hyper-v: introduce Hyper-V support infrastructure.

[Jan: fix build with CONFIG_USER_ONLY]

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

1 files changed, 64 insertions, 0 deletions

diff --git a/target-i386/hyperv.c b/target-i386/hyperv.c
new file mode 100644
index 0000000000..f284e99772
--- /dev/null
+++ b/target-i386/hyperv.c
@@ -0,0 +1,64 @@
+/*
+ * QEMU Hyper-V support
+ *
+ * Copyright Red Hat, Inc. 2011
+ *
+ * Author: Vadim Rozenfeld     <vrozenfe@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "hyperv.h"
+
+static bool hyperv_vapic;
+static bool hyperv_relaxed_timing;
+static int hyperv_spinlock_attempts = HYPERV_SPINLOCK_NEVER_RETRY;
+
+void hyperv_enable_vapic_recommended(bool val)
+{
+    hyperv_vapic = val;
+}
+
+void hyperv_enable_relaxed_timing(bool val)
+{
+    hyperv_relaxed_timing = val;
+}
+
+void hyperv_set_spinlock_retries(int val)
+{
+    hyperv_spinlock_attempts = val;
+    if (hyperv_spinlock_attempts < 0xFFF) {
+        hyperv_spinlock_attempts = 0xFFF;
+    }
+}
+
+bool hyperv_enabled(void)
+{
+    return hyperv_hypercall_available() || hyperv_relaxed_timing_enabled();
+}
+
+bool hyperv_hypercall_available(void)
+{
+    if (hyperv_vapic ||
+        (hyperv_spinlock_attempts != HYPERV_SPINLOCK_NEVER_RETRY)) {
+      return true;
+    }
+    return false;
+}
+
+bool hyperv_vapic_recommended(void)
+{
+    return hyperv_vapic;
+}
+
+bool hyperv_relaxed_timing_enabled(void)
+{
+    return hyperv_relaxed_timing;
+}
+
+int hyperv_get_spinlock_retries(void)
+{
+    return hyperv_spinlock_attempts;
+}