Re: [PATCH v2 12/12] RISC-V: KVM: Pass VMID as parameter to kvm_riscv_hfence_xyz() APIs

From: Atish Patra
Date: Sat Jun 14 2025 - 15:18:31 EST




On 6/14/25 12:12 PM, Atish Patra wrote:

On 6/12/25 11:57 PM, Anup Patel wrote:
Currently, all kvm_riscv_hfence_xyz() APIs assume VMID to be the
host VMID of the Guest/VM which resticts use of these APIs only
for host TLB maintenance. Let's allow passing VMID as a parameter
to all kvm_riscv_hfence_xyz() APIs so that they can be re-used
for nested virtualization related TLB maintenance.

Signed-off-by: Anup Patel <apatel@xxxxxxxxxxxxxxxx>
---
  arch/riscv/include/asm/kvm_tlb.h  | 17 ++++++---
  arch/riscv/kvm/gstage.c           |  3 +-
  arch/riscv/kvm/tlb.c              | 61 ++++++++++++++++++++-----------
  arch/riscv/kvm/vcpu_sbi_replace.c | 17 +++++----
  arch/riscv/kvm/vcpu_sbi_v01.c     | 25 ++++++-------
  5 files changed, 73 insertions(+), 50 deletions(-)

diff --git a/arch/riscv/include/asm/kvm_tlb.h b/arch/riscv/include/ asm/kvm_tlb.h
index f67e03edeaec..38a2f933ad3a 100644
--- a/arch/riscv/include/asm/kvm_tlb.h
+++ b/arch/riscv/include/asm/kvm_tlb.h
@@ -11,9 +11,11 @@
  enum kvm_riscv_hfence_type {
      KVM_RISCV_HFENCE_UNKNOWN = 0,
      KVM_RISCV_HFENCE_GVMA_VMID_GPA,
+    KVM_RISCV_HFENCE_GVMA_VMID_ALL,
      KVM_RISCV_HFENCE_VVMA_ASID_GVA,
      KVM_RISCV_HFENCE_VVMA_ASID_ALL,
      KVM_RISCV_HFENCE_VVMA_GVA,
+    KVM_RISCV_HFENCE_VVMA_ALL
  };
  struct kvm_riscv_hfence {
@@ -59,21 +61,24 @@ void kvm_riscv_fence_i(struct kvm *kvm,
  void kvm_riscv_hfence_gvma_vmid_gpa(struct kvm *kvm,
                      unsigned long hbase, unsigned long hmask,
                      gpa_t gpa, gpa_t gpsz,
-                    unsigned long order);
+                    unsigned long order, unsigned long vmid);
  void kvm_riscv_hfence_gvma_vmid_all(struct kvm *kvm,
-                    unsigned long hbase, unsigned long hmask);
+                    unsigned long hbase, unsigned long hmask,
+                    unsigned long vmid);
  void kvm_riscv_hfence_vvma_asid_gva(struct kvm *kvm,
                      unsigned long hbase, unsigned long hmask,
                      unsigned long gva, unsigned long gvsz,
-                    unsigned long order, unsigned long asid);
+                    unsigned long order, unsigned long asid,
+                    unsigned long vmid);
  void kvm_riscv_hfence_vvma_asid_all(struct kvm *kvm,
                      unsigned long hbase, unsigned long hmask,
-                    unsigned long asid);
+                    unsigned long asid, unsigned long vmid);
  void kvm_riscv_hfence_vvma_gva(struct kvm *kvm,
                     unsigned long hbase, unsigned long hmask,
                     unsigned long gva, unsigned long gvsz,
-                   unsigned long order);
+                   unsigned long order, unsigned long vmid);
  void kvm_riscv_hfence_vvma_all(struct kvm *kvm,
-                   unsigned long hbase, unsigned long hmask);
+                   unsigned long hbase, unsigned long hmask,
+                   unsigned long vmid);
  #endif
diff --git a/arch/riscv/kvm/gstage.c b/arch/riscv/kvm/gstage.c
index 9c7c44f09b05..24c270d6d0e2 100644
--- a/arch/riscv/kvm/gstage.c
+++ b/arch/riscv/kvm/gstage.c
@@ -117,7 +117,8 @@ static void gstage_tlb_flush(struct kvm_gstage *gstage, u32 level, gpa_t addr)
      if (gstage->flags & KVM_GSTAGE_FLAGS_LOCAL)
          kvm_riscv_local_hfence_gvma_vmid_gpa(gstage->vmid, addr, BIT(order), order);
