[PATCH v7 6/7] migration/multifd: implement qpl compression and decompression

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

QPL compression and decompression will use IAA hardware first.
If IAA hardware is not available, it will automatically fall
back to QPL software path, if the software job also fails,
the uncompressed page is sent directly.

Signed-off-by: Yuan Liu <yuan1.liu@intel.com>
Reviewed-by: Nanhai Zou <nanhai.zou@intel.com>
---
 migration/multifd-qpl.c | 412 +++++++++++++++++++++++++++++++++++++++-
 1 file changed, 408 insertions(+), 4 deletions(-)

diff --git a/migration/multifd-qpl.c b/migration/multifd-qpl.c
index 6791a204d5..18b3384bd5 100644
--- a/migration/multifd-qpl.c
+++ b/migration/multifd-qpl.c
@@ -13,9 +13,14 @@
 #include "qemu/osdep.h"
 #include "qemu/module.h"
 #include "qapi/error.h"
+#include "qapi/qapi-types-migration.h"
+#include "exec/ramblock.h"
 #include "multifd.h"
 #include "qpl/qpl.h"
 
+/* Maximum number of retries to resubmit a job if IAA work queues are full */
+#define MAX_SUBMIT_RETRY_NUM (3)
+
 typedef struct {
     /* the QPL hardware path job */
     qpl_job *job;
@@ -260,6 +265,219 @@ static void multifd_qpl_send_cleanup(MultiFDSendParams *p, Error **errp)
     p->iov = NULL;
 }
 
