xemu/include/qemu/mmap-alloc.h

#ifndef QEMU_MMAP_ALLOC
#define QEMU_MMAP_ALLOC

#include "qemu-common.h"

size_t qemu_fd_getpagesize(int fd);

void *qemu_ram_mmap(int fd, size_t size, size_t align, bool shared);

void qemu_ram_munmap(void *ptr, size_t size);

#endif
exec: factor out duplicate mmap code Anonymous and file-backed RAM allocation are now almost exactly the same. Reduce code duplication by moving RAM mmap code out of oslib-posix.c and exec.c. Reported-by: Marc-André Lureau <mlureau@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Tested-by: Thibaut Collet <thibaut.collet@6wind.com> 2015-09-24 11:41:17 +00:00			`#ifndef QEMU_MMAP_ALLOC`
			`#define QEMU_MMAP_ALLOC`

			`#include "qemu-common.h"`

util/mmap-alloc: fix hugetlb support on ppc64 Since commit 8561c9244ddf1122d "exec: allocate PROT_NONE pages on top of RAM", it is no longer possible to back guest RAM with hugepages on ppc64 hosts: mmap(NULL, 285212672, PROT_NONE, MAP_PRIVATE\|MAP_ANONYMOUS, -1, 0) = 0x3fff57000000 mmap(0x3fff57000000, 268435456, PROT_READ\|PROT_WRITE, MAP_PRIVATE\|MAP_FIXED, 19, 0) = -1 EBUSY (Device or resource busy) This is because on ppc64, Linux fixes a page size for a virtual address at mmap time, so we can't switch a range of memory from anonymous small pages to hugetlbs with MAP_FIXED. See commit d0f13e3c20b6fb73ccb467bdca97fa7cf5a574cd ("[POWERPC] Introduce address space "slices"") in Linux history for the details. Detect this and create the PROT_NONE mapping using the same fd. Naturally, this makes the guard page bigger with hugetlbfs. Based on patch by Greg Kurz. Acked-by: Rik van Riel <riel@redhat.com> Reviewed-by: Greg Kurz <gkurz@linux.vnet.ibm.com> Tested-by: Greg Kurz <gkurz@linux.vnet.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> 2015-12-02 19:14:12 +00:00			`size_t qemu_fd_getpagesize(int fd);`

exec: factor out duplicate mmap code Anonymous and file-backed RAM allocation are now almost exactly the same. Reduce code duplication by moving RAM mmap code out of oslib-posix.c and exec.c. Reported-by: Marc-André Lureau <mlureau@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Tested-by: Thibaut Collet <thibaut.collet@6wind.com> 2015-09-24 11:41:17 +00:00			`void *qemu_ram_mmap(int fd, size_t size, size_t align, bool shared);`

			`void qemu_ram_munmap(void *ptr, size_t size);`

			`#endif`