qemu-kvm/kvm-QIOChannelSocket-Fix-zero-copy-flush-returning-code-.patch
Miroslav Rezanina 85d5f0ed1b * Mon Aug 15 2022 Miroslav Rezanina <mrezanin@redhat.com> - 7.0.0-11
- kvm-QIOChannelSocket-Fix-zero-copy-flush-returning-code-.patch [bz#2107466]
- kvm-Add-dirty-sync-missed-zero-copy-migration-stat.patch [bz#2107466]
- kvm-migration-multifd-Report-to-user-when-zerocopy-not-w.patch [bz#2107466]
- kvm-migration-Avoid-false-positive-on-non-supported-scen.patch [bz#2107466]
- kvm-migration-add-remaining-params-has_-true-in-migratio.patch [bz#2107466]
- kvm-QIOChannelSocket-Add-support-for-MSG_ZEROCOPY-IPV6.patch [bz#2107466]
- kvm-pc-bios-s390-ccw-Fix-booting-with-logical-block-size.patch [bz#2112303]
- kvm-vdpa-Fix-bad-index-calculus-at-vhost_vdpa_get_vring_.patch [bz#2116876]
- kvm-vdpa-Fix-index-calculus-at-vhost_vdpa_svqs_start.patch [bz#2116876]
- kvm-vdpa-Fix-memory-listener-deletions-of-iova-tree.patch [bz#2116876]
- kvm-vdpa-Fix-file-descriptor-leak-on-get-features-error.patch [bz#2116876]
- Resolves: bz#2107466
  (zerocopy capability can be enabled when set migrate capabilities with multifd and compress/xbzrle together)
- Resolves: bz#2112303
  (virtio-blk: Can't boot fresh installation from used 512 cluster_size image under certain conditions)
- Resolves: bz#2116876
  (Fixes for vDPA control virtqueue support in Qemu)
2022-08-15 07:19:39 -04:00

66 lines
2.3 KiB
Diff

From 678981c6bb7c964e1591f6f8aba49e9602f64852 Mon Sep 17 00:00:00 2001
From: Leonardo Bras <leobras@redhat.com>
Date: Mon, 11 Jul 2022 18:11:11 -0300
Subject: [PATCH 01/11] QIOChannelSocket: Fix zero-copy flush returning code 1
when nothing sent
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
RH-Author: Leonardo Brás <leobras@redhat.com>
RH-MergeRequest: 111: zero-copy-send fixes & improvements
RH-Commit: [1/6] cebc887cb61de1572d8ae3232cde45e80c339404 (LeoBras/centos-qemu-kvm)
RH-Bugzilla: 2107466
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
RH-Acked-by: Thomas Huth <thuth@redhat.com>
RH-Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
If flush is called when no buffer was sent with MSG_ZEROCOPY, it currently
returns 1. This return code should be used only when Linux fails to use
MSG_ZEROCOPY on a lot of sendmsg().
Fix this by returning early from flush if no sendmsg(...,MSG_ZEROCOPY)
was attempted.
Fixes: 2bc58ffc2926 ("QIOChannelSocket: Implement io_writev zero copy flag & io_flush for CONFIG_LINUX")
Signed-off-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Acked-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220711211112.18951-2-leobras@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
(cherry picked from commit 927f93e099c4f9184e60a1bc61624ac2d04d0223)
Signed-off-by: Leonardo Bras <leobras@redhat.com>
---
io/channel-socket.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/io/channel-socket.c b/io/channel-socket.c
index 8ae8b212cf..eb7baa2184 100644
--- a/io/channel-socket.c
+++ b/io/channel-socket.c
@@ -717,12 +717,18 @@ static int qio_channel_socket_flush(QIOChannel *ioc,
struct cmsghdr *cm;
char control[CMSG_SPACE(sizeof(*serr))];
int received;
- int ret = 1;
+ int ret;
+
+ if (sioc->zero_copy_queued == sioc->zero_copy_sent) {
+ return 0;
+ }
msg.msg_control = control;
msg.msg_controllen = sizeof(control);
memset(control, 0, sizeof(control));
+ ret = 1;
+
while (sioc->zero_copy_sent < sioc->zero_copy_queued) {
received = recvmsg(sioc->fd, &msg, MSG_ERRQUEUE);
if (received < 0) {
--
2.31.1