Re: [RFC PATCH 0/2] iommu: Avoid unnecessary PRI queue flushes

2020-10-23 Thread Jean-Philippe Brucker
On Mon, Oct 19, 2020 at 02:16:08PM -0700, Raj, Ashok wrote: > Hi Jean > > On Mon, Oct 19, 2020 at 04:08:24PM +0200, Jean-Philippe Brucker wrote: > > On Sat, Oct 17, 2020 at 04:25:25AM -0700, Raj, Ashok wrote: > > > > For devices that *don't* use a stop marker, the PCIe spec says > > > >

Re: [RFC PATCH 0/2] iommu: Avoid unnecessary PRI queue flushes

2020-10-23 Thread Jean-Philippe Brucker
On Mon, Oct 19, 2020 at 11:33:16AM -0700, Jacob Pan wrote: > Hi Jean-Philippe, > > On Mon, 19 Oct 2020 16:08:24 +0200, Jean-Philippe Brucker > wrote: > > > On Sat, Oct 17, 2020 at 04:25:25AM -0700, Raj, Ashok wrote: > > > > For devices that *don't* use a stop marker, the PCIe spec says > > > >

Re: [RFC PATCH 0/2] iommu: Avoid unnecessary PRI queue flushes

2020-10-19 Thread Raj, Ashok
Hi Jean On Mon, Oct 19, 2020 at 04:08:24PM +0200, Jean-Philippe Brucker wrote: > On Sat, Oct 17, 2020 at 04:25:25AM -0700, Raj, Ashok wrote: > > > For devices that *don't* use a stop marker, the PCIe spec says (10.4.1.2): > > > > > > To stop [using a PASID] without using a Stop Marker Message,

Re: [RFC PATCH 0/2] iommu: Avoid unnecessary PRI queue flushes

2020-10-19 Thread Jacob Pan
Hi Jean-Philippe, On Mon, 19 Oct 2020 16:08:24 +0200, Jean-Philippe Brucker wrote: > On Sat, Oct 17, 2020 at 04:25:25AM -0700, Raj, Ashok wrote: > > > For devices that *don't* use a stop marker, the PCIe spec says > > > (10.4.1.2): > > > > > > To stop [using a PASID] without using a Stop

Re: [RFC PATCH 0/2] iommu: Avoid unnecessary PRI queue flushes

2020-10-19 Thread Jean-Philippe Brucker
On Sat, Oct 17, 2020 at 04:25:25AM -0700, Raj, Ashok wrote: > > For devices that *don't* use a stop marker, the PCIe spec says (10.4.1.2): > > > > To stop [using a PASID] without using a Stop Marker Message, the > > function shall: > > 1. Stop queueing new Page Request Messages for this

Re: [RFC PATCH 0/2] iommu: Avoid unnecessary PRI queue flushes

2020-10-17 Thread Raj, Ashok
Hi Jean On Fri, Oct 16, 2020 at 09:59:23AM +0200, Jean-Philippe Brucker wrote: > On Thu, Oct 15, 2020 at 11:22:11AM -0700, Raj, Ashok wrote: > > Hi Jean > > > > + Baolu who is looking into this. > > > > > > On Thu, Oct 15, 2020 at 11:00:27AM +0200, Jean-Philippe Brucker wrote: > > > Add a

Re: [RFC PATCH 0/2] iommu: Avoid unnecessary PRI queue flushes

2020-10-16 Thread Jean-Philippe Brucker
On Thu, Oct 15, 2020 at 11:22:11AM -0700, Raj, Ashok wrote: > Hi Jean > > + Baolu who is looking into this. > > > On Thu, Oct 15, 2020 at 11:00:27AM +0200, Jean-Philippe Brucker wrote: > > Add a parameter to iommu_sva_unbind_device() that tells the IOMMU driver > > whether the PRI queue needs

Re: [RFC PATCH 0/2] iommu: Avoid unnecessary PRI queue flushes

2020-10-15 Thread Raj, Ashok
Hi Jean + Baolu who is looking into this. On Thu, Oct 15, 2020 at 11:00:27AM +0200, Jean-Philippe Brucker wrote: > Add a parameter to iommu_sva_unbind_device() that tells the IOMMU driver > whether the PRI queue needs flushing. When looking at the PCIe spec > again I noticed that most of the

[RFC PATCH 0/2] iommu: Avoid unnecessary PRI queue flushes

2020-10-15 Thread Jean-Philippe Brucker
Add a parameter to iommu_sva_unbind_device() that tells the IOMMU driver whether the PRI queue needs flushing. When looking at the PCIe spec again I noticed that most of the time the SMMUv3 driver doesn't actually need to flush the PRI queue. Does this make sense for Intel VT-d as well or did I