svn commit: r264347 - head/sys/amd64/vmm

[Tycho Nightingale]

Author: tychon
Date: Fri Apr 11 18:19:21 2014
New Revision: 264347
URL: http://svnweb.freebsd.org/changeset/base/264347

Log:
  Account for the "plus 1" encoding of the CPUID Function 4 reported
  core per package and cache sharing values.
  
  Approved by:	grehan (co-mentor)

Modified:
  head/sys/amd64/vmm/x86.c

Modified: head/sys/amd64/vmm/x86.c
==============================================================================
--- head/sys/amd64/vmm/x86.c	Fri Apr 11 16:55:25 2014	(r264346)
+++ head/sys/amd64/vmm/x86.c	Fri Apr 11 18:19:21 2014	(r264347)
@@ -219,9 +219,18 @@ x86_emulate_cpuid(struct vm *vm, int vcp
 
 			/*
 			 * 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: