Re: [PATCH v5 09/23] iommu/vt-d: add svm/sva invalidate function

Lu Baolu
2018-05-14T03:35:05Z

Hi,

On 05/12/2018 04:54 AM, Jacob Pan wrote:
> When Shared Virtual Address (SVA) is enabled for a guest OS via
> vIOMMU, we need to provide invalidation support at IOMMU API and driver
> level. This patch adds Intel VT-d specific function to implement
> iommu passdown invalidate API for shared virtual address.
>
> 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@linux.intel.com>
> Signed-off-by: Ashok Raj <ashok.raj@intel.com>
> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
> ---
> drivers/iommu/intel-iommu.c | 129 ++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 129 insertions(+)
>
> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> index 732a10f..684bd98 100644
> --- a/drivers/iommu/intel-iommu.c
> +++ b/drivers/iommu/intel-iommu.c
> @@ -4973,6 +4973,134 @@ static void intel_iommu_detach_device(struct iommu_domain *domain,
> dmar_remove_one_dev_info(to_dmar_domain(domain), dev);
> }
>
> +/*
> + * 2D array for converting and sanitizing IOMMU generic TLB granularity to
> + * VT-d granularity. Invalidation is typically included in the unmap operation
> + * as a result of DMA or VFIO unmap. However, for assigned device where guest
> + * could own the first level page tables without being shadowed by QEMU. In
> + * this case there is no pass down unmap to the host IOMMU as a result of unmap
> + * in the guest. Only invalidations are trapped and passed down.
> + * In all cases, only first level TLB invalidation (request with PASID) can be
> + * passed down, therefore we do not include IOTLB granularity for request
> + * without PASID (second level).
> + *
> + * For an example, to find the VT-d granularity encoding for IOTLB
> + * type and page selective granularity within PASID:
> + * X: indexed by enum iommu_inv_type
> + * Y: indexed by enum iommu_inv_granularity
> + * [IOMMU_INV_TYPE_TLB][IOMMU_INV_GRANU_PAGE_PASID]
> + *
> + * Granu_map array indicates validity of the table. 1: valid, 0: invalid
> + *
> + */
> +const static int inv_type_granu_map[IOMMU_INV_NR_TYPE][IOMMU_INV_NR_GRANU] = {
> + /* Extended dev TLBs */
> + {1, 1, 1},
> + /* Extended IOTLB */
> + {1, 1, 1},
> + /* PASID cache */
> + {1, 1, 0}
> +};
> +
> +const static u64 inv_type_granu_table[IOMMU_INV_NR_TYPE][IOMMU_INV_NR_GRANU] = {
> + /* extended dev IOTLBs */
> + {QI_DEV_IOTLB_GRAN_ALL, QI_DEV_IOTLB_GRAN_PASID_SEL, 0},
> + /* Extended IOTLB */
> + {QI_GRAN_NONG_ALL, QI_GRAN_NONG_PASID, QI_GRAN_PSI_PASID},
> + /* PASID cache */
> + {QI_PC_ALL_PASIDS, QI_PC_PASID_SEL, 0},
> +};
> +
> +static inline int to_vtd_granularity(int type, int granu, u64 *vtd_granu)
> +{
> + if (type >= IOMMU_INV_NR_TYPE || granu >= IOMMU_INV_NR_GRANU ||
> + !inv_type_granu_map[type][granu])

Alignment should match open parenthesis.

> + return -EINVAL;
> +
> + *vtd_granu = inv_type_granu_table[type][granu];
> +
> + return 0;
> +}
> +
> +static int intel_iommu_sva_invalidate(struct iommu_domain *domain,
> + struct device *dev, struct tlb_invalidate_info *inv_info)

Ditto.

