From: Keir Fraser <keir@xensource.com>
Date: Wed, 24 Oct 2007 09:20:03 +0000 (+0100)
Subject: x86, cpufreq: Allow dom0 kernel to govern cpufreq via the Intel
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~14844
X-Git-Url: https://dgit.raspbian.org/%22http://www.example.com/cgi/success/%22http:/www.example.com/cgi/success?a=commitdiff_plain;h=6cf492cfe939329af84780ec3b9a7aff954077ac;p=xen.git

x86, cpufreq: Allow dom0 kernel to govern cpufreq via the Intel
Enahanced SpeedStep MSR.
From: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Keir Fraser <keir@xensource.com>
---

diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index 8ccbeee2c6..0aa8c8ba54 100644
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -1773,6 +1773,12 @@ static int emulate_privileged_op(struct cpu_user_regs *regs)
                  wrmsr_safe(regs->ecx, eax, edx) )
                 goto fail;
             break;
+        case MSR_IA32_PERF_CTL:
+            if ( (cpufreq_controller != FREQCTL_dom0_kernel) ||
+                 (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL) ||
+                 wrmsr_safe(regs->ecx, eax, edx) )
+                goto fail;
+            break;
         default:
             if ( wrmsr_hypervisor_regs(regs->ecx, eax, edx) )
                 break;