From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:36236 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750752AbbJMS3G (ORCPT ); Tue, 13 Oct 2015 14:29:06 -0400 Subject: Patch "kvm: fix zero length mmio searching" has been added to the 3.14-stable tree To: jasowang@redhat.com, cornelia.huck@de.ibm.com, gleb@kernel.org, gregkh@linuxfoundation.org, pbonzini@redhat.com Cc: , From: Date: Tue, 13 Oct 2015 11:20:59 -0700 Message-ID: <144476045948116@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled kvm: fix zero length mmio searching to the 3.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: kvm-fix-zero-length-mmio-searching.patch and it can be found in the queue-3.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 8f4216c7d28976f7ec1b2bcbfa0a9f787133c45e Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Tue, 15 Sep 2015 14:41:57 +0800 Subject: kvm: fix zero length mmio searching From: Jason Wang commit 8f4216c7d28976f7ec1b2bcbfa0a9f787133c45e upstream. Currently, if we had a zero length mmio eventfd assigned on KVM_MMIO_BUS. It will never be found by kvm_io_bus_cmp() since it always compares the kvm_io_range() with the length that guest wrote. This will cause 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 Reviewed-by: Cornelia Huck Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- virt/kvm/kvm_main.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2797,10 +2797,25 @@ static void kvm_io_bus_destroy(struct kv static inline int kvm_io_bus_cmp(const struct kvm_io_range *r1, const struct kvm_io_range *r2) { - if (r1->addr < r2->addr) + gpa_t addr1 = r1->addr; + gpa_t addr2 = r2->addr; + + if (addr1 < addr2) return -1; - if (r1->addr + r1->len > r2->addr + r2->len) + + /* If r2->len == 0, match the exact address. If r2->len != 0, + * accept any overlapping write. Any order is acceptable for + * overlapping ranges, because kvm_io_bus_get_first_dev ensures + * we process all of them. + */ + if (r2->len) { + addr1 += r1->len; + addr2 += r2->len; + } + + if (addr1 > addr2) return 1; + return 0; } Patches currently in stable-queue which might be from jasowang@redhat.com are queue-3.14/kvm-fix-zero-length-mmio-searching.patch