We want multifd to be able to handle more types of data than just ram
pages. To start decoupling multifd from pages, replace p->pages
(MultiFDPages_t) with the new type MultiFDSendData that hides the
client payload inside an union.
The general idea here is to isolate functions that *need* to handle
MultiFDPages_t and move them in the future to multifd-ram.c, while
multifd.c will stay with only the core functions that handle
MultiFDSendData/MultiFDRecvData.
Reviewed-by: Peter Xu <pet...@redhat.com>
Signed-off-by: Fabiano Rosas <faro...@suse.de>
---
migration/multifd-qpl.c | 6 +--
migration/multifd-uadk.c | 2 +-
migration/multifd-zero-page.c | 2 +-
migration/multifd-zlib.c | 2 +-
migration/multifd-zstd.c | 2 +-
migration/multifd.c | 83 +++++++++++++++++++++--------------
migration/multifd.h | 7 +--
7 files changed, 57 insertions(+), 47 deletions(-)
diff --git a/migration/multifd-qpl.c b/migration/multifd-qpl.c
index db60c05795..21153f1987 100644
--- a/migration/multifd-qpl.c
+++ b/migration/multifd-qpl.c
@@ -406,7 +406,7 @@ retry:
static void multifd_qpl_compress_pages_slow_path(MultiFDSendParams *p)
{
QplData *qpl = p->compress_data;
- MultiFDPages_t *pages = p->pages;
+ MultiFDPages_t *pages = &p->data->u.ram;
uint32_t size = p->page_size;
qpl_job *job = qpl->sw_job;
uint8_t *zbuf = qpl->zbuf;
@@ -437,7 +437,7 @@ static void
multifd_qpl_compress_pages_slow_path(MultiFDSendParams *p)
static void multifd_qpl_compress_pages(MultiFDSendParams *p)
{
QplData *qpl = p->compress_data;
- MultiFDPages_t *pages = p->pages;
+ MultiFDPages_t *pages = &p->data->u.ram;
uint32_t size = p->page_size;
QplHwJob *hw_job;
uint8_t *buf;
@@ -501,7 +501,7 @@ static void multifd_qpl_compress_pages(MultiFDSendParams *p)
static int multifd_qpl_send_prepare(MultiFDSendParams *p, Error **errp)
{
QplData *qpl = p->compress_data;
- MultiFDPages_t *pages = p->pages;
+ MultiFDPages_t *pages = &p->data->u.ram;
uint32_t len = 0;
if (!multifd_send_prepare_common(p)) {
diff --git a/migration/multifd-uadk.c b/migration/multifd-uadk.c
index 1ed1c6afe6..9d99807af5 100644
--- a/migration/multifd-uadk.c
+++ b/migration/multifd-uadk.c
@@ -177,7 +177,7 @@ static int multifd_uadk_send_prepare(MultiFDSendParams *p,
Error **errp)
uint32_t page_size = multifd_ram_page_size();
uint8_t *buf = uadk_data->buf;
int ret = 0;
- MultiFDPages_t *pages = p->pages;
+ MultiFDPages_t *pages = &p->data->u.ram;
if (!multifd_send_prepare_common(p)) {
goto out;
diff --git a/migration/multifd-zero-page.c b/migration/multifd-zero-page.c
index cc624e36b3..6506a4aa89 100644
--- a/migration/multifd-zero-page.c
+++ b/migration/multifd-zero-page.c
@@ -46,7 +46,7 @@ static void swap_page_offset(ram_addr_t *pages_offset, int a,
int b)
*/
void multifd_send_zero_page_detect(MultiFDSendParams *p)
{
- MultiFDPages_t *pages = p->pages;
+ MultiFDPages_t *pages = &p->data->u.ram;
RAMBlock *rb = pages->block;
int i = 0;
int j = pages->num - 1;
diff --git a/migration/multifd-zlib.c b/migration/multifd-zlib.c
index e47d7f70dc..66517c1067 100644
--- a/migration/multifd-zlib.c
+++ b/migration/multifd-zlib.c
@@ -123,7 +123,7 @@ static void zlib_send_cleanup(MultiFDSendParams *p, Error
**errp)
*/
static int zlib_send_prepare(MultiFDSendParams *p, Error **errp)
{
- MultiFDPages_t *pages = p->pages;
+ MultiFDPages_t *pages = &p->data->u.ram;
struct zlib_data *z = p->compress_data;
z_stream *zs = &z->zs;
uint32_t out_size = 0;
diff --git a/migration/multifd-zstd.c b/migration/multifd-zstd.c
index 1812fd1b48..04ac711cf4 100644
--- a/migration/multifd-zstd.c
+++ b/migration/multifd-zstd.c
@@ -119,7 +119,7 @@ static void zstd_send_cleanup(MultiFDSendParams *p, Error
**errp)
*/
static int zstd_send_prepare(MultiFDSendParams *p, Error **errp)
{
- MultiFDPages_t *pages = p->pages;
+ MultiFDPages_t *pages = &p->data->u.ram;
struct zstd_data *z = p->compress_data;
int ret;
uint32_t i;
diff --git a/migration/multifd.c b/migration/multifd.c
index 717e71f539..c310d28532 100644
--- a/migration/multifd.c
+++ b/migration/multifd.c
@@ -49,8 +49,7 @@ typedef struct {
struct {
MultiFDSendParams *params;
- /* array of pages to sent */
- MultiFDPages_t *pages;
+ MultiFDSendData *data;
/*
* Global number of generated multifd packets.
