[PATCH v1 15/26] x86/virt/tdx: Extend tdx_page_array to support IOMMU_MT

[Xu Yilun <yilun.xu@linux.intel.com>]

IOMMU_MT is another TDX Module defined structure similar to HPA_ARRAY_T
and HPA_LIST_INFO. The difference is it supports multi-order contiguous
pages. It adds an additional NUM_PAGES field for every multi-order page
entry.

Add an dedicated allocation helper for IOMMU_MT. Maybe a general
allocation helper for multi-order is better but could postponed until
another user appears.

Signed-off-by: Xu Yilun <yilun.xu@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 arch/x86/include/asm/tdx.h  |  2 ++
 arch/x86/virt/vmx/tdx/tdx.c | 71 +++++++++++++++++++++++++++++++++++--
 2 files changed, 70 insertions(+), 3 deletions(-)

diff --git a/arch/x86/include/asm/tdx.h b/arch/x86/include/asm/tdx.h
index 1eeb77a6790a..4078fc497779 100644
--- a/arch/x86/include/asm/tdx.h
+++ b/arch/x86/include/asm/tdx.h
@@ -157,6 +157,8 @@ void tdx_page_array_ctrl_leak(struct tdx_page_array *array);
 int tdx_page_array_ctrl_release(struct tdx_page_array *array,
 				unsigned int nr_released,
 				u64 released_hpa);
+struct tdx_page_array *
+tdx_page_array_create_iommu_mt(unsigned int iq_order, unsigned int nr_mt_pages);
 
 struct tdx_td {
 	/* TD root structure: */
diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c
index bbf93cad5bf2..46cdb5aaaf68 100644
--- a/arch/x86/virt/vmx/tdx/tdx.c
+++ b/arch/x86/virt/vmx/tdx/tdx.c
@@ -316,8 +316,15 @@ static int tdx_page_array_fill_root(struct tdx_page_array *array,
 			    TDX_PAGE_ARRAY_MAX_NENTS);
 
 	entries = (u64 *)page_address(array->root);
-	for (i = 0; i < array->nents; i++)
-		entries[i] = page_to_phys(array->pages[offset + i]);
+	for (i = 0; i < array->nents; i++) {
+		struct page *page = array->pages[offset + i];
+
+		entries[i] = page_to_phys(page);
+
+		/* Now only for iommu_mt */
+		if (compound_nr(page) > 1)
+			entries[i] |= compound_nr(page);
+	}
 
 	return array->nents;
 }
@@ -327,7 +334,7 @@ static void tdx_free_pages_bulk(unsigned int nr_pages, struct page **pages)
 	unsigned long i;
 
 	for (i = 0; i < nr_pages; i++)
-		__free_page(pages[i]);
+		put_page(pages[i]);
 }
 
 static int tdx_alloc_pages_bulk(unsigned int nr_pages, struct page **pages)
@@ -466,6 +473,10 @@ static bool tdx_page_array_validate_release(struct tdx_page_array *array,
 			struct page *page = array->pages[offset + i];
 			u64 val = page_to_phys(page);
 
+			/* Now only for iommu_mt */
+			if (compound_nr(page) > 1)
+				val |= compound_nr(page);
+
 			if (val != entries[i]) {
 				pr_err("%s entry[%d] [0x%llx] doesn't match page hpa [0x%llx]\n",
 				       __func__, i, entries[i], val);
@@ -516,6 +527,60 @@ int tdx_page_array_ctrl_release(struct tdx_page_array *array,
 }
 EXPORT_SYMBOL_GPL(tdx_page_array_ctrl_release);
 
+struct tdx_page_array *
+tdx_page_array_create_iommu_mt(unsigned int iq_order, unsigned int nr_mt_pages)
+{
+	unsigned int nr_entries = 2 + nr_mt_pages;
+	int ret;
+
+	if (nr_entries > TDX_PAGE_ARRAY_MAX_NENTS)
+		return NULL;
+
+	struct tdx_page_array *array __free(kfree) = kzalloc(sizeof(*array),
+							     GFP_KERNEL);
+	if (!array)
+		return NULL;
+
+	struct page *root __free(__free_page) = alloc_page(GFP_KERNEL |
+							   __GFP_ZERO);
+	if (!root)
+		return NULL;
+
+	struct page **pages __free(kfree) = kcalloc(nr_entries, sizeof(*pages),
+						    GFP_KERNEL);
+	if (!pages)
+		return NULL;
+
+	/* TODO: folio_alloc_node() is preferred, but need numa info */
+	struct folio *t_iq __free(folio_put) = folio_alloc(GFP_KERNEL |
+							   __GFP_ZERO,
+							   iq_order);
+	if (!t_iq)
+		return NULL;
+
+	struct folio *t_ctxiq __free(folio_put) = folio_alloc(GFP_KERNEL |
+							      __GFP_ZERO,
+							      iq_order);
+	if (!t_ctxiq)
+		return NULL;
+
+	ret = tdx_alloc_pages_bulk(nr_mt_pages, pages + 2);
+	if (ret)
+		return NULL;
+
+	pages[0] = folio_page(no_free_ptr(t_iq), 0);
+	pages[1] = folio_page(no_free_ptr(t_ctxiq), 0);
+
+	array->nr_pages = nr_entries;
+	array->pages = no_free_ptr(pages);
+	array->root = no_free_ptr(root);
+
+	tdx_page_array_fill_root(array, 0);
+
+	return no_free_ptr(array);
+}
+EXPORT_SYMBOL_GPL(tdx_page_array_create_iommu_mt);
+
 #define HPA_LIST_INFO_FIRST_ENTRY	GENMASK_U64(11, 3)
 #define HPA_LIST_INFO_PFN		GENMASK_U64(51, 12)
 #define HPA_LIST_INFO_LAST_ENTRY	GENMASK_U64(63, 55)
-- 
2.25.1