Implement kvm check vmid and update vmid, the vmid should be checked before vcpu enter guest. Signed-off-by: Tianrui Zhao <zhaotianrui@xxxxxxxxxxx> --- arch/loongarch/kvm/vmid.c | 64 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 64 insertions(+) create mode 100644 arch/loongarch/kvm/vmid.c diff --git a/arch/loongarch/kvm/vmid.c b/arch/loongarch/kvm/vmid.c new file mode 100644 index 000000000..82729968e --- /dev/null +++ b/arch/loongarch/kvm/vmid.c @@ -0,0 +1,64 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2020-2023 Loongson Technology Corporation Limited + */ + +#include <linux/kvm_host.h> +#include "trace.h" + +static void _kvm_update_vpid(struct kvm_vcpu *vcpu, int cpu) +{ + struct kvm_context *context; + unsigned long vpid; + + context = per_cpu_ptr(vcpu->kvm->arch.vmcs, cpu); + vpid = context->vpid_cache + 1; + if (!(vpid & context->vpid_mask)) { + /* finish round of 64 bit loop */ + if (unlikely(!vpid)) + vpid = context->vpid_mask + 1; + + /* vpid 0 reserved for root */ + ++vpid; + + /* start new vpid cycle */ + kvm_flush_tlb_all(); + } + + context->vpid_cache = vpid; + vcpu->arch.vpid[cpu] = vpid; +} + +void _kvm_check_vmid(struct kvm_vcpu *vcpu, int cpu) +{ + struct kvm_context *context; + bool migrated; + unsigned long ver, old, vpid; + + /* + * Are we entering guest context on a different CPU to last time? + * If so, the VCPU's guest TLB state on this CPU may be stale. + */ + context = per_cpu_ptr(vcpu->kvm->arch.vmcs, cpu); + migrated = (vcpu->arch.last_exec_cpu != cpu); + vcpu->arch.last_exec_cpu = cpu; + + /* + * Check if our vpid is of an older version + * + * We also discard the stored vpid if we've executed on + * another CPU, as the guest mappings may have changed without + * hypervisor knowledge. + */ + ver = vcpu->arch.vpid[cpu] & ~context->vpid_mask; + old = context->vpid_cache & ~context->vpid_mask; + if (migrated || (ver != old)) { + _kvm_update_vpid(vcpu, cpu); + trace_kvm_vpid_change(vcpu, vcpu->arch.vpid[cpu]); + } + + /* Restore GSTAT(0x50).vpid */ + vpid = (vcpu->arch.vpid[cpu] & context->vpid_mask) + << CSR_GSTAT_GID_SHIFT; + change_csr_gstat(context->vpid_mask << CSR_GSTAT_GID_SHIFT, vpid); +} -- 2.31.1