Uses QAT to offload deflate compression and decompression in the
'qatzip' compression method for multifd migration.
Signed-off-by: Bryan Zhang <bryan.zh...@bytedance.com>
Signed-off-by: Hao Xiang <hao.xi...@linux.dev>
---
migration/multifd-qatzip.c | 331 +++++++++++++++++++++++++++++++++----
1 file changed, 298 insertions(+), 33 deletions(-)
diff --git a/migration/multifd-qatzip.c b/migration/multifd-qatzip.c
index f66336a4a7..13835cf76f 100644
--- a/migration/multifd-qatzip.c
+++ b/migration/multifd-qatzip.c
@@ -18,86 +18,351 @@
#include "migration.h"
#include "options.h"
#include "multifd.h"
+#include <qatzip.h>
-/*
- * This is an intermediary file to introduce 'qatzip' as an option for multifd
- * compression. The actual method implementations are no-ops.
- */
+struct qatzip_data {
+ /*
+ * Unique session for use with QATzip API
+ */
+ QzSession_T sess;
+
+ /*
+ * For compression: Buffer for pages to compress
+ * For decompression: Buffer for data to decompress
+ */
+ uint8_t *in_buf;
+ uint32_t in_len;
+ /*
+ * For compression: Output buffer of compressed data
+ * For decompression: Output buffer of decompressed data
+ */
+ uint8_t *out_buf;
+ uint32_t out_len;
+};
+
+/**
+ * qatzip_send_setup: Set up QATzip session and private buffers.
+ *
+ * @param p Multifd channel params
+ * @param errp Pointer to error, which will be set in case of error
+ * @return 0 on success, -1 on error (and *errp will be set)
+ */
static int qatzip_send_setup(MultiFDSendParams *p, Error **errp)
{
- if (migrate_zero_copy_send()) {
- p->write_flags |= QIO_CHANNEL_WRITE_FLAG_ZERO_COPY;
+ struct qatzip_data *q;
+ QzSessionParamsDeflate_T params;
+ const char *err_msg;
+ int ret;
+ int sw_fallback;
+
+ q = g_new0(struct qatzip_data, 1);
+ p->data = q;
+
+ sw_fallback = 0;
+ if (migrate_multifd_qatzip_sw_fallback()) {
+ sw_fallback = 1;
+ }
+
+ ret = qzInit(&q->sess, sw_fallback);
+ if (ret != QZ_OK && ret != QZ_DUPLICATE) {
+ err_msg = "qzInit failed";
+ goto err_free_q;
+ }
+
+ ret = qzGetDefaultsDeflate(¶ms);
+ if (ret != QZ_OK) {
+ err_msg = "qzGetDefaultsDeflate failed";
+ goto err_close;
+ }
+
+ /* Make sure to use configured QATzip compression level. */
+ params.common_params.comp_lvl = migrate_multifd_qatzip_level();
+
+ ret = qzSetupSessionDeflate(&q->sess, ¶ms);
+ if (ret != QZ_OK && ret != QZ_DUPLICATE) {
+ err_msg = "qzSetupSessionDeflate failed";
+ goto err_close;
+ }
+
+ /* TODO Add support for larger packets. */
+ if (MULTIFD_PACKET_SIZE > UINT32_MAX) {
+ err_msg = "packet size too large for QAT";
+ goto err_close;
+ }
+
+ q->in_len = MULTIFD_PACKET_SIZE;
+ q->in_buf = qzMalloc(q->in_len, 0, PINNED_MEM);
+ if (!q->in_buf) {
+ err_msg = "qzMalloc failed";
+ goto err_close;
+ }
+
+ q->out_len = qzMaxCompressedLength(MULTIFD_PACKET_SIZE, &q->sess);
+ q->out_buf = qzMalloc(q->out_len, 0, PINNED_MEM);
+ if (!q->out_buf) {
+ err_msg = "qzMalloc failed";
+ goto err_free_inbuf;
}
return 0;
+
+err_free_inbuf:
+ qzFree(q->in_buf);
+err_close:
+ qzClose(&q->sess);
+err_free_q:
+ g_free(q);
+ error_setg(errp, "multifd %u: %s", p->id, err_msg);
+ return -1;
}
+/**
+ * qatzip_send_cleanup: Tear down QATzip session and release private buffers.
