viridian: add init hooks

This patch adds domain and vcpu init hooks for viridian features. The init
hooks do not yet do anything; the functionality will be added to by
subsequent patches.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>

xen/arch/x86/hvm/hvm.c

@@ -666,6 +666,10 @@ int hvm_domain_initialise(struct domain *d)
     if ( hvm_tsc_scaling_supported )
         d->arch.hvm.tsc_scaling_ratio = hvm_default_tsc_scaling_ratio;
 
+    rc = viridian_domain_init(d);
+    if ( rc )
+        goto fail2;
+
     rc = hvm_funcs.domain_initialise(d);
     if ( rc != 0 )
         goto fail2;
@@ -687,6 +691,7 @@ int hvm_domain_initialise(struct domain *d)
     hvm_destroy_cacheattr_region_list(d);
     destroy_perdomain_mapping(d, PERDOMAIN_VIRT_START, 0);
  fail:
+    viridian_domain_deinit(d);
     return rc;
 }
 
@@ -1526,6 +1531,10 @@ int hvm_vcpu_initialise(struct vcpu *v)
          && (rc = nestedhvm_vcpu_initialise(v)) < 0 ) /* teardown: nestedhvm_vcpu_destroy */
         goto fail5;
 
+    rc = viridian_vcpu_init(v);
+    if ( rc )
+        goto fail5;
+
     rc = hvm_all_ioreq_servers_add_vcpu(d, v);
     if ( rc != 0 )
         goto fail6;
@@ -1553,6 +1562,7 @@ int hvm_vcpu_initialise(struct vcpu *v)
  fail2:
     hvm_vcpu_cacheattr_destroy(v);
  fail1:
+    viridian_vcpu_deinit(v);
     return rc;
 }
 

xen/arch/x86/hvm/viridian/viridian.c

@@ -417,6 +417,16 @@ int guest_rdmsr_viridian(const struct vcpu *v, uint32_t idx, uint64_t *val)
     return X86EMUL_OKAY;
 }
 
+int viridian_vcpu_init(struct vcpu *v)
+{
+    return 0;
+}
+
+int viridian_domain_init(struct domain *d)
+{
+    return 0;
+}
+
 void viridian_vcpu_deinit(struct vcpu *v)
 {
     viridian_synic_wrmsr(v, HV_X64_MSR_VP_ASSIST_PAGE, 0);

xen/include/asm-x86/hvm/viridian.h

@@ -80,6 +80,9 @@ viridian_hypercall(struct cpu_user_regs *regs);
 void viridian_time_ref_count_freeze(struct domain *d);
 void viridian_time_ref_count_thaw(struct domain *d);
 
+int viridian_vcpu_init(struct vcpu *v);
+int viridian_domain_init(struct domain *d);
+
 void viridian_vcpu_deinit(struct vcpu *v);
 void viridian_domain_deinit(struct domain *d);