linux-kernel - [PATCH 7/9] KVM: Expose the architectural performance monitoring CPUID leaf

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Date:	Thu,  3 Nov 2011 14:31:36 +0200
From:	Gleb Natapov <gleb@...hat.com>
To:	kvm@...r.kernel.org
Cc:	avi@...hat.com, mtosatti@...hat.com, linux-kernel@...r.kernel.org,
	mingo@...e.hu, a.p.zijlstra@...llo.nl, acme@...stprotocols.net
Subject: [PATCH 7/9] KVM: Expose the architectural performance monitoring CPUID leaf

From: Avi Kivity <avi@...hat.com>

Provide a CPUID leaf that describes the emulated PMU.

Signed-off-by: Avi Kivity <avi@...hat.com>
Signed-off-by: Gleb Natapov <gleb@...hat.com>
---
 arch/x86/kvm/x86.c |   23 ++++++++++++++++++++++-
 1 files changed, 22 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 5ea4cb8..56153a9 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2543,6 +2543,28 @@ static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
 	}
 	case 9:
 		break;
+	case 0xa: { /* Architectural Performance Monitoring */
+		struct x86_pmu_capability cap;
+
+		perf_get_x86_pmu_capability(&cap);
+
+		/*
+		 * Only support guest architectural pmu on a host
+		 * with architectural pmu.
+		 */
+		if (!cap.version)
+			memset(&cap, 0, sizeof(cap));
+
+		entry->eax = min(cap.version, 2)
+			| (cap.num_counters_gp << 8)
+			| (cap.bit_width_gp << 16)
+			| (cap.events_mask_len << 24);
+		entry->ebx = cap.events_mask;
+		entry->ecx = 0;
+		entry->edx = cap.num_counters_fixed
+			| (cap.bit_width_fixed << 5);
+		break;
+	}
 	/* function 0xb has additional index. */
 	case 0xb: {
 		int i, level_type;
@@ -2637,7 +2659,6 @@ static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
 	case 3: /* Processor serial number */
 	case 5: /* MONITOR/MWAIT */
 	case 6: /* Thermal management */
-	case 0xA: /* Architectural Performance Monitoring */
 	case 0x80000007: /* Advanced power management */
 	case 0xC0000002:
 	case 0xC0000003:
-- 
1.7.5.3

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