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>
Reviewed-by: Paolo Bonzini <pbonz...@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
