From: Stefan Hajnoczi <stefanha@redhat.com>
To: qemu-devel@nongnu.org
Cc: "Kevin Wolf" <kwolf@redhat.com>,
"Laurent Vivier" <lvivier@redhat.com>,
"Thomas Huth" <thuth@redhat.com>,
"Eduardo Habkost" <ehabkost@redhat.com>,
qemu-block@nongnu.org, "Michael S. Tsirkin" <mst@redhat.com>,
jasowang@redhat.com, cohuck@redhat.com,
"Stefan Hajnoczi" <stefanha@redhat.com>,
"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
"Raphael Norwitz" <raphael.norwitz@nutanix.com>,
"Gonglei (Arei)" <arei.gonglei@huawei.com>,
"Gerd Hoffmann" <kraxel@redhat.com>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Marc-André Lureau" <marcandre.lureau@redhat.com>,
"Fam Zheng" <fam@euphon.net>, "Max Reitz" <mreitz@redhat.com>
Subject: [PATCH 5/5] virtio: enable VIRTIO_F_RING_PACKED for all devices
Date: Fri, 22 May 2020 18:17:26 +0100 [thread overview]
Message-ID: <20200522171726.648279-6-stefanha@redhat.com> (raw)
In-Reply-To: <20200522171726.648279-1-stefanha@redhat.com>
The packed virtqueue layout was introduced in VIRTIO 1.1. It is a single
ring instead of a split avail/used ring design. There are CPU cache
advantages to this layout and it is also suited better to hardware
implementation.
The vhost-net backend has already supported packed virtqueues for some
time. Performance benchmarks show that virtio-blk performance on NVMe
drives is also improved.
Go ahead and enable this feature for all VIRTIO devices. Keep it
disabled for QEMU 5.0 and earlier machine types.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
include/hw/virtio/virtio.h | 2 +-
hw/core/machine.c | 18 +++++++++++++++++-
2 files changed, 18 insertions(+), 2 deletions(-)
diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index b69d517496..fd5b4a2044 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -292,7 +292,7 @@ typedef struct VirtIORNGConf VirtIORNGConf;
DEFINE_PROP_BIT64("iommu_platform", _state, _field, \
VIRTIO_F_IOMMU_PLATFORM, false), \
DEFINE_PROP_BIT64("packed", _state, _field, \
- VIRTIO_F_RING_PACKED, false)
+ VIRTIO_F_RING_PACKED, true)
hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n);
bool virtio_queue_enabled(VirtIODevice *vdev, int n);
diff --git a/hw/core/machine.c b/hw/core/machine.c
index bb3a7b18b1..3598c3c825 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -28,7 +28,23 @@
#include "hw/mem/nvdimm.h"
#include "migration/vmstate.h"
-GlobalProperty hw_compat_5_0[] = {};
+GlobalProperty hw_compat_5_0[] = {
+ { "vhost-user-blk", "packed", "off" },
+ { "vhost-user-fs-device", "packed", "off" },
+ { "vhost-vsock-device", "packed", "off" },
+ { "virtio-9p-device", "packed", "off" },
+ { "virtio-balloon-device", "packed", "off" },
+ { "virtio-blk-device", "packed", "off" },
+ { "virtio-crypto-device", "packed", "off" },
+ { "virtio-gpu-device", "packed", "off" },
+ { "virtio-input-device", "packed", "off" },
+ { "virtio-iommu-device", "packed", "off" },
+ { "virtio-net-device", "packed", "off" },
+ { "virtio-pmem", "packed", "off" },
+ { "virtio-rng-device", "packed", "off" },
+ { "virtio-scsi-common", "packed", "off" },
+ { "virtio-serial-device", "packed", "off" },
+};
const size_t hw_compat_5_0_len = G_N_ELEMENTS(hw_compat_5_0);
GlobalProperty hw_compat_4_2[] = {
--
2.25.3
next prev parent reply other threads:[~2020-05-22 17:21 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-22 17:17 [PATCH 0/5] virtio: enable VIRTIO_F_RING_PACKED for all devices Stefan Hajnoczi
2020-05-22 17:17 ` [PATCH 1/5] tests/libqos: mask out VIRTIO_F_RING_PACKED for now Stefan Hajnoczi
2020-05-22 19:21 ` Thomas Huth
2020-05-22 17:17 ` [PATCH 2/5] vhost: involve device backends in feature negotiation Stefan Hajnoczi
2020-05-27 14:28 ` Marc-André Lureau
2020-05-29 15:20 ` Stefan Hajnoczi
2020-05-29 7:04 ` Jason Wang
2020-05-29 13:56 ` Stefan Hajnoczi
2020-05-29 14:29 ` Dr. David Alan Gilbert
2020-06-03 14:44 ` Stefan Hajnoczi
2020-06-01 12:51 ` Jason Wang
2020-06-03 14:39 ` Stefan Hajnoczi
2020-05-22 17:17 ` [PATCH 3/5] vhost-user-blk: add VIRTIO_F_RING_PACKED feature bit Stefan Hajnoczi
2020-05-25 4:06 ` Raphael Norwitz
2020-05-22 17:17 ` [PATCH 4/5] vhost-scsi: add VIRTIO_F_VERSION_1 and VIRTIO_F_RING_PACKED Stefan Hajnoczi
2020-05-25 4:02 ` Raphael Norwitz
2020-05-22 17:17 ` Stefan Hajnoczi [this message]
2020-05-26 17:29 ` [PATCH 5/5] virtio: enable VIRTIO_F_RING_PACKED for all devices Dr. David Alan Gilbert
2020-05-29 7:15 ` Jason Wang
2020-05-29 15:28 ` Stefan Hajnoczi
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