On Tue, 05 Jun 2018 13:06:54 -0600 Alex Williamson <[email protected]> wrote:
> device_is_rmrr_locked() allows graphics and USB devices to participate > in the IOMMU API despite, and ignoring their RMRR association, however > intel_iommu_get_resv_regions() still includes the RMRRs as unavailable > IOVA space for the device. Are we ignoring the RMRR for these devices > or are we not? If vfio starts consuming reserved regions, perhaps we > no longer need to consider devices with RMRRs excluded from the IOMMU > API interface, but we have a transitional problem that these allowed > devices still impose incompatible IOVA restrictions per the reserved > region reporting. Dive further down the rabbit hole by also ignoring > RMRRs for "known" devices in the reserved region reporting. > > Signed-off-by: Alex Williamson <[email protected]> > --- > drivers/iommu/intel-iommu.c | 35 > +++++++++++++++++++++-------------- 1 file changed, 21 insertions(+), > 14 deletions(-) > > If this is the approach we want to take, I could pull this in via the > vfio tree, along with Shameer's patches which expose an IOVA list and > enforce it to userspace, otherwise I'm afraid Shameer's patches will > be blocked a while longer. Thanks, > I think this patch makes sense in that it makes IOVA reserved range check consistent. Thanks, Jacob > Alex > > diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c > index 749d8f235346..f312f93199c5 100644 > --- a/drivers/iommu/intel-iommu.c > +++ b/drivers/iommu/intel-iommu.c > @@ -2864,19 +2864,24 @@ static bool device_has_rmrr(struct device > *dev) > * any use of the RMRR regions will be torn down before assigning > the device > * to a guest. > */ > -static bool device_is_rmrr_locked(struct device *dev) > +static bool rmrr_is_ignored(struct device *dev) > { > - if (!device_has_rmrr(dev)) > - return false; > - > if (dev_is_pci(dev)) { > struct pci_dev *pdev = to_pci_dev(dev); > > if (IS_USB_DEVICE(pdev) || IS_GFX_DEVICE(pdev)) > - return false; > + return true; > } > > - return true; > + return false; > +} > + > +static bool device_is_rmrr_locked(struct device *dev) > +{ > + if (!device_has_rmrr(dev)) > + return false; > + > + return !rmrr_is_ignored(dev); > } > > static int iommu_should_identity_map(struct device *dev, int startup) > @@ -5141,17 +5146,19 @@ static void > intel_iommu_get_resv_regions(struct device *device, struct device > *i_dev; int i; > > - rcu_read_lock(); > - for_each_rmrr_units(rmrr) { > - for_each_active_dev_scope(rmrr->devices, > rmrr->devices_cnt, > - i, i_dev) { > - if (i_dev != device) > - continue; > + if (!rmrr_is_ignored(device)) { > + rcu_read_lock(); > + for_each_rmrr_units(rmrr) { > + for_each_active_dev_scope(rmrr->devices, > + rmrr->devices_cnt, > i, i_dev) { > + if (i_dev != device) > + continue; > > - list_add_tail(&rmrr->resv->list, head); > + list_add_tail(&rmrr->resv->list, > head); > + } > } > + rcu_read_unlock(); > } > - rcu_read_unlock(); > > reg = iommu_alloc_resv_region(IOAPIC_RANGE_START, > IOAPIC_RANGE_END - > IOAPIC_RANGE_START + 1, > > _______________________________________________ > iommu mailing list > [email protected] > https://lists.linuxfoundation.org/mailman/listinfo/iommu [Jacob Pan] _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