      else
-        kvm_riscv_hfence_gvma_vmid_gpa(gstage->kvm, -1UL, 0, addr, BIT(order), order);
+        kvm_riscv_hfence_gvma_vmid_gpa(gstage->kvm, -1UL, 0, addr, BIT(order), order,
+                           gstage->vmid);
  }
  int kvm_riscv_gstage_set_pte(struct kvm_gstage *gstage,
diff --git a/arch/riscv/kvm/tlb.c b/arch/riscv/kvm/tlb.c
index 349fcfc93f54..3c5a70a2b927 100644
--- a/arch/riscv/kvm/tlb.c
+++ b/arch/riscv/kvm/tlb.c
@@ -251,6 +251,12 @@ void kvm_riscv_hfence_process(struct kvm_vcpu *vcpu)
                  kvm_riscv_local_hfence_gvma_vmid_gpa(d.vmid, d.addr,
                                       d.size, d.order);
              break;
+        case KVM_RISCV_HFENCE_GVMA_VMID_ALL:
+            if (kvm_riscv_nacl_available())
+                nacl_hfence_gvma_vmid_all(nacl_shmem(), d.vmid);
+            else
+                kvm_riscv_local_hfence_gvma_vmid_all(d.vmid);
+            break;
          case KVM_RISCV_HFENCE_VVMA_ASID_GVA:
              kvm_riscv_vcpu_pmu_incr_fw(vcpu, SBI_PMU_FW_HFENCE_VVMA_ASID_RCVD);
              if (kvm_riscv_nacl_available())
@@ -276,6 +282,13 @@ void kvm_riscv_hfence_process(struct kvm_vcpu *vcpu)
                  kvm_riscv_local_hfence_vvma_gva(d.vmid, d.addr,
                                  d.size, d.order);
              break;
+        case KVM_RISCV_HFENCE_VVMA_ALL:
+            kvm_riscv_vcpu_pmu_incr_fw(vcpu, SBI_PMU_FW_HFENCE_VVMA_RCVD);
+            if (kvm_riscv_nacl_available())
+                nacl_hfence_vvma_all(nacl_shmem(), d.vmid);
+            else
+                kvm_riscv_local_hfence_vvma_all(d.vmid);
+            break;
          default:
              break;
          }
@@ -328,14 +341,13 @@ void kvm_riscv_fence_i(struct kvm *kvm,
  void kvm_riscv_hfence_gvma_vmid_gpa(struct kvm *kvm,
                      unsigned long hbase, unsigned long hmask,
                      gpa_t gpa, gpa_t gpsz,
-                    unsigned long order)
+                    unsigned long order, unsigned long vmid)
  {
-    struct kvm_vmid *v = &kvm->arch.vmid;
      struct kvm_riscv_hfence data;
      data.type = KVM_RISCV_HFENCE_GVMA_VMID_GPA;
      data.asid = 0;
-    data.vmid = READ_ONCE(v->vmid);
+    data.vmid = vmid;
      data.addr = gpa;
      data.size = gpsz;
      data.order = order;
@@ -344,23 +356,28 @@ void kvm_riscv_hfence_gvma_vmid_gpa(struct kvm *kvm,
  }
  void kvm_riscv_hfence_gvma_vmid_all(struct kvm *kvm,
-                    unsigned long hbase, unsigned long hmask)
+                    unsigned long hbase, unsigned long hmask,
+                    unsigned long vmid)
  {
-    make_xfence_request(kvm, hbase, hmask, KVM_REQ_TLB_FLUSH,
-                KVM_REQ_TLB_FLUSH, NULL);
+    struct kvm_riscv_hfence data = {0};
+
+    data.type = KVM_RISCV_HFENCE_GVMA_VMID_ALL;
+    data.vmid = vmid;
+    make_xfence_request(kvm, hbase, hmask, KVM_REQ_HFENCE,
+                KVM_REQ_TLB_FLUSH, &data);
  }
  void kvm_riscv_hfence_vvma_asid_gva(struct kvm *kvm,
                      unsigned long hbase, unsigned long hmask,
                      unsigned long gva, unsigned long gvsz,
-                    unsigned long order, unsigned long asid)
+                    unsigned long order, unsigned long asid,
+                    unsigned long vmid)
  {
-    struct kvm_vmid *v = &kvm->arch.vmid;
      struct kvm_riscv_hfence data;
      data.type = KVM_RISCV_HFENCE_VVMA_ASID_GVA;
