hyper-v: introduce Hyper-V support infrastructure.

[Jan: fix build with CONFIG_USER_ONLY]

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

Makefile.target

@@ -199,6 +199,8 @@ obj-$(CONFIG_NO_KVM) += kvm-stub.o
 obj-y += memory.o savevm.o
 LIBS+=-lz
 
+obj-i386-y +=hyperv.o
+
 QEMU_CFLAGS += $(VNC_TLS_CFLAGS)
 QEMU_CFLAGS += $(VNC_SASL_CFLAGS)
 QEMU_CFLAGS += $(VNC_JPEG_CFLAGS)

target-i386/cpuid.c

@@ -27,6 +27,8 @@
 #include "qemu-option.h"
 #include "qemu-config.h"
 
+#include "hyperv.h"
+
 /* feature flags taken from "Intel Processor Identification and the CPUID
  * Instruction" and AMD's "CPUID Specification".  In cases of disagreement
  * between feature naming conventions, aliases may be added.
@@ -716,6 +718,14 @@ static int cpu_x86_find_by_name(x86_def_t *x86_cpu_def, const char *cpu_model)
                     goto error;
                 }
                 x86_cpu_def->tsc_khz = tsc_freq / 1000;
+            } else if (!strcmp(featurestr, "hv_spinlocks")) {
+                char *err;
+                numvalue = strtoul(val, &err, 0);
+                if (!*val || *err) {
+                    fprintf(stderr, "bad numerical value %s\n", val);
+                    goto error;
+                }
+                hyperv_set_spinlock_retries(numvalue);
             } else {
                 fprintf(stderr, "unrecognized feature %s\n", featurestr);
                 goto error;
@@ -724,6 +734,10 @@ static int cpu_x86_find_by_name(x86_def_t *x86_cpu_def, const char *cpu_model)
             check_cpuid = 1;
         } else if (!strcmp(featurestr, "enforce")) {
             check_cpuid = enforce_cpuid = 1;
+        } else if (!strcmp(featurestr, "hv_relaxed")) {
+            hyperv_enable_relaxed_timing(true);
+        } else if (!strcmp(featurestr, "hv_vapic")) {
+            hyperv_enable_vapic_recommended(true);
         } else {
             fprintf(stderr, "feature string `%s' not in format (+feature|-feature|feature=xyz)\n", featurestr);
             goto error;

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;
+}

target-i386/hyperv.h

@@ -0,0 +1,43 @@
+/*
+ * 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.
+ *
+ */
+
+#ifndef QEMU_HW_HYPERV_H
+#define QEMU_HW_HYPERV_H 1
+
+#include "qemu-common.h"
+#include <asm/hyperv.h>
+
+#ifndef HYPERV_SPINLOCK_NEVER_RETRY
+#define HYPERV_SPINLOCK_NEVER_RETRY             0xFFFFFFFF
+#endif
+
+#ifndef KVM_CPUID_SIGNATURE_NEXT
+#define KVM_CPUID_SIGNATURE_NEXT                0x40000100
+#endif
+
+#ifndef CONFIG_USER_ONLY
+void hyperv_enable_vapic_recommended(bool val);
+void hyperv_enable_relaxed_timing(bool val);
+void hyperv_set_spinlock_retries(int val);
+#else
+static inline void hyperv_enable_vapic_recommended(bool val) { }
+static inline void hyperv_enable_relaxed_timing(bool val) { }
+static inline void hyperv_set_spinlock_retries(int val) { }
+#endif
+
+bool hyperv_enabled(void);
+bool hyperv_hypercall_available(void);
+bool hyperv_vapic_recommended(void);
+bool hyperv_relaxed_timing_enabled(void);
+int hyperv_get_spinlock_retries(void);
+
+#endif /* QEMU_HW_HYPERV_H */