diff options
Diffstat (limited to 'include/qemu/mmap-alloc.h')
-rw-r--r-- | include/qemu/mmap-alloc.h | 60 |
1 files changed, 56 insertions, 4 deletions
diff --git a/include/qemu/mmap-alloc.h b/include/qemu/mmap-alloc.h index 50385e3f81..8344daaa03 100644 --- a/include/qemu/mmap-alloc.h +++ b/include/qemu/mmap-alloc.h @@ -1,14 +1,66 @@ #ifndef QEMU_MMAP_ALLOC_H #define QEMU_MMAP_ALLOC_H -#include "qemu-common.h" +typedef enum { + QEMU_FS_TYPE_UNKNOWN = 0, + QEMU_FS_TYPE_TMPFS, + QEMU_FS_TYPE_HUGETLBFS, + QEMU_FS_TYPE_NUM, +} QemuFsType; size_t qemu_fd_getpagesize(int fd); +QemuFsType qemu_fd_getfs(int fd); -size_t qemu_mempath_getpagesize(const char *mem_path); +/** + * qemu_ram_mmap: mmap anonymous memory, the specified file or device. + * + * mmap() abstraction to map guest RAM, simplifying flag handling, taking + * care of alignment requirements and installing guard pages. + * + * Parameters: + * @fd: the file or the device to mmap + * @size: the number of bytes to be mmaped + * @align: if not zero, specify the alignment of the starting mapping address; + * otherwise, the alignment in use will be determined by QEMU. + * @qemu_map_flags: QEMU_MAP_* flags + * @map_offset: map starts at offset of map_offset from the start of fd + * + * Internally, MAP_PRIVATE, MAP_ANONYMOUS and MAP_SHARED_VALIDATE are set + * implicitly based on other parameters. + * + * Return: + * On success, return a pointer to the mapped area. + * On failure, return MAP_FAILED. + */ +void *qemu_ram_mmap(int fd, + size_t size, + size_t align, + uint32_t qemu_map_flags, + off_t map_offset); -void *qemu_ram_mmap(int fd, size_t size, size_t align, bool shared); +void qemu_ram_munmap(int fd, void *ptr, size_t size); -void qemu_ram_munmap(void *ptr, size_t size); +/* + * Abstraction of PROT_ and MAP_ flags as passed to mmap(), for example, + * consumed by qemu_ram_mmap(). + */ + +/* Map PROT_READ instead of PROT_READ | PROT_WRITE. */ +#define QEMU_MAP_READONLY (1 << 0) + +/* Use MAP_SHARED instead of MAP_PRIVATE. */ +#define QEMU_MAP_SHARED (1 << 1) + +/* + * Use MAP_SYNC | MAP_SHARED_VALIDATE if supported. Ignored without + * QEMU_MAP_SHARED. If mapping fails, warn and fallback to !QEMU_MAP_SYNC. + */ +#define QEMU_MAP_SYNC (1 << 2) + +/* + * Use MAP_NORESERVE to skip reservation of swap space (or huge pages if + * applicable). Bail out if not supported/effective. + */ +#define QEMU_MAP_NORESERVE (1 << 3) #endif |