Re: [PATCH 4/6] vhost_vdpa: support doorbell mapping via mmap

2020-06-03 Thread Jason Wang
On 2020/6/3 下午2:34, Michael S. Tsirkin wrote: On Wed, Jun 03, 2020 at 12:18:44PM +0800, Jason Wang wrote: On 2020/6/2 下午9:31, Michael S. Tsirkin wrote: On Tue, Jun 02, 2020 at 02:49:38PM +0800, Jason Wang wrote: On 2020/6/2 下午12:56, Michael S. Tsirkin wrote: On Tue, Jun 02, 2020 at

Re: [PATCH 4/6] vhost_vdpa: support doorbell mapping via mmap

2020-06-03 Thread Michael S. Tsirkin
On Wed, Jun 03, 2020 at 12:18:44PM +0800, Jason Wang wrote: > > On 2020/6/2 下午9:31, Michael S. Tsirkin wrote: > > On Tue, Jun 02, 2020 at 02:49:38PM +0800, Jason Wang wrote: > > > On 2020/6/2 下午12:56, Michael S. Tsirkin wrote: > > > > On Tue, Jun 02, 2020 at 03:22:49AM +0800, kbuild test robot

Re: [PATCH 4/6] vhost_vdpa: support doorbell mapping via mmap

2020-06-02 Thread Jason Wang
On 2020/6/2 下午9:31, Michael S. Tsirkin wrote: On Tue, Jun 02, 2020 at 02:49:38PM +0800, Jason Wang wrote: On 2020/6/2 下午12:56, Michael S. Tsirkin wrote: On Tue, Jun 02, 2020 at 03:22:49AM +0800, kbuild test robot wrote: Hi Jason, I love your patch! Yet something to improve: [auto build

Re: [PATCH 4/6] vhost_vdpa: support doorbell mapping via mmap

2020-06-02 Thread Michael S. Tsirkin
On Tue, Jun 02, 2020 at 02:49:38PM +0800, Jason Wang wrote: > > On 2020/6/2 下午12:56, Michael S. Tsirkin wrote: > > On Tue, Jun 02, 2020 at 03:22:49AM +0800, kbuild test robot wrote: > > > Hi Jason, > > > > > > I love your patch! Yet something to improve: > > > > > > [auto build test ERROR on

Re: [PATCH 4/6] vhost_vdpa: support doorbell mapping via mmap

2020-06-02 Thread Jason Wang
On 2020/6/2 下午12:56, Michael S. Tsirkin wrote: On Tue, Jun 02, 2020 at 03:22:49AM +0800, kbuild test robot wrote: Hi Jason, I love your patch! Yet something to improve: [auto build test ERROR on vhost/linux-next] [also build test ERROR on linus/master v5.7 next-20200529] [if your patch is

Re: [PATCH 4/6] vhost_vdpa: support doorbell mapping via mmap

2020-06-01 Thread Michael S. Tsirkin
On Tue, Jun 02, 2020 at 03:22:49AM +0800, kbuild test robot wrote: > Hi Jason, > > I love your patch! Yet something to improve: > > [auto build test ERROR on vhost/linux-next] > [also build test ERROR on linus/master v5.7 next-20200529] > [if your patch is applied to the wrong git tree, please

Re: [virtio-dev] Re: [PATCH 4/6] vhost_vdpa: support doorbell mapping via mmap

2020-06-01 Thread Jason Wang
On 2020/5/30 上午2:30, Rob Miller wrote: Given the need for 4K doorbell such that QEMU can easily map, ect, and assuming that I have a HW device which exposes 2 VQ's, with a notification area off of BAR3, offset=whatever, notifier_multiplier=4, we don't need to have 2 x 4K pages mapped into the

Re: [PATCH 4/6] vhost_vdpa: support doorbell mapping via mmap

2020-06-01 Thread kbuild test robot
Hi Jason, I love your patch! Yet something to improve: [auto build test ERROR on vhost/linux-next] [also build test ERROR on linus/master v5.7 next-20200529] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system. BTW, we also suggest to use '--base'

Re: [PATCH 4/6] vhost_vdpa: support doorbell mapping via mmap

2020-05-29 Thread Rob Miller via Virtualization
Given the need for 4K doorbell such that QEMU can easily map, ect, and assuming that I have a HW device which exposes 2 VQ's, with a notification area off of BAR3, offset=whatever, notifier_multiplier=4, we don't need to have 2 x 4K pages mapped into the VM for both doorbells do we? The guest

Re: [PATCH 4/6] vhost_vdpa: support doorbell mapping via mmap

2020-05-29 Thread Jason Wang
On 2020/5/29 下午5:16, Mika Penttilä wrote: Hi, On 29.5.2020 11.03, Jason Wang wrote: Currently the doorbell is relayed via eventfd which may have significant overhead because of the cost of vmexits or syscall. This patch introduces mmap() based doorbell mapping which can eliminate the overhead