xemu/include/qemu/mmap-alloc.h
Peter Maydell 5b3e34315a include: Move QEMU_MAP_* constants to mmap-alloc.h
The QEMU_MAP_* constants are used only as arguments to the
qemu_ram_mmap() function.  Move them to mmap-alloc.h, where that
function's prototype is defined.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220208200856.3558249-4-peter.maydell@linaro.org
2022-02-21 13:30:20 +00:00

62 lines
1.8 KiB
C

#ifndef QEMU_MMAP_ALLOC_H
#define QEMU_MMAP_ALLOC_H
size_t qemu_fd_getpagesize(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_munmap(int fd, 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