[edk2-devel] [PATCH v2 19/23] OvmfPkg/BaseMemEncryptSevLib: Maximize Page State Change efficiency

["Lendacky, Thomas via groups.io" <thomas.lendacky=amd.com@groups.io>]

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4654

Similar to the Page State Change optimization added previously, also take
into account the possiblity of using the SVSM for PVALIDATE instructions.
Conditionally adjust the maximum number of entries based on how many
entries the SVSM calling area can support.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
---
 OvmfPkg/Library/BaseMemEncryptSevLib/X64/SnpPageStateChangeInternal.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/SnpPageStateChangeInternal.c b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/SnpPageStateChangeInternal.c
index 4e1225d12797..7060cd61b21c 100644
--- a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/SnpPageStateChangeInternal.c
+++ b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/SnpPageStateChangeInternal.c
@@ -18,6 +18,7 @@
 
 #include <Register/Amd/Ghcb.h>
 #include <Register/Amd/Msr.h>
+#include <Register/Amd/Svsm.h>
 
 #include "SnpPageStateChange.h"
 
@@ -78,6 +79,7 @@ BuildPageStateBuffer (
   UINTN                 Index;
   UINTN                 IndexMax;
   UINTN                 PscIndexMax;
+  UINTN                 SvsmIndexMax;
 
   // Clear the page state structure
   SetMem (Info, InfoSize, 0);
@@ -96,6 +98,11 @@ BuildPageStateBuffer (
     IndexMax = MIN (IndexMax, PscIndexMax);
   }
 
+  SvsmIndexMax = (IndexMax / SVSM_PVALIDATE_MAX_ENTRY) * SVSM_PVALIDATE_MAX_ENTRY;
+  if (SvsmIndexMax > 0) {
+    IndexMax = MIN (IndexMax, SvsmIndexMax);
+  }
+
   //
   // Populate the page state entry structure
   //
-- 
2.42.0



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