      data.asid = asid;
-    data.vmid = READ_ONCE(v->vmid);
+    data.vmid = vmid;
      data.addr = gva;
      data.size = gvsz;
      data.order = order;
@@ -370,15 +387,13 @@ void kvm_riscv_hfence_vvma_asid_gva(struct kvm *kvm,
  void kvm_riscv_hfence_vvma_asid_all(struct kvm *kvm,
                      unsigned long hbase, unsigned long hmask,
-                    unsigned long asid)
+                    unsigned long asid, unsigned long vmid)
  {
-    struct kvm_vmid *v = &kvm->arch.vmid;
-    struct kvm_riscv_hfence data;
+    struct kvm_riscv_hfence data = {0};
      data.type = KVM_RISCV_HFENCE_VVMA_ASID_ALL;
      data.asid = asid;
-    data.vmid = READ_ONCE(v->vmid);
-    data.addr = data.size = data.order = 0;
+    data.vmid = vmid;
      make_xfence_request(kvm, hbase, hmask, KVM_REQ_HFENCE,
                  KVM_REQ_HFENCE_VVMA_ALL, &data);
  }
@@ -386,14 +401,13 @@ void kvm_riscv_hfence_vvma_asid_all(struct kvm *kvm,
  void kvm_riscv_hfence_vvma_gva(struct kvm *kvm,
                     unsigned long hbase, unsigned long hmask,
                     unsigned long gva, unsigned long gvsz,
-                   unsigned long order)
+                   unsigned long order, unsigned long vmid)
  {
-    struct kvm_vmid *v = &kvm->arch.vmid;
      struct kvm_riscv_hfence data;
      data.type = KVM_RISCV_HFENCE_VVMA_GVA;
      data.asid = 0;
-    data.vmid = READ_ONCE(v->vmid);
+    data.vmid = vmid;
      data.addr = gva;
      data.size = gvsz;
      data.order = order;
@@ -402,16 +416,21 @@ void kvm_riscv_hfence_vvma_gva(struct kvm *kvm,
  }
  void kvm_riscv_hfence_vvma_all(struct kvm *kvm,
-                   unsigned long hbase, unsigned long hmask)
+                   unsigned long hbase, unsigned long hmask,
+                   unsigned long vmid)
  {
-    make_xfence_request(kvm, hbase, hmask, KVM_REQ_HFENCE_VVMA_ALL,
-                KVM_REQ_HFENCE_VVMA_ALL, NULL);
+    struct kvm_riscv_hfence data = {0};
+
+    data.type = KVM_RISCV_HFENCE_VVMA_ALL;
+    data.vmid = vmid;
+    make_xfence_request(kvm, hbase, hmask, KVM_REQ_HFENCE,
+                KVM_REQ_HFENCE_VVMA_ALL, &data);
  }
  int kvm_arch_flush_remote_tlbs_range(struct kvm *kvm, gfn_t gfn, u64 nr_pages)
  {
      kvm_riscv_hfence_gvma_vmid_gpa(kvm, -1UL, 0,
                         gfn << PAGE_SHIFT, nr_pages << PAGE_SHIFT,
-                       PAGE_SHIFT);
+                       PAGE_SHIFT, READ_ONCE(kvm->arch.vmid.vmid));
      return 0;
  }
diff --git a/arch/riscv/kvm/vcpu_sbi_replace.c b/arch/riscv/kvm/ vcpu_sbi_replace.c
index b17fad091bab..b490ed1428a6 100644
--- a/arch/riscv/kvm/vcpu_sbi_replace.c
+++ b/arch/riscv/kvm/vcpu_sbi_replace.c
@@ -96,6 +96,7 @@ static int kvm_sbi_ext_rfence_handler(struct kvm_vcpu *vcpu, struct kvm_run *run
      unsigned long hmask = cp->a0;
      unsigned long hbase = cp->a1;
      unsigned long funcid = cp->a6;
+    unsigned long vmid;
      switch (funcid) {
      case SBI_EXT_RFENCE_REMOTE_FENCE_I:
@@ -103,22 +104,22 @@ static int kvm_sbi_ext_rfence_handler(struct kvm_vcpu *vcpu, struct kvm_run *run
          kvm_riscv_vcpu_pmu_incr_fw(vcpu, SBI_PMU_FW_FENCE_I_SENT);
          break;
      case SBI_EXT_RFENCE_REMOTE_SFENCE_VMA:
+        vmid = READ_ONCE(vcpu->kvm->arch.vmid.vmid);
          if ((cp->a2 == 0 && cp->a3 == 0) || cp->a3 == -1UL)
-            kvm_riscv_hfence_vvma_all(vcpu->kvm, hbase, hmask);
+            kvm_riscv_hfence_vvma_all(vcpu->kvm, hbase, hmask, vmid);

