x86/mm: Add SME support for read_cr3_pa()

The CR3 register entry can contain the SME encryption mask that indicates
the PGD is encrypted.  The encryption mask should not be used when
creating a virtual address from the CR3 register, so remove the SME
encryption mask in the read_cr3_pa() function.

During early boot SME will need to use a native version of read_cr3_pa(),
so create native_read_cr3_pa().

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Toshimitsu Kani <toshi.kani@hpe.com>
Cc: kasan-dev@googlegroups.com
Cc: kvm@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-efi@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/767b085c384a46f67f451f8589903a462c7ff68a.1500319216.git.thomas.lendacky@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/include/asm/processor-flags.h

@@ -2,6 +2,7 @@
 #define _ASM_X86_PROCESSOR_FLAGS_H
 
 #include <uapi/asm/processor-flags.h>
+#include <linux/mem_encrypt.h>
 
 #ifdef CONFIG_VM86
 #define X86_VM_MASK	X86_EFLAGS_VM
@@ -32,8 +33,8 @@
  * CR3_ADDR_MASK is the mask used by read_cr3_pa().
  */
 #ifdef CONFIG_X86_64
-/* Mask off the address space ID bits. */
-#define CR3_ADDR_MASK 0x7FFFFFFFFFFFF000ull
+/* Mask off the address space ID and SME encryption bits. */
+#define CR3_ADDR_MASK __sme_clr(0x7FFFFFFFFFFFF000ull)
 #define CR3_PCID_MASK 0xFFFull
 #else
 /*

arch/x86/include/asm/processor.h

@@ -240,6 +240,11 @@ static inline unsigned long read_cr3_pa(void)
 	return __read_cr3() & CR3_ADDR_MASK;
 }
 
+static inline unsigned long native_read_cr3_pa(void)
+{
+	return __native_read_cr3() & CR3_ADDR_MASK;
+}
+
 static inline void load_cr3(pgd_t *pgdir)
 {
 	write_cr3(__sme_pa(pgdir));