On Mon, 13 May 2019 09:13:01 +0200
Eric Auger <eric.au...@redhat.com> wrote:
> When reading the vtd specification and especially the
> Reserved Memory Region Reporting Structure chapter,
> it is not obvious a device scope element cannot be a
> PCI-PCI bridge, in which case all downstream ports are
> likely to access the reserved memory region. Let's handle
> this case in device_has_rmrr.
>
> Fixes: ea2447f700ca ("intel-iommu: Prevent devices with RMRRs from
> being placed into SI Domain")
>
> Signed-off-by: Eric Auger <eric.au...@redhat.com>
> ---
> drivers/iommu/intel-iommu.c | 32 +++++++++++++++++++++++---------
> 1 file changed, 23 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> index e2134b13c9ae..89d82a1d50b1 100644
> --- a/drivers/iommu/intel-iommu.c
> +++ b/drivers/iommu/intel-iommu.c
> @@ -736,12 +736,31 @@ static int iommu_dummy(struct device *dev)
> return dev->archdata.iommu == DUMMY_DEVICE_DOMAIN_INFO;
> }
>
> +static bool
> +is_downstream_to_pci_bridge(struct device *deva, struct device *devb)
> +{
> + struct pci_dev *pdeva, *pdevb;
> +
is there a more illustrative name for these. i guess deva is is the
bridge dev?
> + if (!dev_is_pci(deva) || !dev_is_pci(devb))
> + return false;
> +
> + pdeva = to_pci_dev(deva);
> + pdevb = to_pci_dev(devb);
> +
> + if (pdevb->subordinate &&
> + pdevb->subordinate->number <= pdeva->bus->number &&
> + pdevb->subordinate->busn_res.end >= pdeva->bus->number)
> + return true;
> +
> + return false;
> +}
> +
this seems to be a separate cleanup patch.
> static struct intel_iommu *device_to_iommu(struct device *dev, u8
> *bus, u8 *devfn) {
> struct dmar_drhd_unit *drhd = NULL;
> struct intel_iommu *iommu;
> struct device *tmp;
> - struct pci_dev *ptmp, *pdev = NULL;
> + struct pci_dev *pdev = NULL;
> u16 segment = 0;
> int i;
>
> @@ -787,13 +806,7 @@ static struct intel_iommu
> *device_to_iommu(struct device *dev, u8 *bus, u8 *devf goto out;
> }
>
> - if (!pdev || !dev_is_pci(tmp))
> - continue;
> -
> - ptmp = to_pci_dev(tmp);
> - if (ptmp->subordinate &&
> - ptmp->subordinate->number <=
> pdev->bus->number &&
> - ptmp->subordinate->busn_res.end >=
> pdev->bus->number)
> + if (is_downstream_to_pci_bridge(dev, tmp))
> goto got_pdev;
> }
>
> @@ -2886,7 +2899,8 @@ static bool device_has_rmrr(struct device *dev)
> */
> for_each_active_dev_scope(rmrr->devices,
> rmrr->devices_cnt, i, tmp)
> - if (tmp == dev) {
> + if (tmp == dev ||
> + is_downstream_to_pci_bridge(dev, tmp)) {
> rcu_read_unlock();
> return true;
> }
[Jacob Pan]
