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authorAlexander Graf <agraf@suse.de>2009-09-15 11:37:46 +0200
committerAvi Kivity <avi@redhat.com>2009-12-03 08:32:10 +0100
commit10474ae8945ce08622fd1f3464e55bd817bf2376 (patch)
treed390843b5107e600fbbf745eb24d85d745fe449f /arch/s390/kvm
parentKVM: SVM: remove needless mmap_sem acquision from nested_svm_map (diff)
downloadlinux-10474ae8945ce08622fd1f3464e55bd817bf2376.tar.xz
linux-10474ae8945ce08622fd1f3464e55bd817bf2376.zip
KVM: Activate Virtualization On Demand
X86 CPUs need to have some magic happening to enable the virtualization extensions on them. This magic can result in unpleasant results for users, like blocking other VMMs from working (vmx) or using invalid TLB entries (svm). Currently KVM activates virtualization when the respective kernel module is loaded. This blocks us from autoloading KVM modules without breaking other VMMs. To circumvent this problem at least a bit, this patch introduces on demand activation of virtualization. This means, that instead virtualization is enabled on creation of the first virtual machine and disabled on destruction of the last one. So using this, KVM can be easily autoloaded, while keeping other hypervisors usable. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/s390/kvm')
-rw-r--r--arch/s390/kvm/kvm-s390.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 00e2ce8e91f5..544505893c9f 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -74,9 +74,10 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
static unsigned long long *facilities;
/* Section: not file related */
-void kvm_arch_hardware_enable(void *garbage)
+int kvm_arch_hardware_enable(void *garbage)
{
/* every s390 is virtualization enabled ;-) */
+ return 0;
}
void kvm_arch_hardware_disable(void *garbage)