Merge tag 'pull-migration-20220720c' of https://gitlab.com/dagrh/qemu into staging

Migration pull 2022-07-20

This replaces yesterdays pull and:
  a) Fixes some test build errors without TLS
  b) Reenabled the zlib acceleration on s390
     now that we have Ilya's fix

  Hyman's dirty page rate limit set
  Ilya's fix for zlib vs migration
  Peter's postcopy-preempt
  Cleanup from Dan
  zero-copy tidy ups from Leo
  multifd doc fix from Juan
  Revert disable of zlib acceleration on s390x

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

# gpg: Signature made Wed 20 Jul 2022 12:18:56 BST
# gpg:                using RSA key 45F5C71B4A0CB7FB977A9FA90516331EBC5BFDE7
# gpg: Good signature from "Dr. David Alan Gilbert (RH2) <dgilbert@redhat.com>" [full]
# Primary key fingerprint: 45F5 C71B 4A0C B7FB 977A  9FA9 0516 331E BC5B FDE7

* tag 'pull-migration-20220720c' of https://gitlab.com/dagrh/qemu: (30 commits)
  Revert "gitlab: disable accelerated zlib for s390x"
  migration: Avoid false-positive on non-supported scenarios for zero-copy-send
  multifd: Document the locking of MultiFD{Send/Recv}Params
  migration/multifd: Report to user when zerocopy not working
  Add dirty-sync-missed-zero-copy migration stat
  QIOChannelSocket: Fix zero-copy flush returning code 1 when nothing sent
  migration: remove unreachable code after reading data
  tests: Add postcopy preempt tests
  tests: Add postcopy tls recovery migration test
  tests: Add postcopy tls migration test
  tests: Move MigrateCommon upper
  migration: Respect postcopy request order in preemption mode
  migration: Enable TLS for preempt channel
  migration: Export tls-[creds|hostname|authz] params to cmdline too
  migration: Add helpers to detect TLS capability
  migration: Add property x-postcopy-preempt-break-huge
  migration: Create the postcopy preempt channel asynchronously
  migration: Postcopy recover with preempt enabled
  migration: Postcopy preemption enablement
  migration: Postcopy preemption preparation on channel creation
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 28 insertions, 3 deletions

diff --git a/migration/qemu-file.c b/migration/qemu-file.c
index 1e80d496b7..4f400c2e52 100644
--- a/migration/qemu-file.c
+++ b/migration/qemu-file.c
@@ -161,6 +161,33 @@ int qemu_file_get_error_obj(QEMUFile *f, Error **errp)
 }
 
 /*
+ * Get last error for either stream f1 or f2 with optional Error*.
+ * The error returned (non-zero) can be either from f1 or f2.
+ *
+ * If any of the qemufile* is NULL, then skip the check on that file.
+ *
+ * When there is no error on both qemufile, zero is returned.
+ */
+int qemu_file_get_error_obj_any(QEMUFile *f1, QEMUFile *f2, Error **errp)
+{
+    int ret = 0;
+
+    if (f1) {
+        ret = qemu_file_get_error_obj(f1, errp);
+        /* If there's already error detected, return */
+        if (ret) {
+            return ret;
+        }
+    }
+
+    if (f2) {
+        ret = qemu_file_get_error_obj(f2, errp);
+    }
+
+    return ret;
+}
+
+/*
  * Set the last error for stream f with optional Error*
  */
 void qemu_file_set_error_obj(QEMUFile *f, int ret, Error *err)
@@ -384,10 +411,8 @@ static ssize_t qemu_fill_buffer(QEMUFile *f)
         f->total_transferred += len;
     } else if (len == 0) {
         qemu_file_set_error_obj(f, -EIO, local_error);
-    } else if (len != -EAGAIN) {
-        qemu_file_set_error_obj(f, len, local_error);
     } else {
-        error_free(local_error);
+        qemu_file_set_error_obj(f, len, local_error);
     }
 
     return len;