commit 80b7706e4cbaa51d65bd6fea83bd0e59856f50e9
author Joerg Roedel <joerg.roedel@amd.com> Fri Mar 30 17:02:14 2007 +0300
committer Avi Kivity <avi@qumranet.com> Thu May 03 10:52:28 2007 +0300
tree c688c8b9cd07c2555facd657e8e8e3ed508b93be
parent b8836737d92c139be770eae3d6574e33d1224caf

KVM: SVM: enable LBRV virtualization if available

This patch enables the virtualization of the last branch record MSRs on
SVM if this feature is available in hardware. It also introduces a small
and simple check feature for specific SVM extensions.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

drivers/kvm/svm.c

diff --git a/drivers/kvm/svm.c b/drivers/kvm/svm.c
index 303e959..b7e1410 100644
--- a/drivers/kvm/svm.c
+++ b/drivers/kvm/svm.c
@@ -44,6 +44,10 @@
 #define KVM_EFER_LMA (1 << 10)
 #define KVM_EFER_LME (1 << 8)
 
+#define SVM_FEATURE_NPT  (1 << 0)
+#define SVM_FEATURE_LBRV (1 << 1)
+#define SVM_DEATURE_SVML (1 << 2)
+
 unsigned long iopm_base;
 unsigned long msrpm_base;
 
@@ -68,6 +72,7 @@
 };
 
 static DEFINE_PER_CPU(struct svm_cpu_data *, svm_data);
+static uint32_t svm_features;
 
 struct svm_init_data {
 	int cpu;
@@ -82,6 +87,11 @@
 
 #define MAX_INST_SIZE 15
 
+static inline u32 svm_has(u32 feat)
+{
+	return svm_features & feat;
+}
+
 static unsigned get_addr_size(struct kvm_vcpu *vcpu)
 {
 	struct vmcb_save_area *sa = &vcpu->svm->vmcb->save;
@@ -302,6 +312,7 @@
 	svm_data->asid_generation = 1;
 	svm_data->max_asid = cpuid_ebx(SVM_CPUID_FUNC) - 1;
 	svm_data->next_asid = svm_data->max_asid + 1;
+	svm_features = cpuid_edx(SVM_CPUID_FUNC);
 
 	asm volatile ( "sgdt %0" : "=m"(gdt_descr) );
 	gdt = (struct desc_struct *)gdt_descr.address;
@@ -511,6 +522,8 @@
 	control->msrpm_base_pa = msrpm_base;
 	control->tsc_offset = 0;
 	control->int_ctl = V_INTR_MASKING_MASK;
+	if (svm_has(SVM_FEATURE_LBRV))
+		control->lbr_ctl = 1ULL;
 
 	init_seg(&save->es);
 	init_seg(&save->ss);