> From: Alex Williamson [mailto:alex.williamson@xxxxxxxxxx] > Sent: Wednesday, November 6, 2019 6:42 AM > To: Liu, Yi L <yi.l.liu@xxxxxxxxx> > Subject: Re: [RFC v2 1/3] vfio: VFIO_IOMMU_CACHE_INVALIDATE > > On Fri, 25 Oct 2019 11:20:40 +0000 > "Liu, Yi L" <yi.l.liu@xxxxxxxxx> wrote: > > > Hi Kevin, > > > > > From: Tian, Kevin > > > Sent: Friday, October 25, 2019 5:14 PM > > > To: Liu, Yi L <yi.l.liu@xxxxxxxxx>; alex.williamson@xxxxxxxxxx; > > > Subject: RE: [RFC v2 1/3] vfio: VFIO_IOMMU_CACHE_INVALIDATE > > > > > > > From: Liu, Yi L > > > > Sent: Thursday, October 24, 2019 8:26 PM > > > > > > > > From: Liu Yi L <yi.l.liu@xxxxxxxxxxxxxxx> > > > > > > > > When the guest "owns" the stage 1 translation structures, the > > > > host IOMMU driver has no knowledge of caching structure updates > > > > unless the guest invalidation requests are trapped and passed down to the host. > > > > > > > > This patch adds the VFIO_IOMMU_CACHE_INVALIDATE ioctl with aims at > > > > propagating guest stage1 IOMMU cache invalidations to the host. > > > > > > > > Cc: Kevin Tian <kevin.tian@xxxxxxxxx> > > > > Signed-off-by: Liu Yi L <yi.l.liu@xxxxxxxxxxxxxxx> > > > > Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx> > > > > Signed-off-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx> > > > > --- > > > > drivers/vfio/vfio_iommu_type1.c | 55 > > > > +++++++++++++++++++++++++++++++++++++++++ > > > > include/uapi/linux/vfio.h | 13 ++++++++++ > > > > 2 files changed, 68 insertions(+) > > > > > > > > diff --git a/drivers/vfio/vfio_iommu_type1.c > > > > b/drivers/vfio/vfio_iommu_type1.c index 96fddc1d..cd8d3a5 100644 > > > > --- a/drivers/vfio/vfio_iommu_type1.c > > > > +++ b/drivers/vfio/vfio_iommu_type1.c > > > > @@ -124,6 +124,34 @@ struct vfio_regions { > > > > #define IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu) \ > > > > (!list_empty(&iommu->domain_list)) > > > > > > > > +struct domain_capsule { > > > > + struct iommu_domain *domain; > > > > + void *data; > > > > +}; > > > > + > > > > +/* iommu->lock must be held */ > > > > +static int > > > > +vfio_iommu_lookup_dev(struct vfio_iommu *iommu, > > > > + int (*fn)(struct device *dev, void *data), > > > > + void *data) > > > > > > 'lookup' usually means find a device and then return. But the real > > > purpose here is to loop all the devices within this container and > > > then do something. Does it make more sense to be vfio_iommu_for_each_dev? > > +1 > > > yep, I can replace it. > > > > > > > > > +{ > > > > + struct domain_capsule dc = {.data = data}; > > > > + struct vfio_domain *d; > > [...] > > > 2315,6 +2352,24 @@ > > > > static long vfio_iommu_type1_ioctl(void *iommu_data, > > > > > > > > return copy_to_user((void __user *)arg, &unmap, minsz) ? > > > > -EFAULT : 0; > > > > + } else if (cmd == VFIO_IOMMU_CACHE_INVALIDATE) { > > > > + struct vfio_iommu_type1_cache_invalidate ustruct; > > > > > > it's weird to call a variable as struct. > > > > Will fix it. > > > > > > + int ret; > > > > + > > > > + minsz = offsetofend(struct > > > > vfio_iommu_type1_cache_invalidate, > > > > + info); > > > > + > > > > + if (copy_from_user(&ustruct, (void __user *)arg, minsz)) > > > > + return -EFAULT; > > > > + > > > > + if (ustruct.argsz < minsz || ustruct.flags) > > > > + return -EINVAL; > > > > + > > > > + mutex_lock(&iommu->lock); > > > > + ret = vfio_iommu_lookup_dev(iommu, vfio_cache_inv_fn, > > > > + &ustruct); > > > > + mutex_unlock(&iommu->lock); > > > > + return ret; > > > > } > > > > > > > > return -ENOTTY; > > > > diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h > > > > index 9e843a1..ccf60a2 100644 > > > > --- a/include/uapi/linux/vfio.h > > > > +++ b/include/uapi/linux/vfio.h > > > > @@ -794,6 +794,19 @@ struct vfio_iommu_type1_dma_unmap { > > > > #define VFIO_IOMMU_ENABLE _IO(VFIO_TYPE, VFIO_BASE + 15) > > > > #define VFIO_IOMMU_DISABLE _IO(VFIO_TYPE, VFIO_BASE + 16) > > > > > > > > +/** > > > > + * VFIO_IOMMU_CACHE_INVALIDATE - _IOWR(VFIO_TYPE, VFIO_BASE + > > > > 24, > > What's going on with these ioctl numbers? AFAICT[1] we've used up through > VFIO_BASE + 21, this jumps to 24, the next patch skips to 27, then the last patch fills > in 28 & 29. Thanks, Hi Alex, I rebase my patch to Eric's nested stage translation patches. His base also introduced IOCTLs. I should have made it better. I'll try to sync with Eric to serialize the IOCTLs. [PATCH v6 00/22] SMMUv3 Nested Stage Setup by Eric Auger https://lkml.org/lkml/2019/3/17/124 Thanks, Yi Liu > Alex > > [1] git grep -h VFIO_BASE | grep "VFIO_BASE +" | grep -e ^#define | \ > awk '{print $NF}' | tr -d ')' | sort -u -n
