Re: Re: [RFC v4 06/11] vduse: Implement an MMU-based IOMMU driver

2021-03-07 Thread Yongji Xie
On Mon, Mar 8, 2021 at 3:04 PM Jason Wang wrote: > > > On 2021/3/8 1:05 下午, Yongji Xie wrote: > > On Mon, Mar 8, 2021 at 11:52 AM Jason Wang wrote: > >> > >> On 2021/3/8 11:45 上午, Yongji Xie wrote: > >>> On Mon, Mar 8, 2021 at 11:17 AM Jason Wang wrote: > On 2021/3/5 3:59 下午, Yongji Xie wro

Re: [RFC v4 06/11] vduse: Implement an MMU-based IOMMU driver

2021-03-07 Thread Jason Wang
On 2021/3/8 1:05 下午, Yongji Xie wrote: On Mon, Mar 8, 2021 at 11:52 AM Jason Wang wrote: On 2021/3/8 11:45 上午, Yongji Xie wrote: On Mon, Mar 8, 2021 at 11:17 AM Jason Wang wrote: On 2021/3/5 3:59 下午, Yongji Xie wrote: On Fri, Mar 5, 2021 at 3:27 PM Jason Wang wrote: On 2021/3/5 3:13 下午

Re: Re: [RFC v4 06/11] vduse: Implement an MMU-based IOMMU driver

2021-03-07 Thread Yongji Xie
On Mon, Mar 8, 2021 at 11:52 AM Jason Wang wrote: > > > On 2021/3/8 11:45 上午, Yongji Xie wrote: > > On Mon, Mar 8, 2021 at 11:17 AM Jason Wang wrote: > >> > >> On 2021/3/5 3:59 下午, Yongji Xie wrote: > >>> On Fri, Mar 5, 2021 at 3:27 PM Jason Wang wrote: > On 2021/3/5 3:13 下午, Yongji Xie wro

Re: [RFC v4 06/11] vduse: Implement an MMU-based IOMMU driver

2021-03-07 Thread Jason Wang
On 2021/3/8 11:45 上午, Yongji Xie wrote: On Mon, Mar 8, 2021 at 11:17 AM Jason Wang wrote: On 2021/3/5 3:59 下午, Yongji Xie wrote: On Fri, Mar 5, 2021 at 3:27 PM Jason Wang wrote: On 2021/3/5 3:13 下午, Yongji Xie wrote: On Fri, Mar 5, 2021 at 2:52 PM Jason Wang wrote: On 2021/3/5 2:15 下午,

Re: Re: [RFC v4 06/11] vduse: Implement an MMU-based IOMMU driver

2021-03-07 Thread Yongji Xie
On Mon, Mar 8, 2021 at 11:17 AM Jason Wang wrote: > > > On 2021/3/5 3:59 下午, Yongji Xie wrote: > > On Fri, Mar 5, 2021 at 3:27 PM Jason Wang wrote: > >> > >> On 2021/3/5 3:13 下午, Yongji Xie wrote: > >>> On Fri, Mar 5, 2021 at 2:52 PM Jason Wang wrote: > On 2021/3/5 2:15 下午, Yongji Xie wrote

Re: [RFC v4 06/11] vduse: Implement an MMU-based IOMMU driver

2021-03-07 Thread Jason Wang
On 2021/3/5 3:59 下午, Yongji Xie wrote: On Fri, Mar 5, 2021 at 3:27 PM Jason Wang wrote: On 2021/3/5 3:13 下午, Yongji Xie wrote: On Fri, Mar 5, 2021 at 2:52 PM Jason Wang wrote: On 2021/3/5 2:15 下午, Yongji Xie wrote: Sorry if I've asked this before. But what's the reason for maintaing a d

