diff options
Diffstat (limited to 'arch/loongarch/kvm/main.c')
| -rw-r--r-- | arch/loongarch/kvm/main.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/arch/loongarch/kvm/main.c b/arch/loongarch/kvm/main.c index d0b941459a6b..b6864d6e5ec8 100644 --- a/arch/loongarch/kvm/main.c +++ b/arch/loongarch/kvm/main.c @@ -245,6 +245,24 @@ void kvm_check_vpid(struct kvm_vcpu *vcpu) trace_kvm_vpid_change(vcpu, vcpu->arch.vpid); vcpu->cpu = cpu; kvm_clear_request(KVM_REQ_TLB_FLUSH_GPA, vcpu); + + /* + * LLBCTL is a separated guest CSR register from host, a general + * exception ERET instruction clears the host LLBCTL register in + * host mode, and clears the guest LLBCTL register in guest mode. + * ERET in tlb refill exception does not clear LLBCTL register. + * + * When secondary mmu mapping is changed, guest OS does not know + * even if the content is changed after mapping is changed. + * + * Here clear WCLLB of the guest LLBCTL register when mapping is + * changed. Otherwise, if mmu mapping is changed while guest is + * executing LL/SC pair, LL loads with the old address and set + * the LLBCTL flag, SC checks the LLBCTL flag and will store the + * new address successfully since LLBCTL_WCLLB is on, even if + * memory with new address is changed on other VCPUs. + */ + set_gcsr_llbctl(CSR_LLBCTL_WCLLB); } /* Restore GSTAT(0x50).vpid */ |