Re: [PATCH Part1 v5 11/38] x86/compressed: Add helper for validating pages in the decompression stage

Brijesh Singh <brijesh.singh@xxxxxxx> · Mon, 23 Aug 2021 13:55:16 -0500

On 8/23/21 9:16 AM, Borislav Petkov wrote:
On Fri, Aug 20, 2021 at 10:19:06AM -0500, Brijesh Singh wrote:

diff --git a/arch/x86/include/asm/sev-common.h b/arch/x86/include/asm/sev-common.h
index d426c30ae7b4..1cd8ce838af8 100644
--- a/arch/x86/include/asm/sev-common.h
+++ b/arch/x86/include/asm/sev-common.h
@@ -57,6 +57,26 @@
  #define GHCB_MSR_AP_RESET_HOLD_REQ	0x006
  #define GHCB_MSR_AP_RESET_HOLD_RESP	0x007
  
+/* SNP Page State Change */

Let's make it very clear here that those cmd numbers below are actually
part of the protocol and not randomly chosen:

/*
  * ...
  *
  * 0x014 – SNP Page State Change Request
  *
  * GHCBData[55:52] – Page operation:
  *   0x0001 – Page assignment, Private
  *   0x0002 – Page assignment, Shared
  */


Noted.

thanks






