[PATCH v6 6/7] migration/multifd: implement qpl compression and decompression

[Yuan Liu <yuan1.liu@intel.com>]

each qpl job is used to (de)compress a normal page and it can
be processed independently by the IAA hardware. All qpl jobs
are submitted to the hardware at once, and wait for all jobs
completion. If hardware path(IAA) is not available, use software
for compression and decompression.

Signed-off-by: Yuan Liu <yuan1.liu@intel.com>
Reviewed-by: Nanhai Zou <nanhai.zou@intel.com>
---
 migration/multifd-qpl.c | 284 +++++++++++++++++++++++++++++++++++++++-
 1 file changed, 280 insertions(+), 4 deletions(-)

diff --git a/migration/multifd-qpl.c b/migration/multifd-qpl.c
index 89fa51091a..9a1fddbdd0 100644
--- a/migration/multifd-qpl.c
+++ b/migration/multifd-qpl.c
@@ -13,6 +13,7 @@
 #include "qemu/osdep.h"
 #include "qemu/module.h"
 #include "qapi/error.h"
+#include "exec/ramblock.h"
 #include "migration.h"
 #include "multifd.h"
 #include "qpl/qpl.h"
@@ -204,6 +205,139 @@ static void multifd_qpl_send_cleanup(MultiFDSendParams *p, Error **errp)
     p->iov = NULL;
 }
 
