KVM: VMX: Add support for guest/host-only profiling

Support guest/host-only profiling by switch perf msrs on
a guest entry if needed.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 55e849b52d9efaef691cebdea2ba9194c71449ca..98f4b0bcc660214696f0316a3f3492a11ddca8eb 100644 (file)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -39,6 +39,7 @@
 #include <asm/mce.h>
 #include <asm/i387.h>
 #include <asm/xcr.h>
+#include <asm/perf_event.h>
 
 #include "trace.h"
 
@@ -6050,6 +6051,24 @@ static void vmx_cancel_injection(struct kvm_vcpu *vcpu)
        vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, 0);
 }
 
+static void atomic_switch_perf_msrs(struct vcpu_vmx *vmx)
+{
+       int i, nr_msrs;
+       struct perf_guest_switch_msr *msrs;
+
+       msrs = perf_guest_get_msrs(&nr_msrs);
+
+       if (!msrs)
+               return;
+
+       for (i = 0; i < nr_msrs; i++)
+               if (msrs[i].host == msrs[i].guest)
+                       clear_atomic_switch_msr(vmx, msrs[i].msr);
+               else
+                       add_atomic_switch_msr(vmx, msrs[i].msr, msrs[i].guest,
+                                       msrs[i].host);
+}
+
 #ifdef CONFIG_X86_64
 #define R "r"
 #define Q "q"
@@ -6099,6 +6118,8 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
        if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP)
                vmx_set_interrupt_shadow(vcpu, 0);
 
+       atomic_switch_perf_msrs(vmx);
+
        vmx->__launched = vmx->loaded_vmcs->launched;
        asm(
                /* Store host registers */