+/**
+ * multifd_qpl_prepare_job: prepare the job
+ *
+ * Set the QPL job parameters and properties.
+ *
+ * @job: pointer to the qpl_job structure
+ * @is_compression: indicates compression and decompression
+ * @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 length of the output data
+ */
+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 compression level 1 */
+    job->level = 1;
+}
+
+/**
+ * multifd_qpl_prepare_job: prepare the compression job
+ *
+ * Set the compression job parameters and properties.
+ *
+ * @job: pointer to the qpl_job structure
+ * @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 length of the output data
+ */
+static void multifd_qpl_prepare_comp_job(qpl_job *job, uint8_t *input,
+                                         uint32_t input_len, uint8_t *output,
+                                         uint32_t output_len)
+{
+    multifd_qpl_prepare_job(job, true, input, input_len, output, output_len);
+}
+
+/**
+ * multifd_qpl_prepare_job: prepare the decompression job
+ *
+ * Set the decompression job parameters and properties.
+ *
+ * @job: pointer to the qpl_job structure
+ * @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 length of the output data
+ */
+static void multifd_qpl_prepare_decomp_job(qpl_job *job, uint8_t *input,
+                                           uint32_t input_len, uint8_t *output,
+                                           uint32_t output_len)
+{
+    multifd_qpl_prepare_job(job, false, input, input_len, output, output_len);
+}
+
+/**
+ * multifd_qpl_fill_iov: fill in the IOV
+ *
+ * Fill in the QPL packet IOV
+ *
+ * @p: Params for the channel being used
+ * @data: pointer to the IOV data
+ * @len: The length of the IOV data
+ */
+static void multifd_qpl_fill_iov(MultiFDSendParams *p, uint8_t *data,
+                                 uint32_t len)
+{
+    p->iov[p->iovs_num].iov_base = data;
+    p->iov[p->iovs_num].iov_len = len;
+    p->iovs_num++;
+    p->next_packet_size += len;
+}
+
+/**
+ * multifd_qpl_fill_packet: fill the compressed page into the QPL packet
+ *
+ * Fill the compressed page length and IOV into the QPL packet
+ *
+ * @idx: The index of the compressed length array
+ * @p: Params for the channel being used
+ * @data: pointer to the compressed page buffer
+ * @len: The length of the compressed page
+ */
+static void multifd_qpl_fill_packet(uint32_t idx, MultiFDSendParams *p,
+                                    uint8_t *data, uint32_t len)
+{
+    QplData *qpl = p->compress_data;
+
+    qpl->zlen[idx] = cpu_to_be32(len);
+    multifd_qpl_fill_iov(p, data, len);
+}
+
+/**
+ * multifd_qpl_submit_job: submit a job to the hardware
+ *
+ * Submit a QPL hardware job to the IAA device
+ *
+ * Returns true if the job is submitted successfully, otherwise false.
+ *
+ * @job: pointer to the qpl_job structure
+ */
+static bool multifd_qpl_submit_job(qpl_job *job)
+{
+    qpl_status status;
+    uint32_t num = 0;
+
+retry:
+    status = qpl_submit_job(job);
+    if (status == QPL_STS_QUEUES_ARE_BUSY_ERR) {
+        if (num < MAX_SUBMIT_RETRY_NUM) {
+            num++;
+            goto retry;
+        }
+    }
+    return (status == QPL_STS_OK);
+}
+
+/**
+ * multifd_qpl_compress_pages_slow_path: compress pages using slow path
+ *
+ * Compress the pages using software. If compression fails, the page will
+ * be sent directly.
+ *
+ * @p: Params for the channel being used
+ */
+static void multifd_qpl_compress_pages_slow_path(MultiFDSendParams *p)
+{
+    QplData *qpl = p->compress_data;
+    uint32_t size = p->page_size;
+    qpl_job *job = qpl->sw_job;
+    uint8_t *zbuf = qpl->zbuf;
+    uint8_t *buf;
+
+    for (int i = 0; i < p->pages->normal_num; i++) {
+        buf = p->pages->block->host + p->pages->offset[i];
+        /* Set output length to less than the page to reduce decompression */
+        multifd_qpl_prepare_comp_job(job, buf, size, zbuf, size - 1);
+        if (qpl_execute_job(job) == QPL_STS_OK) {
+            multifd_qpl_fill_packet(i, p, zbuf, job->total_out);
+        } else {
+            /* send the page directly */
+            multifd_qpl_fill_packet(i, p, buf, size);
+        }
+        zbuf += size;
+    }
+}
+
+/**
+ * multifd_qpl_compress_pages: compress pages
+ *
+ * Submit the pages to the IAA hardware for compression. If hardware
+ * compression fails, it falls back to software compression. If software
+ * compression also fails, the page is sent directly
+ *
+ * @p: Params for the channel being used
+ */
+static void multifd_qpl_compress_pages(MultiFDSendParams *p)
+{
+    QplData *qpl = p->compress_data;
+    MultiFDPages_t *pages = p->pages;
+    uint32_t size = p->page_size;
+    QplHwJob *hw_job;
+    uint8_t *buf;
+    uint8_t *zbuf;
+
+    for (int i = 0; i < pages->normal_num; i++) {
+        buf = pages->block->host + pages->offset[i];
+        zbuf = qpl->zbuf + (size * i);
+        hw_job = &qpl->hw_jobs[i];
+        /* Set output length to less than the page to reduce decompression */
+        multifd_qpl_prepare_comp_job(hw_job->job, buf, size, zbuf, size - 1);
+        if (multifd_qpl_submit_job(hw_job->job)) {
+            hw_job->fallback_sw_path = false;
+        } else {
+            hw_job->fallback_sw_path = true;
+            /* Set output length less than page size to reduce decompression */
+            multifd_qpl_prepare_comp_job(qpl->sw_job, buf, size, zbuf,
+                                         size - 1);
+            if (qpl_execute_job(qpl->sw_job) == QPL_STS_OK) {
+                hw_job->sw_output = zbuf;
+                hw_job->sw_output_len = qpl->sw_job->total_out;
+            } else {
+                hw_job->sw_output = buf;
+                hw_job->sw_output_len = size;
+            }
+        }
+    }
+
+    for (int i = 0; i < pages->normal_num; i++) {
+        buf = pages->block->host + pages->offset[i];
+        zbuf = qpl->zbuf + (size * i);
+        hw_job = &qpl->hw_jobs[i];
+        if (hw_job->fallback_sw_path) {
+            multifd_qpl_fill_packet(i, p, hw_job->sw_output,
+                                    hw_job->sw_output_len);
+            continue;
+        }
+        if (qpl_wait_job(hw_job->job) == QPL_STS_OK) {
+            multifd_qpl_fill_packet(i, p, zbuf, hw_job->job->total_out);
+        } else {
+            /* send the page directly */
+            multifd_qpl_fill_packet(i, p, buf, size);
+        }
+    }
+}
+
 /**
  * multifd_qpl_send_prepare: prepare data to be able to send
  *
@@ -273,8 +491,26 @@ 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 len = 0;
+
+    if (!multifd_send_prepare_common(p)) {
+        goto out;
+    }
+
+    /* The first IOV is used to store the compressed page lengths */
+    len = p->pages->normal_num * sizeof(uint32_t);
+    multifd_qpl_fill_iov(p, (uint8_t *) qpl->zlen, len);
+    if (qpl->hw_avail) {
+        multifd_qpl_compress_pages(p);
+    } else {
+        multifd_qpl_compress_pages_slow_path(p);
+    }
+
+out:
+    p->flags |= MULTIFD_FLAG_QPL;
+    multifd_send_fill_packet(p);
+    return 0;
 }
 
 /**
@@ -312,6 +548,134 @@ static void multifd_qpl_recv_cleanup(MultiFDRecvParams *p)
     p->compress_data = NULL;
 }
 
