Messages in this thread | | | Subject | Re: [PATCH V9 03/10] iommu/vt-d: Add nested translation helper function | From | Auger Eric <> | Date | Wed, 12 Feb 2020 13:43:17 +0100 |
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Hi Jacob, On 1/29/20 7:01 AM, Jacob Pan wrote: > Nested translation mode is supported in VT-d 3.0 Spec.CH 3.8. > With PASID granular translation type set to 0x11b, translation > result from the first level(FL) also subject to a second level(SL) > page table translation. This mode is used for SVA virtualization, > where FL performs guest virtual to guest physical translation and > SL performs guest physical to host physical translation. You may also describe what the patch brings. The above text does not. > > Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> > Signed-off-by: Liu, Yi L <yi.l.liu@linux.intel.com> > --- > drivers/iommu/intel-pasid.c | 225 ++++++++++++++++++++++++++++++++++++++++++++ > drivers/iommu/intel-pasid.h | 12 +++ > include/linux/intel-iommu.h | 3 + > 3 files changed, 240 insertions(+) > > diff --git a/drivers/iommu/intel-pasid.c b/drivers/iommu/intel-pasid.c > index 22b30f10b396..bd067af4d20b 100644 > --- a/drivers/iommu/intel-pasid.c > +++ b/drivers/iommu/intel-pasid.c > @@ -359,6 +359,76 @@ pasid_set_flpm(struct pasid_entry *pe, u64 value) > pasid_set_bits(&pe->val[2], GENMASK_ULL(3, 2), value << 2); > } > > +/* > + * Setup the Extended Memory Type(EMT) field (Bits 91-93) > + * of a scalable mode PASID entry. > + */ > +static inline void > +pasid_set_emt(struct pasid_entry *pe, u64 value) > +{ > + pasid_set_bits(&pe->val[1], GENMASK_ULL(29, 27), value << 27); > +} > + > +/* > + * Setup the Page Attribute Table (PAT) field (Bits 96-127) > + * of a scalable mode PASID entry. > + */ > +static inline void > +pasid_set_pat(struct pasid_entry *pe, u64 value) pat is 32b > +{ > + pasid_set_bits(&pe->val[1], GENMASK_ULL(63, 32), value << 32); > +} > + > +/* > + * Setup the Cache Disable (CD) field (Bit 89) > + * of a scalable mode PASID entry. > + */ > +static inline void > +pasid_set_cd(struct pasid_entry *pe) > +{ > + pasid_set_bits(&pe->val[1], 1 << 25, 1 << 25); BIT_ULL() here and below? My preference would have been to a have a helper converting absolute field boundaries (as the spec, Fig 9-36 describes those with absolute values) into the right val and offset. I think it would be less error prone globally. > +} > + > +/* > + * Setup the Extended Memory Type Enable (EMTE) field (Bit 90) > + * of a scalable mode PASID entry. > + */ > +static inline void > +pasid_set_emte(struct pasid_entry *pe) > +{ > + pasid_set_bits(&pe->val[1], 1 << 26, 1 << 26);> +} > + > +/* > + * Setup the Extended Access Flag Enable (EAFE) field (Bit 135) > + * of a scalable mode PASID entry. > + */ > +static inline void > +pasid_set_eafe(struct pasid_entry *pe) > +{ > + pasid_set_bits(&pe->val[2], 1 << 7, 1 << 7); > +} > + > +/* > + * Setup the Page-level Cache Disable (PCD) field (Bit 95) > + * of a scalable mode PASID entry. > + */ > +static inline void > +pasid_set_pcd(struct pasid_entry *pe) > +{ > + pasid_set_bits(&pe->val[1], 1 << 31, 1 << 31); > +} > + > +/* > + * Setup the Page-level Write-Through (PWT)) field (Bit 94) )) > + * of a scalable mode PASID entry. > + */ > +static inline void > +pasid_set_pwt(struct pasid_entry *pe) > +{ > + pasid_set_bits(&pe->val[1], 1 << 30, 1 << 30); > +} > + > static void > pasid_cache_invalidation_with_pasid(struct intel_iommu *iommu, > u16 did, int pasid) > @@ -596,3 +666,158 @@ int intel_pasid_setup_pass_through(struct intel_iommu *iommu, > > return 0; > } > + > +static int intel_pasid_setup_bind_data(struct