From: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Date: Fri, 22 Jul 2016 17:14:01 +0000 (-0400)
Subject: tools/libxc: Properly increment ApicIdCoreSize field on AMD
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~707
X-Git-Url: https://dgit.raspbian.org/%22http:/www.example.com/cgi/%22https:///%22http:/www.example.com/cgi/%22https:/?a=commitdiff_plain;h=a3336a507519c1d28db3bbff8e439aa3811733f3;p=xen.git

tools/libxc: Properly increment ApicIdCoreSize field on AMD

Current code incorrectly adds 1 to full register instead of
incrementing the field in bits 15:12.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
---

diff --git a/tools/libxc/xc_cpuid_x86.c b/tools/libxc/xc_cpuid_x86.c
index 84f4e0810b..fbbac9e25a 100644
--- a/tools/libxc/xc_cpuid_x86.c
+++ b/tools/libxc/xc_cpuid_x86.c
@@ -331,7 +331,8 @@ static void amd_xc_cpuid_policy(xc_interface *xch,
          * ECX[15:12] is ApicIdCoreSize: ECX[7:0] is NumberOfCores (minus one).
          * Update to reflect vLAPIC_ID = vCPU_ID * 2.
          */
-        regs[2] = ((regs[2] & 0xf000u) + 1) | ((regs[2] & 0xffu) << 1) | 1u;
+        regs[2] = ((regs[2] + (1u << 12)) & 0xf000u) |
+                  ((regs[2] & 0xffu) << 1) | 1u;
         break;
 
     case 0x8000000a: {