Hi Liu, On 6/14/19 2:38 PM, Liu, Yi L wrote: > Hi Eric, > >> From: Eric Auger [mailto:eric.auger@xxxxxxxxxx] >> Sent: Monday, May 27, 2019 12:10 AM >> Subject: [PATCH v8 23/29] vfio: VFIO_IOMMU_CACHE_INVALIDATE >> >> 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. >> >> Signed-off-by: Liu, Yi L <yi.l.liu@xxxxxxxxxxxxxxx> >> Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx> >> >> --- >> v6 -> v7: >> - Use iommu_capsule struct >> - renamed vfio_iommu_for_each_dev into vfio_iommu_lookup_dev >> due to checkpatch error related to for_each_dev suffix >> >> v2 -> v3: >> - introduce vfio_iommu_for_each_dev back in this patch >> >> v1 -> v2: >> - s/TLB/CACHE >> - remove vfio_iommu_task usage >> - commit message rewording >> --- >> 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 b2d609d6fe83..6fda4fbc9bfa 100644 >> --- a/drivers/vfio/vfio_iommu_type1.c >> +++ b/drivers/vfio/vfio_iommu_type1.c >> @@ -120,6 +120,34 @@ 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) >> +{ >> + struct domain_capsule dc = {.data = data}; >> + struct vfio_domain *d; >> + struct vfio_group *g; >> + int ret = 0; >> + >> + list_for_each_entry(d, &iommu->domain_list, next) { >> + dc.domain = d->domain; >> + list_for_each_entry(g, &d->group_list, next) { >> + ret = iommu_group_for_each_dev(g->iommu_group, >> + &dc, fn); >> + if (ret) >> + break; >> + } >> + } >> + return ret; >> +} >> + >> static int put_pfn(unsigned long pfn, int prot); >> >> /* >> @@ -1795,6 +1823,15 @@ vfio_attach_pasid_table(struct vfio_iommu *iommu, >> return ret; >> } >> >> +static int vfio_cache_inv_fn(struct device *dev, void *data) { >> + struct domain_capsule *dc = (struct domain_capsule *)data; >> + struct vfio_iommu_type1_cache_invalidate *ustruct = >> + (struct vfio_iommu_type1_cache_invalidate *)dc->data; >> + >> + return iommu_cache_invalidate(dc->domain, dev, &ustruct->info); } >> + >> static long vfio_iommu_type1_ioctl(void *iommu_data, >> unsigned int cmd, unsigned long arg) { @@ - >> 1881,6 +1918,24 @@ static long vfio_iommu_type1_ioctl(void *iommu_data, >> } else if (cmd == VFIO_IOMMU_DETACH_PASID_TABLE) { >> vfio_detach_pasid_table(iommu); >> return 0; >> + } else if (cmd == VFIO_IOMMU_CACHE_INVALIDATE) { >> + struct vfio_iommu_type1_cache_invalidate ustruct; >> + 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) > > May remove the flags field? > >> + 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 >> 4316dd8cb5b5..055aa9b9745a 100644 >> --- a/include/uapi/linux/vfio.h >> +++ b/include/uapi/linux/vfio.h >> @@ -785,6 +785,19 @@ struct vfio_iommu_type1_attach_pasid_table { >> */ >> #define VFIO_IOMMU_DETACH_PASID_TABLE _IO(VFIO_TYPE, VFIO_BASE + 23) >> >> +/** >> + * VFIO_IOMMU_CACHE_INVALIDATE - _IOWR(VFIO_TYPE, VFIO_BASE + 24, >> + * struct vfio_iommu_type1_cache_invalidate) >> + * >> + * Propagate guest IOMMU cache invalidation to the host. >> + */ >> +struct vfio_iommu_type1_cache_invalidate { >> + __u32 argsz; >> + __u32 flags; > > Looks like there is no more usage on "flags". is it? Agreed. However all the other vfio structs embed it. vfio_iommu_type1_dma_unmap (VFIO_IOMMU_UNMAP_DMA) or vfio_iommu_type1_info (VFIO_IOMMU_GET_INFO) also feature it and do not use it either if I am not wrong. So I guess flags is a common pattern for the API and somehow allows to extend the API if needed. So I would be inclined to keep it, no? Thanks Eric > > Regards, > Yi Liu > >> + struct iommu_cache_invalidate_info info; }; >> +#define VFIO_IOMMU_CACHE_INVALIDATE _IO(VFIO_TYPE, VFIO_BASE + 24) >> + >> /* -------- Additional API for SPAPR TCE (Server POWERPC) IOMMU -------- */ >> >> /* >> -- >> 2.20.1 >