intel_iommu *iommu, > + struct pasid_entry *pte, > + struct iommu_gpasid_bind_data_vtd *pasid_data) > +{ > + /* > + * Not all guest PASID table entry fields are passed down during bind, > + * here we only set up the ones that are dependent on guest settings. > + * Execution related bits such as NXE, SMEP are not meaningful to IOMMU, > + * therefore not set. Other fields, such as snoop related, are set based > + * on host needs regardless of guest settings. s/of /of / > + */ > + if (pasid_data->flags & IOMMU_SVA_VTD_GPASID_SRE) { > + if (!ecap_srs(iommu->ecap)) { > + pr_err("No supervisor request support on %s\n", > + iommu->name); > + return -EINVAL; > + } > + pasid_set_sre(pte); > + } > + > + if (pasid_data->flags & IOMMU_SVA_VTD_GPASID_EAFE) { > + if (!ecap_eafs(iommu->ecap)) { > + pr_err("No extended access flag support on %s\n", > + iommu->name); > + return -EINVAL; > + } > + pasid_set_eafe(pte); > + } > + > + /* > + * Memory type is only applicable to devices inside processor coherent > + * domain. PCIe devices are not included. We can skip the rest of the > + * flags if IOMMU does not support MTS. > + */ > + if (ecap_mts(iommu->ecap)) { > + if (pasid_data->flags & IOMMU_SVA_VTD_GPASID_EMTE) { > + pasid_set_emte(pte); > + pasid_set_emt(pte, pasid_data->emt); > + } > + if (pasid_data->flags & IOMMU_SVA_VTD_GPASID_PCD) > + pasid_set_pcd(pte); > + if (pasid_data->flags & IOMMU_SVA_VTD_GPASID_PWT) > + pasid_set_pwt(pte); > + if (pasid_data->flags & IOMMU_SVA_VTD_GPASID_CD) > + pasid_set_cd(pte); > + pasid_set_pat(pte, pasid_data->pat); why isn't the pat struct member also guarded by a flag. If I understand correctly it should not be set of MTS is not supported. > + } else if (pasid_data->flags & IOMMU_SVA_VTD_GPASID_EMT_MASK) { > + pr_warn("No memory type support for bind guest PASID on %s\n", > + iommu->name); why not pr_err() here as well? > + return -EINVAL; > + } > + > + return 0; > + > +} > + > +/** > + * intel_pasid_setup_nested() - Set up PASID entry for nested translation. > + * This could be used for guest shared virtual address. In this case, the > + * first level page tables are used for GVA-GPA translation in the guest, > + * second level page tables are used for GPA-HPA translation. > + * > + * @iommu: Iommu which the device belong to s/Iommu/iommu or IOMMU, belongs > + * @dev: Device to be set up for translation > + * @gpgd: FLPTPTR: First Level Page translation pointer in GPA > + * @pasid: PASID to be programmed in the device PASID table > + * @pasid_data: Additional PASID info from the guest bind request > + * @domain: Domain info for setting up second level page tables > + * @addr_width: Address width of the first level (guest) > + */ > +int intel_pasid_setup_nested(struct intel_iommu *iommu, > + struct device *dev, pgd_t *gpgd, > + int pasid, struct iommu_gpasid_bind_data_vtd *pasid_data, > + struct dmar_domain *domain, > + int addr_width) > +{ > + struct pasid_entry *pte; > + struct dma_pte *pgd; > + int ret = 0; > + u64 pgd_val; > + int agaw; > + u16 did; > + > + if (!ecap_nest(iommu->ecap)) { > + pr_err("IOMMU: %s: No nested translation support\n", > + iommu->name); > + return -EINVAL; > + } > + > + pte = intel_pasid_get_entry(dev, pasid); in intel_pasid_get_entry() there may be one WARN_ON hitting in some conditions. But I see other callers of intel_pasid_get_entry also have the WARN_ON. > + if (WARN_ON(!pte)) > + return -EINVAL; > + > + /* > + * Caller must ensure PASID entry is not in use, i.e. not bind the > + * same PASID to the same device twice. > + */ > + if (pasid_pte_is_present(pte)) > + return -EBUSY; > + > + pasid_clear_entry(pte); > + > + /* Sanity