[PATCH v3 21/22] iommu/amd: Add translation DTE and VFctrl TransDevID helpers

[Suravee Suthikulpanit]

The hardware vIOMMU uses a per-VM translate device ID (TransDevID) to
index the host device table when guest IOMMU traffic needs GPA->SPA
translation.  The VF Control guest miscellaneous register tells the
IOMMU which TransDevID to use; the corresponding device table entry
(DTE) points at the nested IOMMU v1 page table that performs the walk
from guest physical to system physical addresses.

Add amd_iommu_set_translate_dte() and amd_iommu_clear_translate_dte()
to install or clear that DTE for a given TransDevID slot through
iommu_dev_data and the existing DTE update path, restoring IVRS
persistent bits via amd_iommu_make_clear_dte() on teardown.  Add
amd_iommu_update_vfctrl_mmio_translate_devid() to publish the
TransDevID in VFctrl guest-misc MMIO, and
VIOMMU_VFCTRL_GUEST_MISC_CONTROL_OFFSET for the register offset.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
---
 drivers/iommu/amd/amd_iommu_types.h |  1 +
 drivers/iommu/amd/iommu.c           | 78 ++++++++++++++++++++++++++++-
 2 files changed, 77 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/amd/amd_iommu_types.h b/drivers/iommu/amd/amd_iommu_types.h
index 91cdb61b5254..cd10e33c1317 100644
--- a/drivers/iommu/amd/amd_iommu_types.h
+++ b/drivers/iommu/amd/amd_iommu_types.h
@@ -495,6 +495,7 @@ extern bool amdr_ivrs_remap_support;
 /* VIOMMU stuff */
 #define VIOMMU_VF_MMIO_ENTRY_SIZE		4096
 #define VIOMMU_VFCTRL_MMIO_ENTRY_SIZE		64
+#define VIOMMU_VFCTRL_GUEST_MISC_CONTROL_OFFSET	0x10
 
 /* Host ioremap/request_mem_region sizes for VF / VF_CNTL BARs */
 #define VIOMMU_VF_MMIO_MAP_SIZE		0x10000000UL
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index fd25c4c361f3..410c2f91064a 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -213,7 +213,12 @@ void amd_iommu_update_dte(struct amd_iommu *iommu,
 			     struct dev_table_entry *new)
 {
 	update_dte256(iommu, dev_data, new);
-	clone_aliases(iommu, dev_data->dev);
+	/*
+	 * The dev_data for trans_devid does not have struct dev.
+	 * So clone_aliases is not supported for translate-device-id.
+	 */
+	if (dev_data->dev)
+		clone_aliases(iommu, dev_data->dev);
 	device_flush_dte(iommu, dev_data);
 	amd_iommu_completion_wait(iommu);
 }
@@ -1747,7 +1752,11 @@ static int device_flush_dte(struct amd_iommu *iommu, struct iommu_dev_data *dev_
 	u16 alias;
 	int ret;
 
-	if (dev_is_pci(dev_data->dev))
+	/*
+	 * The dev_data for trans_devid does not have struct dev.
+	 * So, it is not considered as a PCI device.
+	 */
+	if (dev_data->dev && dev_is_pci(dev_data->dev))
 		pdev = to_pci_dev(dev_data->dev);
 
 	if (pdev)
@@ -3281,6 +3290,71 @@ static bool amd_iommu_enforce_cache_coherency(struct iommu_domain *domain)
 	return true;
 }
 
+#if IS_ENABLED(CONFIG_AMD_IOMMU_IOMMUFD)
+
+void amd_iommu_update_vfctrl_mmio_translate_devid(struct amd_iommu *iommu,
+						  u16 gid, u32 devid)
+{
+	writeq((devid & 0xFFFFULL) << 16,
+	       VIOMMU_VFCTRL_MMIO_BASE(iommu, gid) +
+	       VIOMMU_VFCTRL_GUEST_MISC_CONTROL_OFFSET);
+}
+
+int amd_iommu_set_translate_dte(struct amd_iommu *iommu,
+				 struct protection_domain *pdom,
+				 u16 gid, u32 trans_devid)
+{
+	struct dev_table_entry new = {};
+	struct iommu_dev_data *trans_dev_data;
+	struct pt_iommu_amdv1_hw_info pt_info;
+
+	trans_dev_data = search_dev_data(iommu, trans_devid);
+	if (!trans_dev_data) {
+		trans_dev_data = amd_iommu_alloc_dev_data(iommu, trans_devid);
+		if (!trans_dev_data) {
+			pr_err("%s: Failed to allocate dev_data for translate-device-id %#x\n",
+			       __func__, trans_devid);
+			return -ENOMEM;
+		}
+	}
+
+	trans_dev_data->dev = NULL;
+	trans_dev_data->devid = trans_devid;
+	trans_dev_data->domain = pdom;
+	trans_dev_data->gid = gid;
+
+	amd_iommu_make_clear_dte(iommu, trans_devid, &new);
+	/* Setup DTE for v1 page table at the offset specified by trans_devid */
+	pt_iommu_amdv1_hw_info(&pdom->amdv1, &pt_info);
+
+	pr_debug("%s: gid=%#x, iommu_devid=%#x, devid=%#x, host_pt_root=%#llx, mode=%#x\n",
+		 __func__, gid, iommu->devid, trans_devid, pt_info.host_pt_root, pt_info.mode);
+
+	amd_iommu_set_dte_v1(trans_dev_data, pdom, pdom->id, &pt_info, &new);
+	amd_iommu_update_dte(iommu, trans_dev_data, &new);
+	return 0;
+}
+
+void amd_iommu_clear_translate_dte(struct amd_iommu *iommu, u32 trans_devid)
+{
+	struct dev_table_entry new = {};
+	struct iommu_dev_data *trans_dev_data;
+
+	pr_debug("%s: iommu_devid=%#x, trans_devid=%#x\n",
+		 __func__, iommu->devid, trans_devid);
+
+	trans_dev_data = search_dev_data(iommu, trans_devid);
+	if (!trans_dev_data) {
+		WARN_ON_ONCE(1);
+		return;
+	}
+
+	amd_iommu_make_clear_dte(iommu, trans_devid, &new);
+	amd_iommu_update_dte(iommu, trans_dev_data, &new);
+	amd_iommu_free_dev_data(iommu, trans_dev_data);
+}
+#endif /* CONFIG_AMD_IOMMU_IOMMUFD */
+
 const struct iommu_ops amd_iommu_ops = {
 	.capable = amd_iommu_capable,
 	.hw_info = amd_iommufd_hw_info,
-- 
2.34.1