Re: [Xen-devel] Paravitrualization drivers query
On Fri, Jul 21, 2017 at 12:42:04PM +0530, shishir tiwari wrote: > > Hi > > > > I am trying understand Xen Pv drivers and i writing my own pv fronend and > > backend driver. > > > > 1. For driver internal communication how do i create/write node in backend > > driver and how to read in fronted drivers. > > 2.how do i create one shared page in backend driver to write/read data in > > frontend driver. > > > > >Depending on where your driver lives >(kernel or userspace), the APIs are > >going to be different. > > > My driver will be in kernel space. I want to create some Node and shared > page or queue. So I can transfer data for domu to dom0. > > > > I gone-through kernel code and but its tittle bit confusing to me. > > >>Which bits do you find confusing? > > > I am not able to understand who first create Node and shared memory by xen > or domO or may be by frontend drivers The nodes are first created by the toolstack, then filled in by backend and frontend. ___ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
Re: [Xen-devel] Paravitrualization drivers query
On 07/21/2017 03:12 PM, shishir tiwari wrote: > > > Hi > > > > I am trying understand Xen Pv drivers and i writing my own pv fronend > and > > backend driver. > > > > 1. For driver internal communication how do i create/write node in > backend > > driver and how to read in fronted drivers. > > 2.how do i create one shared page in backend driver to write/read data > in > > frontend driver. > > > > >Depending on where your driver lives >(kernel or userspace), the APIs are > >going to be different. > > > My driver will be in kernel space. I want to create some Node and shared page > or > queue. So I can transfer data for domu to dom0. Hi Shishir I suggest you read about drivers/net/xen-netfront.c and drivers/net/xen-netback/* in linux kernel. You would rely on xenbus/xenstore to read/write node in frontend or backend and the corresponding APIs are xenbus_write, xenbus_printf, xenbus_read, etc. To create shared page between frontend and backend, you create use grant tale mechanism. Generally, each grant table reference is used to indicate one shared memory page. The frontend allocates a page to share and bind this page to a grant table reference. This reference is then passed to backend via xenstore or ring buffer. Backend maps the shared page with this reference via APIs like gnttab_map_refs(). I suggest you read about the book "Definitive Guide to Xen Hypervisor" and read about linux paravirtual driver code. Dongli Zhang > > > > I gone-through kernel code and but its tittle bit confusing to me. > > >>Which bits do you find confusing? > > > I am not able to understand who first create Node and shared memory by xen or > domO or may be by frontend drivers > > > > > ___ > Xen-devel mailing list > Xen-devel@lists.xen.org > https://lists.xen.org/xen-devel > ___ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
Re: [Xen-devel] Paravitrualization drivers query
> Hi > > I am trying understand Xen Pv drivers and i writing my own pv fronend and > backend driver. > > 1. For driver internal communication how do i create/write node in backend > driver and how to read in fronted drivers. > 2.how do i create one shared page in backend driver to write/read data in > frontend driver. > >Depending on where your driver lives >(kernel or userspace), the APIs are >going to be different. My driver will be in kernel space. I want to create some Node and shared page or queue. So I can transfer data for domu to dom0. > I gone-through kernel code and but its tittle bit confusing to me. >>Which bits do you find confusing? I am not able to understand who first create Node and shared memory by xen or domO or may be by frontend drivers ___ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
Re: [Xen-devel] Paravitrualization drivers query
On Thu, Jul 20, 2017 at 08:29:48PM +0530, shishir tiwari wrote: > Hi > > I am trying understand Xen Pv drivers and i writing my own pv fronend and > backend driver. > > 1. For driver internal communication how do i create/write node in backend > driver and how to read in fronted drivers. > 2.how do i create one shared page in backend driver to write/read data in > frontend driver. > Depending on where your driver lives (kernel or userspace), the APIs are going to be different. > I gone-through kernel code and but its tittle bit confusing to me. Which bits do you find confusing? ___ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
[Xen-devel] Paravitrualization drivers query
Hi I am trying understand Xen Pv drivers and i writing my own pv fronend and backend driver. 1. For driver internal communication how do i create/write node in backend driver and how to read in fronted drivers. 2.how do i create one shared page in backend driver to write/read data in frontend driver. I gone-through kernel code and but its tittle bit confusing to me. someone share set api for this it would help me lot. Thanks Shishir tiwari ___ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel