hv: fail the probing immediately when we are not in hyperv platform
Jason Wang [Fri, 17 Aug 2012 10:52:43 +0000 (18:52 +0800)]
We wait for about 5 seconds for the success of the hyperv registration even if
we were not in hyperv platform. This is suboptimal, so the patch check the cpuid
in the beginning of hv_acpi_init() instead of in vmbus_bus_init() to fail the
probing immediately.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hv/hv.c
drivers/hv/vmbus_drv.c

index 771e24f..3648f8f 100644 (file)
@@ -39,28 +39,6 @@ struct hv_context hv_context = {
 };
 
 /*
- * query_hypervisor_presence
- * - Query the cpuid for presence of windows hypervisor
- */
-static int query_hypervisor_presence(void)
-{
-       unsigned int eax;
-       unsigned int ebx;
-       unsigned int ecx;
-       unsigned int edx;
-       unsigned int op;
-
-       eax = 0;
-       ebx = 0;
-       ecx = 0;
-       edx = 0;
-       op = HVCPUID_VERSION_FEATURES;
-       cpuid(op, &eax, &ebx, &ecx, &edx);
-
-       return ecx & HV_PRESENT_BIT;
-}
-
-/*
  * query_hypervisor_info - Get version info of the windows hypervisor
  */
 static int query_hypervisor_info(void)
@@ -160,9 +138,6 @@ int hv_init(void)
        memset(hv_context.synic_message_page, 0,
               sizeof(void *) * NR_CPUS);
 
-       if (!query_hypervisor_presence())
-               goto cleanup;
-
        max_leaf = query_hypervisor_info();
 
        /*
index b76e8b3..f40dd57 100644 (file)
@@ -719,10 +719,35 @@ static struct acpi_driver vmbus_acpi_driver = {
        },
 };
 
+/*
+ * query_hypervisor_presence
+ * - Query the cpuid for presence of windows hypervisor
+ */
+static int query_hypervisor_presence(void)
+{
+       unsigned int eax;
+       unsigned int ebx;
+       unsigned int ecx;
+       unsigned int edx;
+       unsigned int op;
+
+       eax = 0;
+       ebx = 0;
+       ecx = 0;
+       edx = 0;
+       op = HVCPUID_VERSION_FEATURES;
+       cpuid(op, &eax, &ebx, &ecx, &edx);
+
+       return ecx & HV_PRESENT_BIT;
+}
+
 static int __init hv_acpi_init(void)
 {
        int ret, t;
 
+       if (!query_hypervisor_presence())
+               return -ENODEV;
+
        init_completion(&probe_event);
 
        /*