+/**
+ * multifd_qpl_prepare_job: prepare a compression or decompression job
+ *
+ * Prepare a compression or decompression job and configure job attributes
+ * including job compression level and flags.
+ *
+ * @job: pointer to the QplData structure
+ * @is_compression: compression or decompression indication
+ * @input: pointer to the input data buffer
+ * @input_len: the length of the input data
+ * @output: pointer to the output data buffer
+ * @output_len: the size of the output data buffer
+ */
+static void multifd_qpl_prepare_job(qpl_job *job, bool is_compression,
+                                    uint8_t *input, uint32_t input_len,
+                                    uint8_t *output, uint32_t output_len)
+{
+    job->op = is_compression ? qpl_op_compress : qpl_op_decompress;
+    job->next_in_ptr = input;
+    job->next_out_ptr = output;
+    job->available_in = input_len;
+    job->available_out = output_len;
+    job->flags = QPL_FLAG_FIRST | QPL_FLAG_LAST | QPL_FLAG_OMIT_VERIFY;
+    /* only supports one compression level */
+    job->level = 1;
+}
+
+/**
+ * multifd_qpl_build_packet: build a qpl compressed data packet
+ *
+ * The qpl compressed data packet consists of two parts, one part stores
+ * the compressed length of each page, and the other part is the compressed
+ * data of each page. The zbuf_hdr stores the compressed length of all pages,
+ * and use a separate IOV to store the compressed data of each page.
+ *
+ * @qpl: pointer to the QplData structure
+ * @p: Params for the channel that we are using
+ * @idx: The index of the compressed length array
+ * @addr: pointer to the compressed data
+ * @len: The length of the compressed data
+ */
+static void multifd_qpl_build_packet(QplData *qpl, MultiFDSendParams *p,
+                                     uint32_t idx, uint8_t *addr, uint32_t len)
+{
+    qpl->zbuf_hdr[idx] = cpu_to_be32(len);
+    p->iov[p->iovs_num].iov_base = addr;
+    p->iov[p->iovs_num].iov_len = len;
+    p->iovs_num++;
+    p->next_packet_size += len;
+}
+
+/**
+ * multifd_qpl_compress_pages: compress normal pages
+ *
+ * Each normal page will be compressed independently, and the compression jobs
+ * will be submitted to the IAA hardware in non-blocking mode, waiting for all
+ * jobs to be completed and filling the compressed length and data into the
+ * sending IOVs. If IAA device is not available, the software path is used.
+ *
+ * Returns 0 for success or -1 for error
+ *
+ * @p: Params for the channel that we are using
+ * @errp: pointer to an error
+ */
+static int multifd_qpl_compress_pages(MultiFDSendParams *p, Error **errp)
+{
+    qpl_status status;
+    QplData *qpl = p->compress_data;
+    MultiFDPages_t *pages = p->pages;
+    uint8_t *zbuf = qpl->zbuf;
+    uint8_t *host = pages->block->host;
+    uint32_t job_num = pages->normal_num;
+    qpl_job *job = NULL;
+
+    assert(job_num <= qpl->total_job_num);
+    /* submit all compression jobs */
+    for (int i = 0; i < job_num; i++) {
+        job = qpl->job_array[i];
+        multifd_qpl_prepare_job(job, true, host + pages->offset[i],
+                                p->page_size, zbuf, p->page_size - 1);
+        /* if hardware path(IAA) is unavailable, call the software path */
+        if (!qpl->iaa_avail) {
+            status = qpl_execute_job(job);
+            if (status == QPL_STS_OK) {
+                multifd_qpl_build_packet(qpl, p, i, zbuf, job->total_out);
+            } else if (status == QPL_STS_MORE_OUTPUT_NEEDED) {
+                /* compressed length exceeds page size, send page directly */
+                multifd_qpl_build_packet(qpl, p, i, host + pages->offset[i],
+                                         p->page_size);
+            } else {
+                error_setg(errp, "multifd %u: qpl_execute_job error %d",
+                           p->id, status);
+                return -1;
+            }
+            zbuf += p->page_size;
+            continue;
+        }
+retry:
+        status = qpl_submit_job(job);
+        if (status == QPL_STS_OK) {
+            zbuf += p->page_size;
+        } else if (status == QPL_STS_QUEUES_ARE_BUSY_ERR) {
+            goto retry;
+        } else {
+            error_setg(errp, "multifd %u: qpl_submit_job failed with error %d",
+                       p->id, status);
+            return -1;
+        }
+    }
+    if (!qpl->iaa_avail) {
+        goto done;
+    }
+    /* wait all jobs to complete for hardware(IAA) path */
+    for (int i = 0; i < job_num; i++) {
+        job = qpl->job_array[i];
+        status = qpl_wait_job(job);
+        if (status == QPL_STS_OK) {
+            multifd_qpl_build_packet(qpl, p, i, qpl->zbuf + (p->page_size * i),
+                                     job->total_out);
+        } else if (status == QPL_STS_MORE_OUTPUT_NEEDED) {
+            /* compressed data length exceeds page size, send page directly */
+            multifd_qpl_build_packet(qpl, p, i, host + pages->offset[i],
+                                     p->page_size);
+        } else {
+            error_setg(errp, "multifd %u: qpl_wait_job failed with error %d",
+                       p->id, status);
+            return -1;
+        }
+    }
+done:
+    return 0;
+}
+
 /**
  * multifd_qpl_send_prepare: prepare data to be able to send
  *
@@ -217,8 +351,28 @@ static void multifd_qpl_send_cleanup(MultiFDSendParams *p, Error **errp)
  */
 static int multifd_qpl_send_prepare(MultiFDSendParams *p, Error **errp)
 {
-    /* Implement in next patch */
-    return -1;
+    QplData *qpl = p->compress_data;
+    uint32_t hdr_size;
+
+    if (!multifd_send_prepare_common(p)) {
+        goto out;
+    }
+
+    assert(p->pages->normal_num <= qpl->total_job_num);
+    hdr_size = p->pages->normal_num * sizeof(uint32_t);
+    /* prepare the header that stores the lengths of all compressed data */
+    p->iov[1].iov_base = (uint8_t *) qpl->zbuf_hdr;
+    p->iov[1].iov_len = hdr_size;
+    p->iovs_num++;
+    p->next_packet_size += hdr_size;
+    if (multifd_qpl_compress_pages(p, errp) != 0) {
+        return -1;
+    }
+
+out:
+    p->flags |= MULTIFD_FLAG_QPL;
+    multifd_send_fill_packet(p);
+    return 0;
 }
 
 /**
@@ -256,6 +410,88 @@ static void multifd_qpl_recv_cleanup(MultiFDRecvParams *p)
     p->compress_data = NULL;
 }
 
