From 1181a9cbcaf37a82aa7bf117ef209f554b8c4a71 Mon Sep 17 00:00:00 2001

From: Juan Quintela <quintela@redhat.com>

Date: Wed, 18 May 2022 02:52:24 -0300

Subject: [PATCH 11/37] multifd: Move iov from pages to params

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RH-Author: Leonardo Brás <leobras@redhat.com>

RH-MergeRequest: 191: MSG_ZEROCOPY + Multifd @ rhel8.7

RH-Commit: [11/26] 24dff3ef68cf3327811242193502319ed3e3940a

RH-Bugzilla: 2072049

RH-Acked-by: Peter Xu <peterx@redhat.com>

RH-Acked-by: Daniel P. Berrangé <berrange@redhat.com>

RH-Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

This will allow us to reduce the number of system calls on the next patch.

Signed-off-by: Juan Quintela <quintela@redhat.com>

(cherry picked from commit 226468ba3dea950ab4bb0b729878dde25812da1c)

Signed-off-by: Leonardo Bras <leobras@redhat.com>

---

 migration/multifd.c | 34 ++++++++++++++++++++++++----------

 migration/multifd.h |  8 ++++++--

 2 files changed, 30 insertions(+), 12 deletions(-)

diff --git a/migration/multifd.c b/migration/multifd.c

index d0d19470f9..5004f394aa 100644

--- a/migration/multifd.c

+++ b/migration/multifd.c

@@ -86,7 +86,16 @@ static void nocomp_send_cleanup(MultiFDSendParams *p, Error **errp)

  */

 static int nocomp_send_prepare(MultiFDSendParams *p, Error **errp)

 {

-    p->next_packet_size = p->pages->num * qemu_target_page_size();

+    MultiFDPages_t *pages = p->pages;

+    size_t page_size = qemu_target_page_size();

+

+    for (int i = 0; i < p->pages->num; i++) {

+        p->iov[p->iovs_num].iov_base = pages->block->host + pages->offset[i];

+        p->iov[p->iovs_num].iov_len = page_size;

+        p->iovs_num++;

+    }

+

+    p->next_packet_size = p->pages->num * page_size;

     p->flags |= MULTIFD_FLAG_NOCOMP;

     return 0;

 }

@@ -104,7 +113,7 @@ static int nocomp_send_prepare(MultiFDSendParams *p, Error **errp)

  */

 static int nocomp_send_write(MultiFDSendParams *p, uint32_t used, Error **errp)

 {

-    return qio_channel_writev_all(p->c, p->pages->iov, used, errp);

+    return qio_channel_writev_all(p->c, p->iov, p->iovs_num, errp);

 }

 /**

@@ -146,13 +155,18 @@ static void nocomp_recv_cleanup(MultiFDRecvParams *p)

 static int nocomp_recv_pages(MultiFDRecvParams *p, Error **errp)

 {

     uint32_t flags = p->flags & MULTIFD_FLAG_COMPRESSION_MASK;

+    size_t page_size = qemu_target_page_size();

     if (flags != MULTIFD_FLAG_NOCOMP) {

         error_setg(errp, "multifd %u: flags received %x flags expected %x",

                    p->id, flags, MULTIFD_FLAG_NOCOMP);

         return -1;

     }

-    return qio_channel_readv_all(p->c, p->pages->iov, p->pages->num, errp);

+    for (int i = 0; i < p->pages->num; i++) {

+        p->iov[i].iov_base = p->pages->block->host + p->pages->offset[i];

+        p->iov[i].iov_len = page_size;

+    }

+    return qio_channel_readv_all(p->c, p->iov, p->pages->num, errp);

 }

 static MultiFDMethods multifd_nocomp_ops = {

@@ -242,7 +256,6 @@ static MultiFDPages_t *multifd_pages_init(size_t size)

     MultiFDPages_t *pages = g_new0(MultiFDPages_t, 1);

     pages->allocated = size;

-    pages->iov = g_new0(struct iovec, size);

     pages->offset = g_new0(ram_addr_t, size);

     return pages;

@@ -254,8 +267,6 @@ static void multifd_pages_clear(MultiFDPages_t *pages)

     pages->allocated = 0;

     pages->packet_num = 0;

     pages->block = NULL;

-    g_free(pages->iov);

-    pages->iov = NULL;

     g_free(pages->offset);

     pages->offset = NULL;

     g_free(pages);

@@ -365,8 +376,6 @@ static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp)

             return -1;

         }

         p->pages->offset[i] = offset;

-        p->pages->iov[i].iov_base = block->host + offset;

-        p->pages->iov[i].iov_len = page_size;

     }

     return 0;

@@ -470,8 +479,6 @@ int multifd_queue_page(QEMUFile *f, RAMBlock *block, ram_addr_t offset)

     if (pages->block == block) {

         pages->offset[pages->num] = offset;

-        pages->iov[pages->num].iov_base = block->host + offset;

-        pages->iov[pages->num].iov_len = qemu_target_page_size();

         pages->num++;

         if (pages->num < pages->allocated) {

@@ -564,6 +571,8 @@ void multifd_save_cleanup(void)

         p->packet_len = 0;

         g_free(p->packet);

         p->packet = NULL;

+        g_free(p->iov);

+        p->iov = NULL;

         multifd_send_state->ops->send_cleanup(p, &local_err);

         if (local_err) {

             migrate_set_error(migrate_get_current(), local_err);

@@ -651,6 +660,7 @@ static void *multifd_send_thread(void *opaque)

             uint32_t used = p->pages->num;

             uint64_t packet_num = p->packet_num;

             uint32_t flags = p->flags;

+            p->iovs_num = 0;

             if (used) {

                 ret = multifd_send_state->ops->send_prepare(p, &local_err);

@@ -919,6 +929,7 @@ int multifd_save_setup(Error **errp)

         p->packet->version = cpu_to_be32(MULTIFD_VERSION);

         p->name = g_strdup_printf("multifdsend_%d", i);

         p->tls_hostname = g_strdup(s->hostname);

+        p->iov = g_new0(struct iovec, page_count);

         socket_send_channel_create(multifd_new_send_channel_async, p);

     }

@@ -1018,6 +1029,8 @@ int multifd_load_cleanup(Error **errp)

         p->packet_len = 0;

         g_free(p->packet);

         p->packet = NULL;

+        g_free(p->iov);

+        p->iov = NULL;

         multifd_recv_state->ops->recv_cleanup(p);

     }

     qemu_sem_destroy(&multifd_recv_state->sem_sync);

@@ -1158,6 +1171,7 @@ int multifd_load_setup(Error **errp)

                       + sizeof(uint64_t) * page_count;

         p->packet = g_malloc0(p->packet_len);

         p->name = g_strdup_printf("multifdrecv_%d", i);

+        p->iov = g_new0(struct iovec, page_count);

     }

     for (i = 0; i < thread_count; i++) {

diff --git a/migration/multifd.h b/migration/multifd.h

index e57adc783b..c3f18af364 100644

--- a/migration/multifd.h

+++ b/migration/multifd.h

@@ -62,8 +62,6 @@ typedef struct {

     uint64_t packet_num;

     /* offset of each page */

     ram_addr_t *offset;

-    /* pointer to each page */

-    struct iovec *iov;

     RAMBlock *block;

 } MultiFDPages_t;

@@ -110,6 +108,10 @@ typedef struct {

     uint64_t num_pages;

     /* syncs main thread and channels */

     QemuSemaphore sem_sync;

+    /* buffers to send */

+    struct iovec *iov;

+    /* number of iovs used */

+    uint32_t iovs_num;

     /* used for compression methods */

     void *data;

 }  MultiFDSendParams;

@@ -149,6 +151,8 @@ typedef struct {

     uint64_t num_pages;

     /* syncs main thread and channels */

     QemuSemaphore sem_sync;

+    /* buffers to recv */

+    struct iovec *iov;

     /* used for de-compression methods */

     void *data;

 } MultiFDRecvParams;

-- 

2.35.3