[Xen-devel] [PATCH 2/2] x86/viridian: TSC and APIC Frequency MSRs

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

These viridian MSRs are read-only sources of the TSC and APIC frequency (in
units of Hz)

From: Paul Durrant <paul.durrant@xxxxxxxxxx>
Signed-off-by: Paul Durrant <paul.durrant@xxxxxxxxxx>
Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CC: Keir Fraser <keir@xxxxxxx>
CC: Jan Beulich <JBeulich@xxxxxxxx>
---
 xen/arch/x86/hvm/viridian.c      |   16 +++++++++++++++-
 xen/arch/x86/hvm/vlapic.c        |    3 ---
 xen/include/asm-x86/hvm/vlapic.h |    3 +++
 xen/include/asm-x86/perfc_defn.h |    2 ++
 4 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/xen/arch/x86/hvm/viridian.c b/xen/arch/x86/hvm/viridian.c
index f363037..2b86d66 100644
--- a/xen/arch/x86/hvm/viridian.c
+++ b/xen/arch/x86/hvm/viridian.c
@@ -21,6 +21,8 @@
 #define VIRIDIAN_MSR_HYPERCALL                  0x40000001
 #define VIRIDIAN_MSR_VP_INDEX                   0x40000002
 #define VIRIDIAN_MSR_TIME_REF_COUNT             0x40000020
+#define VIRIDIAN_MSR_TSC_FREQUENCY              0x40000022
+#define VIRIDIAN_MSR_APIC_FREQUENCY             0x40000023
 #define VIRIDIAN_MSR_EOI                        0x40000070
 #define VIRIDIAN_MSR_ICR                        0x40000071
 #define VIRIDIAN_MSR_TPR                        0x40000072
@@ -38,6 +40,7 @@
 #define CPUID3A_MSR_APIC_ACCESS (1 << 4)
 #define CPUID3A_MSR_HYPERCALL   (1 << 5)
 #define CPUID3A_MSR_VP_INDEX    (1 << 6)
+#define CPUID3A_MSR_FREQ        (1 << 11)
 
 /* Viridian CPUID 4000004, Implementation Recommendations. */
 #define CPUID4A_MSR_BASED_APIC  (1 << 3)
@@ -88,7 +91,8 @@ int cpuid_viridian_leaves(unsigned int leaf, unsigned int 
*eax,
         *eax = (CPUID3A_MSR_REF_COUNT   |
                 CPUID3A_MSR_APIC_ACCESS |
                 CPUID3A_MSR_HYPERCALL   |
-                CPUID3A_MSR_VP_INDEX);
+                CPUID3A_MSR_VP_INDEX    |
+                CPUID3A_MSR_FREQ);
         break;
     case 4:
         /* Recommended hypercall usage. */
@@ -313,6 +317,16 @@ int rdmsr_viridian_regs(uint32_t idx, uint64_t *val)
         *val = hvm_get_guest_time(v) / 100;
         break;
 
+    case VIRIDIAN_MSR_TSC_FREQUENCY:
+        perfc_incr(mshv_rdmsr_tsc_frequency);
+        *val = (uint64_t)d->arch.tsc_khz * 1000ull;
+        break;
+
+    case VIRIDIAN_MSR_APIC_FREQUENCY:
+        perfc_incr(mshv_rdmsr_apic_frequency);
+        *val = 1000000000ull / APIC_BUS_CYCLE_NS;
+        break;
+
     case VIRIDIAN_MSR_ICR:
         perfc_incr(mshv_rdmsr_icr);
         *val = (((uint64_t)vlapic_get_reg(vcpu_vlapic(v), APIC_ICR2) << 32) |
diff --git a/xen/arch/x86/hvm/vlapic.c b/xen/arch/x86/hvm/vlapic.c
index 5c33d3a..bc06010 100644
--- a/xen/arch/x86/hvm/vlapic.c
+++ b/xen/arch/x86/hvm/vlapic.c
@@ -44,9 +44,6 @@
 #define VLAPIC_VERSION                  0x00050014
 #define VLAPIC_LVT_NUM                  6
 
-/* vlapic's frequence is 100 MHz */
-#define APIC_BUS_CYCLE_NS               10
-
 #define LVT_MASK \
     APIC_LVT_MASKED | APIC_SEND_PENDING | APIC_VECTOR_MASK
 
diff --git a/xen/include/asm-x86/hvm/vlapic.h b/xen/include/asm-x86/hvm/vlapic.h
index eb6dec9..66f0aff 100644
--- a/xen/include/asm-x86/hvm/vlapic.h
+++ b/xen/include/asm-x86/hvm/vlapic.h
@@ -80,6 +80,9 @@ struct vlapic {
     } init_sipi;
 };
 
+/* vlapic's frequence is 100 MHz */
+#define APIC_BUS_CYCLE_NS               10
+
 static inline uint32_t vlapic_get_reg(struct vlapic *vlapic, uint32_t reg)
 {
     return *((uint32_t *)(&vlapic->regs->data[reg]));
diff --git a/xen/include/asm-x86/perfc_defn.h b/xen/include/asm-x86/perfc_defn.h
index bd251f5..6c590aa 100644
--- a/xen/include/asm-x86/perfc_defn.h
+++ b/xen/include/asm-x86/perfc_defn.h
@@ -119,6 +119,8 @@ PERFCOUNTER(mshv_rdmsr_osid,            "MS Hv rdmsr Guest 
OS ID")
 PERFCOUNTER(mshv_rdmsr_hc_page,         "MS Hv rdmsr hypercall page")
 PERFCOUNTER(mshv_rdmsr_vp_index,        "MS Hv rdmsr vp index")
 PERFCOUNTER(mshv_rdmsr_time_ref_count,  "MS Hv rdmsr time reference count")
+PERFCOUNTER(mshv_rdmsr_tsc_frequency,   "MS Hv rdmsr TSC frequency")
+PERFCOUNTER(mshv_rdmsr_apic_frequency,  "MS Hv rdmsr APIC frequency")
 PERFCOUNTER(mshv_rdmsr_icr,             "MS Hv rdmsr icr")
 PERFCOUNTER(mshv_rdmsr_tpr,             "MS Hv rdmsr tpr")
 PERFCOUNTER(mshv_rdmsr_apic_assist,     "MS Hv rdmsr APIC assist")
-- 
1.7.10.4


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