From 9c88e61dc0891a7f4781aff2a06a1de8ae86ea93 Mon Sep 17 00:00:00 2001
From: jhb <jhb@ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f>
Date: Mon, 21 Jul 2014 18:26:51 +0000
Subject: [PATCH] MFC 264347: Account for the "plus 1" encoding of the CPUID
 Function 4 reported core per package and cache sharing values.

git-svn-id: svn://svn.freebsd.org/base/stable/10@268952 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
---
 sys/amd64/vmm/x86.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/sys/amd64/vmm/x86.c b/sys/amd64/vmm/x86.c
index e81b43e85..ef1557f85 100644
--- a/sys/amd64/vmm/x86.c
+++ b/sys/amd64/vmm/x86.c
@@ -219,9 +219,18 @@ x86_emulate_cpuid(struct vm *vm, int vcpu_id,
 
 			/*
 			 * Do not expose topology.
+			 *
+			 * The maximum number of processor cores in
+			 * this physical processor package and the
+			 * maximum number of threads sharing this
+			 * cache are encoded with "plus 1" encoding.
+			 * Adding one to the value in this register
+			 * field to obtains the actual value.
+			 *
+			 * Therefore 0 for both indicates 1 core per
+			 * package and no cache sharing.
 			 */
 			regs[0] &= 0xffff8000;
-			regs[0] |= 0x04008000;
 			break;
 
 		case CPUID_0000_0007:
-- 
2.45.0