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/0013-PVE-virtio-balloon-improve-query-balloon.patch

@@ -14,10 +14,10 @@ Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
  3 files changed, 81 insertions(+), 4 deletions(-)
 
 diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c
-index 163d244eb4..389907f1f8 100644
+index 73ac5eb675..bbfe7eca62 100644
 --- a/hw/virtio/virtio-balloon.c
 +++ b/hw/virtio/virtio-balloon.c
-@@ -813,8 +813,37 @@ static uint64_t virtio_balloon_get_features(VirtIODevice *vdev, uint64_t f,
+@@ -806,8 +806,37 @@ static uint64_t virtio_balloon_get_features(VirtIODevice *vdev, uint64_t f,
  static void virtio_balloon_stat(void *opaque, BalloonInfo *info)
  {
      VirtIOBalloon *dev = opaque;
@@ -58,10 +58,10 @@ index 163d244eb4..389907f1f8 100644
  
  static void virtio_balloon_to_target(void *opaque, ram_addr_t target)
 diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
-index 634968498b..5482dd0569 100644
+index c6cd6f91dd..15572befb1 100644
 --- a/monitor/hmp-cmds.c
 +++ b/monitor/hmp-cmds.c
-@@ -708,7 +708,35 @@ void hmp_info_balloon(Monitor *mon, const QDict *qdict)
+@@ -715,7 +715,35 @@ void hmp_info_balloon(Monitor *mon, const QDict *qdict)
          return;
      }
  
@@ -99,10 +99,10 @@ index 634968498b..5482dd0569 100644
      qapi_free_BalloonInfo(info);
  }
 diff --git a/qapi/machine.json b/qapi/machine.json
-index d25a481ce4..3627172aed 100644
+index 6afd1936b0..8b4be9b718 100644
 --- a/qapi/machine.json
 +++ b/qapi/machine.json
-@@ -1018,10 +1018,30 @@
+@@ -1054,9 +1054,29 @@
  # @actual: the logical size of the VM in bytes
  #          Formula used: logical_vm_size = vm_ram_size - balloon_size
  #
@@ -123,7 +123,6 @@ index d25a481ce4..3627172aed 100644
 +# @max_mem: amount of memory (in bytes) assigned to the guest
 +#
  # Since: 0.14
- #
  ##
 -{ 'struct': 'BalloonInfo', 'data': {'actual': 'int' } }
 +{ 'struct': 'BalloonInfo',