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 X-Spam-Level: X-Spam-Status: No, score=-3.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 79A69C352A4 for ; Thu, 6 Feb 2020 20:02:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 514A82464E for ; Thu, 6 Feb 2020 20:02:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="hBgEOeyp" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727974AbgBFUCK (ORCPT ); Thu, 6 Feb 2020 15:02:10 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:27868 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727791AbgBFUCJ (ORCPT ); Thu, 6 Feb 2020 15:02:09 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1581019327; 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=/yqizwNchM67CZ4udbXR6GdfQrlh05oiSzFTK/80D3I=; b=hBgEOeypVUq/Bk2/Mv0ebgPHdEH3aAt0k107JNazcsLPVG9J1D3PV/i+25ZFnhJxJO05js hdFJxlXUuCQ6NRRREzORuw6u9AAM2OlkpJd4UxQfk01ohUjkL61misp0lN4y7H9B0X6/HK PlGhGIOkvYMGNsnmW4+vePI6cz1WO4U= Received: from mail-qv1-f69.google.com (mail-qv1-f69.google.com [209.85.219.69]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-390-FcpskbkKN9K57xg_5UPCew-1; Thu, 06 Feb 2020 15:02:05 -0500 X-MC-Unique: FcpskbkKN9K57xg_5UPCew-1 Received: by mail-qv1-f69.google.com with SMTP id z9so4390472qvo.10 for ; Thu, 06 Feb 2020 12:02:05 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=/yqizwNchM67CZ4udbXR6GdfQrlh05oiSzFTK/80D3I=; b=YkGiAP/wgVTxh6GZLZVwZ5eiG2x6AI0Srt38VjDEoa6ptQBL1iPTwYuRSgcGrdZg6Q Ph/itm+r6H9NBIaP+ynd105dsCzpCirp+5CoRHjMwEH9NVU0OLJ1MZOpQfWcx30pDJJa Ods05o3OqLY180iDg01jAter6NrPY1Q/KzbiZNCQi+Y1Piy6+5iiSNiCajDEZItrXDbc HSc+oHqvHEioKi9XAo6h6D6DHGtzOPWqZahJyknah1PZYLsVHdDb7XjXil5EaIJgtift VkzhvJh9k69jn27sLo0w+0dB+DIjLwhck2zXZuu4GbwylQTIdsx4M0fNlluBuLtL1082 uYfg== X-Gm-Message-State: APjAAAWhI8TGPtXpFN3O/EuLKxKY1OaVvZd3uNQu1y24xFiYOjQ/yFJq Z2rHNQhjIONs3/qGpF3rvqD8yx0DWnKwzfmTEJMn87Oi/6PyUZq5ZcImE4we2RvrnRhzq3Z5h9D SkafRz/56RCCL X-Received: by 2002:ac8:19b6:: with SMTP id u51mr4287207qtj.319.1581019324646; Thu, 06 Feb 2020 12:02:04 -0800 (PST) X-Google-Smtp-Source: APXvYqzOujc3lNLMWX/FRlR8tea+183dvvLwpGv6w6oIURj933aU7qyXuyTi9CIJeDyrMsTLUQvKYA== X-Received: by 2002:ac8:19b6:: with SMTP id u51mr4287163qtj.319.1581019324320; Thu, 06 Feb 2020 12:02:04 -0800 (PST) Received: from xz-x1 ([2607:9880:19c8:32::2]) by smtp.gmail.com with ESMTPSA id k50sm163595qtc.90.2020.02.06.12.02.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 06 Feb 2020 12:02:03 -0800 (PST) Date: Thu, 6 Feb 2020 15:02:00 -0500 From: Peter Xu To: Sean Christopherson Cc: Paolo Bonzini , Paul Mackerras , Christian Borntraeger , Janosch Frank , David Hildenbrand , Cornelia Huck , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Marc Zyngier , James Morse , Julien Thierry , Suzuki K Poulose , linux-mips@vger.kernel.org, kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, Christoffer Dall , Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= Subject: Re: [PATCH v5 15/19] KVM: Provide common implementation for generic dirty log functions Message-ID: <20200206200200.GC700495@xz-x1> References: <20200121223157.15263-1-sean.j.christopherson@intel.com> <20200121223157.15263-16-sean.j.christopherson@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200121223157.15263-16-sean.j.christopherson@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Tue, Jan 21, 2020 at 02:31:53PM -0800, Sean Christopherson wrote: [...] > -int kvm_vm_ioctl_clear_dirty_log(struct kvm *kvm, struct kvm_clear_dirty_log *log) > +void kvm_arch_dirty_log_tlb_flush(struct kvm *kvm, > + struct kvm_memory_slot *memslot) If it's to flush TLB for a memslot, shall we remove the "dirty_log" in the name of the function, because it has nothing to do with dirty logging any more? And... > { > - struct kvm_memslots *slots; > - struct kvm_memory_slot *memslot; > - bool flush = false; > - int r; > - > - mutex_lock(&kvm->slots_lock); > - > - r = kvm_clear_dirty_log_protect(kvm, log, &flush); > - > - if (flush) { > - slots = kvm_memslots(kvm); > - memslot = id_to_memslot(slots, log->slot); > - > - /* Let implementation handle TLB/GVA invalidation */ > - kvm_mips_callbacks->flush_shadow_memslot(kvm, memslot); > - } > - > - mutex_unlock(&kvm->slots_lock); > - return r; > + /* Let implementation handle TLB/GVA invalidation */ > + kvm_mips_callbacks->flush_shadow_memslot(kvm, memslot); ... This may not directly related to the current patch, but I'm confused on why MIPS cannot use kvm_flush_remote_tlbs() to flush TLBs. I know nothing about MIPS code, but IIUC here flush_shadow_memslot() is a heavier operation that will also invalidate the shadow pages. Seems to be an overkill here when we only changed write permission of the PTEs? I tried to check the first occurance (2a31b9db15353) but I didn't find out any clue of it so far. But that matters to this patch because if MIPS can use kvm_flush_remote_tlbs(), then we probably don't need this arch-specific hook any more and we can directly call kvm_flush_remote_tlbs() after sync dirty log when flush==true. > } > > long kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) > diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c > index 97ce6c4f7b48..0adaf4791a6d 100644 > --- a/arch/powerpc/kvm/book3s.c > +++ b/arch/powerpc/kvm/book3s.c > @@ -799,6 +799,11 @@ int kvmppc_core_check_requests(struct kvm_vcpu *vcpu) > return vcpu->kvm->arch.kvm_ops->check_requests(vcpu); > } > > +void kvm_arch_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot) Since at it, maybe we can start to use __weak attribute for new hooks especially when it's empty for most archs? E.g., define: void __weak kvm_arch_sync_dirty_log(...) {} In the common code, then only define it again in arch that has non-empty implementation of this method? -- Peter Xu