[RFC,2/5] LoongArch: KVM: Add separate vmid feature support

Commit Message

Bibo Mao Nov. 13, 2024, 3:17 a.m. UTC

Feature cpu_has_guestid is used to check whether separate vmid/vpid
is supported or not. Also add different vmid updating function.

Signed-off-by: Bibo Mao <[e-mail]>
---
 arch/loongarch/include/asm/kvm_host.h |  2 ++
 arch/loongarch/kvm/main.c             | 30 +++++++++++++++++++++++----
 arch/loongarch/kvm/tlb.c              | 14 +++++++++++++
 3 files changed, 42 insertions(+), 4 deletions(-)

Patch

diff --git a/arch/loongarch/include/asm/kvm_host.h b/arch/loongarch/include/asm/kvm_host.h
index 6151c7c470d5..92ec3660d221 100644
--- a/arch/loongarch/include/asm/kvm_host.h
+++ b/arch/loongarch/include/asm/kvm_host.h
@@ -279,6 +279,8 @@  static inline int kvm_get_pmu_num(struct kvm_vcpu_arch *arch)
 int kvm_arch_vcpu_dump_regs(struct kvm_vcpu *vcpu);
 
 /* MMU handling */
+void kvm_flush_tlb_all_stage1(void);
+void kvm_flush_tlb_all_stage2(void);
 void kvm_flush_tlb_all(void);
 void kvm_flush_tlb_gpa(struct kvm_vcpu *vcpu, unsigned long gpa);
 int kvm_handle_mm_fault(struct kvm_vcpu *vcpu, unsigned long badv, bool write);
diff --git a/arch/loongarch/kvm/main.c b/arch/loongarch/kvm/main.c
index 8c16bff80053..afb2e10eba68 100644
--- a/arch/loongarch/kvm/main.c
+++ b/arch/loongarch/kvm/main.c
@@ -207,15 +207,17 @@  static void kvm_update_vpid(struct kvm_vcpu *vcpu, int cpu)
 		++vpid; /* vpid 0 reserved for root */
 
 		/* start new vpid cycle */
-		kvm_flush_tlb_all();
+		if (!cpu_has_guestid)
+			kvm_flush_tlb_all();
+		else
+			kvm_flush_tlb_all_stage1();
 	}
 
 	context->vpid_cache = vpid;
 	vcpu->arch.vpid = vpid;
-	vcpu->arch.vmid = vcpu->arch.vpid & vpid_mask;
 }
 
-void kvm_check_vpid(struct kvm_vcpu *vcpu)
+static void __kvm_check_vpid(struct kvm_vcpu *vcpu)
 {
 	int cpu;
 	bool migrated;
@@ -243,7 +245,6 @@  void kvm_check_vpid(struct kvm_vcpu *vcpu)
 		kvm_update_vpid(vcpu, cpu);
 		trace_kvm_vpid_change(vcpu, vcpu->arch.vpid);
 		vcpu->cpu = cpu;
-		kvm_clear_request(KVM_REQ_TLB_FLUSH_GPA, vcpu);
 	}
 
 	/* Restore GSTAT(0x50).vpid */
@@ -251,6 +252,27 @@  void kvm_check_vpid(struct kvm_vcpu *vcpu)
 	change_csr_gstat(vpid_mask << CSR_GSTAT_GID_SHIFT, vpid);
 }
 
+static void __kvm_check_vmid(struct kvm_vcpu *vcpu)
+{
+	unsigned long vmid;
+
+	/* On some machines like 3A5000, vmid needs the same with vpid */
+	if (!cpu_has_guestid) {
+		vmid = vcpu->arch.vpid & vpid_mask;
+		if (vcpu->arch.vmid != vmid) {
+			vcpu->arch.vmid = vmid;
+			kvm_clear_request(KVM_REQ_TLB_FLUSH_GPA, vcpu);
+		}
+		return;
+	}
+}
+
+void kvm_check_vpid(struct kvm_vcpu *vcpu)
+{
+	__kvm_check_vpid(vcpu);
+	__kvm_check_vmid(vcpu);
+}
+
 void kvm_init_vmcs(struct kvm *kvm)
 {
 	kvm->arch.vmcs = vmcs;
diff --git a/arch/loongarch/kvm/tlb.c b/arch/loongarch/kvm/tlb.c
index 38daf936021d..1d95e2208e82 100644
--- a/arch/loongarch/kvm/tlb.c
+++ b/arch/loongarch/kvm/tlb.c
@@ -21,6 +21,20 @@  void kvm_flush_tlb_all(void)
 	local_irq_restore(flags);
 }
 
+/* Invalidate all stage1 TLB entries including GVA-->GPA mappings */
+void kvm_flush_tlb_all_stage1(void)
+{
+	lockdep_assert_irqs_disabled();
+	invtlb_all(INVGTLB_ALLGID_GVA_TO_GPA, 0, 0);
+}
+
+/* Invalidate all stage2 TLB entries including GPA-->HPA  mappings */
+void kvm_flush_tlb_all_stage2(void)
+{
+	lockdep_assert_irqs_disabled();
+	invtlb_all(INVTLB_ALLGID_GPA_TO_HPA, 0, 0);
+}
+
 void kvm_flush_tlb_gpa(struct kvm_vcpu *vcpu, unsigned long gpa)
 {
 	unsigned int vmid;