From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-183.mta1.migadu.com (out-183.mta1.migadu.com [95.215.58.183]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1503816C696 for ; Mon, 5 Aug 2024 23:56:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.183 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722902190; cv=none; b=X7ZPRPS/5V4kJKIfgIm6joCDYzLzCKXr0APOytbIVafaOItgMQM1W7RNoq1CjDEoY+WA2cFPg++tFUVV6y36bzcjIWIJ+B5i01xIicsH7EEa0e9htXmyWX5AuUOfQHbs+Lam3twyZtjABkmbQEPRpcUd2Xmw24G7h2SHsFd7OFY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722902190; c=relaxed/simple; bh=Il0vorw5sMMNi5kRXAvIxumP3y5S5hrk5bLk6JKlfbE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=GfbbJ5w7tTHyzOOobXbX9uJ0UPTJLd5WY3snjgcaFrhIaC07OuMXQf4VAP4MfsUXSE7CMqaVwRTpZjMV/jk8eabidsM1IbLDwVRznUPzeEWmY3QRiCGL41iwqBAhy3gQePrAWw7uX9CvTHiKDOza1ZFF1lTWiIKnuOoGuZbVSho= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=ltAj9C7x; arc=none smtp.client-ip=95.215.58.183 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="ltAj9C7x" Date: Mon, 5 Aug 2024 23:56:18 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1722902186; 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=pN1+APSAtAExH8nmjZxjfeQ8B4XYksdtaPF9+NGomwI=; b=ltAj9C7xL0C220uapJ5lUkG5kNHP2zZtS1WYxPlhAzd6j+Tb/QV3RDuco0pM+j1z556Q9A hoU/lQELQ0mjJMI+uXIgqaezOeALKRjbAQbjCFVaZB2D2C3tgIkiE36obKMbKTDvluByU8 L3cwZkpNHubjmM0zvEZGMwTs9FMKJX4= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Oliver Upton To: Sean Christopherson Cc: Paolo Bonzini , Marc Zyngier , Tianrui Zhao , Bibo Mao , Huacai Chen , Michael Ellerman , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Christian Borntraeger , Janosch Frank , Claudio Imbrenda , kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, David Matlack , David Stevens , Fuad Tabba Subject: Re: [PATCH v12 54/84] KVM: arm64: Mark "struct page" pfns accessed/dirty before dropping mmu_lock Message-ID: References: <20240726235234.228822-1-seanjc@google.com> <20240726235234.228822-55-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-mips@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Migadu-Flow: FLOW_OUT On Mon, Aug 05, 2024 at 04:53:01PM -0700, Sean Christopherson wrote: > On Mon, Aug 05, 2024, Oliver Upton wrote: > > > > --- > > > > arch/arm64/kvm/mmu.c | 10 ++++++---- > > > > 1 file changed, 6 insertions(+), 4 deletions(-) > > > > > > > > diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c > > > > index 22ee37360c4e..ce13c3d884d5 100644 > > > > --- a/arch/arm64/kvm/mmu.c > > > > +++ b/arch/arm64/kvm/mmu.c > > > > @@ -1685,15 +1685,17 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, > > > > } > > > > > > > > out_unlock: > > > > + if (writable && !ret) > > > > + kvm_set_pfn_dirty(pfn); > > > > > > I'm guessing you meant kvm_release_pfn_dirty() here, because this leaks > > > a reference. > > Doh, I did indeed. Alternatively, this could be: > > if (writable && !ret) > kvm_set_pfn_dirty(pfn); > > kvm_release_pfn_clean(pfn); > > It won't matter in the end, because this just becomes: > > kvm_release_faultin_page(kvm, page, !!ret, writable); > > So I guess the question is if you prefer to make the switch to an if-else in this > path, or more implicitly in the conversion to kvm_release_faultin_page(). > > I made the same goof for RISC-V, perhaps to prove that I too can copy+paste arm64's > MMU code ;-) LOL, whatever way you want to address it is fine by me, just wanted to make sure this intermediate bug wouldn't bite an unlucky bisection. -- Thanks, Oliver