Messages in this thread | | | Date | Fri, 26 Apr 2019 13:11:22 -0700 | From | Jacob Pan <> | Subject | Re: [PATCH v2 10/19] iommu/vt-d: Add custom allocator for IOASID |
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On Wed, 24 Apr 2019 19:27:26 +0200 Auger Eric <eric.auger@redhat.com> wrote:
> 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 will fix > > custom IOASID allocator which takes precedence over the default > > IDR based allocator. > nit: s/IDR based// . It is xarray based now. right, changed code but not commit message :) > 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? right, should never happen. > > + /* > > + * 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? It meant the PASID is still being used, bond to a device doing DMA etc. thus -EBUSY. But I will make the free a void function. > > + } > > + 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
[Jacob Pan]
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