[RFC, PATCH 20/22] x86/mm: Implement anon_vma_encrypted() and anon_vma_keyid()

[Kirill A. Shutemov]

This patch implements helpers to check if given VMA is encrypted and
with which KeyID.

Signed-off-by: Kirill A. Shutemov <kirill.shute...@linux.intel.com>
---
 arch/x86/include/asm/mktme.h | 14 ++++++++++++++
 arch/x86/mm/mktme.c          | 11 +++++++++++
 2 files changed, 25 insertions(+)

diff --git a/arch/x86/include/asm/mktme.h b/arch/x86/include/asm/mktme.h
index c8f41837351a..56c7e9b14ab6 100644
--- a/arch/x86/include/asm/mktme.h
+++ b/arch/x86/include/asm/mktme.h
@@ -4,11 +4,20 @@
 #include <linux/types.h>
 
 struct vm_area_struct;
+struct anon_vma;
 
 struct page *__alloc_zeroed_encrypted_user_highpage(gfp_t gfp,
                struct vm_area_struct *vma, unsigned long vaddr);
 
 #ifdef CONFIG_X86_INTEL_MKTME
+#define arch_anon_vma arch_anon_vma
+struct arch_anon_vma {
+       int keyid;
+};
+
+#define arch_anon_vma_init(anon_vma, vma) \
+       anon_vma->arch_anon_vma.keyid = vma_keyid(vma);
+
 extern phys_addr_t mktme_keyid_mask;
 extern int mktme_nr_keyids;
 extern int mktme_keyid_shift;
@@ -19,6 +28,11 @@ bool vma_is_encrypted(struct vm_area_struct *vma);
 #define vma_keyid vma_keyid
 int vma_keyid(struct vm_area_struct *vma);
 
+#define anon_vma_encrypted anon_vma_encrypted
+bool anon_vma_encrypted(struct anon_vma *anon_vma);
+
+#define anon_vma_keyid anon_vma_keyid
+int anon_vma_keyid(struct anon_vma *anon_vma);
 #else
 #define mktme_keyid_mask       ((phys_addr_t)0)
 #define mktme_nr_keyids                0
diff --git a/arch/x86/mm/mktme.c b/arch/x86/mm/mktme.c
index ef0eb1eb8d6e..69172aabc07c 100644
--- a/arch/x86/mm/mktme.c
+++ b/arch/x86/mm/mktme.c
@@ -1,4 +1,5 @@
 #include <linux/mm.h>
+#include <linux/rmap.h>
 #include <linux/highmem.h>
 #include <asm/mktme.h>
 
@@ -28,6 +29,16 @@ int vma_keyid(struct vm_area_struct *vma)
        return (prot & mktme_keyid_mask) >> mktme_keyid_shift;
 }
 
+bool anon_vma_encrypted(struct anon_vma *anon_vma)
+{
+       return anon_vma_keyid(anon_vma);
+}
+
+int anon_vma_keyid(struct anon_vma *anon_vma)
+{
+       return anon_vma->arch_anon_vma.keyid;
+}
+
 void prep_encrypt_page(struct page *page, gfp_t gfp, unsigned int order)
 {
        void *v = page_to_virt(page);
-- 
2.16.1