[tip:x86/hyperv] X86: Add a check to catch Xen emulation of Hyper-V
Commit-ID: db34bbb767bdfa1ebed7214b876fe01c5b7ee457 Gitweb: http://git.kernel.org/tip/db34bbb767bdfa1ebed7214b876fe01c5b7ee457 Author: K. Y. Srinivasan AuthorDate: Sun, 3 Feb 2013 17:22:38 -0800 Committer: H. Peter Anvin CommitDate: Tue, 12 Feb 2013 16:27:03 -0800 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 Link: http://lkml.kernel.org/r/1359940959-32168-2-git-send-email-...@microsoft.com Signed-off-by: H. Peter Anvin --- arch/x86/kernel/cpu/mshyperv.c | 7 +++ 1 file changed, 7 insertions(+) diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index 646d192..4dab317 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, , _signature[0], _signature[1], _signature[2]); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[tip:x86/hyperv] X86: Add a check to catch Xen emulation of Hyper-V
Commit-ID: db34bbb767bdfa1ebed7214b876fe01c5b7ee457 Gitweb: http://git.kernel.org/tip/db34bbb767bdfa1ebed7214b876fe01c5b7ee457 Author: K. Y. Srinivasan k...@microsoft.com AuthorDate: Sun, 3 Feb 2013 17:22:38 -0800 Committer: H. Peter Anvin h...@linux.intel.com CommitDate: Tue, 12 Feb 2013 16:27:03 -0800 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 k...@microsoft.com Link: http://lkml.kernel.org/r/1359940959-32168-2-git-send-email-...@microsoft.com Signed-off-by: H. Peter Anvin h...@linux.intel.com --- arch/x86/kernel/cpu/mshyperv.c | 7 +++ 1 file changed, 7 insertions(+) diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index 646d192..4dab317 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]); -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