*
@@ -109,6 +108,28 @@ static size_t multifd_ram_payload_size(void)
return sizeof(MultiFDPages_t) + n * sizeof(ram_addr_t);
}
+static MultiFDSendData *multifd_send_data_alloc(void)
+{
+ size_t max_payload_size, size_minus_payload;
+
+ /*
+ * MultiFDPages_t has a flexible array at the end, account for it
+ * when allocating MultiFDSendData. Use max() in case other types
+ * added to the union in the future are larger than
+ * (MultiFDPages_t + flex array).
+ */
+ max_payload_size = MAX(multifd_ram_payload_size(), sizeof(MultiFDPayload));
+
+ /*
+ * Account for any holes the compiler might insert. We can't pack
+ * the structure because that misaligns the members and triggers
+ * Waddress-of-packed-member.
+ */
+ size_minus_payload = sizeof(MultiFDSendData) - sizeof(MultiFDPayload);
+
+ return g_malloc0(size_minus_payload + max_payload_size);
+}
+
static bool multifd_use_packets(void)
{
return !migrate_mapped_ram();
@@ -121,7 +142,7 @@ void multifd_send_channel_created(void)
static void multifd_set_file_bitmap(MultiFDSendParams *p)
{
- MultiFDPages_t *pages = p->pages;
+ MultiFDPages_t *pages = &p->data->u.ram;
assert(pages->block);
@@ -177,7 +198,7 @@ static void nocomp_send_cleanup(MultiFDSendParams *p, Error
**errp)
static void multifd_send_prepare_iovs(MultiFDSendParams *p)
{
- MultiFDPages_t *pages = p->pages;
+ MultiFDPages_t *pages = &p->data->u.ram;
uint32_t page_size = multifd_ram_page_size();
for (int i = 0; i < pages->normal_num; i++) {
@@ -403,21 +424,10 @@ static int multifd_recv_initial_packet(QIOChannel *c,
Error **errp)
return msg.id;
}
-static MultiFDPages_t *multifd_pages_init(uint32_t n)
-{
- return g_malloc0(multifd_ram_payload_size());
-}
-
-static void multifd_pages_clear(MultiFDPages_t *pages)
-{
- multifd_pages_reset(pages);
- g_free(pages);
-}
-
void multifd_send_fill_packet(MultiFDSendParams *p)
{
MultiFDPacket_t *packet = p->packet;
- MultiFDPages_t *pages = p->pages;
+ MultiFDPages_t *pages = &p->data->u.ram;
uint64_t packet_num;
uint32_t zero_num = pages->num - pages->normal_num;
int i;
@@ -599,7 +609,7 @@ static bool multifd_send_pages(void)
int i;
static int next_channel;
MultiFDSendParams *p = NULL; /* make happy gcc */
- MultiFDPages_t *pages = multifd_send_state->pages;
+ MultiFDSendData *tmp;
if (multifd_send_should_exit()) {
return false;
@@ -634,11 +644,14 @@ static bool multifd_send_pages(void)
* qatomic_store_release() in multifd_send_thread().
*/
smp_mb_acquire();
- assert(!p->pages->num);
- multifd_send_state->pages = p->pages;
- p->pages = pages;
+
+ assert(!p->data->u.ram.num);
+
+ tmp = multifd_send_state->data;
+ multifd_send_state->data = p->data;
+ p->data = tmp;
/*
- * Making sure p->pages is setup before marking pending_job=true. Pairs
+ * Making sure p->data is setup before marking pending_job=true. Pairs
* with the qatomic_load_acquire() in multifd_send_thread().
