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Mon, 17 Aug 2020 07:05:34 +0000 From: "Liu, Yi L" To: Auger Eric , "alex.williamson@redhat.com" , "baolu.lu@linux.intel.com" , "joro@8bytes.org" , "Lu, Baolu" Subject: RE: [PATCH v6 15/15] iommu/vt-d: Support reporting nesting capability info Thread-Topic: [PATCH v6 15/15] iommu/vt-d: Support reporting nesting capability info Thread-Index: AQHWZKdN2jQ/iA01+E66P0YDXHPJ1qk6wIWAgAE+lvA= Date: Mon, 17 Aug 2020 07:05:34 +0000 Message-ID: References: <1595917664-33276-1-git-send-email-yi.l.liu@intel.com> <1595917664-33276-16-git-send-email-yi.l.liu@intel.com> <7fe337fa-abbc-82be-c8e8-b9e2a6179b90@redhat.com> In-Reply-To: <7fe337fa-abbc-82be-c8e8-b9e2a6179b90@redhat.com> Accept-Language: en-US Content-Language: en-US X-Mentions: baolu.lu@intel.com X-MS-Has-Attach: X-MS-TNEF-Correlator: dlp-reaction: no-action dlp-version: 11.5.1.3 dlp-product: dlpe-windows authentication-results: redhat.com; dkim=none (message not signed) header.d=none;redhat.com; dmarc=none action=none header.from=intel.com; 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charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" Hi Eric, > Auger Eric > Sent: Sunday, August 16, 2020 8:01 PM > > Hi Yi, > > On 7/28/20 8:27 AM, Liu Yi L wrote: > > This patch reports nesting info, and only supports the case where all > > the physical iomms have the same CAP/ECAP MASKS. > s/iomms/iommus yep. > > > > Cc: Kevin Tian > > CC: Jacob Pan > > Cc: Alex Williamson > > Cc: Eric Auger > > Cc: Jean-Philippe Brucker > > Cc: Joerg Roedel > > Cc: Lu Baolu > > Signed-off-by: Liu Yi L > > Signed-off-by: Jacob Pan > > --- > > v2 -> v3: > > *) remove cap/ecap_mask in iommu_nesting_info. > > --- > > drivers/iommu/intel/iommu.c | 81 > +++++++++++++++++++++++++++++++++++++++++++-- > > include/linux/intel-iommu.h | 16 +++++++++ > > 2 files changed, 95 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c > > index 88f4647..0835804 100644 > > --- a/drivers/iommu/intel/iommu.c > > +++ b/drivers/iommu/intel/iommu.c > > @@ -5660,12 +5660,16 @@ static inline bool iommu_pasid_support(void) > > static inline bool nested_mode_support(void) > > { > > struct dmar_drhd_unit *drhd; > > - struct intel_iommu *iommu; > > + struct intel_iommu *iommu, *prev = NULL; > > bool ret = true; > > > > rcu_read_lock(); > > for_each_active_iommu(iommu, drhd) { > > - if (!sm_supported(iommu) || !ecap_nest(iommu->ecap)) { > > + if (!prev) > > + prev = iommu; > > + if (!sm_supported(iommu) || !ecap_nest(iommu->ecap) || > > + (VTD_CAP_MASK & (iommu->cap ^ prev->cap)) || > > + (VTD_ECAP_MASK & (iommu->ecap ^ prev->ecap))) { > > ret = false; > > break; > So this changes the behavior of DOMAIN_ATTR_NESTING. Shouldn't it have a > Fixes tag as well? And maybe add the capability getter in a separate patch? yes, this changed the behavior. so it would be better to be a separate patch and upstream along? how about your idea? @Lu, Baolu :-) > > } > > @@ -6081,6 +6085,78 @@ intel_iommu_domain_set_attr(struct iommu_domain > *domain, > > return ret; > > } > > > > +static int intel_iommu_get_nesting_info(struct iommu_domain *domain, > > + struct iommu_nesting_info *info) > > +{ > > + struct dmar_domain *dmar_domain = to_dmar_domain(domain); > > + u64 cap = VTD_CAP_MASK, ecap = VTD_ECAP_MASK; > > + struct device_domain_info *domain_info; > > + struct iommu_nesting_info_vtd vtd; > > + unsigned long flags; > > + unsigned int size; > > + perhaps better to acquire the lock here. [1] > > + if (domain->type != IOMMU_DOMAIN_UNMANAGED || > > + !