[tip:x86/hyperv] x86/hyperv: Check frequency MSRs presence according to the specification

2017-06-22 Thread tip-bot for Vitaly Kuznetsov 
Commit-ID:  2cf0284223a40773bd0ec76a409a7cbf0607ca28
Gitweb: http://git.kernel.org/tip/2cf0284223a40773bd0ec76a409a7cbf0607ca28
Author: Vitaly Kuznetsov 
AuthorDate: Thu, 22 Jun 2017 18:07:29 +0800
Committer:  Thomas Gleixner 
CommitDate: Thu, 22 Jun 2017 15:35:11 +0200

x86/hyperv: Check frequency MSRs presence according to the specification

Hyper-V TLFS specifies two bits which should be checked before accessing
frequency MSRs:

- AccessFrequencyMsrs (BIT(11) in EAX) which indicates if we have access to
  frequency MSRs.
- FrequencyMsrsAvailable (BIT(8) in EDX) which indicates is these MSRs are
  present.
  
Rename and specify these bits accordingly.

Signed-off-by: Vitaly Kuznetsov 
Signed-off-by: Thomas Gleixner 
Cc: Stephen Hemminger 
Cc: Haiyang Zhang 
Cc: Ladi Prosek 
Cc: Jork Loeser 
Cc: de...@linuxdriverproject.org
Cc: "K. Y. Srinivasan" 
Link: http://lkml.kernel.org/r/20170622100730.18112-2-vkuzn...@redhat.com

---
 arch/x86/include/uapi/asm/hyperv.h | 15 ++-
 arch/x86/kernel/cpu/mshyperv.c |  3 ++-
 2 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/arch/x86/include/uapi/asm/hyperv.h 
b/arch/x86/include/uapi/asm/hyperv.h
index 432df4b..f4fef5a 100644
--- a/arch/x86/include/uapi/asm/hyperv.h
+++ b/arch/x86/include/uapi/asm/hyperv.h
@@ -34,16 +34,10 @@
 #define HV_X64_MSR_REFERENCE_TSC   0x4021
 
 /*
- * There is a single feature flag that signifies the presence of the MSR
- * that can be used to retrieve both the local APIC Timer frequency as
- * well as the TSC frequency.
+ * There is a single feature flag that signifies if the partition has access
+ * to MSRs with local APIC and TSC frequencies.
  */
-
-/* Local APIC timer frequency MSR (HV_X64_MSR_APIC_FREQUENCY) is available */
-#define HV_X64_MSR_APIC_FREQUENCY_AVAILABLE (1 << 11)
-
-/* TSC frequency MSR (HV_X64_MSR_TSC_FREQUENCY) is available */
-#define HV_X64_MSR_TSC_FREQUENCY_AVAILABLE (1 << 11)
+#define HV_X64_ACCESS_FREQUENCY_MSRS   (1 << 11)
 
 /*
  * Basic SynIC MSRs (HV_X64_MSR_SCONTROL through HV_X64_MSR_EOM
@@ -73,6 +67,9 @@
   */
 #define HV_X64_MSR_STAT_PAGES_AVAILABLE(1 << 8)
 
+/* Frequency MSRs available */
+#define HV_FEATURE_FREQUENCY_MSRS_AVAILABLE(1 << 8)
+
 /* Crash MSR available */
 #define HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE (1 << 10)
 
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 04cb8d3..3563c8e 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -194,7 +194,8 @@ static void __init ms_hyperv_init_platform(void)
}
 
 #ifdef CONFIG_X86_LOCAL_APIC
-   if (ms_hyperv.features & HV_X64_MSR_APIC_FREQUENCY_AVAILABLE) {
+   if (ms_hyperv.features & HV_X64_ACCESS_FREQUENCY_MSRS &&
+   ms_hyperv.misc_features & HV_FEATURE_FREQUENCY_MSRS_AVAILABLE) {
/*
 * Get the APIC frequency.
 */