Re: Re: [RFC v4 06/11] vduse: Implement an MMU-based IOMMU driver

2021-03-04 Thread Yongji Xie
On Fri, Mar 5, 2021 at 3:27 PM Jason Wang wrote: > > > On 2021/3/5 3:13 下午, Yongji Xie wrote: > > On Fri, Mar 5, 2021 at 2:52 PM Jason Wang wrote: > >> > >> On 2021/3/5 2:15 下午, Yongji Xie wrote: > >> > >> Sorry if I've asked this before. > >> > >> But what's the reason for maintaing a dedicated

Re: [RFC v4 06/11] vduse: Implement an MMU-based IOMMU driver

2021-03-04 Thread Jason Wang
On 2021/3/5 3:13 下午, Yongji Xie wrote: On Fri, Mar 5, 2021 at 2:52 PM Jason Wang wrote: On 2021/3/5 2:15 下午, Yongji Xie wrote: Sorry if I've asked this before. But what's the reason for maintaing a dedicated IOTLB here? I think we could reuse vduse_dev->iommu since the device can not be us

Re: Re: [RFC v4 06/11] vduse: Implement an MMU-based IOMMU driver

2021-03-04 Thread Yongji Xie
On Fri, Mar 5, 2021 at 2:52 PM Jason Wang wrote: > > > On 2021/3/5 2:15 下午, Yongji Xie wrote: > > Sorry if I've asked this before. > > But what's the reason for maintaing a dedicated IOTLB here? I think we > could reuse vduse_dev->iommu since the device can not be used by both > virtio and vhost i

Re: Re: [RFC v4 06/11] vduse: Implement an MMU-based IOMMU driver

2021-03-04 Thread Yongji Xie
On Fri, Mar 5, 2021 at 11:36 AM Jason Wang wrote: > > > On 2021/3/4 1:12 下午, Yongji Xie wrote: > > On Thu, Mar 4, 2021 at 12:21 PM Jason Wang wrote: > >> > >> On 2021/2/23 7:50 下午, Xie Yongji wrote: > >>> This implements a MMU-based IOMMU driver to support mapping > >>> kernel dma buffer into use

Re: [RFC v4 06/11] vduse: Implement an MMU-based IOMMU driver

2021-03-04 Thread Jason Wang
On 2021/3/4 1:12 下午, Yongji Xie wrote: On Thu, Mar 4, 2021 at 12:21 PM Jason Wang wrote: On 2021/2/23 7:50 下午, Xie Yongji wrote: This implements a MMU-based IOMMU driver to support mapping kernel dma buffer into userspace. The basic idea behind it is treating MMU (VA->PA) as IOMMU (IOVA->PA

Re: Re: [RFC v4 06/11] vduse: Implement an MMU-based IOMMU driver

2021-03-03 Thread Yongji Xie
On Thu, Mar 4, 2021 at 12:21 PM Jason Wang wrote: > > > On 2021/2/23 7:50 下午, Xie Yongji wrote: > > This implements a MMU-based IOMMU driver to support mapping > > kernel dma buffer into userspace. The basic idea behind it is > > treating MMU (VA->PA) as IOMMU (IOVA->PA). The driver will set > > u

Re: [RFC v4 06/11] vduse: Implement an MMU-based IOMMU driver

2021-03-03 Thread Jason Wang
On 2021/2/23 7:50 下午, Xie Yongji wrote: This implements a MMU-based IOMMU driver to support mapping kernel dma buffer into userspace. The basic idea behind it is treating MMU (VA->PA) as IOMMU (IOVA->PA). The driver will set up MMU mapping instead of IOMMU mapping for the DMA transfer so that t

[RFC v4 06/11] vduse: Implement an MMU-based IOMMU driver

2021-02-23 Thread Xie Yongji
This implements a MMU-based IOMMU driver to support mapping kernel dma buffer into userspace. The basic idea behind it is treating MMU (VA->PA) as IOMMU (IOVA->PA). The driver will set up MMU mapping instead of IOMMU mapping for the DMA transfer so that the userspace process is able to use its virt