diff options
Diffstat (limited to 'include/qemu')
| -rw-r--r-- | include/qemu/mmap-alloc.h | 16 | ||||
| -rw-r--r-- | include/qemu/osdep.h | 34 |
2 files changed, 40 insertions, 10 deletions
diff --git a/include/qemu/mmap-alloc.h b/include/qemu/mmap-alloc.h index 456ff87df1..90d0eee705 100644 --- a/include/qemu/mmap-alloc.h +++ b/include/qemu/mmap-alloc.h @@ -7,18 +7,22 @@ size_t qemu_fd_getpagesize(int fd); size_t qemu_mempath_getpagesize(const char *mem_path); /** - * qemu_ram_mmap: mmap the specified file or device. + * 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. - * @readonly: true for a read-only mapping, false for read/write. - * @shared: map has RAM_SHARED flag. - * @is_pmem: map has RAM_PMEM flag. + * @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. @@ -26,9 +30,7 @@ size_t qemu_mempath_getpagesize(const char *mem_path); void *qemu_ram_mmap(int fd, size_t size, size_t align, - bool readonly, - bool shared, - bool is_pmem, + uint32_t qemu_map_flags, off_t map_offset); void qemu_ram_munmap(int fd, void *ptr, size_t size); diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h index 236a045671..0a54bf7be8 100644 --- a/include/qemu/osdep.h +++ b/include/qemu/osdep.h @@ -195,6 +195,9 @@ extern "C" { #ifndef MAP_FIXED_NOREPLACE #define MAP_FIXED_NOREPLACE 0 #endif +#ifndef MAP_NORESERVE +#define MAP_NORESERVE 0 +#endif #ifndef ENOMEDIUM #define ENOMEDIUM ENODEV #endif @@ -362,10 +365,35 @@ extern "C" { int qemu_daemon(int nochdir, int noclose); void *qemu_try_memalign(size_t alignment, size_t size); void *qemu_memalign(size_t alignment, size_t size); -void *qemu_anon_ram_alloc(size_t size, uint64_t *align, bool shared); +void *qemu_anon_ram_alloc(size_t size, uint64_t *align, bool shared, + bool noreserve); void qemu_vfree(void *ptr); void qemu_anon_ram_free(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) + + #define QEMU_MADV_INVALID -1 #if defined(CONFIG_MADVISE) @@ -410,7 +438,7 @@ void qemu_anon_ram_free(void *ptr, size_t size); #ifdef MADV_REMOVE #define QEMU_MADV_REMOVE MADV_REMOVE #else -#define QEMU_MADV_REMOVE QEMU_MADV_INVALID +#define QEMU_MADV_REMOVE QEMU_MADV_DONTNEED #endif #elif defined(CONFIG_POSIX_MADVISE) @@ -424,7 +452,7 @@ void qemu_anon_ram_free(void *ptr, size_t size); #define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID #define QEMU_MADV_HUGEPAGE QEMU_MADV_INVALID #define QEMU_MADV_NOHUGEPAGE QEMU_MADV_INVALID -#define QEMU_MADV_REMOVE QEMU_MADV_INVALID +#define QEMU_MADV_REMOVE QEMU_MADV_DONTNEED #else /* no-op */ |