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authorJason Wang <jasowang@redhat.com>2013-07-25 10:54:35 +0200
committerH. Peter Anvin <hpa@linux.intel.com>2013-08-05 15:35:33 +0200
commit9df56f19a500bea90d160be1bf77e4fbcd204d3f (patch)
treec2a19340b172daba4f8005788f10cdbfd4455327 /arch/x86/kernel/kvm.c
parentx86, kvm: Switch to use hypervisor_cpuid_base() (diff)
downloadlinux-9df56f19a500bea90d160be1bf77e4fbcd204d3f.tar.xz
linux-9df56f19a500bea90d160be1bf77e4fbcd204d3f.zip
x86: Correctly detect hypervisor
We try to handle the hypervisor compatibility mode by detecting hypervisor through a specific order. This is not robust, since hypervisors may implement each others features. This patch tries to handle this situation by always choosing the last one in the CPUID leaves. This is done by letting .detect() return a priority instead of true/false and just re-using the CPUID leaf where the signature were found as the priority (or 1 if it was found by DMI). Then we can just pick hypervisor who has the highest priority. Other sophisticated detection method could also be implemented on top. Suggested by H. Peter Anvin and Paolo Bonzini. Acked-by: K. Y. Srinivasan <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Doug Covelli <dcovelli@vmware.com> Cc: Borislav Petkov <bp@suse.de> Cc: Dan Hecht <dhecht@vmware.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Link: http://lkml.kernel.org/r/1374742475-2485-4-git-send-email-jasowang@redhat.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'arch/x86/kernel/kvm.c')
-rw-r--r--arch/x86/kernel/kvm.c6
1 files changed, 2 insertions, 4 deletions
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index a96d32cc55b8..7817afdac301 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -498,11 +498,9 @@ void __init kvm_guest_init(void)
#endif
}
-static bool __init kvm_detect(void)
+static uint32_t __init kvm_detect(void)
{
- if (!kvm_para_available())
- return false;
- return true;
+ return kvm_cpuid_base();
}
const struct hypervisor_x86 x86_hyper_kvm __refconst = {