Re: [PATCH 1/3] A device for zero-copy based on KVM virtio-net.

On Wed, Apr 07, 2010 at 10:41:08AM +0800, Xin, Xiaohui wrote: Michael, Qemu needs a userspace write, is that a synchronous one or asynchronous one? It's a synchronous non-blocking write. Sorry, why the Qemu live migration needs the device have a userspace write? how does the write

Re:[PATCH 1/3] A device for zero-copy based on KVM virtio-net.

From: Xin Xiaohui xiaohui@intel.com --- Michael, Thanks a lot for the explanation. I have drafted a patch for the qemu write after I looked into tun driver. Does it do in right way? Thanks Xiaohui drivers/vhost/mpassthru.c | 45 + 1 files

Re: [PATCH 1/3] A device for zero-copy based on KVM virtio-net.

On Wed, Apr 07, 2010 at 05:00:39PM +0800, xiaohui@intel.com wrote: From: Xin Xiaohui xiaohui@intel.com --- Michael, Thanks a lot for the explanation. I have drafted a patch for the qemu write after I looked into tun driver. Does it do in right way? Thanks Xiaohui

Re: [PATCH 1/3] A device for zero-copy based on KVM virtio-net.

On Tue, Apr 06, 2010 at 01:41:37PM +0800, Xin, Xiaohui wrote: Michael, For the DOS issue, I'm not sure how much the limit get_user_pages() can pin is reasonable, should we compute the bindwidth to make it? There's a ulimit for locked memory. Can we use this, decreasing the value for

RE: [PATCH 1/3] A device for zero-copy based on KVM virtio-net.

Michael, Qemu needs a userspace write, is that a synchronous one or asynchronous one? It's a synchronous non-blocking write. Sorry, why the Qemu live migration needs the device have a userspace write? how does the write operation work? And why a read operation is not cared here? Thanks

RE: [PATCH 1/3] A device for zero-copy based on KVM virtio-net.

Michael, For the DOS issue, I'm not sure how much the limit get_user_pages() can pin is reasonable, should we compute the bindwidth to make it? There's a ulimit for locked memory. Can we use this, decreasing the value for rlimit array? We can do this when backend is enabled and re-increment

Re:[PATCH 1/3] A device for zero-copy based on KVM virtio-net.

Add a device to utilize the vhost-net backend driver for copy-less data transfer between guest FE and host NIC. It pins the guest user space to the host memory and provides proto_ops as sendmsg/recvmsg to vhost-net. Signed-off-by: Xin Xiaohui xiaohui@intel.com Signed-off-by: Zhao Yu

Re: [PATCH 1/3] A device for zero-copy based on KVM virtio-net.

On Thu, Apr 01, 2010 at 05:27:18PM +0800, Xin Xiaohui wrote: Add a device to utilize the vhost-net backend driver for copy-less data transfer between guest FE and host NIC. It pins the guest user space to the host memory and provides proto_ops as sendmsg/recvmsg to vhost-net. Signed-off-by:

[PATCH 1/3] A device for zero-copy based on KVM virtio-net.

Add a device to utilize the vhost-net backend driver for copy-less data transfer between guest FE and host NIC. It pins the guest user space to the host memory and provides proto_ops as sendmsg/recvmsg to vhost-net. Signed-off-by: Xin Xiaohui xiaohui@intel.com Signed-off-by: Zhao Yu

Re: [PATCH 1/3] A device for zero-copy based on KVM virtio-net.

Le mercredi 10 février 2010 à 19:48 +0800, Xin Xiaohui a écrit : Add a device to utilize the vhost-net backend driver for copy-less data transfer between guest FE and host NIC. It pins the guest user space to the host memory and provides proto_ops as sendmsg/recvmsg to vhost-net.

RE: [PATCH 1/3] A device for zero-copy based on KVM virtio-net.

Eric, Thanks. I will look into that. But don't stop there. Please comments more. :-) Thanks Xiaohui -Original Message- From: Eric Dumazet [mailto:eric.duma...@gmail.com] Sent: Wednesday, February 10, 2010 11:18 PM To: Xin, Xiaohui Cc: net...@vger.kernel.org; kvm@vger.kernel.org;