This patch doesn't apply cleanly on 6.16-rc1.

<<<<<<< HEAD
                if (cp->a2 == 0 && cp->a3 == 0)
                        kvm_riscv_hfence_vvma_all(vcpu->kvm, hbase, hmask);
=======
                vmid = READ_ONCE(vcpu->kvm->arch.vmid.vmid);
                if ((cp->a2 == 0 && cp->a3 == 0) || cp->a3 == -1UL)
                        kvm_riscv_hfence_vvma_all(vcpu->kvm, hbase, hmask, vmid);
>>>>>>> 57ec61198cc1 (RISC-V: KVM: Pass VMID as parameter to kvm_riscv_hfence_xyz() APIs)
else
                        kvm_riscv_hfence_vvma_gva(vcpu->kvm, hbase, hmask,
                                                  cp->a2, cp->a3, PAGE_SHIFT, vmid);
                kvm_riscv_vcpu_pmu_incr_fw(vcpu, SBI_PMU_FW_HFENCE_VVMA_SENT);
break;
        case SBI_EXT_RFENCE_REMOTE_SFENCE_VMA_ASID:
<<<<<<< HEAD
                if (cp->a2 == 0 && cp->a3 == 0)
kvm_riscv_hfence_vvma_asid_all(vcpu->kvm,
                                                       hbase, hmask, cp->a4);
=======
                vmid = READ_ONCE(vcpu->kvm->arch.vmid.vmid);
                if ((cp->a2 == 0 && cp->a3 == 0) || cp->a3 == -1UL)
kvm_riscv_hfence_vvma_asid_all(vcpu->kvm, hbase, hmask,
                                                       cp->a4, vmid);
>>>>>>> 57ec61198cc1 (RISC-V: KVM: Pass VMID as parameter to kvm_riscv_hfence_xyz() APIs)



ohh you already queued the PATCH1 from v1 of this series. If I try to rebase on top of riscv_kvm_queue, I see the following error in b4 shazam.