*/
qatomic_store_release(&p->pending_job, true);
@@ -668,7 +681,7 @@ bool multifd_queue_page(RAMBlock *block, ram_addr_t offset)
MultiFDPages_t *pages;
retry:
- pages = multifd_send_state->pages;
+ pages = &multifd_send_state->data->u.ram;
/* If the queue is empty, we can already enqueue now */
if (multifd_queue_empty(pages)) {
@@ -798,8 +811,8 @@ static bool multifd_send_cleanup_channel(MultiFDSendParams
*p, Error **errp)
qemu_sem_destroy(&p->sem_sync);
g_free(p->name);
p->name = NULL;
- multifd_pages_clear(p->pages);
- p->pages = NULL;
+ g_free(p->data);
+ p->data = NULL;
p->packet_len = 0;
g_free(p->packet);
p->packet = NULL;
@@ -816,8 +829,8 @@ static void multifd_send_cleanup_state(void)
qemu_sem_destroy(&multifd_send_state->channels_ready);
g_free(multifd_send_state->params);
multifd_send_state->params = NULL;
- multifd_pages_clear(multifd_send_state->pages);
- multifd_send_state->pages = NULL;
+ g_free(multifd_send_state->data);
+ multifd_send_state->data = NULL;
g_free(multifd_send_state);
multifd_send_state = NULL;
}
@@ -866,11 +879,13 @@ int multifd_send_sync_main(void)
{
int i;
bool flush_zero_copy;
+ MultiFDPages_t *pages;
if (!migrate_multifd()) {
return 0;
}
- if (multifd_send_state->pages->num) {
+ pages = &multifd_send_state->data->u.ram;
+ if (pages->num) {
if (!multifd_send_pages()) {
error_report("%s: multifd_send_pages fail", __func__);
return -1;
@@ -945,11 +960,11 @@ static void *multifd_send_thread(void *opaque)
}
/*
- * Read pending_job flag before p->pages. Pairs with the
+ * Read pending_job flag before p->data. Pairs with the
* qatomic_store_release() in multifd_send_pages().
*/
if (qatomic_load_acquire(&p->pending_job)) {
- MultiFDPages_t *pages = p->pages;
+ MultiFDPages_t *pages = &p->data->u.ram;
p->iovs_num = 0;
assert(pages->num);
@@ -961,7 +976,7 @@ static void *multifd_send_thread(void *opaque)
if (migrate_mapped_ram()) {
ret = file_write_ramblock_iov(p->c, p->iov, p->iovs_num,
- pages, &local_err);
+ &p->data->u.ram, &local_err);
} else {
ret = qio_channel_writev_full_all(p->c, p->iov, p->iovs_num,
NULL, 0, p->write_flags,
@@ -981,7 +996,7 @@ static void *multifd_send_thread(void *opaque)
p->next_packet_size = 0;
/*
- * Making sure p->pages is published before saying "we're
+ * Making sure p->data is published before saying "we're
* free". Pairs with the smp_mb_acquire() in
* multifd_send_pages().
*/
@@ -1176,7 +1191,7 @@ bool multifd_send_setup(void)
thread_count = migrate_multifd_channels();
multifd_send_state = g_malloc0(sizeof(*multifd_send_state));
multifd_send_state->params = g_new0(MultiFDSendParams, thread_count);
- multifd_send_state->pages = multifd_pages_init(page_count);
+ multifd_send_state->data = multifd_send_data_alloc();
qemu_sem_init(&multifd_send_state->channels_created, 0);
qemu_sem_init(&multifd_send_state->channels_ready, 0);
qatomic_set(&multifd_send_state->exiting, 0);
@@ -1189,7 +1204,7 @@ bool multifd_send_setup(void)
qemu_sem_init(&p->sem, 0);
qemu_sem_init(&p->sem_sync, 0);
p->id = i;
- p->pages = multifd_pages_init(page_count);
+ p->data = multifd_send_data_alloc();
if (use_packets) {
p->packet_len = sizeof(MultiFDPacket_t)
@@ -1694,7 +1709,7 @@ void multifd_recv_new_channel(QIOChannel *ioc, Error
**errp)
bool multifd_send_prepare_common(MultiFDSendParams *p)
{
- MultiFDPages_t *pages = p->pages;
+ MultiFDPages_t *pages = &p->data->u.ram;
multifd_send_zero_page_detect(p);
if (!pages->normal_num) {
diff --git a/migration/multifd.h b/migration/multifd.h
index a7fdd97f70..c2ba4cad13 100644
--- a/migration/multifd.h
+++ b/migration/multifd.h
@@ -152,12 +152,7 @@ typedef struct {
*/
bool pending_job;
bool pending_sync;
- /* array of pages to sent.
- * The owner of 'pages' depends of 'pending_job' value:
- * pending_job == 0 -> migration_thread can use it.
- * pending_job != 0 -> multifd_channel can use it.
- */
- MultiFDPages_t *pages;
+ MultiFDSendData *data;
/* thread local variables. No locking required */
--
2.35.3