+/**
+ * multifd_qpl_decompress_pages: decompress normal pages
+ *
+ * Each compressed page will be decompressed independently, and the
+ * decompression jobs will be submitted to the IAA hardware in non-blocking
+ * mode, waiting for all jobs to be completed and loading the decompressed
+ * data into guest memory. If IAA device is not available, the software path
+ * is used.
+ *
+ * Returns 0 for success or -1 for error
+ *
+ * @p: Params for the channel that we are using
+ * @errp: pointer to an error
+ */
+static int multifd_qpl_decompress_pages(MultiFDRecvParams *p, Error **errp)
+{
+    qpl_status status;
+    qpl_job *job;
+    QplData *qpl = p->compress_data;
+    uint32_t job_num = p->normal_num;
+    uint32_t off = 0;
+
+    assert(job_num <= qpl->total_job_num);
+    /* submit all decompression jobs */
+    for (int i = 0; i < job_num; i++) {
+        /* if the data size is the same as the page size, load it directly */
+        if (qpl->zbuf_hdr[i] == p->page_size) {
+            memcpy(p->host + p->normal[i], qpl->zbuf + off, p->page_size);
+            off += p->page_size;
+            continue;
+        }
+        job = qpl->job_array[i];
+        multifd_qpl_prepare_job(job, false, qpl->zbuf + off, qpl->zbuf_hdr[i],
+                                p->host + p->normal[i], p->page_size);
+        /* if hardware path(IAA) is unavailable, call the software path */
+        if (!qpl->iaa_avail) {
+            status = qpl_execute_job(job);
+            if (status == QPL_STS_OK) {
+                off += qpl->zbuf_hdr[i];
+                continue;
+            }
+            error_setg(errp, "multifd %u: qpl_execute_job failed with error %d",
+                       p->id, status);
+            return -1;
+        }
+retry:
+        status = qpl_submit_job(job);
+        if (status == QPL_STS_OK) {
+            off += qpl->zbuf_hdr[i];
+        } else if (status == QPL_STS_QUEUES_ARE_BUSY_ERR) {
+            goto retry;
+        } else {
+            error_setg(errp, "multifd %u: qpl_submit_job failed with error %d",
+                       p->id, status);
+            return -1;
+        }
+    }
+    if (!qpl->iaa_avail) {
+        goto done;
+    }
+    /* wait all jobs to complete for hardware(IAA) path */
+    for (int i = 0; i < job_num; i++) {
+        if (qpl->zbuf_hdr[i] == p->page_size) {
+            continue;
+        }
+        job = qpl->job_array[i];
+        status = qpl_wait_job(job);
+        if (status != QPL_STS_OK) {
+            error_setg(errp, "multifd %u: qpl_wait_job failed with error %d",
+                       p->id, status);
+            return -1;
+        }
+        if (job->total_out != p->page_size) {
+            error_setg(errp, "multifd %u: decompressed len %u, expected len %u",
+                       p->id, job->total_out, p->page_size);
+            return -1;
+        }
+    }
+done:
+    return 0;
+}
+
 /**
  * multifd_qpl_recv: read the data from the channel into actual pages
  *
@@ -269,8 +505,48 @@ static void multifd_qpl_recv_cleanup(MultiFDRecvParams *p)
  */
 static int multifd_qpl_recv(MultiFDRecvParams *p, Error **errp)
 {
-    /* Implement in next patch */
-    return -1;
+    QplData *qpl = p->compress_data;
+    uint32_t in_size = p->next_packet_size;
+    uint32_t flags = p->flags & MULTIFD_FLAG_COMPRESSION_MASK;
+    uint32_t hdr_len = p->normal_num * sizeof(uint32_t);
+    uint32_t data_len = 0;
+    int ret;
+
+    if (flags != MULTIFD_FLAG_QPL) {
+        error_setg(errp, "multifd %u: flags received %x flags expected %x",
+                   p->id, flags, MULTIFD_FLAG_QPL);
+        return -1;
+    }
+    multifd_recv_zero_page_process(p);
+    if (!p->normal_num) {
+        assert(in_size == 0);
+        return 0;
+    }
+
+    /* read compressed data lengths */
+    assert(hdr_len < in_size);
+    ret = qio_channel_read_all(p->c, (void *) qpl->zbuf_hdr, hdr_len, errp);
+    if (ret != 0) {
+        return ret;
+    }
+    assert(p->normal_num <= qpl->total_job_num);
+    for (int i = 0; i < p->normal_num; i++) {
+        qpl->zbuf_hdr[i] = be32_to_cpu(qpl->zbuf_hdr[i]);
+        data_len += qpl->zbuf_hdr[i];
+        assert(qpl->zbuf_hdr[i] <= p->page_size);
+    }
+
+    /* read compressed data */
+    assert(in_size == hdr_len + data_len);
+    ret = qio_channel_read_all(p->c, (void *) qpl->zbuf, data_len, errp);
+    if (ret != 0) {
+        return ret;
+    }
+
+    if (multifd_qpl_decompress_pages(p, errp) != 0) {
+        return -1;
+    }
+    return 0;
 }
 
 static MultiFDMethods multifd_qpl_ops = {
-- 
2.39.3