commit 271a1940e91a32fab6165841279f250204f53ae4
author Peter Xu <peterx@redhat.com> Fri Jun 13 10:12:10 2025 -0400
committer Fabiano Rosas <farosas@suse.de> Fri Jul 11 10:37:38 2025 -0300
tree 0f07c6bdb4ca385b72698154154550fd027575c0
parent a098761f63e019b75a23575bb8d5a520c0dbce64

migration/postcopy: Add blocktime fault counts per-vcpu

Add a field to count how many remote faults one vCPU has taken.  So far
it's still not used, but will be soon.

Reviewed-by: Fabiano Rosas <farosas@suse.de>
Link: https://lore.kernel.org/r/20250613141217.474825-8-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>

migration/postcopy-ram.c

diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index 9dfa92a..15ea106 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -116,6 +116,8 @@
     uint64_t *vcpu_blocktime_start;
     /* blocktime per vCPU */
     uint64_t *vcpu_blocktime_total;
+    /* count of faults per vCPU */
+    uint64_t *vcpu_faults_count;
     /* page address per vCPU */
     uintptr_t *vcpu_addr;
     /* total blocktime when all vCPUs are stopped */
@@ -136,6 +138,7 @@
 {
     g_free(ctx->vcpu_blocktime_start);
     g_free(ctx->vcpu_blocktime_total);
+    g_free(ctx->vcpu_faults_count);
     g_free(ctx->vcpu_addr);
     g_free(ctx);
 }
@@ -155,6 +158,7 @@
 
     ctx->vcpu_blocktime_start = g_new0(uint64_t, smp_cpus);
     ctx->vcpu_blocktime_total = g_new0(uint64_t, smp_cpus);
+    ctx->vcpu_faults_count = g_new0(uint64_t, smp_cpus);
     ctx->vcpu_addr = g_new0(uintptr_t, smp_cpus);
     ctx->exit_notifier.notify = migration_exit_cb;
     qemu_add_exit_notifier(&ctx->exit_notifier);
@@ -857,6 +861,7 @@
     dc->last_begin = current;
     dc->vcpu_blocktime_start[cpu] = current;
     dc->vcpu_addr[cpu] = addr;
+    dc->vcpu_faults_count[cpu]++;
 
     /*
      * The caller should only inject a blocktime entry when the page is