> +{
> + struct intel_iommu *iommu;
> + struct dmar_domain *dmar_domain = to_dmar_domain(domain);
> + struct device_domain_info *info;
> + u16 did, sid;
> + u8 bus, devfn;
> + int ret = 0;
> + u64 granu;
> + unsigned long flags;
> +

I prefer to keep this in order.

struct dmar_domain *dmar_domain = to_dmar_domain(domain);
struct device_domain_info *info;
struct intel_iommu *iommu;
unsigned long flags;
u8 bus, devfn;
u16 did, sid;
int ret = 0;
u64 granu;

> + if (!inv_info || !dmar_domain ||
> + inv_info->hdr.type != TLB_INV_HDR_VERSION_1)

Ditto.

> + return -EINVAL;
> +
> + iommu = device_to_iommu(dev, &bus, &devfn);
> + if (!iommu)
> + return -ENODEV;
> +
> + if (!dev || !dev_is_pci(dev))
> + return -ENODEV;
> +
> + did = dmar_domain->iommu_did[iommu->seq_id];
> + sid = PCI_DEVID(bus, devfn);
> + ret = to_vtd_granularity(inv_info->hdr.type, inv_info->granularity,
> + &granu);
> + if (ret) {
> + pr_err("Invalid range type %d, granu %d\n", inv_info->hdr.type,
> + inv_info->granularity);
> + return ret;
> + }
> +
> + spin_lock(&iommu->lock);
> + spin_lock_irqsave(&device_domain_lock, flags);
> +
> + switch (inv_info->hdr.type) {
> + case IOMMU_INV_TYPE_TLB:
> + if (inv_info->size &&
> + (inv_info->addr & ((1 << (VTD_PAGE_SHIFT + inv_info->size)) - 1))) {
> + pr_err("Addr out of range, addr 0x%llx, size order %d\n",
> + inv_info->addr, inv_info->size);
> + ret = -ERANGE;
> + goto out_unlock;
> + }
> +
> + qi_flush_eiotlb(iommu, did, mm_to_dma_pfn(inv_info->addr),
> + inv_info->pasid,
> + inv_info->size, granu,
> + inv_info->flags & IOMMU_INVALIDATE_GLOBAL_PAGE);
> + /**
> + * Always flush device IOTLB if ATS is enabled since guest
> + * vIOMMU exposes CM = 1, no device IOTLB flush will be passed
> + * down.
> + */
> + info = iommu_support_dev_iotlb(dmar_domain, iommu, bus, devfn);
> + if (info && info->ats_enabled) {
> + qi_flush_dev_eiotlb(iommu, sid,
> + inv_info->pasid, info->ats_qdep,
> + inv_info->addr, inv_info->size,
> + granu);
> + }
> + break;
> + case IOMMU_INV_TYPE_PASID:
> + qi_flush_pasid(iommu, did, granu, inv_info->pasid);
> +
> + break;
> + default:
> + dev_err(dev, "Unknown IOMMU invalidation type %d\n",
> + inv_info->hdr.type);

There are three types of invalidation:

enum iommu_inv_type {
IOMMU_INV_TYPE_DTLB,
IOMMU_INV_TYPE_TLB,
IOMMU_INV_TYPE_PASID,
IOMMU_INV_NR_TYPE
};

So "unsupported" looks better than "unknown" in the message.

> + ret = -EINVAL;
> + }
> +out_unlock:
> + spin_unlock(&iommu->lock);
> + spin_unlock_irqrestore(&device_domain_lock, flags);
> +
> + return ret;
> +}
> +
> static int intel_iommu_map(struct iommu_domain *domain,
> unsigned long iova, phys_addr_t hpa,
> size_t size, int iommu_prot)
> @@ -5401,6 +5529,7 @@ const struct iommu_ops intel_iommu_ops = {
> #ifdef CONFIG_INTEL_IOMMU_SVM
> .bind_pasid_table = intel_iommu_bind_pasid_table,
> .unbind_pasid_table = intel_iommu_unbind_pasid_table,
> + .sva_invalidate = intel_iommu_sva_invalidate,
> #endif
> .map = intel_iommu_map,
> .unmap = intel_iommu_unmap,

Best regards,
Lu Baolu