This patch allows us to distinguish between two length values for each block: max_length - length of memory block that was allocated used_length - length of block used by QEMU/guest
Currently, we set used_length - max_length, unconditionally. Follow-up patches allow used_length <= max_length. Signed-off-by: Michael S. Tsirkin <m...@redhat.com> --- include/exec/cpu-all.h | 3 ++- arch_init.c | 19 +++++++++--------- exec.c | 52 +++++++++++++++++++++++++++----------------------- 3 files changed, 40 insertions(+), 34 deletions(-) diff --git a/include/exec/cpu-all.h b/include/exec/cpu-all.h index 62f5581..6f2130e 100644 --- a/include/exec/cpu-all.h +++ b/include/exec/cpu-all.h @@ -303,7 +303,8 @@ typedef struct RAMBlock { struct MemoryRegion *mr; uint8_t *host; ram_addr_t offset; - ram_addr_t length; + ram_addr_t used_length; + ram_addr_t max_length; uint32_t flags; char idstr[256]; /* Reads can take either the iothread or the ramlist lock. diff --git a/arch_init.c b/arch_init.c index 7680d28..106f46e 100644 --- a/arch_init.c +++ b/arch_init.c @@ -522,7 +522,7 @@ static void migration_bitmap_sync(void) address_space_sync_dirty_bitmap(&address_space_memory); QTAILQ_FOREACH(block, &ram_list.blocks, next) { - migration_bitmap_sync_range(block->mr->ram_addr, block->length); + migration_bitmap_sync_range(block->mr->ram_addr, block->used_length); } trace_migration_bitmap_sync_end(migration_dirty_pages - num_dirty_pages_init); @@ -668,7 +668,7 @@ static int ram_find_and_save_block(QEMUFile *f, bool last_stage) offset >= last_offset) { break; } - if (offset >= block->length) { + if (offset >= block->used_length) { offset = 0; block = QTAILQ_NEXT(block, next); if (!block) { @@ -727,7 +727,7 @@ uint64_t ram_bytes_total(void) uint64_t total = 0; QTAILQ_FOREACH(block, &ram_list.blocks, next) - total += block->length; + total += block->used_length; return total; } @@ -831,7 +831,7 @@ static int ram_save_setup(QEMUFile *f, void *opaque) QTAILQ_FOREACH(block, &ram_list.blocks, next) { uint64_t block_pages; - block_pages = block->length >> TARGET_PAGE_BITS; + block_pages = block->used_length >> TARGET_PAGE_BITS; migration_dirty_pages += block_pages; } @@ -844,7 +844,7 @@ static int ram_save_setup(QEMUFile *f, void *opaque) QTAILQ_FOREACH(block, &ram_list.blocks, next) { qemu_put_byte(f, strlen(block->idstr)); qemu_put_buffer(f, (uint8_t *)block->idstr, strlen(block->idstr)); - qemu_put_be64(f, block->length); + qemu_put_be64(f, block->used_length); } qemu_mutex_unlock_ramlist(); @@ -1015,7 +1015,7 @@ static inline void *host_from_stream_offset(QEMUFile *f, uint8_t len; if (flags & RAM_SAVE_FLAG_CONTINUE) { - if (!block || block->length <= offset) { + if (!block || block->max_length <= offset) { error_report("Ack, bad migration stream!"); return NULL; } @@ -1028,7 +1028,8 @@ static inline void *host_from_stream_offset(QEMUFile *f, id[len] = 0; QTAILQ_FOREACH(block, &ram_list.blocks, next) { - if (!strncmp(id, block->idstr, sizeof(id)) && block->length > offset) { + if (!strncmp(id, block->idstr, sizeof(id)) && + block->max_length > offset) { return memory_region_get_ram_ptr(block->mr) + offset; } } @@ -1085,10 +1086,10 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id) QTAILQ_FOREACH(block, &ram_list.blocks, next) { if (!strncmp(id, block->idstr, sizeof(id))) { - if (block->length != length) { + if (block->used_length != length) { error_report("Length mismatch: %s: 0x" RAM_ADDR_FMT " in != 0x" RAM_ADDR_FMT, id, length, - block->length); + block->used_length); ret = -EINVAL; } break; diff --git a/exec.c b/exec.c index a89aa6c..b69216a 100644 --- a/exec.c +++ b/exec.c @@ -812,11 +812,11 @@ static RAMBlock *qemu_get_ram_block(ram_addr_t addr) /* The list is protected by the iothread lock here. */ block = ram_list.mru_block; - if (block && addr - block->offset < block->length) { + if (block && addr - block->offset < block->max_length) { goto found; } QTAILQ_FOREACH(block, &ram_list.blocks, next) { - if (addr - block->offset < block->length) { + if (addr - block->offset < block->max_length) { goto found; } } @@ -1305,13 +1305,14 @@ static ram_addr_t ram_block_add(RAMBlock *new_block, Error **errp) /* This assumes the iothread lock is taken here too. */ qemu_mutex_lock_ramlist(); - new_block->offset = find_ram_offset(new_block->length); + new_block->offset = find_ram_offset(new_block->max_length); if (!new_block->host) { if (xen_enabled()) { - xen_ram_alloc(new_block->offset, new_block->length, new_block->mr); + xen_ram_alloc(new_block->offset, new_block->max_length, + new_block->mr); } else { - new_block->host = phys_mem_alloc(new_block->length, + new_block->host = phys_mem_alloc(new_block->max_length, &new_block->mr->align); if (!new_block->host) { error_setg_errno(errp, errno, @@ -1320,13 +1321,13 @@ static ram_addr_t ram_block_add(RAMBlock *new_block, Error **errp) qemu_mutex_unlock_ramlist(); return -1; } - memory_try_enable_merging(new_block->host, new_block->length); + memory_try_enable_merging(new_block->host, new_block->max_length); } } /* Keep the list sorted from biggest to smallest block. */ QTAILQ_FOREACH(block, &ram_list.blocks, next) { - if (block->length < new_block->length) { + if (block->max_length < new_block->max_length) { break; } } @@ -1350,14 +1351,15 @@ static ram_addr_t ram_block_add(RAMBlock *new_block, Error **errp) old_ram_size, new_ram_size); } } - cpu_physical_memory_set_dirty_range(new_block->offset, new_block->length); + cpu_physical_memory_set_dirty_range(new_block->offset, + new_block->used_length); - qemu_ram_setup_dump(new_block->host, new_block->length); - qemu_madvise(new_block->host, new_block->length, QEMU_MADV_HUGEPAGE); - qemu_madvise(new_block->host, new_block->length, QEMU_MADV_DONTFORK); + qemu_ram_setup_dump(new_block->host, new_block->max_length); + qemu_madvise(new_block->host, new_block->max_length, QEMU_MADV_HUGEPAGE); + qemu_madvise(new_block->host, new_block->max_length, QEMU_MADV_DONTFORK); if (kvm_enabled()) { - kvm_setup_guest_memory(new_block->host, new_block->length); + kvm_setup_guest_memory(new_block->host, new_block->max_length); } return new_block->offset; @@ -1391,7 +1393,8 @@ ram_addr_t qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr, size = TARGET_PAGE_ALIGN(size); new_block = g_malloc0(sizeof(*new_block)); new_block->mr = mr; - new_block->length = size; + new_block->used_length = size; + new_block->max_length = size; new_block->flags = share ? RAM_SHARED : 0; new_block->host = file_ram_alloc(new_block, size, mem_path, errp); @@ -1420,7 +1423,8 @@ ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void *host, size = TARGET_PAGE_ALIGN(size); new_block = g_malloc0(sizeof(*new_block)); new_block->mr = mr; - new_block->length = size; + new_block->used_length = size; + new_block->max_length = max_size; new_block->fd = -1; new_block->host = host; if (host) { @@ -1475,11 +1479,11 @@ void qemu_ram_free(ram_addr_t addr) xen_invalidate_map_cache_entry(block->host); #ifndef _WIN32 } else if (block->fd >= 0) { - munmap(block->host, block->length); + munmap(block->host, block->max_length); close(block->fd); #endif } else { - qemu_anon_ram_free(block->host, block->length); + qemu_anon_ram_free(block->host, block->max_length); } g_free(block); break; @@ -1499,7 +1503,7 @@ void qemu_ram_remap(ram_addr_t addr, ram_addr_t length) QTAILQ_FOREACH(block, &ram_list.blocks, next) { offset = addr - block->offset; - if (offset < block->length) { + if (offset < block->max_length) { vaddr = ramblock_ptr(block, offset); if (block->flags & RAM_PREALLOC) { ; @@ -1575,7 +1579,7 @@ void *qemu_get_ram_ptr(ram_addr_t addr) return xen_map_cache(addr, 0, 0); } else if (block->host == NULL) { block->host = - xen_map_cache(block->offset, block->length, 1); + xen_map_cache(block->offset, block->max_length, 1); } } return ramblock_ptr(block, addr - block->offset); @@ -1594,9 +1598,9 @@ static void *qemu_ram_ptr_length(ram_addr_t addr, hwaddr *size) RAMBlock *block; QTAILQ_FOREACH(block, &ram_list.blocks, next) { - if (addr - block->offset < block->length) { - if (addr - block->offset + *size > block->length) - *size = block->length - addr + block->offset; + if (addr - block->offset < block->max_length) { + if (addr - block->offset + *size > block->max_length) + *size = block->max_length - addr + block->offset; return ramblock_ptr(block, addr - block->offset); } } @@ -1619,7 +1623,7 @@ MemoryRegion *qemu_ram_addr_from_host(void *ptr, ram_addr_t *ram_addr) } block = ram_list.mru_block; - if (block && block->host && host - block->host < block->length) { + if (block && block->host && host - block->host < block->max_length) { goto found; } @@ -1628,7 +1632,7 @@ MemoryRegion *qemu_ram_addr_from_host(void *ptr, ram_addr_t *ram_addr) if (block->host == NULL) { continue; } - if (host - block->host < block->length) { + if (host - block->host < block->max_length) { goto found; } } @@ -2873,7 +2877,7 @@ void qemu_ram_foreach_block(RAMBlockIterFunc func, void *opaque) RAMBlock *block; QTAILQ_FOREACH(block, &ram_list.blocks, next) { - func(block->host, block->offset, block->length, opaque); + func(block->host, block->offset, block->used_length, opaque); } } #endif -- MST