From: Hui Min Mina Chou If multiple VCPUs of the same Guest/VM run on the same Host CPU, hfence.vvma only flushes that Host CPU’s VS-stage TLB. Other Host CPUs may retain stale VS-stage entries. When a VCPU later migrates to a different Host CPU, it can hit these stale GVA to GPA mappings, causing unexpected faults in the Guest. To fix this, kvm_riscv_gstage_vmid_sanitize() is extended to flush both G-stage and VS-stage TLBs whenever a VCPU migrates to a different Host CPU. This ensures that no stale VS-stage mappings remain after VCPU migration. Fixes: 92e450507d56 ("RISC-V: KVM: Cleanup stale TLB entries when host CPU changes") Signed-off-by: Hui Min Mina Chou Signed-off-by: Ben Zong-You Xie Reviewed-by: Radim Krčmář --- v3: - Resolved build warning; updated header declaration and call side to kvm_riscv_local_tlb_sanitize v2: - Updated Fixes commit to 92e450507d56 - Renamed function to kvm_riscv_local_tlb_sanitize arch/riscv/include/asm/kvm_vmid.h | 2 +- arch/riscv/kvm/vcpu.c | 2 +- arch/riscv/kvm/vmid.c | 8 +++++++- 3 files changed, 9 insertions(+), 3 deletions(-) diff --git a/arch/riscv/include/asm/kvm_vmid.h b/arch/riscv/include/asm/kvm_vmid.h index ab98e1434fb7..75fb6e872ccd 100644 --- a/arch/riscv/include/asm/kvm_vmid.h +++ b/arch/riscv/include/asm/kvm_vmid.h @@ -22,6 +22,6 @@ 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); +void kvm_riscv_local_tlb_sanitize(struct kvm_vcpu *vcpu); #endif diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c index 3ebcfffaa978..796218e4a462 100644 --- a/arch/riscv/kvm/vcpu.c +++ b/arch/riscv/kvm/vcpu.c @@ -968,7 +968,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) * Note: This should be done after G-stage VMID has been * updated using kvm_riscv_gstage_vmid_ver_changed() */ - kvm_riscv_gstage_vmid_sanitize(vcpu); + kvm_riscv_local_tlb_sanitize(vcpu); trace_kvm_entry(vcpu); diff --git a/arch/riscv/kvm/vmid.c b/arch/riscv/kvm/vmid.c index 3b426c800480..6323f5383d36 100644 --- a/arch/riscv/kvm/vmid.c +++ b/arch/riscv/kvm/vmid.c @@ -125,7 +125,7 @@ void kvm_riscv_gstage_vmid_update(struct kvm_vcpu *vcpu) kvm_make_request(KVM_REQ_UPDATE_HGATP, v); } -void kvm_riscv_gstage_vmid_sanitize(struct kvm_vcpu *vcpu) +void kvm_riscv_local_tlb_sanitize(struct kvm_vcpu *vcpu) { unsigned long vmid; @@ -146,4 +146,10 @@ void kvm_riscv_gstage_vmid_sanitize(struct kvm_vcpu *vcpu) vmid = READ_ONCE(vcpu->kvm->arch.vmid.vmid); kvm_riscv_local_hfence_gvma_vmid_all(vmid); + + /* + * Flush VS-stage TLBs entry after VCPU migration to avoid using + * stale entries. + */ + kvm_riscv_local_hfence_vvma_all(vmid); } -- 2.34.1