From: "Guo Ren (Alibaba DAMO Academy)" When a vCPU migrates to a different host CPU, the new CPU may retain stale VS-stage TLB entries (GVA → GPA) left by a previous run of the same guest. Issue an HFENCE.VVMA (all ASIDs, all addresses) inside kvm_riscv_mmu_update_hgatp() whenever the vCPU is loaded on a CPU different from the one it last exited on. Signed-off-by: Guo Ren (Alibaba DAMO Academy) --- Does this patch solve your problem? I would prefer to issue a full HFENCE.VVMA whenever a new VMID is installed on a pCPU. --- arch/riscv/include/asm/kvm_mmu.h | 2 +- arch/riscv/kvm/mmu.c | 5 ++++- arch/riscv/kvm/vcpu.c | 4 ++-- 3 files changed, 7 insertions(+), 4 deletions(-) diff --git a/arch/riscv/include/asm/kvm_mmu.h b/arch/riscv/include/asm/kvm_mmu.h index 5439e76f0a96..f0c5d2d01052 100644 --- a/arch/riscv/include/asm/kvm_mmu.h +++ b/arch/riscv/include/asm/kvm_mmu.h @@ -16,6 +16,6 @@ int kvm_riscv_mmu_map(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot, struct kvm_gstage_mapping *out_map); int kvm_riscv_mmu_alloc_pgd(struct kvm *kvm); void kvm_riscv_mmu_free_pgd(struct kvm *kvm); -void kvm_riscv_mmu_update_hgatp(struct kvm_vcpu *vcpu); +void kvm_riscv_mmu_update_hgatp(struct kvm_vcpu *vcpu, int cpu); #endif diff --git a/arch/riscv/kvm/mmu.c b/arch/riscv/kvm/mmu.c index 082f9b261733..b76a90f5811a 100644 --- a/arch/riscv/kvm/mmu.c +++ b/arch/riscv/kvm/mmu.c @@ -705,7 +705,7 @@ void kvm_riscv_mmu_free_pgd(struct kvm *kvm) free_pages((unsigned long)pgd, get_order(kvm_riscv_gstage_pgd_size)); } -void kvm_riscv_mmu_update_hgatp(struct kvm_vcpu *vcpu) +void kvm_riscv_mmu_update_hgatp(struct kvm_vcpu *vcpu, int cpu) { struct kvm_arch *ka = &vcpu->kvm->arch; unsigned long hgatp = kvm_riscv_gstage_mode(ka->pgd_levels) @@ -718,4 +718,7 @@ void kvm_riscv_mmu_update_hgatp(struct kvm_vcpu *vcpu) if (!kvm_riscv_gstage_vmid_bits()) kvm_riscv_local_hfence_gvma_all(); + + if (vcpu->arch.last_exit_cpu != cpu) + asm volatile(HFENCE_VVMA(zero, zero) : : : "memory"); } diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c index cf6e231e76e2..9692f5f5a70a 100644 --- a/arch/riscv/kvm/vcpu.c +++ b/arch/riscv/kvm/vcpu.c @@ -593,7 +593,7 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) csr_write(CSR_VSATP, csr->vsatp); } - kvm_riscv_mmu_update_hgatp(vcpu); + kvm_riscv_mmu_update_hgatp(vcpu, cpu); kvm_riscv_vcpu_aia_load(vcpu, cpu); @@ -686,7 +686,7 @@ static int kvm_riscv_check_vcpu_requests(struct kvm_vcpu *vcpu) kvm_riscv_reset_vcpu(vcpu, true); if (kvm_check_request(KVM_REQ_UPDATE_HGATP, vcpu)) - kvm_riscv_mmu_update_hgatp(vcpu); + kvm_riscv_mmu_update_hgatp(vcpu, vcpu->cpu); if (kvm_check_request(KVM_REQ_FENCE_I, vcpu)) kvm_riscv_fence_i_process(vcpu); -- 2.43.0