On 17/05/2017 09:17, Maxime Coquelin wrote: > > > On 05/17/2017 07:57 AM, Peter Xu wrote: >> On Wed, May 17, 2017 at 12:23:42PM +0800, Peter Xu wrote: >>> On Tue, May 16, 2017 at 06:51:03PM +0200, Maxime Coquelin wrote: >>>> Hi Peter, >>>> >>>> On 05/16/2017 03:24 PM, Maxime Coquelin wrote: >>>>> >>>>> >>>>> On 05/15/2017 10:50 AM, Peter Xu wrote: >>>>>> The problem is that, address_space_get_iotlb_entry() shares a lot >>>>>> with >>>>>> address_space_translate(). This patch tries to abstract the >>>>>> shared elements. >>>>>> >>>>>> Originally, this work is derived from discussion from VT-d >>>>>> passthrough >>>>>> series discussions [1]. But for sure we can just see this series as a >>>>>> standalone cleanup. So I posted it separately here. >>>>>> >>>>>> Smoke tests are done with general VM boots, IOs, especially with >>>>>> vhost >>>>>> dmar configurations. >>>>>> >>>>>> I believe with current series I can throw away the old patch [1], >>>>>> which may be good. But before that, please kindly review. Thanks. >>>>> >>>>> I faced the problem the old patch fixes when declaring and >>>>> attaching an >>>>> IOMMU device, but booting the kernel with intel_iommu=off. >>>>> >>>>> I tested again with patches 1 & 4 of your series, and I confirm it >>>>> fixes >>>>> the issue: >>>>> Tested-by: Maxime Coquelin <maxime.coque...@redhat.com> >>>> >>>> I did some more testing with my "vhost-user IOMMU" setup, and the >>>> series >>>> actually breaks with IOMMU device attached, and intel_iommu=on. >>>> >>>> The main difference with the previous passing test is the guest RAM >>>> size. In the working setup, it is 2G of 2M hugepages, vs. 4G of 2M >>>> hugepages in the failing one. Note that I also reproduce with >>>> vhost-kernel >>>> backend. >>>> >>>> The error happens in the first vhost_device_iotlb_miss() call: >>>> qemu-system-x86_64: Fail to lookup the translated address b5d7c000 >>>> >>>> I don't have the root cause yet, I'll keep you updated. >>> >>> Maxime, >>> >>> Thanks a lot for help testing this series! >>> >>> I reproduced this problem, and this is not a problem obvious enough >>> for me. Let me investigate as well. >>> >>> -- >>> Peter Xu >> >> Maxime, >> >> Could you help try adding this change upon current to see whether >> problem solved? > > Hi Peter, > > Yes, problem is solved with below change.
Cool---Peter, please send the new patch 4 as toplevel message! Thanks, Paolo
