Commit 1f94ea81 authored by Jason Wang's avatar Jason Wang Committed by Greg Kroah-Hartman

hv: vmbus_drv: detect hyperv through x86_hyper

There are two reasons we need to use x86_hyper instead of
query_hypervisor_presence():

- Not only hyperv but also other hypervisors such as kvm would set
  X86_FEATURE_HYTPERVISOR, so query_hypervisor_presence() will return true even
  in kvm. This may cause extra delay of 5 seconds before failing the probing in
  kvm guest.
- The hypervisor has been detected in init_hypervisor(), so no need to do the
  work again.
Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Acked-by: default avatarK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 82aceae4
...@@ -34,6 +34,7 @@ ...@@ -34,6 +34,7 @@
#include <linux/completion.h> #include <linux/completion.h>
#include <linux/hyperv.h> #include <linux/hyperv.h>
#include <asm/hyperv.h> #include <asm/hyperv.h>
#include <asm/hypervisor.h>
#include "hyperv_vmbus.h" #include "hyperv_vmbus.h"
...@@ -719,33 +720,11 @@ static struct acpi_driver vmbus_acpi_driver = { ...@@ -719,33 +720,11 @@ 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) static int __init hv_acpi_init(void)
{ {
int ret, t; int ret, t;
if (!query_hypervisor_presence()) if (x86_hyper != &x86_hyper_ms_hyperv)
return -ENODEV; return -ENODEV;
init_completion(&probe_event); init_completion(&probe_event);
......
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