From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="U+1FHY37" Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B21AB10F1 for ; Thu, 30 Nov 2023 01:46:07 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1701337566; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=PfGI1qlZAEAF2BhJp3RmJxUya50qDURSNVaHY6y9EXQ=; b=U+1FHY37/Pn3SjfZwwZL8EhYDSM0wvCGofnyA465OdN7FFx5iRcIoaD1pY5JJM3NpwcGVi MzC8tWJ/jQfQB9BtEbaBirpX0ZYKXlDiwBBmKMmCywA1H55DcVxGEEloAcdbOx9w7TRyH+ xVDpsFE9IGuwER4tCijK8E0TS58QlBc= Received: from mail-wr1-f72.google.com (mail-wr1-f72.google.com [209.85.221.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-635-4bSl4dm3MZqDVSA0Ou4dnA-1; Thu, 30 Nov 2023 04:46:05 -0500 X-MC-Unique: 4bSl4dm3MZqDVSA0Ou4dnA-1 Received: by mail-wr1-f72.google.com with SMTP id ffacd0b85a97d-3331258269fso803911f8f.1 for ; Thu, 30 Nov 2023 01:46:05 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701337563; x=1701942363; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=PfGI1qlZAEAF2BhJp3RmJxUya50qDURSNVaHY6y9EXQ=; b=EDLBVWrTgvJGdI/+5llmHLBt1DlvUz1q0X/induO/LhjMby3qpY+iD5kZAAvPsbE6N XkmIvfMjgxDJimHWY+/xIAM4ZfRkl2U4ML/RZIyz+AVSc1uGfTDOMeraQqFqxafAcGEd zRlRGEW06yYnXsoA7dMP3cS/kJ7UXfp2gkMKNX1hQ5FXTdQ00TK8GdP597l0dDMpI9N2 YvoOIPc2dv+d2PDBOuwmnfZDJMLzX7JqXiwviON5cGk0Kkb0W8WgvUqkAFaaB19AWS6e 7UyUIwRnj2tJ7ikBEaZ7w6DZxLlz6+npj9JstQlcnK7aozHLG2jSm150UShSm0OKUUuN FmEQ== X-Gm-Message-State: AOJu0Yw7sS+4Ms3mJ4OiHmjkjdGX7eQqO/9VV5CH2bwP9c2ZA8ZMhqfU qpdnfu0TEE1k1Uh53svjrYiBjflUffO/yQRE3TjUDBrsvgatxe7bniNW8YmJ+7s/09lYEq1EocD GIPDH8RiVtywejjgIJmC+ X-Received: by 2002:adf:f18a:0:b0:333:2003:f8d5 with SMTP id h10-20020adff18a000000b003332003f8d5mr1300585wro.47.1701337563314; Thu, 30 Nov 2023 01:46:03 -0800 (PST) X-Google-Smtp-Source: AGHT+IFZ1YqAf91AEdYFb/UmG1d2aec7j4UFFqWCYZRHFF8ZmzzWbiemhO2JFaP7Qe8H76kv8gs1Wg== X-Received: by 2002:adf:f18a:0:b0:333:2003:f8d5 with SMTP id h10-20020adff18a000000b003332003f8d5mr1300567wro.47.1701337562911; Thu, 30 Nov 2023 01:46:02 -0800 (PST) Received: from redhat.com ([2.55.10.128]) by smtp.gmail.com with ESMTPSA id t3-20020adfe443000000b00332fcdafc22sm1036634wrm.70.2023.11.30.01.46.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 30 Nov 2023 01:46:02 -0800 (PST) Date: Thu, 30 Nov 2023 04:45:58 -0500 From: "Michael S. Tsirkin" To: Xuan Zhuo Cc: virtualization@lists.linux-foundation.org, Jason Wang , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , netdev@vger.kernel.org, bpf@vger.kernel.org, Christoph Hellwig Subject: Re: [PATCH vhost v13 11/12] virtio_ring: introduce dma sync api for virtqueue Message-ID: <20231130044512-mutt-send-email-mst@kernel.org> References: <20230810123057.43407-1-xuanzhuo@linux.alibaba.com> <20230810123057.43407-12-xuanzhuo@linux.alibaba.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230810123057.43407-12-xuanzhuo@linux.alibaba.com> On Thu, Aug 10, 2023 at 08:30:56PM +0800, Xuan Zhuo wrote: > These API has been introduced: > > * virtqueue_dma_need_sync > * virtqueue_dma_sync_single_range_for_cpu > * virtqueue_dma_sync_single_range_for_device > > These APIs can be used together with the premapped mechanism to sync the > DMA address. > > Signed-off-by: Xuan Zhuo > --- > drivers/virtio/virtio_ring.c | 76 ++++++++++++++++++++++++++++++++++++ > include/linux/virtio.h | 8 ++++ > 2 files changed, 84 insertions(+) > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > index 916479c9c72c..81ecb29c88f1 100644 > --- a/drivers/virtio/virtio_ring.c > +++ b/drivers/virtio/virtio_ring.c > @@ -3175,4 +3175,80 @@ int virtqueue_dma_mapping_error(struct virtqueue *_vq, dma_addr_t addr) > } > EXPORT_SYMBOL_GPL(virtqueue_dma_mapping_error); > > +/** > + * virtqueue_dma_need_sync - check a dma address needs sync > + * @_vq: the struct virtqueue we're talking about. > + * @addr: DMA address > + * > + * Check if the dma address mapped by the virtqueue_dma_map_* APIs needs to be > + * synchronized > + * > + * return bool > + */ > +bool virtqueue_dma_need_sync(struct virtqueue *_vq, dma_addr_t addr) > +{ > + struct vring_virtqueue *vq = to_vvq(_vq); > + > + if (!vq->use_dma_api) > + return false; > + > + return dma_need_sync(vring_dma_dev(vq), addr); > +} > +EXPORT_SYMBOL_GPL(virtqueue_dma_need_sync); > + > +/** > + * virtqueue_dma_sync_single_range_for_cpu - dma sync for cpu > + * @_vq: the struct virtqueue we're talking about. > + * @addr: DMA address > + * @offset: DMA address offset > + * @size: buf size for sync > + * @dir: DMA direction > + * > + * Before calling this function, use virtqueue_dma_need_sync() to confirm that > + * the DMA address really needs to be synchronized > + * > + */ > +void virtqueue_dma_sync_single_range_for_cpu(struct virtqueue *_vq, > + dma_addr_t addr, > + unsigned long offset, size_t size, > + enum dma_data_direction dir) > +{ > + struct vring_virtqueue *vq = to_vvq(_vq); > + struct device *dev = vring_dma_dev(vq); > + > + if (!vq->use_dma_api) > + return; > + > + dma_sync_single_range_for_cpu(dev, addr, offset, size, > + DMA_BIDIRECTIONAL); > +} Why did you use DMA_BIDIRECTIONAL here? Why is "dir" ignored? > +EXPORT_SYMBOL_GPL(virtqueue_dma_sync_single_range_for_cpu); > + > +/** > + * virtqueue_dma_sync_single_range_for_device - dma sync for device > + * @_vq: the struct virtqueue we're talking about. > + * @addr: DMA address > + * @offset: DMA address offset > + * @size: buf size for sync > + * @dir: DMA direction > + * > + * Before calling this function, use virtqueue_dma_need_sync() to confirm that > + * the DMA address really needs to be synchronized > + */ > +void virtqueue_dma_sync_single_range_for_device(struct virtqueue *_vq, > + dma_addr_t addr, > + unsigned long offset, size_t size, > + enum dma_data_direction dir) > +{ > + struct vring_virtqueue *vq = to_vvq(_vq); > + struct device *dev = vring_dma_dev(vq); > + > + if (!vq->use_dma_api) > + return; > + > + dma_sync_single_range_for_device(dev, addr, offset, size, > + DMA_BIDIRECTIONAL); > +} > +EXPORT_SYMBOL_GPL(virtqueue_dma_sync_single_range_for_device); > + > MODULE_LICENSE("GPL"); same question here. > diff --git a/include/linux/virtio.h b/include/linux/virtio.h > index 79e3c74391e0..1311a7fbe675 100644 > --- a/include/linux/virtio.h > +++ b/include/linux/virtio.h > @@ -220,4 +220,12 @@ void virtqueue_dma_unmap_single_attrs(struct virtqueue *_vq, dma_addr_t addr, > size_t size, enum dma_data_direction dir, > unsigned long attrs); > int virtqueue_dma_mapping_error(struct virtqueue *_vq, dma_addr_t addr); > + > +bool virtqueue_dma_need_sync(struct virtqueue *_vq, dma_addr_t addr); > +void virtqueue_dma_sync_single_range_for_cpu(struct virtqueue *_vq, dma_addr_t addr, > + unsigned long offset, size_t size, > + enum dma_data_direction dir); > +void virtqueue_dma_sync_single_range_for_device(struct virtqueue *_vq, dma_addr_t addr, > + unsigned long offset, size_t size, > + enum dma_data_direction dir); > #endif /* _LINUX_VIRTIO_H */ > -- > 2.32.0.3.g01195cf9f