diff options
| author | K. Y. Srinivasan <kys@microsoft.com> | 2013-02-03 17:22:38 -0800 |
|---|---|---|
| committer | H. Peter Anvin <hpa@linux.intel.com> | 2013-02-12 16:27:03 -0800 |
| commit | db34bbb767bdfa1ebed7214b876fe01c5b7ee457 (patch) | |
| tree | 6cbccf53064b6c56b0a74b551a34e81238008568 /arch/x86/kernel/cpu/mshyperv.c | |
| parent | 32068f6527b8f1822a30671dedaf59c567325026 (diff) | |
X86: Add a check to catch Xen emulation of Hyper-V
Xen emulates Hyper-V to host enlightened Windows. Looks like this
emulation may be turned on by default even for Linux guests. Check and
fail Hyper-V detection if we are on Xen.
[ hpa: the problem here is that Xen doesn't emulate Hyper-V well
enough, and if the Xen support isn't compiled in, we end up stubling
over the Hyper-V emulation and try to activate it -- and it fails. ]
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Link: http://lkml.kernel.org/r/1359940959-32168-2-git-send-email-kys@microsoft.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'arch/x86/kernel/cpu/mshyperv.c')
| -rw-r--r-- | arch/x86/kernel/cpu/mshyperv.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index 646d192b18a2..4dab317f79b9 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -30,6 +30,13 @@ static bool __init ms_hyperv_platform(void) if (!boot_cpu_has(X86_FEATURE_HYPERVISOR)) return false; + /* + * Xen emulates Hyper-V to support enlightened Windows. + * Check to see first if we are on a Xen Hypervisor. + */ + if (xen_cpuid_base()) + return false; + cpuid(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS, &eax, &hyp_signature[0], &hyp_signature[1], &hyp_signature[2]); |