Implement kvm check vmid and update vmid, the vmid should be checked before
vcpu enter guest.
Reviewed-by: Bibo Mao <maobibo@xxxxxxxxxxx>
Signed-off-by: Tianrui Zhao <zhaotianrui@xxxxxxxxxxx>
---
arch/loongarch/kvm/vmid.c | 66 +++++++++++++++++++++++++++++++++++++++
1 file changed, 66 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 000000000000..fc25ddc3b74a
--- /dev/null
+++ b/arch/loongarch/kvm/vmid.c
@@ -0,0 +1,66 @@
+// 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 & vpid_mask)) {
+ /* finish round of 64 bit loop */
+ if (unlikely(!vpid))
+ vpid = vpid_mask + 1;
+
+ /* vpid 0 reserved for root */
+ ++vpid;
+
+ /* start new vpid cycle */
+ kvm_flush_tlb_all();
+ }
+
+ context->vpid_cache = vpid;
+ vcpu->arch.vpid = vpid;
+}
+
+void _kvm_check_vmid(struct kvm_vcpu *vcpu)
+{
+ struct kvm_context *context;
+ bool migrated;
+ unsigned long ver, old, vpid;
+ int cpu;
+
+ cpu = smp_processor_id();
+ /*
+ * 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->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 & ~vpid_mask;
+ old = context->vpid_cache & ~vpid_mask;
+ if (migrated || (ver != old)) {
+ _kvm_update_vpid(vcpu, cpu);
+ trace_kvm_vpid_change(vcpu, vcpu->arch.vpid);
+ vcpu->cpu = cpu;
+ }
+
+ /* Restore GSTAT(0x50).vpid */
+ vpid = (vcpu->arch.vpid & vpid_mask)
+ << CSR_GSTAT_GID_SHIFT;
+ change_csr_gstat(vpid_mask << CSR_GSTAT_GID_SHIFT, vpid);
+}
--
2.39.1
