x86: allow disabling the emulated HPET

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>

diff --git a/xen/arch/x86/hvm/hpet.c b/xen/arch/x86/hvm/hpet.c
index facab83dc517feb77b5de037cca42c3c54188811..5e020aecfa76eff74c661ff3bbf201c6eacb6d36 100644 (file)
--- a/xen/arch/x86/hvm/hpet.c
+++ b/xen/arch/x86/hvm/hpet.c
@@ -517,6 +517,9 @@ static int hpet_save(struct domain *d, hvm_domain_context_t *h)
     int rc;
     uint64_t guest_time;
 
+    if ( !has_vhpet(d) )
+        return 0;
+
     write_lock(&hp->lock);
     guest_time = (v->arch.hvm_vcpu.guest_time ?: hvm_get_guest_time(v)) /
                  STIME_PER_HPET_TICK;
@@ -577,6 +580,9 @@ static int hpet_load(struct domain *d, hvm_domain_context_t *h)
     uint64_t guest_time;
     int i;
 
+    if ( !has_vhpet(d) )
+        return -ENODEV;
+
     write_lock(&hp->lock);
 
     /* Reload the HPET registers */
@@ -635,6 +641,9 @@ void hpet_init(struct domain *d)
     HPETState *h = domain_vhpet(d);
     int i;
 
+    if ( !has_vhpet(d) )
+        return;
+
     memset(h, 0, sizeof(HPETState));
 
     rwlock_init(&h->lock);
@@ -662,6 +671,7 @@ void hpet_init(struct domain *d)
     }
 
     register_mmio_handler(d, &hpet_mmio_ops);
+    d->arch.hvm_domain.params[HVM_PARAM_HPET_ENABLED] = 1;
 }
 
 void hpet_deinit(struct domain *d)
@@ -669,6 +679,9 @@ void hpet_deinit(struct domain *d)
     int i;
     HPETState *h = domain_vhpet(d);
 
+    if ( !has_vhpet(d) )
+        return;
+
     write_lock(&h->lock);
 
     if ( hpet_enabled(h) )

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 21f42a7f0e5dad62ab895ffa3e1b83ff99fc5734..4490e9de3fb5f67c13d3e1618863cf4b20397d11 100644 (file)
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -1605,7 +1605,6 @@ int hvm_domain_initialise(struct domain *d)
 
     hvm_init_guest_time(d);
 
-    d->arch.hvm_domain.params[HVM_PARAM_HPET_ENABLED] = 1;
     d->arch.hvm_domain.params[HVM_PARAM_TRIPLE_FAULT_REASON] = SHUTDOWN_reboot;
 
     vpic_init(d);