checking performed by caller to make sure address > + * width matching in two dimensions: > + * 1. CPU vs. IOMMU > + * 2. Guest vs. Host. > + */ > + switch (addr_width) { > + case ADDR_WIDTH_5LEVEL: > + pasid_set_flpm(pte, 1); don't you need to check whether 5-level paging mode is supported (5LP) This data comes from userspace > + break; > + case ADDR_WIDTH_4LEVEL: > + pasid_set_flpm(pte, 0); > + break; > + default: > + dev_err(dev, "Invalid guest address width %d\n", addr_width);> + return -EINVAL; > + } > + > + pasid_set_flptr(pte, (u64)gpgd); don't you need to do some checks on the gpgd versus the max addr_width supported by the HW? > + > + ret = intel_pasid_setup_bind_data(iommu, pte, pasid_data); > + if (ret) { > + dev_err(dev, "Guest PASID bind data not supported\n"); > + return ret; > + } > + > + /* Setup the second level based on the given domain */ > + pgd = domain->pgd; > + > + for (agaw = domain->agaw; agaw != iommu->agaw; agaw--) { > + pgd = phys_to_virt(dma_pte_addr(pgd)); > + if (!dma_pte_present(pgd)) { > + pasid_clear_entry(pte); here you clear the PTE entry while above, on the other error cases you don't. Any reason? > + dev_err(dev, "Invalid domain page table\n"); > + return -EINVAL; > + } > + } Maybe you could introduce an helper as the above code is duplicated in intel_pasid_setup_second_level > + pgd_val = virt_to_phys(pgd); > + pasid_set_slptr(pte, pgd_val); > + pasid_set_fault_enable(pte); > + > + did = domain->iommu_did[iommu->seq_id]; > + pasid_set_domain_id(pte, did); > + > + pasid_set_address_width(pte, agaw); > + pasid_set_page_snoop(pte, !!ecap_smpwc(iommu->ecap)); > + > + pasid_set_translation_type(pte, PASID_ENTRY_PGTT_NESTED); > + pasid_set_present(pte); > + pasid_flush_caches(iommu, pte, pasid, did); > + > + return ret; > +} > diff --git a/drivers/iommu/intel-pasid.h b/drivers/iommu/intel-pasid.h > index 92de6df24ccb..698015ee3f04 100644 > --- a/drivers/iommu/intel-pasid.h > +++ b/drivers/iommu/intel-pasid.h > @@ -36,6 +36,7 @@ > * to vmalloc or even module mappings. > */ > #define PASID_FLAG_SUPERVISOR_MODE BIT(0) > +#define PASID_FLAG_NESTED BIT(1) > > /* > * The PASID_FLAG_FL5LP flag Indicates using 5-level paging for first- > @@ -51,6 +52,11 @@ struct pasid_entry { > u64 val[8]; > }; > > +#define PASID_ENTRY_PGTT_FL_ONLY (1) > +#define PASID_ENTRY_PGTT_SL_ONLY (2) May use the above in the relevant places. Otherwise they may not be used. > +#define PASID_ENTRY_PGTT_NESTED (3) > +#define PASID_ENTRY_PGTT_PT (4) > + > /* The representative of a PASID table */ > struct pasid_table { > void *table; /* pasid table pointer */ > @@ -99,6 +105,12 @@ int intel_pasid_setup_second_level(struct intel_iommu *iommu, > int intel_pasid_setup_pass_through(struct intel_iommu *iommu, > struct dmar_domain *domain, > struct device *dev, int pasid); > +int intel_pasid_setup_nested(struct intel_iommu *iommu, > + struct device *dev, pgd_t *pgd, > + int pasid, > + struct iommu_gpasid_bind_data_vtd *pasid_data, > + struct dmar_domain *domain, > + int addr_width); > void intel_pasid_tear_down_entry(struct intel_iommu *iommu, > struct device *dev, int pasid); > > diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h > index 27c6bbb0a333..c8abf051b2d5 100644 > --- a/include/linux/intel-iommu.h > +++ b/include/linux/intel-iommu.h > @@ -42,6 +42,9 @@ > #define DMA_FL_PTE_PRESENT BIT_ULL(0) > #define DMA_FL_PTE_XD BIT_ULL(63) > > +#define ADDR_WIDTH_5LEVEL (57) > +#define ADDR_WIDTH_4LEVEL (48) > + > #define CONTEXT_TT_MULTI_LEVEL 0 > #define CONTEXT_TT_DEV_IOTLB 1 > #define CONTEXT_TT_PASS_THROUGH 2 >
Thanks
Eric
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