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| author | Jason Wang <jasowang@redhat.com> | 2012-08-17 18:52:43 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-08-17 09:51:59 -0700 |
| commit | 0592969e73ae50ce6852d1aff3d222a335289094 (patch) | |
| tree | 15d579b39ad1835773ae101759832be40500f1ec /drivers/hv/vmbus_drv.c | |
| parent | 4a52c4af48a2a35282ddc4dcf2df83486d636754 (diff) | |
| download | linux-0592969e73ae50ce6852d1aff3d222a335289094.tar.gz linux-0592969e73ae50ce6852d1aff3d222a335289094.tar.bz2 linux-0592969e73ae50ce6852d1aff3d222a335289094.zip | |
hv: fail the probing immediately when we are not in hyperv platform
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>
Diffstat (limited to 'drivers/hv/vmbus_drv.c')
| -rw-r--r-- | drivers/hv/vmbus_drv.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index b76e8b321266..f40dd57bbec1 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -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); /* |