+ *
+ * @param p Multifd channel params
+ * @param errp Pointer to error, which will be set in case of error
+ * @return None
+ */
static void qatzip_send_cleanup(MultiFDSendParams *p, Error **errp)
{
+ struct qatzip_data *q = p->data;
+ const char *err_msg;
+ int ret;
+
+ ret = qzTeardownSession(&q->sess);
+ if (ret != QZ_OK) {
+ err_msg = "qzTeardownSession failed";
+ goto err;
+ }
+
+ ret = qzClose(&q->sess);
+ if (ret != QZ_OK) {
+ err_msg = "qzClose failed";
+ goto err;
+ }
+
+ qzFree(q->in_buf);
+ q->in_buf = NULL;
+ qzFree(q->out_buf);
+ q->out_buf = NULL;
+ g_free(p->data);
+ p->data = NULL;
return;
+
+err:
+ error_setg(errp, "multifd %u: %s", p->id, err_msg);
}
+/**
+ * qatzip_send_prepare: Compress pages and update IO channel info.
+ *
+ * @param p Multifd channel params
+ * @param errp Pointer to error, which will be set in case of error
+ * @return 0 on success, -1 on error (and *errp will be set)
+ */
static int qatzip_send_prepare(MultiFDSendParams *p, Error **errp)
{
- bool use_zero_copy_send = migrate_zero_copy_send();
MultiFDPages_t *pages = p->pages;
+ struct qatzip_data *q = p->data;
int ret;
+ unsigned int in_len, out_len;
- if (!use_zero_copy_send) {
- /*
- * Only !zerocopy needs the header in IOV; zerocopy will
- * send it separately.
- */
- multifd_send_prepare_header(p);
- }
+ multifd_send_prepare_header(p);
+ /* memcpy all the pages into one buffer. */
for (int i = 0; i < pages->num; i++) {
- p->iov[p->iovs_num].iov_base = pages->block->host + pages->offset[i];
- p->iov[p->iovs_num].iov_len = p->page_size;
- p->iovs_num++;
+ memcpy(q->in_buf + (i * p->page_size),
+ p->pages->block->host + pages->offset[i],
+ p->page_size);
}
- p->next_packet_size = pages->num * p->page_size;
- p->flags |= MULTIFD_FLAG_NOCOMP;
-
- multifd_send_fill_packet(p);
+ in_len = pages->num * p->page_size;
+ if (in_len > q->in_len) {
+ error_setg(errp, "multifd %u: unexpectedly large input", p->id);
+ return -1;
+ }
+ out_len = q->out_len;
- if (use_zero_copy_send) {
- /* Send header first, without zerocopy */
- ret = qio_channel_write_all(p->c, (void *)p->packet,
- p->packet_len, errp);
- if (ret != 0) {
- return -1;
- }
+ /*
+ * Unlike other multifd compression implementations, we use a non-streaming
+ * API and place all the data into one buffer, rather than sending each
page
+ * to the compression API at a time. Based on initial benchmarks, the
+ * non-streaming API outperforms the streaming API. Plus, the logic in QEMU
+ * is friendly to using the non-streaming API anyway. If either of these
+ * statements becomes no longer true, we can revisit adding a streaming
+ * implementation.
+ */
+ ret = qzCompress(&q->sess, q->in_buf, &in_len, q->out_buf, &out_len, 1);
+ if (ret != QZ_OK) {
+ error_setg(errp, "multifd %u: QATzip returned %d instead of QZ_OK",
+ p->id, ret);
+ return -1;
+ }
+ if (in_len != pages->num * p->page_size) {
+ error_setg(errp, "multifd %u: QATzip failed to compress all input",
+ p->id);
+ return -1;
}
+ p->iov[p->iovs_num].iov_base = q->out_buf;
+ p->iov[p->iovs_num].iov_len = out_len;
+ p->iovs_num++;
+ p->next_packet_size = out_len;
+ p->flags |= MULTIFD_FLAG_QATZIP;
+
+ multifd_send_fill_packet(p);
+
return 0;
}
+/**
+ * qatzip_recv_setup: Set up QATzip session and allocate private buffers.
