[PATCH v8 RESEND 11/38] x86/mm: Add SME support for read_cr3_pa()

Tom Lendacky
2017-06-27T15:09:36Z

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().

Reviewed-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
---
arch/x86/include/asm/processor-flags.h | 5 +++--
arch/x86/include/asm/processor.h | 5 +++++
2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/processor-flags.h b/arch/x86/include/asm/processor-flags.h
index 79aa2f9..f5d3e50 100644
--- a/arch/x86/include/asm/processor-flags.h
+++ b/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
/*
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 8010c97..ab878bd 100644
--- a/arch/x86/include/asm/processor.h
+++ b/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));