From: Kangjie Xu <kangjie.xu@linux.alibaba.com>
To: maxime.coquelin@redhat.com, chenbo.xia@intel.com
Cc: dev@dpdk.org, hengqi@linux.alibaba.com, xuanzhuo@linux.alibaba.com
Subject: Re: [PATCH 1/1] vhost: support VIRTIO_F_RING_RESET for vhost-user
Date: Wed, 27 Jul 2022 16:56:57 +0800 [thread overview]
Message-ID: <7faa7081-6fec-68ea-992c-71a089840802@linux.alibaba.com> (raw)
In-Reply-To: <20220719072650.118176-1-kangjie.xu@linux.alibaba.com>
This patch will be updated in the future. We'll fix some issues based on
some review comments from QEMU community.
We intend to add a new vhost protocol message for virtqueue reset.
Please let me know any questions or suggestions you might have.
Thanks
在 2022/7/19 15:26, Kangjie Xu 写道:
> Add VIRTIO_F_RING_RESET, which indicates that the driver can reset a
> queue individually.
>
> VIRTIO_F_RING_RESET feature is added to virtio-spec 1.2. The relevant
> information is in
> https://github.com/oasis-tcs/virtio-spec/issues/124
> https://github.com/oasis-tcs/virtio-spec/issues/139
>
> The implementation only adds the feature bit in supported features. It
> does not require any other changes because we reuse the existing vhost
> protocol.
>
> The virtqueue reset process can be concluded as two parts:
> 1. The driver can reset a virtqueue. When it is triggered,
> VHOST_USER_SET_VRING_ENABLE message with "payload.state.num" set to 0
> is sent to DPDK. Then the virtqueue will be disabled in DPDK.
> 2. After the virtqueue is disabled, the driver may optionally re-enable
> it. To avoid confusion with VHOST_USER_SET_VRING_ENABLE, we call this
> part as "restart". The virtqueue's information may be changed when
> restarting it. Thus, the information of the reset virtqueue should be
> updated. This part is basically similar to when the virtqueue is started
> for the first time, except that the restart process does not need to set
> features and set mem table since they does not change. QEMU will send
> messages containing size, base, addr, kickfd and callfd of the virtqueue
> in order. Specifically, the DPDK will receive these messages in order:
> a. VHOST_USER_SET_VRING_NUM
> b. VHOST_USER_SET_VRING_BASE
> c. VHOST_USER_SET_VRING_ADDR
> d. VHOST_USER_SET_VRING_KICK
> e. VHOST_USER_SET_VRING_CALL
> f. VHOST_USER_SET_VRING_ENABLE
> The last VHOST_USER_SET_VRING_ENABLE message with "payload.state.num" set
> to 1, will be sent to enable the virtqueue and the restart process is
> finished.
>
> Signed-off-by: Kangjie Xu <kangjie.xu@linux.alibaba.com>
> Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> ---
> Test environment:
> Host: 5.4.189
> Qemu: QEMU emulator version 7.0.50 (With vq reset support)
> Guest: 5.19.0-rc3 (With vq reset support)
> DPDK: 22.07-rc1
> Test Cmd: ethtool -g eth1; ethtool -G eth1 rx $1 tx $2;
> ethtool -g eth1;
>
> The driver can resize the virtio queue, then virtio queue reset
> function should be triggered.
>
> Guest Kernel Patch:
> https://lore.kernel.org/bpf/20220629065656.54420-1-xuanzhuo@linux.alibaba.com
>
> QEMU Patch:
> https://lore.kernel.org/qemu-devel/cover.1658141552.git.kangjie.xu@linux.alibaba.com
>
> lib/vhost/vhost.h | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/lib/vhost/vhost.h b/lib/vhost/vhost.h
> index 14235aaf81..9711ded7dd 100644
> --- a/lib/vhost/vhost.h
> +++ b/lib/vhost/vhost.h
> @@ -378,6 +378,11 @@ struct vhost_msg {
> #define VIRTIO_F_VERSION_1 32
> #endif
>
> +/* This feature indicates that the driver can reset a queue individually. */
> +#ifndef VIRTIO_F_RING_RESET
> +#define VIRTIO_F_RING_RESET 40
> +#endif
> +
> /* Declare packed ring related bits for older kernels */
> #ifndef VIRTIO_F_RING_PACKED
>
> @@ -440,7 +445,8 @@ struct vring_packed_desc_event {
> (1ULL << VIRTIO_NET_F_MTU) | \
> (1ULL << VIRTIO_F_IN_ORDER) | \
> (1ULL << VIRTIO_F_IOMMU_PLATFORM) | \
> - (1ULL << VIRTIO_F_RING_PACKED))
> + (1ULL << VIRTIO_F_RING_PACKED) | \
> + (1ULL << VIRTIO_F_RING_RESET))
>
>
> struct guest_page {
prev parent reply other threads:[~2022-07-27 8:57 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-19 7:26 Kangjie Xu
2022-07-27 8:56 ` Kangjie Xu [this message]
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