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From: Like Xu <like.xu@linux.intel.com>
To: Peter Zijlstra <peterz@infradead.org>,
	Paolo Bonzini <pbonzini@redhat.com>,
	eranian@google.com, kvm@vger.kernel.org
Cc: Ingo Molnar <mingo@redhat.com>,
	Sean Christopherson <seanjc@google.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
	Andi Kleen <andi@firstfloor.org>,
	Kan Liang <kan.liang@linux.intel.com>,
	wei.w.wang@intel.com, luwei.kang@intel.com,
	linux-kernel@vger.kernel.org
Subject: [PATCH v3 13/17] KVM: x86/pmu: Add hook to emulate pebs for cross-mapped counters
Date: Mon,  4 Jan 2021 21:15:38 +0800	[thread overview]
Message-ID: <20210104131542.495413-14-like.xu@linux.intel.com> (raw)
In-Reply-To: <20210104131542.495413-1-like.xu@linux.intel.com>

To emulate PEBS facility, KVM may needs setup context such as
guest DS PEBS fields correctly before vm-entry and this part
will be implemented in the vmx handle_event() hook.

When the cross-map happens to any enabled PEBS counter, it will make
PMU request and exit to kvm_pmu_handle_event() for some rewrite stuff
and then back to cross-map check again and finally to vm-entry.

In this hook, KVM would rewrite the state for the guest and it won't
move events, hence races with the NMI PMI are not a problem.

Signed-off-by: Like Xu <like.xu@linux.intel.com>
---
 arch/x86/kvm/pmu.c           | 3 +++
 arch/x86/kvm/pmu.h           | 1 +
 arch/x86/kvm/vmx/pmu_intel.c | 9 +++++++++
 arch/x86/kvm/vmx/vmx.c       | 3 ---
 4 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index 3bfed803ed17..e898da4699c9 100644
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -340,6 +340,9 @@ void kvm_pmu_handle_event(struct kvm_vcpu *vcpu)
 	 */
 	if (unlikely(pmu->need_cleanup))
 		kvm_pmu_cleanup(vcpu);
+
+	if (kvm_x86_ops.pmu_ops->handle_event)
+		kvm_x86_ops.pmu_ops->handle_event(vcpu);
 }
 
 /* check if idx is a valid index to access PMU */
diff --git a/arch/x86/kvm/pmu.h b/arch/x86/kvm/pmu.h
index f5ec94e9a1dc..b1e52e33f08c 100644
--- a/arch/x86/kvm/pmu.h
+++ b/arch/x86/kvm/pmu.h
@@ -45,6 +45,7 @@ struct kvm_pmu_ops {
 	void (*refresh)(struct kvm_vcpu *vcpu);
 	void (*init)(struct kvm_vcpu *vcpu);
 	void (*reset)(struct kvm_vcpu *vcpu);
+	void (*handle_event)(struct kvm_vcpu *vcpu);
 };
 
 static inline u64 pmc_bitmask(struct kvm_pmc *pmc)
diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index 99d9453e0176..2a06f923fbc7 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -491,6 +491,14 @@ static void intel_pmu_reset(struct kvm_vcpu *vcpu)
 		pmu->global_ovf_ctrl = 0;
 }
 
+static void intel_pmu_handle_event(struct kvm_vcpu *vcpu)
+{
+	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
+
+	if (!(pmu->global_ctrl & pmu->pebs_enable))
+		return;
+}
+
 struct kvm_pmu_ops intel_pmu_ops = {
 	.find_arch_event = intel_find_arch_event,
 	.find_fixed_event = intel_find_fixed_event,
@@ -505,4 +513,5 @@ struct kvm_pmu_ops intel_pmu_ops = {
 	.refresh = intel_pmu_refresh,
 	.init = intel_pmu_init,
 	.reset = intel_pmu_reset,
+	.handle_event = intel_pmu_handle_event,
 };
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index bc30c83e0a62..341794b67f9a 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -6542,9 +6542,6 @@ static void atomic_switch_perf_msrs(struct vcpu_vmx *vmx)
 	if (!msrs)
 		return;
 
-	if (pmu->counter_cross_mapped)
-		msrs[1].guest = 0;
-
 	if (nr_msrs > 2 && msrs[1].guest) {
 		msrs[2].guest = pmu->ds_area;
 		if (nr_msrs > 3)
-- 
2.29.2


  parent reply	other threads:[~2021-01-04 13:29 UTC|newest]

