[PATCH v3 3/5] KVM: LAPIC: Expose per-vCPU timer_advance_ns to userspace

From: Wanpeng Li
Date: Wed Jun 12 2019 - 05:40:54 EST


From: Wanpeng Li <wanpengli@xxxxxxxxxxx>

Expose per-vCPU timer_advance_ns to userspace, so it is able to
query the auto-adjusted value.

Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Radim KrÄmÃÅ <rkrcmar@xxxxxxxxxx>
Cc: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Cc: Liran Alon <liran.alon@xxxxxxxxxx>
Signed-off-by: Wanpeng Li <wanpengli@xxxxxxxxxxx>
---
arch/x86/kvm/debugfs.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

diff --git a/arch/x86/kvm/debugfs.c b/arch/x86/kvm/debugfs.c
index c19c7ed..a6f1f93 100644
--- a/arch/x86/kvm/debugfs.c
+++ b/arch/x86/kvm/debugfs.c
@@ -9,12 +9,22 @@
*/
#include <linux/kvm_host.h>
#include <linux/debugfs.h>
+#include "lapic.h"

bool kvm_arch_has_vcpu_debugfs(void)
{
return true;
}

+static int vcpu_get_timer_advance_ns(void *data, u64 *val)
+{
+ struct kvm_vcpu *vcpu = (struct kvm_vcpu *) data;
+ *val = vcpu->arch.apic->lapic_timer.timer_advance_ns;
+ return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(vcpu_timer_advance_ns_fops, vcpu_get_timer_advance_ns, NULL, "%llu\n");
+
static int vcpu_get_tsc_offset(void *data, u64 *val)
{
struct kvm_vcpu *vcpu = (struct kvm_vcpu *) data;
@@ -51,6 +61,12 @@ int kvm_arch_create_vcpu_debugfs(struct kvm_vcpu *vcpu)
if (!ret)
return -ENOMEM;

+ ret = debugfs_create_file("lapic_timer_advance_ns", 0444,
+ vcpu->debugfs_dentry,
+ vcpu, &vcpu_timer_advance_ns_fops);
+ if (!ret)
+ return -ENOMEM;
+
if (kvm_has_tsc_control) {
ret = debugfs_create_file("tsc-scaling-ratio", 0444,
vcpu->debugfs_dentry,
--
2.7.4