From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [PATCH 2/2] KVM: selftests: Enable dirty_log_test on s390x References: <20190730100112.18205-1-thuth@redhat.com> <20190730100112.18205-3-thuth@redhat.com> From: Thomas Huth Message-ID: <02c5c7b4-c45e-4573-d2c3-ebfa2cd2c9d1@redhat.com> Date: Tue, 30 Jul 2019 19:11:23 +0200 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kselftest-owner@vger.kernel.org List-ID: To: Christian Borntraeger , kvm@vger.kernel.org, Janosch Frank Cc: linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, David Hildenbrand , Cornelia Huck , Paolo Bonzini , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , Shuah Khan , Peter Xu On 30/07/2019 16.57, Christian Borntraeger wrote: > > > On 30.07.19 12:01, Thomas Huth wrote: >> To run the dirty_log_test on s390x, we have to make sure that we >> access the dirty log bitmap with little endian byte ordering and >> we have to properly align the memslot of the guest. >> Also all dirty bits of a segment are set once on s390x when one >> of the pages of a segment are written to for the first time, so >> we have to make sure that we touch all pages during the first >> iteration to keep the test in sync here. > > While this fixes the test (and the migration does work fine), it still > means that s390x overindicates the dirty bit for sparsely populated > 1M segments. It is just a performance issue, but maybe we should try > to get this fixed. I hope you don't expect me to fix this - the gmap code is really not my turf... > Not sure what to do here to remember us about this, > adding this as expected fail? There is no such thing like an expected failure in KVM selftests - that's only available in kvm-unit-tests. So the only option that I currently see is to add a printf("TODO: ...") on s390x here... would that work for you? Thomas