From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: [PATCH] KVM: Drop user return notifier when disabling virtualization on a cpu Date: Sat, 28 Nov 2009 14:18:47 +0200 Message-ID: <1259410727-17246-1-git-send-email-avi@redhat.com> Cc: kvm@vger.kernel.org To: Marcelo Tosatti Return-path: Received: from mx1.redhat.com ([209.132.183.28]:21760 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753943AbZK1MSm (ORCPT ); Sat, 28 Nov 2009 07:18:42 -0500 Received: from int-mx08.intmail.prod.int.phx2.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.21]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id nASCInXH030306 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Sat, 28 Nov 2009 07:18:49 -0500 Sender: kvm-owner@vger.kernel.org List-ID: This way, we don't leave a dangling notifier on cpu hotunplug or module unload. In particular, module unload leaves the notifier pointing into freed memory. Signed-off-by: Avi Kivity --- Please queue for 2.6.33 as well. arch/x86/kvm/x86.c | 9 +++++++++ 1 files changed, 9 insertions(+), 0 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 35eea30..106f9f1 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -201,6 +201,14 @@ void kvm_set_shared_msr(unsigned slot, u64 value) } EXPORT_SYMBOL_GPL(kvm_set_shared_msr); +static void drop_user_return_notifiers(void *ignore) +{ + struct kvm_shared_msrs *smsr = &__get_cpu_var(shared_msrs); + + if (smsr->registered) + kvm_on_user_return(&smsr->urn); +} + unsigned long segment_base(u16 selector) { struct descriptor_table gdt; @@ -5004,6 +5012,7 @@ int kvm_arch_hardware_enable(void *garbage) void kvm_arch_hardware_disable(void *garbage) { kvm_x86_ops->hardware_disable(garbage); + drop_user_return_notifiers(garbage); } int kvm_arch_hardware_setup(void) -- 1.6.5.2