From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8CEEAC433F5 for ; Mon, 18 Oct 2021 11:23:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7396160F9D for ; Mon, 18 Oct 2021 11:23:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231316AbhJRLZV (ORCPT ); Mon, 18 Oct 2021 07:25:21 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:38291 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231271AbhJRLZU (ORCPT ); Mon, 18 Oct 2021 07:25:20 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1634556189; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=DH9MmuWPIFv8Xp2QWT2sodcLkmf50VTNvopcpg7U4YM=; b=cQJcyW+c4/Nmuc3RFniOWr4SOarAOWfJV59DpuT3Oe8E60s1PkWMEgwAUVaKJk3QCoY/Al e0MvdCGPZeGV+rsBCyaaDSQte/VVp8/J8PZP6FbsidNuaO8PyR2DN6CfRBwDPaonZHcfps 37THpLABk6zoTPkB4yVQU25tgaaz8tE= Received: from mail-wm1-f71.google.com (mail-wm1-f71.google.com [209.85.128.71]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-221-uBDyPJdcNk2xVw8uqTEu5w-1; Mon, 18 Oct 2021 07:23:07 -0400 X-MC-Unique: uBDyPJdcNk2xVw8uqTEu5w-1 Received: by mail-wm1-f71.google.com with SMTP id s10-20020a1cf20a000000b0030d66991388so3070580wmc.7 for ; Mon, 18 Oct 2021 04:23:07 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:in-reply-to:references:date :message-id:mime-version; bh=DH9MmuWPIFv8Xp2QWT2sodcLkmf50VTNvopcpg7U4YM=; b=Paq50zTtB6VYZZl0/oruoNUgABZB/jAG0HQ6uFfhLjgHJ/yXwjzJm7BuPhrqiJdYcu oiX7mW6gVyLOSf5KDqDK/rj29x2EB5bZM1dlMf6UgU4ekJLakVaFQoJb98O1cy8/n3gp 68xtC+GRfpobMT7RXaiJzmJpaqmapzOIneISiBNb2DDN5jchtWVfV0jmHTiQFUKqbQje E4Bd7BSxIxKdVB5iMWmCYy7vZGg4msIJnrrGpllUucWdOi3ESU65tPSeDwWcHylVAJVL 4hdurWACGvHYB9IptOm2137AKi6ng71g0k/trlTKBiQ/gyaHcCKwRiPPQtGigeOsv2/9 hoSQ== X-Gm-Message-State: AOAM532EIGMB5ms9/IQnpEfPJoHPWTzdpFIoF0ixU11n8Oh4dW+SwDcY Wo5ItUrOxAMnvbacnrW0ASRwUxMOmpztlJPsT8nl0uyeY9nWMq7PBo37A55QyzCrtDmbSlTBdiJ FGO3X0WXnl7OP X-Received: by 2002:adf:d1e3:: with SMTP id g3mr35329029wrd.63.1634556186814; Mon, 18 Oct 2021 04:23:06 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzE/NxmnDikAIWz7KVPC9n9ISxaSf9rTpK5oYp0RHeXe6M+UoOV2w6tzahEFy7lHBOVHl0z7w== X-Received: by 2002:adf:d1e3:: with SMTP id g3mr35329003wrd.63.1634556186611; Mon, 18 Oct 2021 04:23:06 -0700 (PDT) Received: from vitty.brq.redhat.com (g-server-2.ign.cz. [91.219.240.2]) by smtp.gmail.com with ESMTPSA id t1sm2185823wre.32.2021.10.18.04.23.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 18 Oct 2021 04:23:06 -0700 (PDT) From: Vitaly Kuznetsov To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, Wanpeng Li , Jim Mattson , Tom Lendacky , David Matlack , linux-kernel@vger.kernel.org, Maxim Levitsky Subject: Re: [PATCH RFC] KVM: SVM: reduce guest MAXPHYADDR by one in case C-bit is a physical bit In-Reply-To: <87ee8iye6b.fsf@vitty.brq.redhat.com> References: <20211015150524.2030966-1-vkuznets@redhat.com> <87ee8iye6b.fsf@vitty.brq.redhat.com> Date: Mon, 18 Oct 2021 13:23:04 +0200 Message-ID: <874k9ey3tz.fsf@vitty.brq.redhat.com> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Vitaly Kuznetsov writes: > Sean Christopherson writes: > >> On Fri, Oct 15, 2021, Vitaly Kuznetsov wrote: >>> Several selftests (memslot_modification_stress_test, kvm_page_table_test, >>> dirty_log_perf_test,.. ) which rely on vm_get_max_gfn() started to fail >>> since commit ef4c9f4f65462 ("KVM: selftests: Fix 32-bit truncation of >>> vm_get_max_gfn()") on AMD EPYC 7401P: >>> >>> ./tools/testing/selftests/kvm/demand_paging_test >>> Testing guest mode: PA-bits:ANY, VA-bits:48, 4K pages >>> guest physical test memory offset: 0xffffbffff000 >> >> This look a lot like the signature I remember from the original bug[1]. I assume >> you're hitting the magic HyperTransport region[2]. I thought that was fixed, but >> the hack-a-fix for selftests never got applied[3]. >> >> [1] https://lore.kernel.org/lkml/20210623230552.4027702-4-seanjc@google.com/ > > Hey, > > it seems I'm only three months late to the party! > >> [2] https://lkml.kernel.org/r/7e3a90c0-75a1-b8fe-dbcf-bda16502ace9@amd.com >> [3] https://lkml.kernel.org/r/20210805105423.412878-1-pbonzini@redhat.com >> > > This patch helps indeed FWIW, 'access_tracking_perf_test' remains broken even after the patch is applied: # ./access_tracking_perf_test Testing guest mode: PA-bits:ANY, VA-bits:48, 4K pages guest physical test memory offset: 0xfffcbffff000 Populating memory : 3.858448918s Writing to populated memory : 0.937319626s Reading from populated memory : 0.003073207s ==== Test Assertion Failure ==== lib/kvm_util.c:1382: false pid=6422 tid=6425 errno=4 - Interrupted system call 1 0x000000000040667d: addr_gpa2hva at kvm_util.c:1382 2 (inlined by) addr_gpa2hva at kvm_util.c:1376 3 (inlined by) addr_gva2hva at kvm_util.c:2245 4 0x0000000000402909: lookup_pfn at access_tracking_perf_test.c:98 5 (inlined by) mark_vcpu_memory_idle at access_tracking_perf_test.c:152 6 (inlined by) vcpu_thread_main at access_tracking_perf_test.c:232 7 0x00007fd02d1cb431: ?? ??:0 8 0x00007fd02d0f9912: ?? ??:0 No vm physical memory at 0xfcbffff000 (and my cpuid hack reducing guest physical address space by half doesn't seem to help either) -- Vitaly