From 44a4ff31c01082ffce08ec3b9a87a4fdf15919d5 Mon Sep 17 00:00:00 2001 From: Jagannathan Raman Date: Fri, 29 Jan 2021 11:46:04 -0500 Subject: memory: alloc RAM from file at offset Allow RAM MemoryRegion to be created from an offset in a file, instead of allocating at offset of 0 by default. This is needed to synchronize RAM between QEMU & remote process. Signed-off-by: Jagannathan Raman Signed-off-by: John G Johnson Signed-off-by: Elena Ufimtseva Reviewed-by: Stefan Hajnoczi Message-id: 609996697ad8617e3b01df38accc5c208c24d74e.1611938319.git.jag.raman@oracle.com Signed-off-by: Stefan Hajnoczi --- util/mmap-alloc.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'util/mmap-alloc.c') diff --git a/util/mmap-alloc.c b/util/mmap-alloc.c index 890fda6a35..e6fa8b598b 100644 --- a/util/mmap-alloc.c +++ b/util/mmap-alloc.c @@ -87,7 +87,8 @@ void *qemu_ram_mmap(int fd, size_t align, bool readonly, bool shared, - bool is_pmem) + bool is_pmem, + off_t map_offset) { int prot; int flags; @@ -150,7 +151,8 @@ void *qemu_ram_mmap(int fd, prot = PROT_READ | (readonly ? 0 : PROT_WRITE); - ptr = mmap(guardptr + offset, size, prot, flags | map_sync_flags, fd, 0); + ptr = mmap(guardptr + offset, size, prot, + flags | map_sync_flags, fd, map_offset); if (ptr == MAP_FAILED && map_sync_flags) { if (errno == ENOTSUP) { @@ -174,7 +176,7 @@ void *qemu_ram_mmap(int fd, * if map failed with MAP_SHARED_VALIDATE | MAP_SYNC, * we will remove these flags to handle compatibility. */ - ptr = mmap(guardptr + offset, size, prot, flags, fd, 0); + ptr = mmap(guardptr + offset, size, prot, flags, fd, map_offset); } if (ptr == MAP_FAILED) { -- cgit 1.4.1