Re: [RFC PATCH 4/8] iommu/vt-d: Add iommu do invalidate function

["Liu, Yi L" <yi.l.liu-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>]

On Fri, May 12, 2017 at 03:59:18PM -0600, Alex Williamson wrote:
> On Wed, 26 Apr 2017 18:12:01 +0800
> "Liu, Yi L" <yi.l.liu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> wrote:
> 
> > From: Jacob Pan <jacob.jun.pan-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> > 
> > This patch adds Intel VT-d specific function to implement
> > iommu_do_invalidate API.
> > 
> > The use case is for supporting caching structure invalidation
> > of assigned SVM capable devices. Emulated IOMMU exposes queue
> > invalidation capability and passes down all descriptors from the guest
> > to the physical IOMMU.
> > 
> > The assumption is that guest to host device ID mapping should be
> > resolved prior to calling IOMMU driver. Based on the device handle,
> > host IOMMU driver can replace certain fields before submit to the
> > invalidation queue.
> > 
> > Signed-off-by: Liu, Yi L <yi.l.liu-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> > Signed-off-by: Jacob Pan <jacob.jun.pan-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> > ---
> >  drivers/iommu/intel-iommu.c | 43 +++++++++++++++++++++++++++++++++++++++++++
> >  include/linux/intel-iommu.h | 11 +++++++++++
> >  2 files changed, 54 insertions(+)
> > 
> > diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> > index 6d5b939..0b098ad 100644
> > --- a/drivers/iommu/intel-iommu.c
> > +++ b/drivers/iommu/intel-iommu.c
> > @@ -5042,6 +5042,48 @@ static void intel_iommu_detach_device(struct iommu_domain *domain,
> >  	dmar_remove_one_dev_info(to_dmar_domain(domain), dev);
> >  }
> >  
> > +static int intel_iommu_do_invalidate(struct iommu_domain *domain,
> > +		struct device *dev, struct tlb_invalidate_info *inv_info)
> > +{
> > +	int ret = 0;
> > +	struct intel_iommu *iommu;
> > +	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
> > +	struct intel_invalidate_data *inv_data;
> > +	struct qi_desc *qi;
> > +	u16 did;
> > +	u8 bus, devfn;
> > +
> > +	if (!inv_info || !dmar_domain || (inv_info->model != INTEL_IOMMU))
> > +		return -EINVAL;
> > +
> > +	iommu = device_to_iommu(dev, &bus, &devfn);
> > +	if (!iommu)
> > +		return -ENODEV;
> > +
> > +	inv_data = (struct intel_invalidate_data *)&inv_info->opaque;
> > +
> > +	/* check SID */
> > +	if (PCI_DEVID(bus, devfn) != inv_data->sid)
> > +		return 0;
> > +
> > +	qi = &inv_data->inv_desc;
> > +
> > +	switch (qi->low & QI_TYPE_MASK) {
> > +	case QI_DIOTLB_TYPE:
> > +	case QI_DEIOTLB_TYPE:
> > +		/* for device IOTLB, we just let it pass through */
> > +		break;
> > +	default:
> > +		did = dmar_domain->iommu_did[iommu->seq_id];
> > +		set_mask_bits(&qi->low, QI_DID_MASK, QI_DID(did));
> > +		break;
> > +	}
> > +
> > +	ret = qi_submit_sync(qi, iommu);
> > +
> > +	return ret;
> 
> nit, ret variable is unnecessary.

yes, would remove it.
 
> > +}
> > +
> >  static int intel_iommu_map(struct iommu_domain *domain,
> >  			   unsigned long iova, phys_addr_t hpa,
> >  			   size_t size, int iommu_prot)
> > @@ -5416,6 +5458,7 @@ static int intel_iommu_unbind_pasid_table(struct iommu_domain *domain,
> >  #ifdef CONFIG_INTEL_IOMMU_SVM
> >  	.bind_pasid_table	= intel_iommu_bind_pasid_table,
> >  	.unbind_pasid_table	= intel_iommu_unbind_pasid_table,
> > +	.do_invalidate		= intel_iommu_do_invalidate,
> >  #endif
> >  	.map		= intel_iommu_map,
> >  	.unmap		= intel_iommu_unmap,
> > diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
> > index ac04f28..9d6562c 100644
> > --- a/include/linux/intel-iommu.h
> > +++ b/include/linux/intel-iommu.h
> > @@ -29,6 +29,7 @@
> >  #include <linux/dma_remapping.h>
> >  #include <linux/mmu_notifier.h>
> >  #include <linux/list.h>
> > +#include <linux/bitops.h>
> >  #include <asm/cacheflush.h>
> >  #include <asm/iommu.h>
> >  
> > @@ -271,6 +272,10 @@ enum {
> >  #define QI_PGRP_RESP_TYPE	0x9
> >  #define QI_PSTRM_RESP_TYPE	0xa
> >  
> > +#define QI_DID(did)		(((u64)did & 0xffff) << 16)
> > +#define QI_DID_MASK		GENMASK(31, 16)
> > +#define QI_TYPE_MASK		GENMASK(3, 0)
> > +
> >  #define QI_IEC_SELECTIVE	(((u64)1) << 4)
> >  #define QI_IEC_IIDEX(idx)	(((u64)(idx & 0xffff) << 32))
> >  #define QI_IEC_IM(m)		(((u64)(m & 0x1f) << 27))
> > @@ -529,6 +534,12 @@ struct intel_svm {
> >  extern struct intel_iommu *intel_svm_device_to_iommu(struct device *dev);
> >  #endif
> >  
> > +struct intel_invalidate_data {
> > +	u16 sid;
> > +	u32 pasid;
> > +	struct qi_desc inv_desc;
> > +};
> 
> This needs to be uapi since the vfio user is expected to create it, so
> we need a uapi version of qi_desc too.
>

yes, would do it.

Thx,
Yi L
 
> > +
> >  extern const struct attribute_group *intel_iommu_groups[];
> >  extern void intel_iommu_debugfs_init(void);
> >  extern struct context_entry *iommu_context_addr(struct intel_iommu *iommu,
>