From: Jagannathan Raman <jag.ra...@oracle.com>
Allow RAM MemoryRegion to be created from an offset in a file, instead
of allocating at offset of 0 by default. This is needed to synchronize
RAM between QEMU & remote process.
Signed-off-by: Jagannathan Raman <jag.ra...@oracle.com>
Signed-off-by: John G Johnson <john.g.john...@oracle.com>
Signed-off-by: Elena Ufimtseva <elena.ufimts...@oracle.com>
Reviewed-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
---
exec.c | 11 +++++++----
include/exec/ram_addr.h | 2 +-
include/qemu/mmap-alloc.h | 3 ++-
memory.c | 2 +-
util/mmap-alloc.c | 7 ++++---
util/oslib-posix.c | 2 +-
6 files changed, 16 insertions(+), 11 deletions(-)
diff --git a/exec.c b/exec.c
index 2874bb5088..d0ac9545f4 100644
--- a/exec.c
+++ b/exec.c
@@ -1801,6 +1801,7 @@ static void *file_ram_alloc(RAMBlock *block,
ram_addr_t memory,
int fd,
bool truncate,
+ off_t offset,
Error **errp)
{
void *area;
@@ -1851,7 +1852,8 @@ static void *file_ram_alloc(RAMBlock *block,
}
area = qemu_ram_mmap(fd, memory, block->mr->align,
- block->flags & RAM_SHARED, block->flags & RAM_PMEM);
+ block->flags & RAM_SHARED, block->flags & RAM_PMEM,
+ offset);
if (area == MAP_FAILED) {
error_setg_errno(errp, errno,
"unable to map backing store for guest RAM");
@@ -2283,7 +2285,7 @@ static void ram_block_add(RAMBlock *new_block, Error
**errp, bool shared)
#ifdef CONFIG_POSIX
RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr,
uint32_t ram_flags, int fd,
- Error **errp)
+ off_t offset, Error **errp)
{
RAMBlock *new_block;
Error *local_err = NULL;
@@ -2328,7 +2330,8 @@ RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size,
MemoryRegion *mr,
new_block->used_length = size;
new_block->max_length = size;
new_block->flags = ram_flags;
- new_block->host = file_ram_alloc(new_block, size, fd, !file_size, errp);
+ new_block->host = file_ram_alloc(new_block, size, fd, !file_size, offset,
+ errp);
if (!new_block->host) {
g_free(new_block);
return NULL;
@@ -2358,7 +2361,7 @@ RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size,
MemoryRegion *mr,
return NULL;
}
- block = qemu_ram_alloc_from_fd(size, mr, ram_flags, fd, errp);
+ block = qemu_ram_alloc_from_fd(size, mr, ram_flags, fd, 0, errp);
if (!block) {
if (created) {
unlink(mem_path);
diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
index 5e59a3d8d7..1b9f489ff0 100644
--- a/include/exec/ram_addr.h
+++ b/include/exec/ram_addr.h
@@ -121,7 +121,7 @@ RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size,
MemoryRegion *mr,
Error **errp);
RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr,
uint32_t ram_flags, int fd,
- Error **errp);
+ off_t offset, Error **errp);
RAMBlock *qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
MemoryRegion *mr, Error **errp);
diff --git a/include/qemu/mmap-alloc.h b/include/qemu/mmap-alloc.h
index e786266b92..4f579858bc 100644
--- a/include/qemu/mmap-alloc.h
+++ b/include/qemu/mmap-alloc.h
@@ -25,7 +25,8 @@ void *qemu_ram_mmap(int fd,
size_t size,
size_t align,
bool shared,
- bool is_pmem);
+ bool is_pmem,
+ off_t start);
void qemu_ram_munmap(int fd, void *ptr, size_t size);
diff --git a/memory.c b/memory.c
index 601b749906..f5fec476b7 100644
--- a/memory.c
+++ b/memory.c
@@ -1596,7 +1596,7 @@ void memory_region_init_ram_from_fd(MemoryRegion *mr,
mr->destructor = memory_region_destructor_ram;
mr->ram_block = qemu_ram_alloc_from_fd(size, mr,
share ? RAM_SHARED : 0,
- fd, &err);
+ fd, 0, &err);
mr->dirty_log_mask = tcg_enabled() ? (1 << DIRTY_MEMORY_CODE) : 0;
if (err) {
mr->size = int128_zero();
diff --git a/util/mmap-alloc.c b/util/mmap-alloc.c
index 27dcccd8ec..a28f7025f0 100644
--- a/util/mmap-alloc.c
+++ b/util/mmap-alloc.c
@@ -86,7 +86,8 @@ void *qemu_ram_mmap(int fd,
size_t size,
size_t align,
bool shared,
- bool is_pmem)
+ bool is_pmem,
+ off_t start)
{
int flags;
int map_sync_flags = 0;
@@ -147,7 +148,7 @@ void *qemu_ram_mmap(int fd,
offset = QEMU_ALIGN_UP((uintptr_t)guardptr, align) - (uintptr_t)guardptr;
ptr = mmap(guardptr + offset, size, PROT_READ | PROT_WRITE,
- flags | map_sync_flags, fd, 0);
+ flags | map_sync_flags, fd, start);
if (ptr == MAP_FAILED && map_sync_flags) {
if (errno == ENOTSUP) {
@@ -172,7 +173,7 @@ void *qemu_ram_mmap(int fd,
* we will remove these flags to handle compatibility.
*/
ptr = mmap(guardptr + offset, size, PROT_READ | PROT_WRITE,
- flags, fd, 0);
+ flags, fd, start);
}
if (ptr == MAP_FAILED) {
diff --git a/util/oslib-posix.c b/util/oslib-posix.c
index 062236a1ab..4c6b9e90c6 100644
--- a/util/oslib-posix.c
+++ b/util/oslib-posix.c
@@ -209,7 +209,7 @@ void *qemu_memalign(size_t alignment, size_t size)
void *qemu_anon_ram_alloc(size_t size, uint64_t *alignment, bool shared)
{
size_t align = QEMU_VMALLOC_ALIGN;
- void *ptr = qemu_ram_mmap(-1, size, align, shared, false);
+ void *ptr = qemu_ram_mmap(-1, size, align, shared, false, 0);
if (ptr == MAP_FAILED) {
return NULL;
--
2.25.GIT
