summaryrefslogtreecommitdiffstats
path: root/migration/ram.c
diff options
context:
space:
mode:
Diffstat (limited to 'migration/ram.c')
-rw-r--r--migration/ram.c109
1 files changed, 67 insertions, 42 deletions
diff --git a/migration/ram.c b/migration/ram.c
index f289fcddd5..719425b9b8 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -600,6 +600,23 @@ static void migration_bitmap_sync_init(void)
iterations_prev = 0;
}
+/* Returns a summary bitmap of the page sizes of all RAMBlocks;
+ * for VMs with just normal pages this is equivalent to the
+ * host page size. If it's got some huge pages then it's the OR
+ * of all the different page sizes.
+ */
+uint64_t ram_pagesize_summary(void)
+{
+ RAMBlock *block;
+ uint64_t summary = 0;
+
+ QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+ summary |= block->page_size;
+ }
+
+ return summary;
+}
+
static void migration_bitmap_sync(void)
{
RAMBlock *block;
@@ -1285,6 +1302,8 @@ static int ram_save_target_page(MigrationState *ms, QEMUFile *f,
* offset to point into the middle of a host page
* in which case the remainder of the hostpage is sent.
* Only dirty target pages are sent.
+ * Note that the host page size may be a huge page for this
+ * block.
*
* Returns: Number of pages written.
*
@@ -1303,6 +1322,8 @@ static int ram_save_host_page(MigrationState *ms, QEMUFile *f,
ram_addr_t dirty_ram_abs)
{
int tmppages, pages = 0;
+ size_t pagesize = qemu_ram_pagesize(pss->block);
+
do {
tmppages = ram_save_target_page(ms, f, pss, last_stage,
bytes_transferred, dirty_ram_abs);
@@ -1313,7 +1334,7 @@ static int ram_save_host_page(MigrationState *ms, QEMUFile *f,
pages += tmppages;
pss->offset += TARGET_PAGE_SIZE;
dirty_ram_abs += TARGET_PAGE_SIZE;
- } while (pss->offset & (qemu_host_page_size - 1));
+ } while (pss->offset & (pagesize - 1));
/* The offset we leave with is the last one we looked at */
pss->offset -= TARGET_PAGE_SIZE;
@@ -1655,12 +1676,17 @@ static void postcopy_chunk_hostpages_pass(MigrationState *ms, bool unsent_pass,
{
unsigned long *bitmap;
unsigned long *unsentmap;
- unsigned int host_ratio = qemu_host_page_size / TARGET_PAGE_SIZE;
+ unsigned int host_ratio = block->page_size / TARGET_PAGE_SIZE;
unsigned long first = block->offset >> TARGET_PAGE_BITS;
unsigned long len = block->used_length >> TARGET_PAGE_BITS;
unsigned long last = first + (len - 1);
unsigned long run_start;
+ if (block->page_size == TARGET_PAGE_SIZE) {
+ /* Easy case - TPS==HPS for a non-huge page RAMBlock */
+ return;
+ }
+
bitmap = atomic_rcu_read(&migration_bitmap_rcu)->bmap;
unsentmap = atomic_rcu_read(&migration_bitmap_rcu)->unsentmap;
@@ -1764,7 +1790,8 @@ static void postcopy_chunk_hostpages_pass(MigrationState *ms, bool unsent_pass,
* Utility for the outgoing postcopy code.
*
* Discard any partially sent host-page size chunks, mark any partially
- * dirty host-page size chunks as all dirty.
+ * dirty host-page size chunks as all dirty. In this case the host-page
+ * is the host-page for the particular RAMBlock, i.e. it might be a huge page
*
* Returns: 0 on success
*/
@@ -1772,11 +1799,6 @@ static int postcopy_chunk_hostpages(MigrationState *ms)
{
struct RAMBlock *block;
- if (qemu_host_page_size == TARGET_PAGE_SIZE) {
- /* Easy case - TPS==HPS - nothing to be done */
- return 0;
- }
-
/* Easiest way to make sure we don't resume in the middle of a host-page */
last_seen_block = NULL;
last_sent_block = NULL;
@@ -1832,7 +1854,7 @@ int ram_postcopy_send_discard_bitmap(MigrationState *ms)
return -EINVAL;
}
- /* Deal with TPS != HPS */
+ /* Deal with TPS != HPS and huge pages */
ret = postcopy_chunk_hostpages(ms);
if (ret) {
rcu_read_unlock();
@@ -1872,6 +1894,8 @@ int ram_discard_range(MigrationIncomingState *mis,
{
int ret = -1;
+ trace_ram_discard_range(block_name, start, length);
+
rcu_read_lock();
RAMBlock *rb = qemu_ram_block_by_name(block_name);
@@ -1881,27 +1905,7 @@ int ram_discard_range(MigrationIncomingState *mis,
goto err;
}
- uint8_t *host_startaddr = rb->host + start;
-
- if ((uintptr_t)host_startaddr & (qemu_host_page_size - 1)) {
- error_report("ram_discard_range: Unaligned start address: %p",
- host_startaddr);
- goto err;
- }
-
- if ((start + length) <= rb->used_length) {
- uint8_t *host_endaddr = host_startaddr + length;
- if ((uintptr_t)host_endaddr & (qemu_host_page_size - 1)) {
- error_report("ram_discard_range: Unaligned end address: %p",
