[PATCH 1/1] physmem: avoid bounce buffer too small

[Heinrich Schuchardt]

virtqueue_map_desc() is called with values of sz exceeding that may exceed
TARGET_PAGE_SIZE. sz = 0x2800 has been observed.

We only support a single bounce buffer. We have to avoid
virtqueue_map_desc() calling address_space_map() multiple times. Otherwise
we see an error

    qemu: virtio: bogus descriptor or out of resources

Increase the minimum size of the bounce buffer to 0x10000 which matches
the largest value of TARGET_PAGE_SIZE for all architectures.

Signed-off-by: Heinrich Schuchardt <heinrich.schucha...@canonical.com>
---
 roms/edk2         | 2 +-
 roms/seabios-hppa | 2 +-
 system/physmem.c  | 8 ++++++--
 3 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/roms/edk2 b/roms/edk2
index edc6681206..b8a3eec88c 160000
--- a/roms/edk2
+++ b/roms/edk2
@@ -1 +1 @@
-Subproject commit edc6681206c1a8791981a2f911d2fb8b3d2f5768
+Subproject commit b8a3eec88cc74bbfe7fb389d026cc7d1d8a989c8
diff --git a/roms/seabios-hppa b/roms/seabios-hppa
index 03774edaad..e4eac85880 160000
--- a/roms/seabios-hppa
+++ b/roms/seabios-hppa
@@ -1 +1 @@
-Subproject commit 03774edaad3bfae090ac96ca5450353c641637d1
+Subproject commit e4eac85880e8677f96d8b9e94de9f2eec9c0751f
diff --git a/system/physmem.c b/system/physmem.c
index e3ebc19eef..3c82da1c86 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -3151,8 +3151,12 @@ void *address_space_map(AddressSpace *as,
             *plen = 0;
             return NULL;
         }
-        /* Avoid unbounded allocations */
-        l = MIN(l, TARGET_PAGE_SIZE);
+        /*
+         * There is only one bounce buffer. The largest occuring value of
+         * parameter sz of virtqueue_map_desc() must fit into the bounce
+         * buffer.
+         */
+        l = MIN(l, 0x10000);
         bounce.buffer = qemu_memalign(TARGET_PAGE_SIZE, l);
         bounce.addr = addr;
         bounce.len = l;
-- 
2.43.0