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-04 13:15 [PATCH v3 00/17] KVM: x86/pmu: Add support to enable Guest PEBS via DS Like Xu
2021-01-04 13:15 ` [PATCH v3 01/17] KVM: x86/pmu: Set MSR_IA32_MISC_ENABLE_EMON bit when vPMU is enabled Like Xu
2021-01-04 13:15 ` [PATCH v3 02/17] KVM: x86/pmu: Use IA32_PERF_CAPABILITIES to adjust features visibility Like Xu
2021-01-04 13:15 ` [PATCH v3 03/17] KVM: x86/pmu: Introduce the ctrl_mask value for fixed counter Like Xu
2021-01-13 18:06   ` Peter Zijlstra
2021-01-14  1:58     ` Xu, Like
2021-01-04 13:15 ` [PATCH v3 04/17] perf: x86/ds: Handle guest PEBS overflow PMI and inject it to guest Like Xu
2021-01-13 18:22   ` Peter Zijlstra
2021-01-13 18:27     ` Peter Zijlstra
2021-01-14  3:39     ` Xu, Like
2021-01-15 12:01       ` Peter Zijlstra
2021-01-15 14:30         ` Xu, Like
2021-01-15 14:44           ` Peter Zijlstra
2021-01-15 15:12             ` Xu, Like
2021-01-25  8:26             ` Like Xu
2021-01-25 11:47               ` Peter Zijlstra
2021-02-02  6:31                 ` Xu, Like
2021-01-14 18:55   ` Sean Christopherson
2021-01-15  2:49     ` Xu, Like
2021-01-15 17:42       ` Sean Christopherson
2021-01-22  5:30         ` Like Xu
2021-01-04 13:15 ` [PATCH v3 05/17] KVM: x86/pmu: Reprogram guest PEBS event to emulate guest PEBS counter Like Xu
2021-01-15 11:33   ` Peter Zijlstra
2021-01-15 13:53     ` Xu, Like
2021-01-04 13:15 ` [PATCH v3 06/17] KVM: x86/pmu: Add IA32_PEBS_ENABLE MSR emulation for extended PEBS Like Xu
2021-01-05 21:11   ` Sean Christopherson
2021-01-07 12:38     ` Xu, Like
2021-01-15 14:46   ` Peter Zijlstra
2021-01-15 15:29     ` Xu, Like
2021-01-04 13:15 ` [PATCH v3 07/17] KVM: x86/pmu: Add IA32_DS_AREA MSR emulation to manage guest DS buffer Like Xu
2021-01-05 21:16   ` Sean Christopherson
2021-01-08  3:05     ` Xu, Like
2021-01-04 13:15 ` [PATCH v3 08/17] KVM: x86/pmu: Add PEBS_DATA_CFG MSR emulation to support adaptive PEBS Like Xu
2021-01-04 13:15 ` [PATCH v3 09/17] KVM: x86: Set PEBS_UNAVAIL in IA32_MISC_ENABLE when PEBS is enabled Like Xu
2021-01-04 13:15 ` [PATCH v3 10/17] KVM: x86/pmu: Expose CPUIDs feature bits PDCM, DS, DTES64 Like Xu
2021-01-04 13:15 ` [PATCH v3 11/17] KVM: x86/pmu: Adjust precise_ip to emulate Ice Lake guest PDIR counter Like Xu
2021-01-04 13:15 ` [PATCH v3 12/17] KVM: x86/pmu: Disable guest PEBS when counters are cross-mapped Like Xu
2021-01-04 13:15 ` Like Xu [this message]
2021-01-04 13:15 ` [PATCH v3 14/17] KVM: vmx/pmu: Limit pebs_interrupt_threshold in the guest DS area Like Xu
2021-01-04 13:15 ` [PATCH v3 15/17] KVM: vmx/pmu: Rewrite applicable_counters field in guest PEBS records Like Xu
2021-01-04 13:15 ` [PATCH v3 16/17] KVM: x86/pmu: Save guest pebs reset values when pebs is configured Like Xu
2021-01-04 13:15 ` [PATCH v3 17/17] KVM: x86/pmu: Adjust guest pebs reset values for crpss-mapped counters Like Xu
2021-01-14 19:10 ` [PATCH v3 00/17] KVM: x86/pmu: Add support to enable Guest PEBS via DS Sean Christopherson
2021-01-15  2:02   ` Xu, Like
2021-01-15 17:57     ` Sean Christopherson
2021-01-15 18:27       ` Andi Kleen
2021-01-15 18:51         ` Sean Christopherson
2021-01-15 19:11           ` Andi Kleen
2021-01-22  9:56           ` Peter Zijlstra
2021-01-25  8:08             ` Like Xu
2021-01-25 11:13               ` Peter Zijlstra
2021-01-25 12:07                 ` Xu, Like
2021-01-25 12:18                   ` Peter Zijlstra
2021-01-25 12:53                     ` Xu, Like

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