+/**
+ * multifd_qpl_process_and_check_job: process and check a QPL job
+ *
+ * Process the job and check whether the job output length is the
+ * same as the specified length
+ *
+ * Returns true if the job execution succeeded and the output length
+ * is equal to the specified length, otherwise false.
+ *
+ * @job: pointer to the qpl_job structure
+ * @is_hardware: indicates whether the job is a hardware job
+ * @len: Specified output length
+ * @errp: pointer to an error
+ */
+static bool multifd_qpl_process_and_check_job(qpl_job *job, bool is_hardware,
+                                              uint32_t len, Error **errp)
+{
+    qpl_status status;
+
+    status = (is_hardware ? qpl_wait_job(job) : qpl_execute_job(job));
+    if (status != QPL_STS_OK) {
+        error_setg(errp, "qpl_execute_job failed with error %d", status);
+        return false;
+    }
+    if (job->total_out != len) {
+        error_setg(errp, "qpl decompressed len %u, expected len %u",
+                   job->total_out, len);
+        return false;
+    }
+    return true;
+}
+
+/**
+ * multifd_qpl_decompress_pages_slow_path: decompress pages using slow path
+ *
+ * Decompress the pages using software
+ *
+ * Returns 0 on success or -1 on error
+ *
+ * @p: Params for the channel being used
+ * @errp: pointer to an error
+ */
+static int multifd_qpl_decompress_pages_slow_path(MultiFDRecvParams *p,
+                                                  Error **errp)
+{
+    QplData *qpl = p->compress_data;
+    uint32_t size = p->page_size;
+    qpl_job *job = qpl->sw_job;
+    uint8_t *zbuf = qpl->zbuf;
+    uint8_t *addr;
+    uint32_t len;
+
+    for (int i = 0; i < p->normal_num; i++) {
+        len = qpl->zlen[i];
+        addr = p->host + p->normal[i];
+        /* the page is uncompressed, load it */
+        if (len == size) {
+            memcpy(addr, zbuf, size);
+            zbuf += size;
+            continue;
+        }
+        multifd_qpl_prepare_decomp_job(job, zbuf, len, addr, size);
+        if (!multifd_qpl_process_and_check_job(job, false, size, errp)) {
+            return -1;
+        }
+        zbuf += len;
+    }
+    return 0;
+}
+
+/**
+ * multifd_qpl_decompress_pages: decompress pages
+ *
+ * Decompress the pages using the IAA hardware. If hardware
+ * decompression fails, it falls back to software decompression.
+ *
+ * Returns 0 on success or -1 on error
+ *
+ * @p: Params for the channel being used
+ * @errp: pointer to an error
+ */
+static int multifd_qpl_decompress_pages(MultiFDRecvParams *p, Error **errp)
+{
+    QplData *qpl = p->compress_data;
+    uint32_t size = p->page_size;
+    uint8_t *zbuf = qpl->zbuf;
+    uint8_t *addr;
+    uint32_t len;
+    qpl_job *job;
+
+    for (int i = 0; i < p->normal_num; i++) {
+        addr = p->host + p->normal[i];
+        len = qpl->zlen[i];
+        /* the page is uncompressed if received length equals the page size */
+        if (len == size) {
+            memcpy(addr, zbuf, size);
+            zbuf += size;
+            continue;
+        }
+
+        job = qpl->hw_jobs[i].job;
+        multifd_qpl_prepare_decomp_job(job, zbuf, len, addr, size);
+        if (multifd_qpl_submit_job(job)) {
+            qpl->hw_jobs[i].fallback_sw_path = false;
+        } else {
+            qpl->hw_jobs[i].fallback_sw_path = true;
+            job = qpl->sw_job;
+            multifd_qpl_prepare_decomp_job(job, zbuf, len, addr, size);
+            if (!multifd_qpl_process_and_check_job(job, false, size, errp)) {
+                return -1;
+            }
+        }
+        zbuf += len;
+    }
+
+    for (int i = 0; i < p->normal_num; i++) {
+        /* ignore pages that have already been processed */
+        if (qpl->zlen[i] == size || qpl->hw_jobs[i].fallback_sw_path) {
+            continue;
+        }
+
+        job = qpl->hw_jobs[i].job;
+        if (!multifd_qpl_process_and_check_job(job, true, size, errp)) {
+            return -1;
+        }
+    }
+    return 0;
+}
 /**
  * multifd_qpl_recv: read the data from the channel into actual pages
  *
@@ -325,8 +689,48 @@ 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 len = 0;
+    uint32_t zbuf_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 page lengths */
+    len = p->normal_num * sizeof(uint32_t);
+    assert(len < in_size);
+    ret = qio_channel_read_all(p->c, (void *) qpl->zlen, len, errp);
+    if (ret != 0) {
+        return ret;
+    }
+    for (int i = 0; i < p->normal_num; i++) {
+        qpl->zlen[i] = be32_to_cpu(qpl->zlen[i]);
+        assert(qpl->zlen[i] <= p->page_size);
+        zbuf_len += qpl->zlen[i];
+    }
+
+    /* read compressed pages */
+    assert(in_size == len + zbuf_len);
+    ret = qio_channel_read_all(p->c, (void *) qpl->zbuf, zbuf_len, errp);
+    if (ret != 0) {
+        return ret;
+    }
+
+    if (qpl->hw_avail) {
+        return multifd_qpl_decompress_pages(p, errp);
+    }
+    return multifd_qpl_decompress_pages_slow_path(p, errp);
 }
 
 static MultiFDMethods multifd_qpl_ops = {
-- 
2.43.0