@@ -1407,8 +1370,7 @@ static int coroutine_fn qemu_rbd_co_block_status(BlockDriverState *bs,
-         status = BDRV_BLOCK_ZERO | BDRV_BLOCK_OFFSET_VALID;
-     }
- 
--    assert(req.bytes > head);
--    *pnum = req.bytes - head;
-+    *pnum = req.bytes;
-     return status;
- }
-