When the kvm file descriptor changes as a part of confidential guest reset,
some architecture specific setups including SEV/SEV-SNP/TDX specific setups
needs to be redone. These changes are implemented as a part of the
kvm_arch_vmfd_change_ops() call which was introduced previously.

Signed-off-by: Ani Sinha <anisinha@redhat.com>
---
 target/i386/kvm/kvm.c | 132 +++++++++++++++++++++++++++++++++++++-----
 1 file changed, 119 insertions(+), 13 deletions(-)

diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index cdfcb70f40..e971f5f8c4 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -3252,9 +3252,126 @@ static int kvm_vm_enable_energy_msrs(KVMState *s)
     return 0;
 }
 
+static int xen_init_wrapper(MachineState *ms, KVMState *s);
+
 int kvm_arch_vmfd_change_ops(MachineState *ms, KVMState *s)
 {
-    abort();
+    Error *local_err = NULL;
+    int ret;
+
+    /*
+     * Initialize confidential context, if required
+     *
+     * If no memory encryption is requested (ms->cgs == NULL) this is
+     * a no-op.
+     *
+     */
+    if (ms->cgs) {
+        ret = confidential_guest_kvm_init(ms->cgs, &local_err);
+        if (ret < 0) {
+            error_report_err(local_err);
+            return ret;
+        }
+    }
+
+    ret = kvm_vm_enable_exception_payload(s);
+    if (ret < 0) {
+        return ret;
+    }
+
+    ret = kvm_vm_enable_triple_fault_event(s);
+    if (ret < 0) {
+        return ret;
+    }
+
+    if (s->xen_version) {
+        ret = xen_init_wrapper(ms, s);
+        if (ret < 0) {
+            return ret;
+        }
+    }
+
+    ret = kvm_vm_set_identity_map_addr(s, KVM_IDENTITY_BASE);
+    if (ret < 0) {
+        return ret;
+    }
+
+    ret = kvm_vm_set_tss_addr(s, KVM_IDENTITY_BASE + 0x1000);
+    if (ret < 0) {
+        return ret;
+    }
+    ret = kvm_vm_set_nr_mmu_pages(s);
+    if (ret < 0) {
+        return ret;
+    }
+
+    if (object_dynamic_cast(OBJECT(ms), TYPE_X86_MACHINE) &&
+        x86_machine_is_smm_enabled(X86_MACHINE(ms))) {
+        memory_listener_register(&smram_listener.listener,
+                                 &smram_address_space);
+    }
+
+    if (enable_cpu_pm) {
+        ret = kvm_vm_enable_disable_exits(s);
+        if (ret < 0) {
+            error_report("kvm: guest stopping CPU not supported: %s",
+                         strerror(-ret));
+            return ret;
+        }
+    }
+
+    if (object_dynamic_cast(OBJECT(ms), TYPE_X86_MACHINE)) {
+        X86MachineState *x86ms = X86_MACHINE(ms);
+
+        if (x86ms->bus_lock_ratelimit > 0) {
+            ret = kvm_vm_enable_bus_lock_exit(s);
+            if (ret < 0) {
+                return ret;
+            }
+        }
+        kvm_set_max_apic_id(x86ms->apic_id_limit);
+    }
+
+    if (kvm_check_extension(s, KVM_CAP_X86_NOTIFY_VMEXIT)) {
+        ret = kvm_vm_enable_notify_vmexit(s);
+        if (ret < 0) {
+            return ret;
+        }
+    }
+
+    if (kvm_vm_check_extension(s, KVM_CAP_X86_USER_SPACE_MSR)) {
+        ret = kvm_vm_enable_userspace_msr(s);
+        if (ret < 0) {
+            return ret;
+        }
+
+        if (s->msr_energy.enable == true) {
+            ret = kvm_vm_enable_energy_msrs(s);
+            if (ret < 0) {
+                return ret;
+            }
+        }
+    }
+
+    return 0;
+}
+
+static int xen_init_wrapper(MachineState *ms, KVMState *s)
+{
+    int ret = 0;
+#ifdef CONFIG_XEN_EMU
+    if (!object_dynamic_cast(OBJECT(ms), TYPE_PC_MACHINE)) {
+        error_report("kvm: Xen support only available in PC machine");
+        return -ENOTSUP;
+    }
+    /* hyperv_enabled() doesn't work yet. */
+    uint32_t msr = XEN_HYPERCALL_MSR;
+    ret = kvm_xen_init(s, msr);
+#else
+    error_report("kvm: Xen support not enabled in qemu");
+    return -ENOTSUP;
+#endif
+    return ret;
 }
 
 int kvm_arch_init(MachineState *ms, KVMState *s)
@@ -3290,21 +3407,10 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
     }
 
     if (s->xen_version) {
-#ifdef CONFIG_XEN_EMU
-        if (!object_dynamic_cast(OBJECT(ms), TYPE_PC_MACHINE)) {
-            error_report("kvm: Xen support only available in PC machine");
-            return -ENOTSUP;
-        }
-        /* hyperv_enabled() doesn't work yet. */
-        uint32_t msr = XEN_HYPERCALL_MSR;
-        ret = kvm_xen_init(s, msr);
+        ret = xen_init_wrapper(ms, s);
         if (ret < 0) {
             return ret;
         }
-#else
-        error_report("kvm: Xen support not enabled in qemu");
-        return -ENOTSUP;
-#endif
     }
 
     ret = kvm_get_supported_msrs(s);
-- 
2.42.0