From: Tiwei Bie <tiwei.bie@intel.com>
To: mst@redhat.com, jasowang@redhat.com, pbonzini@redhat.com,
stefanha@redhat.com, virtualization@lists.linux-foundation.org,
linux-kernel@vger.kernel.org
Cc: dan.daly@intel.com, cunming.liang@intel.com, zhihong.wang@intel.com
Subject: [RFC] virtio: support VIRTIO_F_IO_BARRIER
Date: Thu, 3 May 2018 10:59:55 +0800 [thread overview]
Message-ID: <20180503025955.28816-1-tiwei.bie@intel.com> (raw)
This patch introduces the support for VIRTIO_F_IO_BARRIER.
When this feature is negotiated, driver will use the barriers
suitable for hardware devices.
Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
---
drivers/virtio/virtio_ring.c | 5 +++++
include/uapi/linux/virtio_config.h | 8 +++++++-
2 files changed, 12 insertions(+), 1 deletion(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 21d464a29cf8..edb565643bf4 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -996,6 +996,9 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index,
!context;
vq->event = virtio_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX);
+ if (virtio_has_feature(vdev, VIRTIO_F_IO_BARRIER))
+ vq->weak_barriers = false;
+
/* No callback? Tell other side not to bother us. */
if (!callback) {
vq->avail_flags_shadow |= VRING_AVAIL_F_NO_INTERRUPT;
@@ -1164,6 +1167,8 @@ void vring_transport_features(struct virtio_device *vdev)
break;
case VIRTIO_F_IOMMU_PLATFORM:
break;
+ case VIRTIO_F_IO_BARRIER:
+ break;
default:
/* We don't understand this bit. */
__virtio_clear_bit(vdev, i);
diff --git a/include/uapi/linux/virtio_config.h b/include/uapi/linux/virtio_config.h
index 308e2096291f..6ca8d24bf468 100644
--- a/include/uapi/linux/virtio_config.h
+++ b/include/uapi/linux/virtio_config.h
@@ -49,7 +49,7 @@
* transport being used (eg. virtio_ring), the rest are per-device feature
* bits. */
#define VIRTIO_TRANSPORT_F_START 28
-#define VIRTIO_TRANSPORT_F_END 34
+#define VIRTIO_TRANSPORT_F_END 38
#ifndef VIRTIO_CONFIG_NO_LEGACY
/* Do we get callbacks when the ring is completely used, even if we've
@@ -71,4 +71,10 @@
* this is for compatibility with legacy systems.
*/
#define VIRTIO_F_IOMMU_PLATFORM 33
+
+/*
+ * If clear - driver may use barriers suitable for CPU cores.
+ * If set - driver must use barriers suitable for hardware devices.
+ */
+#define VIRTIO_F_IO_BARRIER 37
#endif /* _UAPI_LINUX_VIRTIO_CONFIG_H */
--
2.11.0
next reply other threads:[~2018-05-03 2:59 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-03 2:59 Tiwei Bie [this message]
2018-05-03 7:30 ` [RFC] virtio: support VIRTIO_F_IO_BARRIER Jason Wang
2018-05-03 7:30 ` Jason Wang
2018-05-03 8:30 ` Tiwei Bie
2018-05-03 8:30 ` Tiwei Bie
2018-05-03 9:09 ` Jason Wang
2018-05-03 9:09 ` Jason Wang
2018-05-03 9:58 ` Tiwei Bie
2018-05-03 9:58 ` Tiwei Bie
2018-05-03 12:57 ` Jason Wang
2018-05-03 12:57 ` Jason Wang
2018-05-03 9:06 ` Stefan Hajnoczi
2018-05-03 9:06 ` Stefan Hajnoczi
2018-05-03 13:26 ` Tiwei Bie
2018-05-03 13:26 ` Tiwei Bie
2018-05-03 13:50 ` Stefan Hajnoczi
2018-05-03 13:50 ` Stefan Hajnoczi
2018-05-03 17:57 ` Michael S. Tsirkin
2018-05-04 1:14 ` Tiwei Bie
2018-05-04 1:14 ` Tiwei Bie
2018-05-03 17:57 ` Michael S. Tsirkin
2018-05-03 2:59 Tiwei Bie
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