b444f5c079
Let's pass flags instead of bools to prepare for passing other flags and update the documentation of qemu_ram_mmap(). Introduce new QEMU_MAP_ flags that abstract the mmap() PROT_ and MAP_ flag handling and simplify it. We expose only flags that are currently supported by qemu_ram_mmap(). Maybe, we'll see qemu_mmap() in the future as well that can implement these flags. Note: We don't use MAP_ flags as some flags (e.g., MAP_SYNC) are only defined for some systems and we want to always be able to identify these flags reliably inside qemu_ram_mmap() -- for example, to properly warn when some future flags are not available or effective on a system. Also, this way we can simplify PROT_ handling as well. Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com> Acked-by: Eduardo Habkost <ehabkost@redhat.com> for memory backend and machine core Signed-off-by: David Hildenbrand <david@redhat.com> Message-Id: <20210510114328.21835-8-david@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
39 lines
1.2 KiB
C
39 lines
1.2 KiB
C
#ifndef QEMU_MMAP_ALLOC_H
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#define QEMU_MMAP_ALLOC_H
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size_t qemu_fd_getpagesize(int fd);
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size_t qemu_mempath_getpagesize(const char *mem_path);
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/**
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* qemu_ram_mmap: mmap anonymous memory, the specified file or device.
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*
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* mmap() abstraction to map guest RAM, simplifying flag handling, taking
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* care of alignment requirements and installing guard pages.
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*
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* Parameters:
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* @fd: the file or the device to mmap
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* @size: the number of bytes to be mmaped
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* @align: if not zero, specify the alignment of the starting mapping address;
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* otherwise, the alignment in use will be determined by QEMU.
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* @qemu_map_flags: QEMU_MAP_* flags
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* @map_offset: map starts at offset of map_offset from the start of fd
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*
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* Internally, MAP_PRIVATE, MAP_ANONYMOUS and MAP_SHARED_VALIDATE are set
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* implicitly based on other parameters.
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*
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* Return:
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* On success, return a pointer to the mapped area.
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* On failure, return MAP_FAILED.
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*/
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void *qemu_ram_mmap(int fd,
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size_t size,
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size_t align,
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uint32_t qemu_map_flags,
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off_t map_offset);
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void qemu_ram_munmap(int fd, void *ptr, size_t size);
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#endif
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