From: Wei Wang <wei.w.wang@intel.com>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: virtio-dev@lists.oasis-open.org, linux-kernel@vger.kernel.org,
qemu-devel@nongnu.org, virtualization@lists.linux-foundation.org,
kvm@vger.kernel.org, linux-mm@kvack.org, mhocko@kernel.org,
akpm@linux-foundation.org, mawilcox@microsoft.com,
david@redhat.com, penguin-kernel@I-love.SAKURA.ne.jp,
cornelia.huck@de.ibm.com, mgorman@techsingularity.net,
aarcange@redhat.com, amit.shah@redhat.com, pbonzini@redhat.com,
willy@infradead.org, liliang.opensource@gmail.com,
yang.zhang.wz@gmail.com, quan.xu@aliyun.com, nilal@redhat.com,
riel@redhat.com
Subject: Re: [PATCH v18 06/10] virtio_ring: add a new API, virtqueue_add_one_desc
Date: Fri, 01 Dec 2017 16:06:05 +0800 [thread overview]
Message-ID: <5A210D6D.3090402@intel.com> (raw)
In-Reply-To: <20171130213231-mutt-send-email-mst@kernel.org>
On 12/01/2017 03:38 AM, Michael S. Tsirkin wrote:
> On Wed, Nov 29, 2017 at 09:55:22PM +0800, Wei Wang wrote:
>> Current virtqueue_add API implementation is based on the scatterlist
>> struct, which uses kaddr. This is inadequate to all the use case of
>> vring. For example:
>> - Some usages don't use IOMMU, in this case the user can directly pass
>> in a physical address in hand, instead of going through the sg
>> implementation (e.g. the VIRTIO_BALLOON_F_SG feature)
>> - Sometimes, a guest physical page may not have a kaddr (e.g. high
>> memory) but need to use vring (e.g. the VIRTIO_BALLOON_F_FREE_PAGE_VQ
>> feature)
>>
>> The new API virtqueue_add_one_desc enables the caller to assign a vring
>> desc with a physical address and len. Also, factor out the common code
>> with virtqueue_add in vring_set_avail.
>>
>> Signed-off-by: Wei Wang <wei.w.wang@intel.com>
>> Cc: Michael S. Tsirkin <mst@redhat.com>
> You previously managed without this patch, and it's preferable
> IMHO since this patchset is already too big.
>
> I don't really understand what is wrong with virtio_add_sgs + sg_set_page.
> I don't think is assumes a kaddr.
>
OK, I will use the previous method to send sgs.
Please have a check if there are other things need to be improved.
Best,
Wei
next prev parent reply other threads:[~2017-12-01 8:04 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-29 13:55 [PATCH v18 00/10] Virtio-balloon Enhancement Wei Wang
2017-11-29 13:55 ` [PATCH v18 01/10] idr: add #include <linux/bug.h> Wei Wang
2017-11-30 0:58 ` Matthew Wilcox
2017-11-30 7:07 ` Michal Hocko
2017-11-30 21:49 ` Andrew Morton
2017-11-29 13:55 ` [PATCH v18 02/10] radix tree test suite: remove ARRAY_SIZE to avoid redefinition Wei Wang
2017-11-29 13:55 ` [PATCH v18 03/10] xbitmap: Introduce xbitmap Wei Wang
2017-11-29 13:55 ` [PATCH v18 04/10] xbitmap: potential improvement Wei Wang
2017-11-29 13:55 ` [PATCH v18 05/10] xbitmap: add more operations Wei Wang
2017-11-30 10:34 ` Tetsuo Handa
2017-11-30 13:35 ` Tetsuo Handa
2017-11-30 14:39 ` Matthew Wilcox
2017-12-03 1:44 ` Tetsuo Handa
2017-12-01 8:02 ` Wei Wang
2017-12-01 13:02 ` Tetsuo Handa
2017-12-01 14:13 ` Matthew Wilcox
2017-12-01 15:09 ` Wang, Wei W
2017-12-01 17:25 ` Matthew Wilcox
2017-12-03 1:50 ` Tetsuo Handa
2017-12-07 12:01 ` Wei Wang
2017-12-07 15:41 ` Michael S. Tsirkin
2017-11-29 13:55 ` [PATCH v18 06/10] virtio_ring: add a new API, virtqueue_add_one_desc Wei Wang
2017-11-30 19:38 ` Michael S. Tsirkin
2017-12-01 8:06 ` Wei Wang [this message]
2017-11-29 13:55 ` [PATCH v18 07/10] virtio-balloon: VIRTIO_BALLOON_F_SG Wei Wang
2017-11-30 10:35 ` Tetsuo Handa
2017-11-30 16:25 ` Wang, Wei W
2017-12-01 15:38 ` Michael S. Tsirkin
2017-12-04 3:46 ` Wei Wang
2017-11-29 13:55 ` [PATCH v18 08/10] mm: support reporting free page blocks Wei Wang
2017-11-29 13:55 ` [PATCH v18 09/10] virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_VQ Wei Wang
2017-11-29 13:55 ` [PATCH v18 10/10] virtio-balloon: don't report free pages when page poisoning is enabled Wei Wang
2017-12-01 15:49 ` Michael S. Tsirkin
2017-12-04 5:39 ` Wei Wang
2017-12-11 6:38 ` Wei Wang
2017-12-11 13:24 ` Michael S. Tsirkin
2017-12-12 12:21 ` Wei Wang
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