From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Fedin Subject: RE: [PATCH v4 0/4] KVM: arm64: BUG FIX: Correctly handle zero register transfers Date: Mon, 07 Dec 2015 12:48:12 +0300 Message-ID: <013501d130d4$635722f0$2a0568d0$@samsung.com> References: <20151205003334.GB3117@hawk.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, 'Marc Zyngier' To: 'Andrew Jones' Return-path: Received: from mailout2.w1.samsung.com ([210.118.77.12]:15882 "EHLO mailout2.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754988AbbLGJsP (ORCPT ); Mon, 7 Dec 2015 04:48:15 -0500 Received: from eucpsbgm1.samsung.com (unknown [203.254.199.244]) by mailout2.w1.samsung.com (Oracle Communications Messaging Server 7.0.5.31.0 64bit (built May 5 2014)) with ESMTP id <0NYZ00KV6F8DXL60@mailout2.w1.samsung.com> for kvm@vger.kernel.org; Mon, 07 Dec 2015 09:48:13 +0000 (GMT) In-reply-to: <20151205003334.GB3117@hawk.localdomain> Content-language: ru Sender: kvm-owner@vger.kernel.org List-ID: Hello! > FYI, I tried writing test cases for this issue with kvm-unit-tests. The > issue didn't reproduce for me. It's quite possible my test cases are > flawed Indeed they are, a very little thing fell through again... :) It's not just SP, it's SP_EL0. And you never initialize it to anything because your code always runs in kernel mode, so it's just zero, so you get your zero. But if you add a little thing in the beginning of your main(): asm volatile("msr sp_el0, %0" : : "r" (0xDEADC0DE0BADC0DE)); then you have it: --- cut --- [root@thunderx-2 kvm-unit-tests]# ./arm-run arm/xzr-test.flat -smp 2 qemu-system-aarch64 -machine virt,accel=kvm:tcg,gic-version=host -cpu host -device virtio-serial-device -device virtconsole,chardev=ctd -chardev testdev,id=ctd -display none -serial stdio -kernel arm/xzr-test.flat -smp 2 PASS: mmio: sanity check: read 0x55555555 FAIL: mmio: 'str wzr' check: read 0x0badc0de vm_setup_vq: virtqueue 0 already setup! base=0xa003e00 chr_testdev_init: chr-testdev: can't init virtqueues --- cut --- Here i run only MMIO test, because i could not compile sysreg one, so i simply commented it out. P.S. Could you also apply something like the following to arm/run: --- cut --- arm/run | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arm/run b/arm/run index 662a856..3890c8c 100755 --- a/arm/run +++ b/arm/run @@ -33,7 +33,11 @@ if $qemu $M -chardev testdev,id=id -initrd . 2>&1 \ exit 2 fi -M='-machine virt,accel=kvm:tcg' +if $qemu $M,? 2>&1 | grep gic-version > /dev/null; then + GIC='gic-version=host,' +fi + +M="-machine virt,${GIC}accel=kvm:tcg" chr_testdev='-device virtio-serial-device' chr_testdev+=' -device virtconsole,chardev=ctd -chardev testdev,id=ctd' --- cut --- Without it qemu does not work on GICv3-only hardware, like my board, because it defaults to gic-version=2. I don't post the patch on the mailing lists, because in order to be able to post this 5-liner i'll need to go through the formal approval procedure at my company, and i just don't want to bother for a single small fix. :) Will do as a "Reported-by:". Kind regards, Pavel Fedin Expert Engineer Samsung Electronics Research center Russia