- host_endaddr);
- goto err;
- }
- ret = postcopy_ram_discard_range(mis, host_startaddr, length);
- } else {
- error_report("ram_discard_range: Overrun block '%s' (%" PRIu64
- "/%zx/" RAM_ADDR_FMT")",
- block_name, start, length, rb->used_length);
- }
+ ret = ram_block_discard_range(rb, start, length);
err:
rcu_read_unlock();
@@ -2010,6 +2014,9 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
qemu_put_byte(f, strlen(block->idstr));
qemu_put_buffer(f, (uint8_t *)block->idstr, strlen(block->idstr));
qemu_put_be64(f, block->used_length);
+ if (migrate_postcopy_ram() && block->page_size != qemu_host_page_size) {
+ qemu_put_be64(f, block->page_size);
+ }
}
rcu_read_unlock();
@@ -2387,7 +2394,7 @@ static int ram_load_postcopy(QEMUFile *f)
{
int flags = 0, ret = 0;
bool place_needed = false;
- bool matching_page_sizes = qemu_host_page_size == TARGET_PAGE_SIZE;
+ bool matching_page_sizes = false;
MigrationIncomingState *mis = migration_incoming_get_current();
/* Temporary page that is later 'placed' */
void *postcopy_host_page = postcopy_get_tmp_page(mis);
@@ -2399,6 +2406,7 @@ static int ram_load_postcopy(QEMUFile *f)
void *host = NULL;
void *page_buffer = NULL;
void *place_source = NULL;
+ RAMBlock *block = NULL;
uint8_t ch;
addr = qemu_get_be64(f);
@@ -2408,7 +2416,7 @@ static int ram_load_postcopy(QEMUFile *f)
trace_ram_load_postcopy_loop((uint64_t)addr, flags);
place_needed = false;
if (flags & (RAM_SAVE_FLAG_COMPRESS | RAM_SAVE_FLAG_PAGE)) {
- RAMBlock *block = ram_block_from_stream(f, flags);
+ block = ram_block_from_stream(f, flags);
host = host_from_ram_block_offset(block, addr);
if (!host) {
@@ -2416,8 +2424,11 @@ static int ram_load_postcopy(QEMUFile *f)
ret = -EINVAL;
break;
}
+ matching_page_sizes = block->page_size == TARGET_PAGE_SIZE;
/*
- * Postcopy requires that we place whole host pages atomically.
+ * Postcopy requires that we place whole host pages atomically;
+ * these may be huge pages for RAMBlocks that are backed by
+ * hugetlbfs.
* To make it atomic, the data is read into a temporary page
* that's moved into place later.
* The migration protocol uses, possibly smaller, target-pages
@@ -2425,9 +2436,9 @@ static int ram_load_postcopy(QEMUFile *f)
* of a host page in order.
*/
page_buffer = postcopy_host_page +
- ((uintptr_t)host & ~qemu_host_page_mask);
+ ((uintptr_t)host & (block->page_size - 1));
/* If all TP are zero then we can optimise the place */
- if (!((uintptr_t)host & ~qemu_host_page_mask)) {
+ if (!((uintptr_t)host & (block->page_size - 1))) {
all_zero = true;
} else {
/* not the 1st TP within the HP */
@@ -2445,7 +2456,7 @@ static int ram_load_postcopy(QEMUFile *f)
* page
*/
place_needed = (((uintptr_t)host + TARGET_PAGE_SIZE) &
- ~qemu_host_page_mask) == 0;
+ (block->page_size - 1)) == 0;
place_source = postcopy_host_page;
}
last_host = host;
@@ -2483,14 +2494,14 @@ static int ram_load_postcopy(QEMUFile *f)
if (place_needed) {
/* This gets called at the last target page in the host page */
+ void *place_dest = host + TARGET_PAGE_SIZE - block->page_size;
+
if (all_zero) {
- ret = postcopy_place_page_zero(mis,
- host + TARGET_PAGE_SIZE -
- qemu_host_page_size);
+ ret = postcopy_place_page_zero(mis, place_dest,
+ block->page_size);
} else {
- ret = postcopy_place_page(mis, host + TARGET_PAGE_SIZE -
- qemu_host_page_size,
- place_source);
+ ret = postcopy_place_page(mis, place_dest,
+ place_source, block->page_size);
}
}
if (!ret) {
@@ -2511,6 +2522,8 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
* be atomic
*/
bool postcopy_running = postcopy_state_get() >= POSTCOPY_INCOMING_LISTENING;
+ /* ADVISE is earlier, it shows the source has the postcopy capability on */
+ bool postcopy_advised = postcopy_state_get() >= POSTCOPY_INCOMING_ADVISE;
seq_iter++;
@@ -2575,6 +2588,18 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
error_report_err(local_err);
}
}
+ /* For postcopy we need to check hugepage sizes match */
+ if (postcopy_advised &&
+ block->page_size != qemu_host_page_size) {
+ uint64_t remote_page_size = qemu_get_be64(f);
+ if (remote_page_size != block->page_size) {
+ error_report("Mismatched RAM page size %s "
+ "(local) %zd != %" PRId64,
+ id, block->page_size,
+ remote_page_size);
+ ret = -EINVAL;
+ }
+ }
ram_control_load_hook(f, RAM_CONTROL_BLOCK_REG,
block->idstr);
} else {
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2025-04-25 20:14:17 +0200