Re: [PATCH v8 04/10] iommu/vt-d: Support flushing more translation cache types

[Lu Baolu]

Hi,

On 1/10/20 5:50 AM, Jacob Pan wrote:
> On Thu, 19 Dec 2019 10:46:51 +0800
> Lu Baolu<baolu.lu@xxxxxxxxxxxxxxx>  wrote:
>
> > Hi,
> >
> > On 12/17/19 3:24 AM, Jacob Pan wrote:
> > > When Shared Virtual Memory is exposed to a guest via vIOMMU,
> > > scalable IOTLB invalidation may be passed down from outside IOMMU
> > > subsystems. This patch adds invalidation functions that can be used
> > > for additional translation cache types.
> > >
> > > Signed-off-by: Jacob Pan<jacob.jun.pan@xxxxxxxxxxxxxxx>
> > > ---
> > >    drivers/iommu/dmar.c        | 46
> > > +++++++++++++++++++++++++++++++++++++++++++++
> > > drivers/iommu/intel-pasid.c |  3 ++- include/linux/intel-iommu.h |
> > > 21 +++++++++++++++++---- 3 files changed, 65 insertions(+), 5
> > > deletions(-)
> > >
> > > diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
> > > index 3acfa6a25fa2..f2f5d75da94a 100644
> > > --- a/drivers/iommu/dmar.c
> > > +++ b/drivers/iommu/dmar.c
> > > @@ -1348,6 +1348,20 @@ void qi_flush_iotlb(struct intel_iommu
> > > *iommu, u16 did, u64 addr, qi_submit_sync(&desc, iommu);
> > >    }
> > >    
> > > +/* PASID-based IOTLB Invalidate */
> > > +void qi_flush_iotlb_pasid(struct intel_iommu *iommu, u16 did, u64
> > > addr, u32 pasid,
> > > +		unsigned int size_order, u64 granu, int ih)
> > > +{
> > > +	struct qi_desc desc = {.qw2 = 0, .qw3 = 0};
> > > +
> > > +	desc.qw0 = QI_EIOTLB_PASID(pasid) | QI_EIOTLB_DID(did) |
> > > +		QI_EIOTLB_GRAN(granu) | QI_EIOTLB_TYPE;
> > > +	desc.qw1 = QI_EIOTLB_ADDR(addr) | QI_EIOTLB_IH(ih) |
> > > +		QI_EIOTLB_AM(size_order);
> > > +
> > > +	qi_submit_sync(&desc, iommu);
> > > +}
> > There's another version of pasid-based iotlb invalidation.
> >
> > https://lkml.org/lkml/2019/12/10/2128
> >
> > Let's consider merging them.
> Absolutely, the difference i see is that the granularity is explicit
> here. Here we do invalidation request from the guest. Perhaps, we can
> look at consolidation once this use case is supported?

Looks good to me. :-)

Best regards,
baolu