qemu-kvm/kvm-migration-Never-call-twice-qemu_target_page_size.patch

From 6a9a5a2809cbbe2982df156722b88efeec998e3d Mon Sep 17 00:00:00 2001
From: Juan Quintela <quintela@redhat.com>
Date: Wed, 18 May 2022 02:52:22 -0300
Subject: [PATCH 01/37] migration: Never call twice qemu_target_page_size()
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RH-Author: Leonardo Brás <leobras@redhat.com>
RH-MergeRequest: 191: MSG_ZEROCOPY + Multifd @ rhel8.7
RH-Commit: [1/26] 809ca84dec80bafc1959df8c9e57f482ee752a97
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>

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
(cherry picked from commit 144fa06b3431e806057ce1438338395b35a3e544)
Signed-off-by: Leonardo Bras <leobras@redhat.com>
---
 migration/migration.c | 7 ++++---
 migration/multifd.c   | 7 ++++---
 migration/savevm.c    | 5 +++--
 3 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/migration/migration.c b/migration/migration.c
index a87ff01b81..8a13294da6 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -992,6 +992,8 @@ static void populate_time_info(MigrationInfo *info, MigrationState *s)
 
 static void populate_ram_info(MigrationInfo *info, MigrationState *s)
 {
+    size_t page_size = qemu_target_page_size();
+
     info->has_ram = true;
     info->ram = g_malloc0(sizeof(*info->ram));
     info->ram->transferred = ram_counters.transferred;
@@ -1000,12 +1002,11 @@ static void populate_ram_info(MigrationInfo *info, MigrationState *s)
     /* legacy value.  It is not used anymore */
     info->ram->skipped = 0;
     info->ram->normal = ram_counters.normal;
-    info->ram->normal_bytes = ram_counters.normal *
-        qemu_target_page_size();
+    info->ram->normal_bytes = ram_counters.normal * page_size;
     info->ram->mbps = s->mbps;
     info->ram->dirty_sync_count = ram_counters.dirty_sync_count;
     info->ram->postcopy_requests = ram_counters.postcopy_requests;
-    info->ram->page_size = qemu_target_page_size();
+    info->ram->page_size = page_size;
     info->ram->multifd_bytes = ram_counters.multifd_bytes;
     info->ram->pages_per_second = s->pages_per_second;
 
diff --git a/migration/multifd.c b/migration/multifd.c
index 7c9deb1921..8125d0015c 100644
--- a/migration/multifd.c
+++ b/migration/multifd.c
@@ -289,7 +289,8 @@ static void multifd_send_fill_packet(MultiFDSendParams *p)
 static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp)
 {
     MultiFDPacket_t *packet = p->packet;
-    uint32_t pages_max = MULTIFD_PACKET_SIZE / qemu_target_page_size();
+    size_t page_size = qemu_target_page_size();
+    uint32_t pages_max = MULTIFD_PACKET_SIZE / page_size;
     RAMBlock *block;
     int i;
 
@@ -358,14 +359,14 @@ static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp)
     for (i = 0; i < p->pages->used; i++) {
         uint64_t offset = be64_to_cpu(packet->offset[i]);
 
-        if (offset > (block->used_length - qemu_target_page_size())) {
+        if (offset > (block->used_length - page_size)) {
             error_setg(errp, "multifd: offset too long %" PRIu64
                        " (max " RAM_ADDR_FMT ")",
                        offset, block->used_length);
             return -1;
         }
         p->pages->iov[i].iov_base = block->host + offset;
-        p->pages->iov[i].iov_len = qemu_target_page_size();
+        p->pages->iov[i].iov_len = page_size;
     }
 
     return 0;
diff --git a/migration/savevm.c b/migration/savevm.c
index d59e976d50..0bef031acb 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1685,6 +1685,7 @@ static int loadvm_postcopy_handle_advise(MigrationIncomingState *mis,
 {
     PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_ADVISE);
     uint64_t remote_pagesize_summary, local_pagesize_summary, remote_tps;
+    size_t page_size = qemu_target_page_size();
     Error *local_err = NULL;
 
     trace_loadvm_postcopy_handle_advise();
@@ -1741,13 +1742,13 @@ static int loadvm_postcopy_handle_advise(MigrationIncomingState *mis,
     }
 
     remote_tps = qemu_get_be64(mis->from_src_file);
-    if (remote_tps != qemu_target_page_size()) {
+    if (remote_tps != page_size) {
         /*
          * Again, some differences could be dealt with, but for now keep it
          * simple.
          */
         error_report("Postcopy needs matching target page sizes (s=%d d=%zd)",
-                     (int)remote_tps, qemu_target_page_size());
+                     (int)remote_tps, page_size);
         return -1;
     }
 
-- 
2.35.3