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 /include/exec | |
| 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 'include/exec')
| -rw-r--r-- | include/exec/memory.h | 2 | ||||
| -rw-r--r-- | include/exec/ram_addr.h | 3 | ||||
| -rw-r--r-- | include/exec/ramblock.h | 1 |
3 files changed, 5 insertions, 1 deletions
diff --git a/include/exec/memory.h b/include/exec/memory.h index 6f24a3dd46..c3661b2276 100644 --- a/include/exec/memory.h +++ b/include/exec/memory.h @@ -1326,6 +1326,7 @@ void memory_region_init_resizeable_ram(MemoryRegion *mr, * @ram_flags: RamBlock flags. Supported flags: RAM_SHARED, RAM_PMEM, * RAM_NORESERVE, * @path: the path in which to allocate the RAM. + * @offset: offset within the file referenced by path * @readonly: true to open @path for reading, false for read/write. * @errp: pointer to Error*, to store an error if it happens. * @@ -1339,6 +1340,7 @@ void memory_region_init_ram_from_file(MemoryRegion *mr, uint64_t align, uint32_t ram_flags, const char *path, + ram_addr_t offset, bool readonly, Error **errp); diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h index f4fb6a2111..90a8269290 100644 --- a/include/exec/ram_addr.h +++ b/include/exec/ram_addr.h @@ -110,6 +110,7 @@ long qemu_maxrampagesize(void); * @ram_flags: RamBlock flags. Supported flags: RAM_SHARED, RAM_PMEM, * RAM_NORESERVE. * @mem_path or @fd: specify the backing file or device + * @offset: Offset into target file * @readonly: true to open @path for reading, false for read/write. * @errp: pointer to Error*, to store an error if it happens * @@ -119,7 +120,7 @@ long qemu_maxrampagesize(void); */ RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr, uint32_t ram_flags, const char *mem_path, - bool readonly, Error **errp); + off_t offset, bool readonly, Error **errp); RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr, uint32_t ram_flags, int fd, off_t offset, bool readonly, Error **errp); diff --git a/include/exec/ramblock.h b/include/exec/ramblock.h index adc03df59c..69c6a53902 100644 --- a/include/exec/ramblock.h +++ b/include/exec/ramblock.h @@ -40,6 +40,7 @@ struct RAMBlock { QLIST_ENTRY(RAMBlock) next; QLIST_HEAD(, RAMBlockNotifier) ramblock_notifiers; int fd; + uint64_t fd_offset; size_t page_size; /* dirty bitmap used during migration */ unsigned long *bmap; |