From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751725AbbIKDRy (ORCPT ); Thu, 10 Sep 2015 23:17:54 -0400 Received: from mx1.redhat.com ([209.132.183.28]:46426 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751618AbbIKDRx (ORCPT ); Thu, 10 Sep 2015 23:17:53 -0400 From: Jason Wang To: gleb@kernel.org, pbonzini@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: mst@redhat.com, cornelia.huck@de.ibm.com, Jason Wang Subject: [PATCH V4 3/4] kvm: fix zero length mmio searching Date: Fri, 11 Sep 2015 11:17:36 +0800 Message-Id: <1441941457-23630-4-git-send-email-jasowang@redhat.com> In-Reply-To: <1441941457-23630-1-git-send-email-jasowang@redhat.com> References: <1441941457-23630-1-git-send-email-jasowang@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently, if we had a zero length mmio eventfd assigned on KVM_MMIO_BUS. It will never found by kvm_io_bus_cmp() since it always compare the kvm_io_range() with the length that guest wrote. This will lead e.g for vhost, kick will be trapped by qemu userspace instead of vhost. Fixing this by using zero length if an iodevice is zero length. Cc: Gleb Natapov Cc: Paolo Bonzini Signed-off-by: Jason Wang --- virt/kvm/kvm_main.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index d8db2f8f..d4c3b66 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -3071,9 +3071,11 @@ static void kvm_io_bus_destroy(struct kvm_io_bus *bus) static inline int kvm_io_bus_cmp(const struct kvm_io_range *r1, const struct kvm_io_range *r2) { + int len = r2->len ? r1->len : 0; + if (r1->addr < r2->addr) return -1; - if (r1->addr + r1->len > r2->addr + r2->len) + if (r1->addr + len > r2->addr + r2->len) return 1; return 0; } -- 2.1.4