From: Anup Patel <apatel@ventanamicro.com>
To: Atish Patra <atish.patra@linux.dev>
Cc: Palmer Dabbelt <palmer@dabbelt.com>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	Alexandre Ghiti <alex@ghiti.fr>,
	Andrew Jones <ajones@ventanamicro.com>,
	Anup Patel <anup@brainfault.org>,
	kvm@vger.kernel.org,
	kvm-riscv@lists.infradead.org,
	linux-riscv@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	Anup Patel <apatel@ventanamicro.com>,
	Atish Patra <atishp@rivosinc.com>,
	Nutty Liu <liujingqi@lanxincomputing.com>
Subject: [PATCH v3 03/12] RISC-V: KVM: Rename and move kvm_riscv_local_tlb_sanitize()
Date: Wed, 18 Jun 2025 17:05:23 +0530
Message-ID: <20250618113532.471448-4-apatel@ventanamicro.com>
In-Reply-To: <20250618113532.471448-1-apatel@ventanamicro.com>
References: <20250618113532.471448-1-apatel@ventanamicro.com>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

The kvm_riscv_local_tlb_sanitize() deals with sanitizing current
VMID related TLB mappings when a VCPU is moved from one host CPU
to another.

Let's move kvm_riscv_local_tlb_sanitize() to VMID management
sources and rename it to kvm_riscv_gstage_vmid_sanitize().

Reviewed-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Nutty Liu<liujingqi@lanxincomputing.com>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 arch/riscv/include/asm/kvm_host.h |  3 +--
 arch/riscv/kvm/tlb.c              | 23 -----------------------
 arch/riscv/kvm/vcpu.c             |  4 ++--
 arch/riscv/kvm/vmid.c             | 23 +++++++++++++++++++++++
 4 files changed, 26 insertions(+), 27 deletions(-)

diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h
index 9a617bf5363d..8aa705ac75a5 100644
--- a/arch/riscv/include/asm/kvm_host.h
+++ b/arch/riscv/include/asm/kvm_host.h
@@ -331,8 +331,6 @@ void kvm_riscv_local_hfence_vvma_gva(unsigned long vmid,
 				     unsigned long order);
 void kvm_riscv_local_hfence_vvma_all(unsigned long vmid);
 
-void kvm_riscv_local_tlb_sanitize(struct kvm_vcpu *vcpu);
-
 void kvm_riscv_fence_i_process(struct kvm_vcpu *vcpu);
 void kvm_riscv_hfence_gvma_vmid_all_process(struct kvm_vcpu *vcpu);
 void kvm_riscv_hfence_vvma_all_process(struct kvm_vcpu *vcpu);
@@ -380,6 +378,7 @@ unsigned long kvm_riscv_gstage_vmid_bits(void);
 int kvm_riscv_gstage_vmid_init(struct kvm *kvm);
 bool kvm_riscv_gstage_vmid_ver_changed(struct kvm_vmid *vmid);
 void kvm_riscv_gstage_vmid_update(struct kvm_vcpu *vcpu);
+void kvm_riscv_gstage_vmid_sanitize(struct kvm_vcpu *vcpu);
 
 int kvm_riscv_setup_default_irq_routing(struct kvm *kvm, u32 lines);
 
diff --git a/arch/riscv/kvm/tlb.c b/arch/riscv/kvm/tlb.c
index 2f91ea5f8493..b3461bfd9756 100644
--- a/arch/riscv/kvm/tlb.c
+++ b/arch/riscv/kvm/tlb.c
@@ -156,29 +156,6 @@ void kvm_riscv_local_hfence_vvma_all(unsigned long vmid)
 	csr_write(CSR_HGATP, hgatp);
 }
 
-void kvm_riscv_local_tlb_sanitize(struct kvm_vcpu *vcpu)
-{
-	unsigned long vmid;
-
-	if (!kvm_riscv_gstage_vmid_bits() ||
-	    vcpu->arch.last_exit_cpu == vcpu->cpu)
-		return;
-
-	/*
-	 * On RISC-V platforms with hardware VMID support, we share same
-	 * VMID for all VCPUs of a particular Guest/VM. This means we might
-	 * have stale G-stage TLB entries on the current Host CPU due to
-	 * some other VCPU of the same Guest which ran previously on the
-	 * current Host CPU.
-	 *
-	 * To cleanup stale TLB entries, we simply flush all G-stage TLB
-	 * entries by VMID whenever underlying Host CPU changes for a VCPU.
-	 */
-
-	vmid = READ_ONCE(vcpu->kvm->arch.vmid.vmid);
-	kvm_riscv_local_hfence_gvma_vmid_all(vmid);
-}
-
 void kvm_riscv_fence_i_process(struct kvm_vcpu *vcpu)
 {
 	kvm_riscv_vcpu_pmu_incr_fw(vcpu, SBI_PMU_FW_FENCE_I_RCVD);
diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
index f9fb3dbbe0c3..a2dd4161e5a4 100644
--- a/arch/riscv/kvm/vcpu.c
+++ b/arch/riscv/kvm/vcpu.c
@@ -962,12 +962,12 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
 		}
 
 		/*
-		 * Cleanup stale TLB enteries
+		 * Sanitize VMID mappings cached (TLB) on current CPU
 		 *
 		 * Note: This should be done after G-stage VMID has been
 		 * updated using kvm_riscv_gstage_vmid_ver_changed()
 		 */
-		kvm_riscv_local_tlb_sanitize(vcpu);
+		kvm_riscv_gstage_vmid_sanitize(vcpu);
 
 		trace_kvm_entry(vcpu);
 
diff --git a/arch/riscv/kvm/vmid.c b/arch/riscv/kvm/vmid.c
index ddc98714ce8e..92c01255f86f 100644
--- a/arch/riscv/kvm/vmid.c
+++ b/arch/riscv/kvm/vmid.c
@@ -122,3 +122,26 @@ void kvm_riscv_gstage_vmid_update(struct kvm_vcpu *vcpu)
 	kvm_for_each_vcpu(i, v, vcpu->kvm)
 		kvm_make_request(KVM_REQ_UPDATE_HGATP, v);
 }
+
+void kvm_riscv_gstage_vmid_sanitize(struct kvm_vcpu *vcpu)
+{
+	unsigned long vmid;
+
+	if (!kvm_riscv_gstage_vmid_bits() ||
+	    vcpu->arch.last_exit_cpu == vcpu->cpu)
+		return;
+
+	/*
+	 * On RISC-V platforms with hardware VMID support, we share same
+	 * VMID for all VCPUs of a particular Guest/VM. This means we might
+	 * have stale G-stage TLB entries on the current Host CPU due to
+	 * some other VCPU of the same Guest which ran previously on the
+	 * current Host CPU.
+	 *
+	 * To cleanup stale TLB entries, we simply flush all G-stage TLB
+	 * entries by VMID whenever underlying Host CPU changes for a VCPU.
+	 */
+
+	vmid = READ_ONCE(vcpu->kvm->arch.vmid.vmid);
+	kvm_riscv_local_hfence_gvma_vmid_all(vmid);
+}
-- 
2.43.0