KVM: SVM: Implement Flush-By-Asid feature

This patch adds the new flush-by-asid of upcoming AMD
processors to the KVM-AMD module.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

arch/x86/include/asm/svm.h

@@ -88,6 +88,8 @@ struct __attribute__ ((__packed__)) vmcb_control_area {
 
 #define TLB_CONTROL_DO_NOTHING 0
 #define TLB_CONTROL_FLUSH_ALL_ASID 1
+#define TLB_CONTROL_FLUSH_ASID 3
+#define TLB_CONTROL_FLUSH_ASID_LOCAL 7
 
 #define V_TPR_MASK 0x0f
 

arch/x86/kvm/svm.c

@@ -3158,7 +3158,6 @@ static void pre_svm_run(struct vcpu_svm *svm)
 
 	struct svm_cpu_data *sd = per_cpu(svm_data, cpu);
 
-	svm->vmcb->control.tlb_ctl = TLB_CONTROL_DO_NOTHING;
 	/* FIXME: handle wraparound of asid_generation */
 	if (svm->asid_generation != sd->asid_generation)
 		new_asid(svm, sd);
@@ -3303,7 +3302,12 @@ static int svm_set_tss_addr(struct kvm *kvm, unsigned int addr)
 
 static void svm_flush_tlb(struct kvm_vcpu *vcpu)
 {
-	to_svm(vcpu)->asid_generation--;
+	struct vcpu_svm *svm = to_svm(vcpu);
+
+	if (static_cpu_has(X86_FEATURE_FLUSHBYASID))
+		svm->vmcb->control.tlb_ctl = TLB_CONTROL_FLUSH_ASID;
+	else
+		svm->asid_generation--;
 }
 
 static void svm_prepare_guest_switch(struct kvm_vcpu *vcpu)
@@ -3529,6 +3533,8 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu)
 
 	svm->next_rip = 0;
 
+	svm->vmcb->control.tlb_ctl = TLB_CONTROL_DO_NOTHING;
+
 	/* if exit due to PF check for async PF */
 	if (svm->vmcb->control.exit_code == SVM_EXIT_EXCP_BASE + PF_VECTOR)
 		svm->apf_reason = kvm_read_and_reset_pf_reason();