diff --git a/backends/hostmem-memfd.c b/backends/hostmem-memfd.c index e5626d4330..69b0ae30bb 100644 --- a/backends/hostmem-memfd.c +++ b/backends/hostmem-memfd.c @@ -55,7 +55,7 @@ memfd_backend_memory_alloc(HostMemoryBackend *backend, Error **errp) name = host_memory_backend_get_name(backend); memory_region_init_ram_from_fd(&backend->mr, OBJECT(backend), name, backend->size, - backend->share, fd, errp); + backend->share, fd, 0, errp); g_free(name); } diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c index 0505b52c98..603e992a7f 100644 --- a/hw/misc/ivshmem.c +++ b/hw/misc/ivshmem.c @@ -495,7 +495,8 @@ static void process_msg_shmem(IVShmemState *s, int fd, Error **errp) /* mmap the region and map into the BAR2 */ memory_region_init_ram_from_fd(&s->server_bar2, OBJECT(s), - "ivshmem.bar2", size, true, fd, &local_err); + "ivshmem.bar2", size, true, fd, 0, + &local_err); if (local_err) { error_propagate(errp, local_err); return; diff --git a/include/exec/memory.h b/include/exec/memory.h index ed292767cd..c6fb714e49 100644 --- a/include/exec/memory.h +++ b/include/exec/memory.h @@ -998,6 +998,7 @@ void memory_region_init_ram_from_file(MemoryRegion *mr, * @size: size of the region. * @share: %true if memory must be mmaped with the MAP_SHARED flag * @fd: the fd to mmap. + * @offset: offset within the file referenced by fd * @errp: pointer to Error*, to store an error if it happens. * * Note that this function does not do anything to cause the data in the @@ -1009,6 +1010,7 @@ void memory_region_init_ram_from_fd(MemoryRegion *mr, uint64_t size, bool share, int fd, + ram_addr_t offset, Error **errp); #endif diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h index 40b16609ab..3cb9791df3 100644 --- a/include/exec/ram_addr.h +++ b/include/exec/ram_addr.h @@ -121,8 +121,8 @@ RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr, uint32_t ram_flags, const char *mem_path, bool readonly, Error **errp); RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr, - uint32_t ram_flags, int fd, bool readonly, - Error **errp); + uint32_t ram_flags, int fd, off_t offset, + bool readonly, 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 8b7a5c70f3..456ff87df1 100644 --- a/include/qemu/mmap-alloc.h +++ b/include/qemu/mmap-alloc.h @@ -17,6 +17,7 @@ size_t qemu_mempath_getpagesize(const char *mem_path); * @readonly: true for a read-only mapping, false for read/write. * @shared: map has RAM_SHARED flag. * @is_pmem: map has RAM_PMEM flag. + * @map_offset: map starts at offset of map_offset from the start of fd * * Return: * On success, return a pointer to the mapped area. @@ -27,7 +28,8 @@ void *qemu_ram_mmap(int fd, size_t align, bool readonly, bool shared, - bool is_pmem); + bool is_pmem, + off_t map_offset); void qemu_ram_munmap(int fd, void *ptr, size_t size); diff --git a/softmmu/memory.c b/softmmu/memory.c index 23e8e33001..874a8fccde 100644 --- a/softmmu/memory.c +++ b/softmmu/memory.c @@ -1612,6 +1612,7 @@ void memory_region_init_ram_from_fd(MemoryRegion *mr, uint64_t size, bool share, int fd, + ram_addr_t offset, Error **errp) { Error *err = NULL; @@ -1621,7 +1622,7 @@ 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, false, &err); + fd, offset, false, &err); if (err) { mr->size = int128_zero(); object_unparent(OBJECT(mr)); diff --git a/softmmu/physmem.c b/softmmu/physmem.c index 96efaef97a..19e0aa9836 100644 --- a/softmmu/physmem.c +++ b/softmmu/physmem.c @@ -1543,6 +1543,7 @@ static void *file_ram_alloc(RAMBlock *block, int fd, bool readonly, bool truncate, + off_t offset, Error **errp) { void *area; @@ -1593,7 +1594,8 @@ static void *file_ram_alloc(RAMBlock *block, } area = qemu_ram_mmap(fd, memory, block->mr->align, readonly, - 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"); @@ -2024,8 +2026,8 @@ 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, bool readonly, - Error **errp) + uint32_t ram_flags, int fd, off_t offset, + bool readonly, Error **errp) { RAMBlock *new_block; Error *local_err = NULL; @@ -2079,7 +2081,7 @@ RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr, new_block->max_length = size; new_block->flags = ram_flags; new_block->host = file_ram_alloc(new_block, size, fd, readonly, - !file_size, errp); + !file_size, offset, errp); if (!new_block->host) { g_free(new_block); return NULL; @@ -2110,7 +2112,7 @@ 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, readonly, errp); + block = qemu_ram_alloc_from_fd(size, mr, ram_flags, fd, 0, readonly, errp); if (!block) { if (created) { unlink(mem_path); diff --git a/util/mmap-alloc.c b/util/mmap-alloc.c index 890fda6a35..e6fa8b598b 100644 --- a/util/mmap-alloc.c +++ b/util/mmap-alloc.c @@ -87,7 +87,8 @@ void *qemu_ram_mmap(int fd, size_t align, bool readonly, bool shared, - bool is_pmem) + bool is_pmem, + off_t map_offset) { int prot; int flags; @@ -150,7 +151,8 @@ void *qemu_ram_mmap(int fd, prot = PROT_READ | (readonly ? 0 : PROT_WRITE); - ptr = mmap(guardptr + offset, size, prot, flags | map_sync_flags, fd, 0); + ptr = mmap(guardptr + offset, size, prot, + flags | map_sync_flags, fd, map_offset); if (ptr == MAP_FAILED && map_sync_flags) { if (errno == ENOTSUP) { @@ -174,7 +176,7 @@ void *qemu_ram_mmap(int fd, * if map failed with MAP_SHARED_VALIDATE | MAP_SYNC, * we will remove these flags to handle compatibility. */ - ptr = mmap(guardptr + offset, size, prot, flags, fd, 0); + ptr = mmap(guardptr + offset, size, prot, flags, fd, map_offset); } if (ptr == MAP_FAILED) { diff --git a/util/oslib-posix.c b/util/oslib-posix.c index bf57d3b030..36820fec16 100644 --- a/util/oslib-posix.c +++ b/util/oslib-posix.c @@ -230,7 +230,7 @@ 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, false, shared, false); + void *ptr = qemu_ram_mmap(-1, size, align, false, shared, false, 0); if (ptr == MAP_FAILED) { return NULL;