* Jagannathan Raman (jag.ra...@oracle.com) wrote:
> 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.
> This will be needed for the following patches.
>
> 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>
This looks reasonable to me, so :
Reviewed-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
but can I suggest you take simple things like this and split them out
into a separate little series; I think people would probably take them
even though the current users have a 0 offset.
Dave
> ---
> 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 c930040..e524185 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -1841,6 +1841,7 @@ static void *file_ram_alloc(RAMBlock *block,
> ram_addr_t memory,
> int fd,
> bool truncate,
> + off_t offset,
> Error **errp)
> {
> Error *err = NULL;
> @@ -1893,7 +1894,8 @@ 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");
> @@ -2322,7 +2324,7 @@ 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;
> @@ -2367,7 +2369,8 @@ 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;
> @@ -2397,7 +2400,7 @@ 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 5e59a3d..1b9f489 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 e786266..4f57985 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 aeaa8dc..131bc6c 100644
> --- a/memory.c
> +++ b/memory.c
> @@ -1595,7 +1595,7 @@ 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 27dcccd..a28f702 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 5a291cc..bd221dd 100644
> --- a/util/oslib-posix.c
> +++ b/util/oslib-posix.c
> @@ -205,7 +205,7 @@ 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;
> --
> 1.8.3.1
>
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
