[PATCH v2 07/26] iommu/amd: Add support for AMD vIOMMU VF MMIO region

[Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>]

The AMD vIOMMU virtualizes guest MMIO registers at the 3rd 4K region.
This is achieved using the iommufd_viommu_alloc_mmap().

Co-developed-by: Vasant Hegde <Vasant.Hegde@amd.com>
Signed-off-by: Vasant Hegde <Vasant.Hegde@amd.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
---
 drivers/iommu/amd/amd_iommu_types.h |  3 +++
 drivers/iommu/amd/amd_viommu.h      |  7 +++++++
 drivers/iommu/amd/iommufd.c         | 18 +++++++++++++++++-
 drivers/iommu/amd/viommu.c          | 11 +++++++++++
 include/uapi/linux/iommufd.h        |  2 ++
 5 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/amd/amd_iommu_types.h b/drivers/iommu/amd/amd_iommu_types.h
index e88e0bacd1a9..cc7049bbfa14 100644
--- a/drivers/iommu/amd/amd_iommu_types.h
+++ b/drivers/iommu/amd/amd_iommu_types.h
@@ -540,6 +540,9 @@ struct amd_iommu_viommu {
 	 * Indexed by guest domain ID.
 	 */
 	struct xarray gdomid_array;
+
+	/* Offset for mmap() of guest VF MMIO; set after iommufd_viommu_alloc_mmap(). */
+	unsigned long vfmmio_mmap_offset;
 };
 
 /*
diff --git a/drivers/iommu/amd/amd_viommu.h b/drivers/iommu/amd/amd_viommu.h
index d0c4fdd00809..447692b9101c 100644
--- a/drivers/iommu/amd/amd_viommu.h
+++ b/drivers/iommu/amd/amd_viommu.h
@@ -12,6 +12,8 @@ int amd_viommu_init(struct amd_iommu *iommu);
 
 void __init amd_viommu_uninit(struct amd_iommu *iommu);
 
+u64 amd_viommu_get_vfmmio_addr(struct amd_iommu *iommu, u16 gid);
+
 #else
 
 static inline int amd_viommu_init(struct amd_iommu *iommu)
@@ -23,6 +25,11 @@ static inline void amd_viommu_uninit(struct amd_iommu *iommu)
 {
 }
 
+static inline u64 amd_viommu_get_vfmmio_addr(struct amd_iommu *iommu, u16 gid)
+{
+	return 0;
+}
+
 #endif /* CONFIG_AMD_IOMMU_IOMMUFD */
 
 #endif /* AMD_VIOMMU_H */
diff --git a/drivers/iommu/amd/iommufd.c b/drivers/iommu/amd/iommufd.c
index 785fa2d575f2..34524c1309c3 100644
--- a/drivers/iommu/amd/iommufd.c
+++ b/drivers/iommu/amd/iommufd.c
@@ -7,6 +7,7 @@
 
 #include "iommufd.h"
 #include "amd_iommu.h"
+#include "amd_viommu.h"
 #include "amd_iommu_types.h"
 
 static const struct iommufd_viommu_ops amd_viommu_ops;
@@ -44,11 +45,12 @@ int amd_iommufd_viommu_init(struct iommufd_viommu *viommu, struct iommu_domain *
 			    const struct iommu_user_data *user_data)
 {
 	int ret;
+	phys_addr_t page_base;
 	unsigned long flags;
 	struct iommu_viommu_amd data;
 	struct protection_domain *pdom = to_pdomain(parent);
-	struct amd_iommu_viommu *aviommu = container_of(viommu, struct amd_iommu_viommu, core);
 	struct amd_iommu *iommu = container_of(viommu->iommu_dev, struct amd_iommu, iommu);
+	struct amd_iommu_viommu *aviommu = container_of(viommu, struct amd_iommu_viommu, core);
 
 	xa_init_flags(&aviommu->gdomid_array, XA_FLAGS_ALLOC1);
 	aviommu->parent = pdom;
@@ -68,6 +70,16 @@ int amd_iommufd_viommu_init(struct iommufd_viommu *viommu, struct iommu_domain *
 	aviommu->gid = ret;
 	pr_debug("%s: gid=%#x", __func__, aviommu->gid);
 
+	page_base = amd_viommu_get_vfmmio_addr(iommu, aviommu->gid);
+
+	ret = iommufd_viommu_alloc_mmap(&aviommu->core,
+					page_base, SZ_4K,
+					(unsigned long *)&data.out_vfmmio_mmap_offset);
+	if (ret)
+		goto err_mmap;
+
+	aviommu->vfmmio_mmap_offset = data.out_vfmmio_mmap_offset;
+
 	ret = iommu_copy_struct_to_user(user_data, &data,
 					IOMMU_VIOMMU_TYPE_AMD,
 					reserved);
@@ -82,6 +94,8 @@ int amd_iommufd_viommu_init(struct iommufd_viommu *viommu, struct iommu_domain *
 
 	return 0;
 err_init:
+	iommufd_viommu_destroy_mmap(&aviommu->core, aviommu->vfmmio_mmap_offset);
+err_mmap:
 	amd_iommu_gid_free(iommu, aviommu->gid);
 err_gid:
 	return ret;
@@ -100,6 +114,8 @@ static void amd_iommufd_viommu_destroy(struct iommufd_viommu *viommu)
 	list_del(&aviommu->pdom_list);
 	spin_unlock_irqrestore(&pdom->lock, flags);
 	xa_destroy(&aviommu->gdomid_array);
+	if (aviommu->vfmmio_mmap_offset)
+		iommufd_viommu_destroy_mmap(&aviommu->core, aviommu->vfmmio_mmap_offset);
 	amd_iommu_gid_free(iommu, aviommu->gid);
 }
 
diff --git a/drivers/iommu/amd/viommu.c b/drivers/iommu/amd/viommu.c
index 014ae16bf58b..9e6eb2f977ec 100644
--- a/drivers/iommu/amd/viommu.c
+++ b/drivers/iommu/amd/viommu.c
@@ -131,6 +131,17 @@ static int __init viommu_vf_vfcntl_init(struct amd_iommu *iommu)
 	return -ENOMEM;
 }
 
+/*
+ * Returns VF MMIO BAR offset for the give guest ID which will be
+ * mapped to guest vIOMMU 3rd 4K MMIO address
+ */
+u64 amd_viommu_get_vfmmio_addr(struct amd_iommu *iommu, u16 gid)
+{
+	/* TODO: Add check for sVIOMMU and set gid[bit 15] */
+	return iommu->vf_base_phys + gid * VIOMMU_VF_MMIO_ENTRY_SIZE;
+}
+EXPORT_SYMBOL(amd_viommu_get_vfmmio_addr);
+
 int __init amd_viommu_init(struct amd_iommu *iommu)
 {
 	int ret;
diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
index 83ed10610957..0b7a3e5b057c 100644
--- a/include/uapi/linux/iommufd.h
+++ b/include/uapi/linux/iommufd.h
@@ -1084,9 +1084,11 @@ struct iommu_viommu_tegra241_cmdqv {
 
 /**
  * struct iommu_viommu_amd - AMD vIOMMU Interface (IOMMU_VIOMMU_TYPE_AMD)
+ * @out_vfmmio_mmap_offset: (out) mmap offset for vIOMMU VF-MMIO
  * @reserved: Must be zero
  */
 struct iommu_viommu_amd {
+	__aligned_u64 out_vfmmio_mmap_offset;
 	__u32 reserved; /* must be last */
 };
 
-- 
2.34.1