Support guest/host-only profiling by switch perf msrs on
a guest entry if needed.
Signed-off-by: Gleb Natapov <gleb@xxxxxxxxxx>
---
arch/x86/kvm/vmx.c | 35 +++++++++++++++++++++++++++++++++++
1 files changed, 35 insertions(+), 0 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index e4cc3c2..fef7bd9 100644
--- 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"
@@ -417,6 +418,9 @@ struct vcpu_vmx {
/* Support for a guest hypervisor (nested VMX) */
struct nested_vmx nested;
+
+ int perf_msrs_cnt;
+ struct perf_guest_switch_msr *perf_msrs;
};
enum segment_cache_field {
@@ -6052,6 +6056,26 @@ 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)
+{
+#ifdef CONFIG_PERF_EVENTS
+ int i;
+
+ if (!cpu_has_arch_perfmon || vmx->perf_msrs_cnt <= 0)
+ return;
+
+ perf_guest_get_msrs(vmx->perf_msrs_cnt, vmx->perf_msrs);
+ for (i = 0; i < vmx->perf_msrs_cnt; i++) {
+ struct perf_guest_switch_msr *msr = &vmx->perf_msrs[i];
+ if (msr->host == msr->guest)
+ clear_atomic_switch_msr(vmx, msr->msr);
+ else
+ add_atomic_switch_msr(vmx, msr->msr, msr->guest,
+ msr->host);
+ }
+#endif
+}
+
#ifdef CONFIG_X86_64
#define R "r"
#define Q "q"
@@ -6101,6 +6125,8 @@ 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 */
@@ -6306,6 +6332,15 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
vmx->nested.current_vmptr = -1ull;
vmx->nested.current_vmcs12 = NULL;
+ vmx->perf_msrs_cnt = perf_guest_get_msrs_count();
+ if (vmx->perf_msrs_cnt > 0) {
+ vmx->perf_msrs = kmalloc(vmx->perf_msrs_cnt *
+ sizeof(struct perf_guest_switch_msr),
+ GFP_KERNEL);
+ if (!vmx->perf_msrs)
+ goto free_vmcs;
+ }
+
return &vmx->vcpu;
free_vmcs:
--
1.7.5.3
--
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