[RFC PATCH for-4.22 v2 2/3] x86/platform: Expose DTS sensors MSR

Teddy Astie posted 3 patches 8 hours ago
[RFC PATCH for-4.22 v2 2/3] x86/platform: Expose DTS sensors MSR
Posted by Teddy Astie 8 hours ago
Intel provide CPU sensors through "DTS" MSRs. As there MSR are core-specific
(or package-specific), we can't reliably fetch them from Dom0 directly.
Expose these MSR (if supported) through XENPF_resource_op so that it is
accessible through hypercall.

Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Teddy Astie <teddy.astie@vates.tech>
---
v2:
 - move DTS MSR out of legacy list, review MSR naming
 - use CPU policy instead of inline CPUID

 xen/arch/x86/include/asm/msr-index.h | 3 +++
 xen/arch/x86/platform_hypercall.c    | 6 ++++++
 2 files changed, 9 insertions(+)

diff --git a/xen/arch/x86/include/asm/msr-index.h b/xen/arch/x86/include/asm/msr-index.h
index df52587c85..7c6af7bd4d 100644
--- a/xen/arch/x86/include/asm/msr-index.h
+++ b/xen/arch/x86/include/asm/msr-index.h
@@ -115,6 +115,9 @@
 #define  MCU_OPT_CTRL_GDS_MIT_DIS           (_AC(1, ULL) <<  4)
 #define  MCU_OPT_CTRL_GDS_MIT_LOCK          (_AC(1, ULL) <<  5)
 
+#define MSR_DTS_TEMPERATURE_TARGET          0x000001a2
+#define MSR_DTS_PACKAGE_THERM_STATUS        0x000001b1
+
 #define MSR_FRED_RSP_SL0                    0x000001cc
 #define MSR_FRED_RSP_SL1                    0x000001cd
 #define MSR_FRED_RSP_SL2                    0x000001ce
diff --git a/xen/arch/x86/platform_hypercall.c b/xen/arch/x86/platform_hypercall.c
index 79bb99e0b6..d9872ddd3e 100644
--- a/xen/arch/x86/platform_hypercall.c
+++ b/xen/arch/x86/platform_hypercall.c
@@ -27,6 +27,7 @@
 #include <asm/current.h>
 #include <public/platform.h>
 #include <acpi/cpufreq/processor_perf.h>
+#include <asm/cpu-policy.h>
 #include <asm/edd.h>
 #include <asm/microcode.h>
 #include <asm/mtrr.h>
@@ -86,6 +87,11 @@ static bool msr_read_allowed(unsigned int msr)
 
     case MSR_MCU_OPT_CTRL:
         return cpu_has_srbds_ctrl;
+    
+    case MSR_IA32_THERM_STATUS:
+    case MSR_DTS_TEMPERATURE_TARGET:
+    case MSR_DTS_PACKAGE_THERM_STATUS:
+        return raw_cpu_policy.basic.pm.dts;
     }
 
     if ( ppin_msr && msr == ppin_msr )
-- 
2.51.2



--
Teddy Astie | Vates XCP-ng Developer

XCP-ng & Xen Orchestra - Vates solutions

web: https://vates.tech