diff options
Diffstat (limited to 'exec.c')
| -rw-r--r-- | exec.c | 82 |
1 files changed, 78 insertions, 4 deletions
@@ -75,6 +75,11 @@ static MemoryRegion io_mem_unassigned; /* RAM is mmap-ed with MAP_SHARED */ #define RAM_SHARED (1 << 1) +/* Only a portion of RAM (used_length) is actually used, and migrated. + * This used_length size can change across reboots. + */ +#define RAM_RESIZEABLE (1 << 2) + #endif struct CPUTailQ cpus = QTAILQ_HEAD_INITIALIZER(cpus); @@ -1186,7 +1191,7 @@ static ram_addr_t find_ram_offset(ram_addr_t size) QTAILQ_FOREACH(block, &ram_list.blocks, next) { ram_addr_t end, next = RAM_ADDR_MAX; - end = block->offset + block->length; + end = block->offset + block->max_length; QTAILQ_FOREACH(next_block, &ram_list.blocks, next) { if (next_block->offset >= end) { @@ -1214,7 +1219,7 @@ ram_addr_t last_ram_offset(void) ram_addr_t last = 0; QTAILQ_FOREACH(block, &ram_list.blocks, next) - last = MAX(last, block->offset + block->length); + last = MAX(last, block->offset + block->max_length); return last; } @@ -1296,6 +1301,49 @@ static int memory_try_enable_merging(void *addr, size_t len) return qemu_madvise(addr, len, QEMU_MADV_MERGEABLE); } +/* Only legal before guest might have detected the memory size: e.g. on + * incoming migration, or right after reset. + * + * As memory core doesn't know how is memory accessed, it is up to + * resize callback to update device state and/or add assertions to detect + * misuse, if necessary. + */ +int qemu_ram_resize(ram_addr_t base, ram_addr_t newsize, Error **errp) +{ + RAMBlock *block = find_ram_block(base); + + assert(block); + + if (block->used_length == newsize) { + return 0; + } + + if (!(block->flags & RAM_RESIZEABLE)) { + error_setg_errno(errp, EINVAL, + "Length mismatch: %s: 0x" RAM_ADDR_FMT + " in != 0x" RAM_ADDR_FMT, block->idstr, + newsize, block->used_length); + return -EINVAL; + } + + if (block->max_length < newsize) { + error_setg_errno(errp, EINVAL, + "Length too large: %s: 0x" RAM_ADDR_FMT + " > 0x" RAM_ADDR_FMT, block->idstr, + newsize, block->max_length); + return -EINVAL; + } + + cpu_physical_memory_clear_dirty_range(block->offset, block->used_length); + block->used_length = newsize; + cpu_physical_memory_set_dirty_range(block->offset, block->used_length); + memory_region_set_size(block->mr, newsize); + if (block->resized) { + block->resized(block->idstr, newsize, block->host); + } + return 0; +} + static ram_addr_t ram_block_add(RAMBlock *new_block, Error **errp) { RAMBlock *block; @@ -1413,7 +1461,12 @@ ram_addr_t qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr, } #endif -ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void *host, +static +ram_addr_t qemu_ram_alloc_internal(ram_addr_t size, ram_addr_t max_size, + void (*resized)(const char*, + uint64_t length, + void *host), + void *host, bool resizeable, MemoryRegion *mr, Error **errp) { RAMBlock *new_block; @@ -1421,15 +1474,21 @@ ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void *host, Error *local_err = NULL; size = TARGET_PAGE_ALIGN(size); + max_size = TARGET_PAGE_ALIGN(max_size); new_block = g_malloc0(sizeof(*new_block)); new_block->mr = mr; + new_block->resized = resized; new_block->used_length = size; new_block->max_length = max_size; + assert(max_size >= size); new_block->fd = -1; new_block->host = host; if (host) { new_block->flags |= RAM_PREALLOC; } + if (resizeable) { + new_block->flags |= RAM_RESIZEABLE; + } addr = ram_block_add(new_block, &local_err); if (local_err) { g_free(new_block); @@ -1439,9 +1498,24 @@ ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void *host, return addr; } +ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void *host, + MemoryRegion *mr, Error **errp) +{ + return qemu_ram_alloc_internal(size, size, NULL, host, false, mr, errp); +} + ram_addr_t qemu_ram_alloc(ram_addr_t size, MemoryRegion *mr, Error **errp) { - return qemu_ram_alloc_from_ptr(size, NULL, mr, errp); + return qemu_ram_alloc_internal(size, size, NULL, NULL, false, mr, errp); +} + +ram_addr_t qemu_ram_alloc_resizeable(ram_addr_t size, ram_addr_t maxsz, + void (*resized)(const char*, + uint64_t length, + void *host), + MemoryRegion *mr, Error **errp) +{ + return qemu_ram_alloc_internal(size, maxsz, resized, NULL, true, mr, errp); } void qemu_ram_free_from_ptr(ram_addr_t addr) |