|
 |
29b115 |
From 5aaf33dbbbc89d58a52337985641723b9ee13541 Mon Sep 17 00:00:00 2001
|
|
|
29b115 |
From: Stefan Hajnoczi <stefanha@redhat.com>
|
|
|
29b115 |
Date: Wed, 27 Apr 2022 15:35:36 +0100
|
|
|
29b115 |
Subject: [PATCH 09/16] virtio-scsi: fix ctrl and event handler functions in
|
|
|
29b115 |
dataplane mode
|
|
|
29b115 |
|
|
|
29b115 |
RH-Author: Stefan Hajnoczi <stefanha@redhat.com>
|
|
|
29b115 |
RH-MergeRequest: 88: virtio-scsi: fix 100% CPU consumption with IOThreads
|
|
|
29b115 |
RH-Commit: [1/6] 3087889041b960f14a6b3893243f78523a78f637 (stefanha/centos-stream-qemu-kvm)
|
|
|
29b115 |
RH-Bugzilla: 2079347
|
|
|
29b115 |
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
|
|
|
29b115 |
RH-Acked-by: Kevin Wolf <kwolf@redhat.com>
|
|
|
29b115 |
RH-Acked-by: Stefano Garzarella <sgarzare@redhat.com>
|
|
|
29b115 |
|
|
|
29b115 |
Commit f34e8d8b8d48d73f36a67b6d5e492ef9784b5012 ("virtio-scsi: prepare
|
|
|
29b115 |
virtio_scsi_handle_cmd for dataplane") prepared the virtio-scsi cmd
|
|
|
29b115 |
virtqueue handler function to be used in both the dataplane and
|
|
|
29b115 |
non-datpalane code paths.
|
|
|
29b115 |
|
|
|
29b115 |
It failed to convert the ctrl and event virtqueue handler functions,
|
|
|
29b115 |
which are not designed to be called from the dataplane code path but
|
|
|
29b115 |
will be since the ioeventfd is set up for those virtqueues when
|
|
|
29b115 |
dataplane starts.
|
|
|
29b115 |
|
|
|
29b115 |
Convert the ctrl and event virtqueue handler functions now so they
|
|
|
29b115 |
operate correctly when called from the dataplane code path. Avoid code
|
|
|
29b115 |
duplication by extracting this code into a helper function.
|
|
|
29b115 |
|
|
|
29b115 |
Fixes: f34e8d8b8d48d73f36a67b6d5e492ef9784b5012 ("virtio-scsi: prepare virtio_scsi_handle_cmd for dataplane")
|
|
|
29b115 |
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
|
|
|
29b115 |
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
|
29b115 |
Message-id: 20220427143541.119567-2-stefanha@redhat.com
|
|
|
29b115 |
[Fixed s/by used/be used/ typo pointed out by Michael Tokarev
|
|
|
29b115 |
<mjt@tls.msk.ru>.
|
|
|
29b115 |
--Stefan]
|
|
|
29b115 |
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
|
|
|
29b115 |
(cherry picked from commit 2f743ef6366c2df4ef51ef3ae318138cdc0125ab)
|
|
|
29b115 |
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
|
|
|
29b115 |
---
|
|
|
29b115 |
hw/scsi/virtio-scsi.c | 42 +++++++++++++++++++++++++++---------------
|
|
|
29b115 |
1 file changed, 27 insertions(+), 15 deletions(-)
|
|
|
29b115 |
|
|
|
29b115 |
diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
|
|
|
29b115 |
index 7f6da33a8a..7b69eeed64 100644
|
|
|
29b115 |
--- a/hw/scsi/virtio-scsi.c
|
|
|
29b115 |
+++ b/hw/scsi/virtio-scsi.c
|
|
|
29b115 |
@@ -472,16 +472,32 @@ bool virtio_scsi_handle_ctrl_vq(VirtIOSCSI *s, VirtQueue *vq)
|
|
|
29b115 |
return progress;
|
|
|
29b115 |
}
|
|
|
29b115 |
|
|
|
29b115 |
+/*
|
|
|
29b115 |
+ * If dataplane is configured but not yet started, do so now and return true on
|
|
|
29b115 |
+ * success.