+ *
+ * @param p Multifd channel params
+ * @param errp Pointer to error, which will be set in case of error
+ * @return 0 on success, -1 on error (and *errp will be set)
+ */
static int qatzip_recv_setup(MultiFDRecvParams *p, Error **errp)
{
+ struct qatzip_data *q;
+ QzSessionParamsDeflate_T params;
+ const char *err_msg;
+ int ret;
+ int sw_fallback;
+
+ q = g_new0(struct qatzip_data, 1);
+ p->data = q;
+
+ sw_fallback = 0;
+ if (migrate_multifd_qatzip_sw_fallback()) {
+ sw_fallback = 1;
+ }
+
+ ret = qzInit(&q->sess, sw_fallback);
+ if (ret != QZ_OK && ret != QZ_DUPLICATE) {
+ err_msg = "qzInit failed";
+ goto err_free_q;
+ }
+
+ ret = qzGetDefaultsDeflate(¶ms);
+ if (ret != QZ_OK) {
+ err_msg = "qzGetDefaultsDeflate failed";
+ goto err_close;
+ }
+
+ /* Make sure to use configured QATzip compression level. */
+ params.common_params.comp_lvl = migrate_multifd_qatzip_level();
+
+ ret = qzSetupSessionDeflate(&q->sess, ¶ms);
+ if (ret != QZ_OK && ret != QZ_DUPLICATE) {
+ err_msg = "qzSetupSessionDeflate failed";
+ goto err_close;
+ }
+
+ /*
+ * Mimic multifd-zlib, which reserves extra space for the
+ * incoming packet.
+ */
+ q->in_len = MULTIFD_PACKET_SIZE * 2;
+ q->in_buf = qzMalloc(q->in_len, 0, PINNED_MEM);
+ if (!q->in_buf) {
+ err_msg = "qzMalloc failed";
+ goto err_close;
+ }
+
+ q->out_len = MULTIFD_PACKET_SIZE;
+ q->out_buf = qzMalloc(q->out_len, 0, PINNED_MEM);
+ if (!q->out_buf) {
+ err_msg = "qzMalloc failed";
+ goto err_free_inbuf;
+ }
+
return 0;
+
+err_free_inbuf:
+ qzFree(q->in_buf);
+err_close:
+ qzClose(&q->sess);
+err_free_q:
+ g_free(q);
+ error_setg(errp, "multifd %u: %s", p->id, err_msg);
+ return -1;
}
+/**
+ * qatzip_recv_cleanup: Tear down QATzip session and release private buffers.
+ *
+ * @param p Multifd channel params
+ * @return None
+ */
static void qatzip_recv_cleanup(MultiFDRecvParams *p)
{
+ struct qatzip_data *q = p->data;
+
+ /* Ignoring return values here due to function signature. */
+ qzTeardownSession(&q->sess);
+ qzClose(&q->sess);
+ qzFree(q->in_buf);
+ qzFree(q->out_buf);
+ g_free(p->data);
}
+
+/**
+ * qatzip_recv_pages: Decompress pages and copy them to the appropriate
+ * locations.
+ *
+ * @param p Multifd channel params
+ * @param errp Pointer to error, which will be set in case of error
+ * @return 0 on success, -1 on error (and *errp will be set)
+ */
static int qatzip_recv_pages(MultiFDRecvParams *p, Error **errp)
{
+ struct qatzip_data *q = p->data;
+ int ret;
+ unsigned int in_len, out_len;
+ uint32_t in_size = p->next_packet_size;
+ uint32_t expected_size = p->normal_num * p->page_size;
uint32_t flags = p->flags & MULTIFD_FLAG_COMPRESSION_MASK;
- if (flags != MULTIFD_FLAG_NOCOMP) {
+ if (in_size > q->in_len) {
+ error_setg(errp, "multifd %u: received unexpectedly large packet",
+ p->id);
+ return -1;
+ }
+
+ if (flags != MULTIFD_FLAG_QATZIP) {
error_setg(errp, "multifd %u: flags received %x flags expected %x",
- p->id, flags, MULTIFD_FLAG_NOCOMP);
+ p->id, flags, MULTIFD_FLAG_QATZIP);
+ return -1;
+ }
+
+ ret = qio_channel_read_all(p->c, (void *)q->in_buf, in_size, errp);
+ if (ret != 0) {
+ return ret;
+ }
+
+ in_len = in_size;
+ out_len = q->out_len;
+ ret = qzDecompress(&q->sess, q->in_buf, &in_len, q->out_buf, &out_len);
+ if (ret != QZ_OK) {
+ error_setg(errp, "multifd %u: qzDecompress failed", p->id);
+ return -1;
+ }
+ if (out_len != expected_size) {
+ error_setg(errp, "multifd %u: packet size received %u size expected
%u",
+ p->id, out_len, expected_size);
return -1;
}
+
+ /* Copy each page to its appropriate location. */
for (int i = 0; i < p->normal_num; i++) {
- p->iov[i].iov_base = p->host + p->normal[i];
- p->iov[i].iov_len = p->page_size;
+ memcpy(p->host + p->normal[i],
+ q->out_buf + p->page_size * i,
+ p->page_size);
}
- return qio_channel_readv_all(p->c, p->iov, p->normal_num, errp);
+ return 0;
}
static MultiFDMethods multifd_qatzip_ops = {
--
2.30.2
