iommufd: Allow fault reporting for non-PRI PCI devices

iommufd_fault_iopf_enable has limitation to PRI on PCI/SRIOV VFs because
the PRI might be a shared resource and current iommu subsystem is not
ready to support enabling/disabling PRI on a VF without any impact on
others.

However, we have devices that appear as PCI but are actually on the AMBA
bus. These fake PCI devices have PASID capability, support stall as well
as SRIOV, so remove the limitation for these devices.

Link: https://patch.msgid.link/r/[email protected]
Co-developed-by: Lu Baolu <[email protected]>
Signed-off-by: Lu Baolu <[email protected]>
Reviewed-by: Lu Baolu <[email protected]>
Signed-off-by: Zhangfei Gao <[email protected]>
Signed-off-by: Jason Gunthorpe <[email protected]>

Author: zhangfeigao

drivers/iommu/iommufd/fault.c

@@ -10,6 +10,7 @@
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/pci.h>
+#include <linux/pci-ats.h>
 #include <linux/poll.h>
 #include <uapi/linux/iommufd.h>
 
@@ -27,8 +28,12 @@ static int iommufd_fault_iopf_enable(struct iommufd_device *idev)
 	 * resource between PF and VFs. There is no coordination for this
 	 * shared capability. This waits for a vPRI reset to recover.
 	 */
-	if (dev_is_pci(dev) && to_pci_dev(dev)->is_virtfn)
-		return -EINVAL;
+	if (dev_is_pci(dev)) {
+		struct pci_dev *pdev = to_pci_dev(dev);
+
+		if (pdev->is_virtfn && pci_pri_supported(pdev))
+			return -EINVAL;
+	}
 
 	mutex_lock(&idev->iopf_lock);
 	/* Device iopf has already been on. */