Re: [PATCH v7 11/36] x86/mm: Add SME support for read_cr3_pa()

Tom Lendacky <thomas.lendacky@xxxxxxx> · Tue, 20 Jun 2017 11:23:03 -0500

On 6/20/2017 11:17 AM, Andy Lutomirski wrote:
On Fri, Jun 16, 2017 at 11:51 AM, Tom Lendacky <thomas.lendacky@xxxxxxx> wrote:
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@xxxxxxx>
---
  arch/x86/include/asm/processor-flags.h |    3 ++-
  arch/x86/include/asm/processor.h       |    5 +++++
  2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/processor-flags.h b/arch/x86/include/asm/processor-flags.h
index 79aa2f9..cb6999c 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
@@ -33,7 +34,7 @@
   */
  #ifdef CONFIG_X86_64
  /* Mask off the address space ID bits. */
-#define CR3_ADDR_MASK 0x7FFFFFFFFFFFF000ull
+#define CR3_ADDR_MASK __sme_clr(0x7FFFFFFFFFFFF000ull)

Can you update the comment one line above, too?

Yup, will do.

Thanks,
Tom








