linux-kernel - [PATCH v2 1/2] KVM: x86: Inject PMI for KVM guest

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Date:   Mon, 18 Feb 2019 19:26:07 -0500
From:   Luwei Kang <luwei.kang@...el.com>
To:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:     tglx@...utronix.de, mingo@...hat.com, bp@...en8.de, hpa@...or.com,
        x86@...nel.org, pbonzini@...hat.com, rkrcmar@...hat.com,
        peterz@...radead.org, acme@...nel.org,
        alexander.shishkin@...ux.intel.com, jolsa@...hat.com,
        namhyung@...nel.org, kan.liang@...ux.intel.com, ak@...ux.intel.com,
        konrad.wilk@...cle.com, Janakarajan.Natarajan@....com,
        mattst88@...il.com, tim.c.chen@...ux.intel.com,
        Luwei Kang <luwei.kang@...el.com>
Subject: [PATCH v2 1/2] KVM: x86: Inject PMI for KVM guest

Inject a PMI for KVM guest when Intel PT working
in Host-Guest mode and Guest ToPA entry memory buffer
was completely filled.

Signed-off-by: Luwei Kang <luwei.kang@...el.com>
---
 arch/x86/events/intel/core.c     |  6 +++++-
 arch/x86/include/asm/msr-index.h |  4 ++++
 arch/x86/kvm/x86.c               | 10 ++++++++++
 include/linux/perf_event.h       |  1 +
 4 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index 730978d..37cecff 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -2273,7 +2273,11 @@ static int handle_pmi_common(struct pt_regs *regs, u64 status)
 	 */
 	if (__test_and_clear_bit(55, (unsigned long *)&status)) {
 		handled++;
-		intel_pt_interrupt();
+		if (unlikely(perf_guest_cbs && perf_guest_cbs->is_in_guest() &&
+			perf_guest_cbs->handle_intel_pt_intr))
+			perf_guest_cbs->handle_intel_pt_intr();
+		else
+			intel_pt_interrupt();
 	}
 
 	/*
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index 8e40c24..ae01fb0 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -775,6 +775,10 @@
 #define MSR_CORE_PERF_GLOBAL_CTRL	0x0000038f
 #define MSR_CORE_PERF_GLOBAL_OVF_CTRL	0x00000390
 
+/* PERF_GLOBAL_OVF_CTL bits */
+#define MSR_CORE_PERF_GLOBAL_OVF_CTRL_TRACE_TOPA_PMI_BIT	55
+#define MSR_CORE_PERF_GLOBAL_OVF_CTRL_TRACE_TOPA_PMI		(1ULL << MSR_CORE_PERF_GLOBAL_OVF_CTRL_TRACE_TOPA_PMI_BIT)
+
 /* Geode defined MSRs */
 #define MSR_GEODE_BUSCONT_CONF0		0x00001900
 
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 941f932..d1f4e0a 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6795,10 +6795,20 @@ static unsigned long kvm_get_guest_ip(void)
 	return ip;
 }
 
+static void kvm_handle_intel_pt_intr(void)
+{
+	struct kvm_vcpu *vcpu = __this_cpu_read(current_vcpu);
+
+	kvm_make_request(KVM_REQ_PMI, vcpu);
+	__set_bit(MSR_CORE_PERF_GLOBAL_OVF_CTRL_TRACE_TOPA_PMI_BIT,
+			(unsigned long *)&vcpu->arch.pmu.global_status);
+}
+
 static struct perf_guest_info_callbacks kvm_guest_cbs = {
 	.is_in_guest		= kvm_is_in_guest,
 	.is_user_mode		= kvm_is_user_mode,
 	.get_guest_ip		= kvm_get_guest_ip,
+	.handle_intel_pt_intr	= kvm_handle_intel_pt_intr,
 };
 
 static void kvm_set_mmio_spte_mask(void)
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index e1a0517..2b26a34 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -30,6 +30,7 @@ struct perf_guest_info_callbacks {
 	int				(*is_in_guest)(void);
 	int				(*is_user_mode)(void);
 	unsigned long			(*get_guest_ip)(void);
+	void				(*handle_intel_pt_intr)(void);
 };
 
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
-- 
1.8.3.1