diff options
Diffstat (limited to 'exec.c')
| -rw-r--r-- | exec.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/exec.c b/exec.c index ffdb518535..a34c348184 100644 --- a/exec.c +++ b/exec.c @@ -65,6 +65,8 @@ #include "exec/ram_addr.h" #include "exec/log.h" +#include "qemu/pmem.h" + #include "migration/vmstate.h" #include "qemu/range.h" @@ -2156,6 +2158,40 @@ int qemu_ram_resize(RAMBlock *block, ram_addr_t newsize, Error **errp) return 0; } +/* + * Trigger sync on the given ram block for range [start, start + length] + * with the backing store if one is available. + * Otherwise no-op. + * @Note: this is supposed to be a synchronous op. + */ +void qemu_ram_writeback(RAMBlock *block, ram_addr_t start, ram_addr_t length) +{ + void *addr = ramblock_ptr(block, start); + + /* The requested range should fit in within the block range */ + g_assert((start + length) <= block->used_length); + +#ifdef CONFIG_LIBPMEM + /* The lack of support for pmem should not block the sync */ + if (ramblock_is_pmem(block)) { + pmem_persist(addr, length); + return; + } +#endif + if (block->fd >= 0) { + /** + * Case there is no support for PMEM or the memory has not been + * specified as persistent (or is not one) - use the msync. + * Less optimal but still achieves the same goal + */ + if (qemu_msync(addr, length, block->fd)) { + warn_report("%s: failed to sync memory range: start: " + RAM_ADDR_FMT " length: " RAM_ADDR_FMT, + __func__, start, length); + } + } +} + /* Called with ram_list.mutex held */ static void dirty_memory_extend(ram_addr_t old_ram_size, ram_addr_t new_ram_size) |