diff options
| author | Alexander Graf <graf@amazon.com> | 2023-04-03 22:14:21 +0000 |
|---|---|---|
| committer | David Hildenbrand <david@redhat.com> | 2023-05-23 16:47:03 +0200 |
| commit | 4b870dc4d0c0895859d34d14ce0272a4bcbccf78 (patch) | |
| tree | 8af35d1db6ba0cd63419627870a0a75aec9bf150 /qapi | |
| parent | 886c0453cbf10eebd42a9ccf89c3e46eb389c357 (diff) | |
hostmem-file: add offset option
Add an option for hostmem-file to start the memory object at an offset
into the target file. This is useful if multiple memory objects reside
inside the same target file, such as a device node.
In particular, it's useful to map guest memory directly into /dev/mem
for experimentation.
To make this work consistently, also fix up all places in QEMU that
expect fd offsets to be 0.
Signed-off-by: Alexander Graf <graf@amazon.com>
Message-Id: <20230403221421.60877-1-graf@amazon.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Peter Xu <peterx@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Diffstat (limited to 'qapi')
| -rw-r--r-- | qapi/qom.json | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/qapi/qom.json b/qapi/qom.json index f61badaba4..7f92ea43e8 100644 --- a/qapi/qom.json +++ b/qapi/qom.json @@ -647,6 +647,10 @@ # selects a default alignment (currently the page size). # (default: 0) # +# @offset: the offset into the target file that the region starts at. You +# can use this option to back multiple regions with a single file. Must +# be a multiple of the page size. (default: 0) (since 8.1) +# # @discard-data: if true, the file contents can be destroyed when QEMU # exits, to avoid unnecessarily flushing data to the backing file. # Note that @discard-data is only an optimization, and QEMU might @@ -668,6 +672,7 @@ { 'struct': 'MemoryBackendFileProperties', 'base': 'MemoryBackendProperties', 'data': { '*align': 'size', + '*offset': 'size', '*discard-data': 'bool', 'mem-path': 'str', '*pmem': { 'type': 'bool', 'if': 'CONFIG_LIBPMEM' }, |