[tip:x86/hyperv] x86/hyperv: Check frequency MSRs presence according to the specification

2017-06-22 Thread tip-bot for Vitaly Kuznetsov 
Commit-ID:  2cf0284223a40773bd0ec76a409a7cbf0607ca28
Gitweb: http://git.kernel.org/tip/2cf0284223a40773bd0ec76a409a7cbf0607ca28
Author: Vitaly Kuznetsov 
AuthorDate: Thu, 22 Jun 2017 18:07:29 +0800
Committer:  Thomas Gleixner 
CommitDate: Thu, 22 Jun 2017 15:35:11 +0200

x86/hyperv: Check frequency MSRs presence according to the specification

Hyper-V TLFS specifies two bits which should be checked before accessing
frequency MSRs:

- AccessFrequencyMsrs (BIT(11) in EAX) which indicates if we have access to
  frequency MSRs.
- FrequencyMsrsAvailable (BIT(8) in EDX) which indicates is these MSRs are
  present.
  
Rename and specify these bits accordingly.

Signed-off-by: Vitaly Kuznetsov 
Signed-off-by: Thomas Gleixner 
Cc: Stephen Hemminger 
Cc: Haiyang Zhang 
Cc: Ladi Prosek 
Cc: Jork Loeser 
Cc: de...@linuxdriverproject.org
Cc: "K. Y. Srinivasan" 
Link: http://lkml.kernel.org/r/20170622100730.18112-2-vkuzn...@redhat.com

---
 arch/x86/include/uapi/asm/hyperv.h | 15 ++-
 arch/x86/kernel/cpu/mshyperv.c |  3 ++-
 2 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/arch/x86/include/uapi/asm/hyperv.h 
b/arch/x86/include/uapi/asm/hyperv.h
index 432df4b..f4fef5a 100644
--- a/arch/x86/include/uapi/asm/hyperv.h
+++ b/arch/x86/include/uapi/asm/hyperv.h
@@ -34,16 +34,10 @@
 #define HV_X64_MSR_REFERENCE_TSC   0x4021
 
 /*
- * There is a single feature flag that signifies the presence of the MSR
- * that can be used to retrieve both the local APIC Timer frequency as
- * well as the TSC frequency.
+ * There is a single feature flag that signifies if the partition has access
+ * to MSRs with local APIC and TSC frequencies.
  */
-
-/* Local APIC timer frequency MSR (HV_X64_MSR_APIC_FREQUENCY) is available */
-#define HV_X64_MSR_APIC_FREQUENCY_AVAILABLE (1 << 11)
-
-/* TSC frequency MSR (HV_X64_MSR_TSC_FREQUENCY) is available */
-#define HV_X64_MSR_TSC_FREQUENCY_AVAILABLE (1 << 11)
+#define HV_X64_ACCESS_FREQUENCY_MSRS   (1 << 11)
 
 /*
  * Basic SynIC MSRs (HV_X64_MSR_SCONTROL through HV_X64_MSR_EOM
@@ -73,6 +67,9 @@
   */
 #define HV_X64_MSR_STAT_PAGES_AVAILABLE(1 << 8)
 
+/* Frequency MSRs available */
+#define HV_FEATURE_FREQUENCY_MSRS_AVAILABLE(1 << 8)
+
 /* Crash MSR available */
 #define HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE (1 << 10)
 
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 04cb8d3..3563c8e 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -194,7 +194,8 @@ static void __init ms_hyperv_init_platform(void)
}
 
 #ifdef CONFIG_X86_LOCAL_APIC
-   if (ms_hyperv.features & HV_X64_MSR_APIC_FREQUENCY_AVAILABLE) {
+   if (ms_hyperv.features & HV_X64_ACCESS_FREQUENCY_MSRS &&
+   ms_hyperv.misc_features & HV_FEATURE_FREQUENCY_MSRS_AVAILABLE) {
/*
 * Get the APIC frequency.
 */