From: Yoshimi Ichiyanagi Date: Sat, 30 Dec 2006 00:49:41 +0000 (-0800) Subject: [PATCH] KVM: Initialize kvm_arch_ops on unload X-Git-Tag: v2.6.20-rc3~16 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=09db28b8a3765a7ec35eba80420c71a7973f5a88;p=linux-2.6 [PATCH] KVM: Initialize kvm_arch_ops on unload The latest version of kvm doesn't initialize kvm_arch_ops in kvm_init(), which causes an error with the following sequence. 1. Load the supported arch's module. 2. Load the unsupported arch's module.　(loading error) 3. Unload the unsupported arch's module. You'll get the following error message after step 3. "BUG: unable to handle to handle kernel paging request at virtual address xxxxxxxx" The problem here is that the unsupported arch's module overwrites kvm_arch_ops of the supported arch's module at step 2. This patch initializes kvm_arch_ops upon loading architecture specific kvm module, and prevents overwriting kvm_arch_ops when kvm_arch_ops is already set correctly. Signed-off-by: Avi Kivity Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c index 38375e2bb7..06314071c6 100644 --- a/drivers/kvm/kvm_main.c +++ b/drivers/kvm/kvm_main.c @@ -1865,6 +1865,11 @@ int kvm_init_arch(struct kvm_arch_ops *ops, struct module *module) { int r; + if (kvm_arch_ops) { + printk(KERN_ERR "kvm: already loaded the other module\n"); + return -EEXIST; + } + kvm_arch_ops = ops; if (!kvm_arch_ops->cpu_has_kvm_support()) { @@ -1907,6 +1912,7 @@ void kvm_exit_arch(void) unregister_reboot_notifier(&kvm_reboot_notifier); on_each_cpu(kvm_arch_ops->hardware_disable, 0, 0, 1); kvm_arch_ops->hardware_unsetup(); + kvm_arch_ops = NULL; } static __init int kvm_init(void)