[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [RFC PATCH V3 10/11] HV/Netvsc: Add Isolation VM support for netvsc driver
- To: Tianyu Lan <ltykernel@xxxxxxxxx>
- From: Christoph Hellwig <hch@xxxxxx>
- Date: Mon, 14 Jun 2021 17:33:39 +0200
- Cc: Christoph Hellwig <hch@xxxxxx>, kys@xxxxxxxxxxxxx, haiyangz@xxxxxxxxxxxxx, sthemmin@xxxxxxxxxxxxx, wei.liu@xxxxxxxxxx, decui@xxxxxxxxxxxxx, tglx@xxxxxxxxxxxxx, mingo@xxxxxxxxxx, bp@xxxxxxxxx, x86@xxxxxxxxxx, hpa@xxxxxxxxx, arnd@xxxxxxxx, dave.hansen@xxxxxxxxxxxxxxx, luto@xxxxxxxxxx, peterz@xxxxxxxxxxxxx, akpm@xxxxxxxxxxxxxxxxxxxx, kirill.shutemov@xxxxxxxxxxxxxxx, rppt@xxxxxxxxxx, hannes@xxxxxxxxxxx, cai@xxxxxx, krish.sadhukhan@xxxxxxxxxx, saravanand@xxxxxx, Tianyu.Lan@xxxxxxxxxxxxx, konrad.wilk@xxxxxxxxxx, m.szyprowski@xxxxxxxxxxx, robin.murphy@xxxxxxx, boris.ostrovsky@xxxxxxxxxx, jgross@xxxxxxxx, sstabellini@xxxxxxxxxx, joro@xxxxxxxxxx, will@xxxxxxxxxx, xen-devel@xxxxxxxxxxxxxxxxxxxx, davem@xxxxxxxxxxxxx, kuba@xxxxxxxxxx, jejb@xxxxxxxxxxxxx, martin.petersen@xxxxxxxxxx, iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx, linux-arch@xxxxxxxxxxxxxxx, linux-hyperv@xxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx, linux-scsi@xxxxxxxxxxxxxxx, netdev@xxxxxxxxxxxxxxx, vkuznets@xxxxxxxxxx, thomas.lendacky@xxxxxxx, brijesh.singh@xxxxxxx, sunilmut@xxxxxxxxxxxxx
- Delivery-date: Mon, 14 Jun 2021 15:33:43 +0000
- List-id: Xen developer discussion <xen-devel.lists.xenproject.org>
On Mon, Jun 14, 2021 at 10:04:06PM +0800, Tianyu Lan wrote:
> The pages in the hv_page_buffer array here are in the kernel linear
> mapping. The packet sent to host will contain an array which contains
> transaction data. In the isolation VM, data in the these pages needs to be
> copied to bounce buffer and so call dma_map_single() here to map these data
> pages with bounce buffer. The vmbus has ring buffer where the send/receive
> packets are copied to/from. The ring buffer has been remapped to the extra
> space above shared gpa boundary/vTom during probing Netvsc driver and so
> not call dma map function for vmbus ring
> buffer.
So why do we have all that PFN magic instead of using struct page or
the usual kernel I/O buffers that contain a page pointer?
|
