Messages in this thread | | | Date | Wed, 5 Sep 2018 13:35:40 -0600 | From | Alex Williamson <> | Subject | Re: [RFC PATCH v2 02/10] iommu/vt-d: Add multiple domains per device query |
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On Thu, 30 Aug 2018 12:09:14 +0800 Lu Baolu <baolu.lu@linux.intel.com> wrote:
> Add the response to IOMMU_CAP_AUX_DOMAIN capability query > through iommu_capable(). Return true if IOMMUs support the > scalable mode, return false otherwise. > > Cc: Ashok Raj <ashok.raj@intel.com> > Cc: Jacob Pan <jacob.jun.pan@linux.intel.com> > Cc: Kevin Tian <kevin.tian@intel.com> > Cc: Liu Yi L <yi.l.liu@intel.com> > Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> > --- > drivers/iommu/intel-iommu.c | 31 +++++++++++++++++++++++++++++-- > 1 file changed, 29 insertions(+), 2 deletions(-) > > diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c > index 3e49d4029058..891ae70e7bf2 100644 > --- a/drivers/iommu/intel-iommu.c > +++ b/drivers/iommu/intel-iommu.c > @@ -5193,12 +5193,39 @@ static phys_addr_t intel_iommu_iova_to_phys(struct iommu_domain *domain, > return phys; > } > > +static inline bool scalable_mode_support(void) > +{ > + struct dmar_drhd_unit *drhd; > + struct intel_iommu *iommu; > + bool ret = true; > + > + rcu_read_lock(); > + for_each_active_iommu(iommu, drhd) { > + if (!sm_supported(iommu)) { > + ret = false; > + break; > + } > + } > + rcu_read_unlock(); > + > + return ret; > +} > + > static bool intel_iommu_capable(enum iommu_cap cap) > { > - if (cap == IOMMU_CAP_CACHE_COHERENCY) > + switch (cap) { > + case IOMMU_CAP_CACHE_COHERENCY: > return domain_update_iommu_snooping(NULL) == 1; > - if (cap == IOMMU_CAP_INTR_REMAP) > + case IOMMU_CAP_INTR_REMAP: > return irq_remapping_enabled == 1; > + case IOMMU_CAP_AUX_DOMAIN: > + return scalable_mode_support(); > + case IOMMU_CAP_NOEXEC: > + /* PASSTHROUGH */ > + default: > + pr_info("Unsupported capability query %d\n", cap); > + break;
Please don't do this, there's no reason to be noisy about a query of a capability that VT-d doesn't know about. We implement capabilities exactly so that relevant drivers can expose a feature and others can happily (and quietly) ignore them. Thanks,
Alex
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