---
Patch failed at 0008 RISC-V: KVM: Factor-out MMU related declarations into separate headers.
----

          else
              kvm_riscv_hfence_vvma_gva(vcpu->kvm, hbase, hmask,
-                          cp->a2, cp->a3, PAGE_SHIFT);
+                          cp->a2, cp->a3, PAGE_SHIFT, vmid);
          kvm_riscv_vcpu_pmu_incr_fw(vcpu, SBI_PMU_FW_HFENCE_VVMA_SENT);
          break;
      case SBI_EXT_RFENCE_REMOTE_SFENCE_VMA_ASID:
+        vmid = READ_ONCE(vcpu->kvm->arch.vmid.vmid);
          if ((cp->a2 == 0 && cp->a3 == 0) || cp->a3 == -1UL)
-            kvm_riscv_hfence_vvma_asid_all(vcpu->kvm,
-                               hbase, hmask, cp->a4);
+            kvm_riscv_hfence_vvma_asid_all(vcpu->kvm, hbase, hmask,
+                               cp->a4, vmid);
          else
-            kvm_riscv_hfence_vvma_asid_gva(vcpu->kvm,
-                               hbase, hmask,
-                               cp->a2, cp->a3,
-                               PAGE_SHIFT, cp->a4);
+            kvm_riscv_hfence_vvma_asid_gva(vcpu->kvm, hbase, hmask, cp->a2,
+                               cp->a3, PAGE_SHIFT, cp->a4, vmid);
          kvm_riscv_vcpu_pmu_incr_fw(vcpu, SBI_PMU_FW_HFENCE_VVMA_ASID_SENT);
          break;
      case SBI_EXT_RFENCE_REMOTE_HFENCE_GVMA:
diff --git a/arch/riscv/kvm/vcpu_sbi_v01.c b/arch/riscv/kvm/ vcpu_sbi_v01.c
index 8f4c4fa16227..368dfddd23d9 100644
--- a/arch/riscv/kvm/vcpu_sbi_v01.c
+++ b/arch/riscv/kvm/vcpu_sbi_v01.c
@@ -23,6 +23,7 @@ static int kvm_sbi_ext_v01_handler(struct kvm_vcpu *vcpu, struct kvm_run *run,
      struct kvm *kvm = vcpu->kvm;
      struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
      struct kvm_cpu_trap *utrap = retdata->utrap;
+    unsigned long vmid;
      switch (cp->a7) {
      case SBI_EXT_0_1_CONSOLE_GETCHAR:
@@ -78,25 +79,21 @@ static int kvm_sbi_ext_v01_handler(struct kvm_vcpu *vcpu, struct kvm_run *run,
          if (cp->a7 == SBI_EXT_0_1_REMOTE_FENCE_I)
              kvm_riscv_fence_i(vcpu->kvm, 0, hmask);
          else if (cp->a7 == SBI_EXT_0_1_REMOTE_SFENCE_VMA) {
+            vmid = READ_ONCE(vcpu->kvm->arch.vmid.vmid);
              if (cp->a1 == 0 && cp->a2 == 0)
-                kvm_riscv_hfence_vvma_all(vcpu->kvm,
-                              0, hmask);
+                kvm_riscv_hfence_vvma_all(vcpu->kvm, 0, hmask, vmid);
              else
-                kvm_riscv_hfence_vvma_gva(vcpu->kvm,
-                              0, hmask,
-                              cp->a1, cp->a2,
-                              PAGE_SHIFT);
+                kvm_riscv_hfence_vvma_gva(vcpu->kvm, 0, hmask, cp->a1,
+                              cp->a2, PAGE_SHIFT, vmid);
          } else {
+            vmid = READ_ONCE(vcpu->kvm->arch.vmid.vmid);
              if (cp->a1 == 0 && cp->a2 == 0)
-                kvm_riscv_hfence_vvma_asid_all(vcpu->kvm,
-                                   0, hmask,
-                                   cp->a3);
+                kvm_riscv_hfence_vvma_asid_all(vcpu->kvm, 0, hmask,
+                                   cp->a3, vmid);
              else
-                kvm_riscv_hfence_vvma_asid_gva(vcpu->kvm,
-                                   0, hmask,
-                                   cp->a1, cp->a2,
-                                   PAGE_SHIFT,
-                                   cp->a3);
+                kvm_riscv_hfence_vvma_asid_gva(vcpu->kvm, 0, hmask,
+                                   cp->a1, cp->a2, PAGE_SHIFT,
+                                   cp->a3, vmid);
          }
          break;
      default: