Messages in this thread Patch in this message | | | Subject | Re: [PATCH v2 10/19] iommu/vt-d: Add custom allocator for IOASID | From | Auger Eric <> | Date | Wed, 24 Apr 2019 19:27:26 +0200 |
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Hi Jacob,
On 4/24/19 1:31 AM, Jacob Pan wrote: > When VT-d driver runs in the guest, PASID allocation must be > performed via virtual command interface. This patch register a registers > custom IOASID allocator which takes precedence over the default > IDR based allocator. nit: s/IDR based// . It is xarray based now. The resulting IOASID allocation will always > come from the host. This ensures that PASID namespace is system- > wide. > > Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> > Signed-off-by: Liu, Yi L <yi.l.liu@intel.com> > Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> > --- > drivers/iommu/intel-iommu.c | 58 +++++++++++++++++++++++++++++++++++++++++++++ > include/linux/intel-iommu.h | 2 ++ > 2 files changed, 60 insertions(+) > > diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c > index d93c4bd..ec6f22d 100644 > --- a/drivers/iommu/intel-iommu.c > +++ b/drivers/iommu/intel-iommu.c > @@ -1711,6 +1711,8 @@ static void free_dmar_iommu(struct intel_iommu *iommu) > if (ecap_prs(iommu->ecap)) > intel_svm_finish_prq(iommu); > } > + ioasid_unregister_allocator(&iommu->pasid_allocator); > + > #endif > } > > @@ -4811,6 +4813,46 @@ static int __init platform_optin_force_iommu(void) > return 1; > } > > +static ioasid_t intel_ioasid_alloc(ioasid_t min, ioasid_t max, void *data) > +{ > + struct intel_iommu *iommu = data; > + ioasid_t ioasid; > + > + /* > + * VT-d virtual command interface always uses the full 20 bit > + * PASID range. Host can partition guest PASID range based on > + * policies but it is out of guest's control. > + */ The above comment does not exactly relate to the check below > + if (min < PASID_MIN || max > PASID_MAX) > + return -EINVAL; > + > + if (vcmd_alloc_pasid(iommu, &ioasid)) > + return INVALID_IOASID; > + > + return ioasid; > +} > + > +static int intel_ioasid_free(ioasid_t ioasid, void *data) > +{ > + struct iommu_pasid_alloc_info *svm; > + struct intel_iommu *iommu = data; > + > + if (!iommu || !cap_caching_mode(iommu->cap)) > + return -EINVAL; can !cap_caching_mode(iommu->cap) be true as the allocator only is set if CM? > + /* > + * Sanity check the ioasid owner is done at upper layer, e.g. VFIO > + * We can only free the PASID when all the devices are unbond. > + */ > + svm = ioasid_find(NULL, ioasid, NULL); > + if (!svm) { you can avoid using the local svm variable. > + pr_warn("Freeing unbond IOASID %d\n", ioasid); unbound > + return -EBUSY; -EINVAL? > + } > + vcmd_free_pasid(iommu, ioasid); > + > + return 0; > +} > + > int __init intel_iommu_init(void) > { > int ret = -ENODEV; > @@ -4912,6 +4954,22 @@ int __init intel_iommu_init(void) > "%s", iommu->name); > iommu_device_set_ops(&iommu->iommu, &intel_iommu_ops); > iommu_device_register(&iommu->iommu); > + if (cap_caching_mode(iommu->cap) && sm_supported(iommu)) { so shouldn't you test VCCAP_REG as well? > + /* > + * Register a custom ASID allocator if we are running > + * in a guest, the purpose is to have a system wide PASID > + * namespace among all PASID users. > + * There can be multiple vIOMMUs in each guest but only > + * one allocator is active. All vIOMMU allocators will > + * eventually be calling the same host allocator. > + */ > + iommu->pasid_allocator.alloc = intel_ioasid_alloc; > + iommu->pasid_allocator.free = intel_ioasid_free; > + iommu->pasid_allocator.pdata = (void *)iommu; > + ret = ioasid_register_allocator(&iommu->pasid_allocator); > + if (ret) > + pr_warn("Custom PASID allocator registeration failed\n"); registration > + } > } > > bus_set_iommu(&pci_bus_type, &intel_iommu_ops); > diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h > index bff907b..c24c8aa 100644 > --- a/include/linux/intel-iommu.h > +++ b/include/linux/intel-iommu.h > @@ -31,6 +31,7 @@ > #include <linux/iommu.h> > #include <linux/io-64-nonatomic-lo-hi.h> > #include <linux/dmar.h> > +#include <linux/ioasid.h> > > #include <asm/cacheflush.h> > #include <asm/iommu.h> > @@ -549,6 +550,7 @@ struct intel_iommu { > #ifdef CONFIG_INTEL_IOMMU_SVM > struct page_req_dsc *prq; > unsigned char prq_name[16]; /* Name for PRQ interrupt */ > + struct ioasid_allocator pasid_allocator; /* Custom allocator for PASIDs */ > #endif > struct q_inval *qi; /* Queued invalidation info */ > u32 *iommu_state; /* Store iommu states between suspend and resume.*/ >
Thanks
Eric
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