From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: [PATCH 1/2] KVM: x86: Terminate early if task_switch_16/32 failed Date: Wed, 14 Apr 2010 15:50:57 +0200 Message-ID: <4BC5C841.5090302@siemens.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Cc: kvm , Gleb Natapov To: Avi Kivity , Marcelo Tosatti Return-path: Received: from goliath.siemens.de ([192.35.17.28]:16739 "EHLO goliath.siemens.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755576Ab0DNNvM (ORCPT ); Wed, 14 Apr 2010 09:51:12 -0400 Sender: kvm-owner@vger.kernel.org List-ID: Stop the switch immediately if task_switch_16/32 returned an error. Only if that step succeeded, the switch should actually take place and update any register states. Signed-off-by: Jan Kiszka --- arch/x86/kvm/emulate.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 083b269..aace565 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -2402,6 +2402,8 @@ static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt, else ret = task_switch_16(ctxt, ops, tss_selector, old_tss_sel, old_tss_base, &next_tss_desc); + if (ret != X86EMUL_CONTINUE) + return ret; if (reason == TASK_SWITCH_CALL || reason == TASK_SWITCH_GATE) ctxt->eflags = ctxt->eflags | X86_EFLAGS_NT;