|
|
|
29b115 |
+ *
|
|
|
29b115 |
+ * Dataplane is started by the core virtio code but virtqueue handler functions
|
|
|
29b115 |
+ * can also be invoked when a guest kicks before DRIVER_OK, so this helper
|
|
|
29b115 |
+ * function helps us deal with manually starting ioeventfd in that case.
|
|
|
29b115 |
+ */
|
|
|
29b115 |
+static bool virtio_scsi_defer_to_dataplane(VirtIOSCSI *s)
|
|
|
29b115 |
+{
|
|
|
29b115 |
+ if (!s->ctx || s->dataplane_started) {
|
|
|
29b115 |
+ return false;
|
|
|
29b115 |
+ }
|
|
|
29b115 |
+
|
|
|
29b115 |
+ virtio_device_start_ioeventfd(&s->parent_obj.parent_obj);
|
|
|
29b115 |
+ return !s->dataplane_fenced;
|
|
|
29b115 |
+}
|
|
|
29b115 |
+
|
|
|
29b115 |
static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
|
|
|
29b115 |
{
|
|
|
29b115 |
VirtIOSCSI *s = (VirtIOSCSI *)vdev;
|
|
|
29b115 |
|
|
|
29b115 |
- if (s->ctx) {
|
|
|
29b115 |
- virtio_device_start_ioeventfd(vdev);
|
|
|
29b115 |
- if (!s->dataplane_fenced) {
|
|
|
29b115 |
- return;
|
|
|
29b115 |
- }
|
|
|
29b115 |
+ if (virtio_scsi_defer_to_dataplane(s)) {
|
|
|
29b115 |
+ return;
|
|
|
29b115 |
}
|
|
|
29b115 |
+
|
|
|
29b115 |
virtio_scsi_acquire(s);
|
|
|
29b115 |
virtio_scsi_handle_ctrl_vq(s, vq);
|
|
|
29b115 |
virtio_scsi_release(s);
|
|
|
29b115 |
@@ -720,12 +736,10 @@ static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
|
|
|
29b115 |
/* use non-QOM casts in the data path */
|
|
|
29b115 |
VirtIOSCSI *s = (VirtIOSCSI *)vdev;
|
|
|
29b115 |
|
|
|
29b115 |
- if (s->ctx && !s->dataplane_started) {
|
|
|
29b115 |
- virtio_device_start_ioeventfd(vdev);
|
|
|
29b115 |
- if (!s->dataplane_fenced) {
|
|
|
29b115 |
- return;
|
|
|
29b115 |
- }
|
|
|
29b115 |
+ if (virtio_scsi_defer_to_dataplane(s)) {
|
|
|
29b115 |
+ return;
|
|
|
29b115 |
}
|
|
|
29b115 |
+
|
|
|
29b115 |
virtio_scsi_acquire(s);
|
|
|
29b115 |
virtio_scsi_handle_cmd_vq(s, vq);
|
|
|
29b115 |
virtio_scsi_release(s);
|
|
|
29b115 |
@@ -855,12 +869,10 @@ static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
|
|
|
29b115 |
{
|
|
|
29b115 |
VirtIOSCSI *s = VIRTIO_SCSI(vdev);
|
|
|
29b115 |
|
|
|
29b115 |
- if (s->ctx) {
|
|
|
29b115 |
- virtio_device_start_ioeventfd(vdev);
|
|
|
29b115 |
- if (!s->dataplane_fenced) {
|
|
|
29b115 |
- return;
|
|
|
29b115 |
- }
|
|
|
29b115 |
+ if (virtio_scsi_defer_to_dataplane(s)) {
|
|
|
29b115 |
+ return;
|
|
|
29b115 |
}
|
|
|
29b115 |
+
|
|
|
29b115 |
virtio_scsi_acquire(s);
|
|
|
29b115 |
virtio_scsi_handle_event_vq(s, vq);
|
|
|
29b115 |
virtio_scsi_release(s);
|
|
|
29b115 |
--
|
|
|
29b115 |
2.31.1
|
|
|
29b115 |
|