[v1,6/6] xen/arm: smmuv3: Add PCI devices support for SMMUv3

Commit Message

Stewart Hildebrand May 1, 2023, 8:03 p.m. UTC

From: Rahul Singh <[e-mail]>

Signed-off-by: Rahul Singh <[e-mail]>
Signed-off-by: Stewart Hildebrand <[e-mail]>
---
downstream->v1:
* rebase
* move 2 replacements of s/dt_device_set_protected(dev_to_dt(dev))/device_set_protected(dev)/
  from this commit to ("xen/arm: Move is_protected flag to struct device")
  so as to not break ability to bisect
* adjust patch title (remove stray space)
* arm_smmu_(de)assign_dev: return error instead of crashing system
* remove arm_smmu_remove_device() stub
* update condition in arm_smmu_reassign_dev
* style fixup

(cherry picked from commit 7ed6c3ab250d899fe6e893a514278e406a2893e8 from
 the downstream branch poc/pci-passthrough from
 https://gitlab.com/xen-project/people/bmarquis/xen-arm-poc.git)
---

This is a file imported from Linux with modifications for Xen. What should be
the coding style used for Xen modifications?
---
 xen/drivers/passthrough/arm/smmu-v3.c | 66 +++++++++++++++++++++++++--
 1 file changed, 63 insertions(+), 3 deletions(-)

Patch

diff --git a/xen/drivers/passthrough/arm/smmu-v3.c b/xen/drivers/passthrough/arm/smmu-v3.c
index 4b452e6fdd00..481a35a8b8d4 100644
--- a/xen/drivers/passthrough/arm/smmu-v3.c
+++ b/xen/drivers/passthrough/arm/smmu-v3.c
@@ -1469,6 +1469,8 @@  static bool arm_smmu_sid_in_range(struct arm_smmu_device *smmu, u32 sid)
 }
 /* Forward declaration */
 static struct arm_smmu_device *arm_smmu_get_by_dev(struct device *dev);
+static int arm_smmu_assign_dev(struct domain *d, u8 devfn,
+			struct device *dev, u32 flag);
 
 static int arm_smmu_add_device(u8 devfn, struct device *dev)
 {
@@ -1527,6 +1529,17 @@  static int arm_smmu_add_device(u8 devfn, struct device *dev)
 	dev_info(dev, "Added master device (SMMUv3 %s StreamIds %u)\n",
 			dev_name(fwspec->iommu_dev), fwspec->num_ids);
 
+#ifdef CONFIG_HAS_PCI
+	if ( dev_is_pci(dev) )
+	{
+		struct pci_dev *pdev = dev_to_pci(dev);
+
+		ret = arm_smmu_assign_dev(pdev->domain, devfn, dev, 0);
+		if (ret)
+			goto err_free_master;
+	}
+#endif
+
 	return 0;
 
 err_free_master:
@@ -2607,6 +2620,31 @@  static int arm_smmu_assign_dev(struct domain *d, u8 devfn,
 	struct arm_smmu_domain *smmu_domain;
 	struct arm_smmu_xen_domain *xen_domain = dom_iommu(d)->arch.priv;
 
+#ifdef CONFIG_HAS_PCI
+	if ( dev_is_pci(dev) && !is_hardware_domain(d) )
+	{
+		struct pci_dev *pdev = dev_to_pci(dev);
+
+		printk(XENLOG_INFO "Assigning device %04x:%02x:%02x.%u to dom%d\n",
+			pdev->seg, pdev->bus, PCI_SLOT(devfn),
+			PCI_FUNC(devfn), d->domain_id);
+
+		/*
+		 * XXX What would be the proper behavior? This could happen if
+		 * pdev->phantom_stride > 0
+		 */
+		if ( devfn != pdev->devfn )
+			return -EOPNOTSUPP;
+
+		list_move(&pdev->domain_list, &d->pdev_list);
+		pdev->domain = d;
+
+		/* dom_io is used as a sentinel for quarantined devices */
+		if ( d == dom_io )
+			return 0;
+	}
+#endif
+
 	spin_lock(&xen_domain->lock);
 
 	/*
@@ -2640,7 +2678,7 @@  out:
 	return ret;
 }
 
-static int arm_smmu_deassign_dev(struct domain *d, struct device *dev)
+static int arm_smmu_deassign_dev(struct domain *d, uint8_t devfn, struct device *dev)
 {
 	struct iommu_domain *io_domain = arm_smmu_get_domain(d, dev);
 	struct arm_smmu_xen_domain *xen_domain = dom_iommu(d)->arch.priv;
@@ -2652,6 +2690,28 @@  static int arm_smmu_deassign_dev(struct domain *d, struct device *dev)
 		return -ESRCH;
 	}
 
+#ifdef CONFIG_HAS_PCI
+	if ( dev_is_pci(dev) )
+	{
+		struct pci_dev *pdev = dev_to_pci(dev);
+
+		printk(XENLOG_INFO "Deassigning device %04x:%02x:%02x.%u from dom%d\n",
+			pdev->seg, pdev->bus, PCI_SLOT(devfn),
+			PCI_FUNC(devfn), d->domain_id);
+
+		/*
+		 * XXX What would be the proper behavior? This could happen if
+		 * pdev->phantom_stride > 0
+		 */
+		if ( devfn != pdev->devfn )
+			return -EOPNOTSUPP;
+
+		/* dom_io is used as a sentinel for quarantined devices */
+		if ( d == dom_io )
+			return 0;
+	}
+#endif
+
 	spin_lock(&xen_domain->lock);
 
 	arm_smmu_detach_dev(master);
@@ -2671,13 +2731,13 @@  static int arm_smmu_reassign_dev(struct domain *s, struct domain *t,
 	int ret = 0;
 
 	/* Don't allow remapping on other domain than hwdom */
-	if ( t && !is_hardware_domain(t) )
+	if ( t && !is_hardware_domain(t) && (t != dom_io) )
 		return -EPERM;
 
 	if (t == s)
 		return 0;
 
-	ret = arm_smmu_deassign_dev(s, dev);
+	ret = arm_smmu_deassign_dev(s, devfn, dev);
 	if (ret)
 		return ret;