(dmar_domain->flags & DOMAIN_FLAG_NESTING_MODE)) > > + return -ENODEV; > > + > > + if (!info) > > + return -EINVAL; > > + > > + size = sizeof(struct iommu_nesting_info) + > > + sizeof(struct iommu_nesting_info_vtd); > > + /* > > + * if provided buffer size is smaller than expected, should > > + * return 0 and also the expected buffer size to caller. > > + */ > > + if (info->argsz < size) { > > + info->argsz = size; > > + return 0; > > + } > > + > > + spin_lock_irqsave(&device_domain_lock, flags); > > + /* > > + * arbitrary select the first domain_info as all nesting > > + * related capabilities should be consistent across iommu > > + * units. > > + */ > > + domain_info = list_first_entry(&dmar_domain->devices, > > + struct device_domain_info, link); > > + cap &= domain_info->iommu->cap; > > + ecap &= domain_info->iommu->ecap; > > + spin_unlock_irqrestore(&device_domain_lock, flags); > > + > > + info->format = IOMMU_PASID_FORMAT_INTEL_VTD; > > + info->features = IOMMU_NESTING_FEAT_SYSWIDE_PASID | > > + IOMMU_NESTING_FEAT_BIND_PGTBL | > > + IOMMU_NESTING_FEAT_CACHE_INVLD; > > + info->addr_width = dmar_domain->gaw; > > + info->pasid_bits = ilog2(intel_pasid_max_id); > > + info->padding = 0; > > + vtd.flags = 0; > > + vtd.padding = 0; > > + vtd.cap_reg = cap; > > + vtd.ecap_reg = ecap; > > + > > + memcpy(info->data, &vtd, sizeof(vtd)); > > + return 0; > > +} > > + > > +static int intel_iommu_domain_get_attr(struct iommu_domain *domain, > > + enum iommu_attr attr, void *data) > > +{ > > + switch (attr) { > > + case DOMAIN_ATTR_NESTING: > > + { > > + struct iommu_nesting_info *info = > > + (struct iommu_nesting_info *)data; > > don't you need to hold a device_domain_lock earlier to make sure domain > attributes can't change behind your back (unmanaged type and nested mode)? do you mean acquire lock at [1]? Regards, Yi Liu > > + > > + return intel_iommu_get_nesting_info(domain, info); > > + } > > + default: > > + return -ENOENT; > > + } > > +} > > + > > /* > > * Check that the device does not live on an external facing PCI port that is > > * marked as untrusted. Such devices should not be able to apply quirks and > > @@ -6103,6 +6179,7 @@ const struct iommu_ops intel_iommu_ops = { > > .domain_alloc = intel_iommu_domain_alloc, > > .domain_free = intel_iommu_domain_free, > > .domain_set_attr = intel_iommu_domain_set_attr, > > + .domain_get_attr = intel_iommu_domain_get_attr, > > .attach_dev = intel_iommu_attach_device, > > .detach_dev = intel_iommu_detach_device, > > .aux_attach_dev = intel_iommu_aux_attach_device, > > diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h > > index f98146b..5acf795 100644 > > --- a/include/linux/intel-iommu.h > > +++ b/include/linux/intel-iommu.h > > @@ -197,6 +197,22 @@ > > #define ecap_max_handle_mask(e) ((e >> 20) & 0xf) > > #define ecap_sc_support(e) ((e >> 7) & 0x1) /* Snooping Control */ > > > > +/* Nesting Support Capability Alignment */ > > +#define VTD_CAP_FL1GP BIT_ULL(56) > > +#define VTD_CAP_FL5LP BIT_ULL(60) > > +#define VTD_ECAP_PRS BIT_ULL(29) > > +#define VTD_ECAP_ERS BIT_ULL(30) > > +#define VTD_ECAP_SRS BIT_ULL(31) > > +#define VTD_ECAP_EAFS BIT_ULL(34) > > +#define VTD_ECAP_PASID BIT_ULL(40) > > + > > +/* Only capabilities marked in below MASKs are reported */ > > +#define VTD_CAP_MASK (VTD_CAP_FL1GP | VTD_CAP_FL5LP) > > + > > +#define VTD_ECAP_MASK (VTD_ECAP_PRS | VTD_ECAP_ERS | \ > > + VTD_ECAP_SRS | VTD_ECAP_EAFS | \ > > + VTD_ECAP_PASID) > > + > > /* Virtual command interface capability */ > > #define vccap_pasid(v) (((v) & DMA_VCS_PAS)) /* PASID allocation > */ > > > > > Thanks > > Eric _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu