KVM: X86: Introduce a tdp_set_cr3 function

This patch introduces a special set_tdp_cr3 function pointer
in kvm_x86_ops which is only used for tpd enabled mmu
contexts. This allows to remove some hacks from svm code.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

arch/x86/include/asm/kvm_host.h

@@ -526,6 +526,8 @@ struct kvm_x86_ops {
 	bool (*rdtscp_supported)(void);
 	void (*adjust_tsc_offset)(struct kvm_vcpu *vcpu, s64 adjustment);
 
+	void (*set_tdp_cr3)(struct kvm_vcpu *vcpu, unsigned long cr3);
+
 	void (*set_supported_cpuid)(u32 func, struct kvm_cpuid_entry2 *entry);
 
 	bool (*has_wbinvd_exit)(void);

arch/x86/kvm/mmu.c

@@ -2714,7 +2714,7 @@ static int init_kvm_tdp_mmu(struct kvm_vcpu *vcpu)
 	context->shadow_root_level = kvm_x86_ops->get_tdp_level();
 	context->root_hpa = INVALID_PAGE;
 	context->direct_map = true;
-	context->set_cr3 = kvm_x86_ops->set_cr3;
+	context->set_cr3 = kvm_x86_ops->set_tdp_cr3;
 
 	if (!is_paging(vcpu)) {
 		context->gva_to_gpa = nonpaging_gva_to_gpa;

arch/x86/kvm/svm.c

@@ -3216,9 +3216,6 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu)
 	savesegment(gs, gs_selector);
 	ldt_selector = kvm_read_ldt();
 	svm->vmcb->save.cr2 = vcpu->arch.cr2;
-	/* required for live migration with NPT */
-	if (npt_enabled)
-		svm->vmcb->save.cr3 = vcpu->arch.cr3;
 
 	clgi();
 
@@ -3340,16 +3337,22 @@ static void svm_set_cr3(struct kvm_vcpu *vcpu, unsigned long root)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
 
-	if (npt_enabled) {
-		svm->vmcb->control.nested_cr3 = root;
-		force_new_asid(vcpu);
-		return;
-	}
-
 	svm->vmcb->save.cr3 = root;
 	force_new_asid(vcpu);
 }
 
+static void set_tdp_cr3(struct kvm_vcpu *vcpu, unsigned long root)
+{
+	struct vcpu_svm *svm = to_svm(vcpu);
+
+	svm->vmcb->control.nested_cr3 = root;
+
+	/* Also sync guest cr3 here in case we live migrate */
+	svm->vmcb->save.cr3 = vcpu->arch.cr3;
+
+	force_new_asid(vcpu);
+}
+
 static int is_disabled(void)
 {
 	u64 vm_cr;
@@ -3576,6 +3579,8 @@ static struct kvm_x86_ops svm_x86_ops = {
 
 	.write_tsc_offset = svm_write_tsc_offset,
 	.adjust_tsc_offset = svm_adjust_tsc_offset,
+
+	.set_tdp_cr3 = set_tdp_cr3,
 };
 
 static int __init svm_init(void)

arch/x86/kvm/vmx.c

@@ -4341,6 +4341,8 @@ static struct kvm_x86_ops vmx_x86_ops = {
 
 	.write_tsc_offset = vmx_write_tsc_offset,
 	.adjust_tsc_offset = vmx_adjust_tsc_offset,
+
+	.set_tdp_cr3 = vmx_set_cr3,
 };
 
 static int __init vmx_init(void)