From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 8D62E49626; Thu, 1 Aug 2024 07:34:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722497697; cv=none; b=C0LKgxEEixIvmvrz2Z71vPPn+rE7jB9LdR4DycUbwMvTH06/gu4HiRrcpjk3UmRiYz+Et59qLPerbK/FMgxrX3o8xuc+wbh71TJdCmSMxItWN+D3HxDT67sIfOwtr7+fYM9C0O/OSY2wLnZ5pU2VA4NGbSFTlL1RirBNwXMYR8Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722497697; c=relaxed/simple; bh=4fAL4cODCnjl0NV8qGw/Qqudnit/5hoHCsZrciMhbUs=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=k5YpY4R0L2a3dtzCWqRnB773xA7F7htuHc5vID+7jZnEq6MkxZW+qSQzIdy50YMa4wXUnOP0Qd83IqLfYQwedCPAuQxxrx0/dAeA0CrSriyf1l8EywNnJAEh9BsXuqVJHS70NhnTqxbL1krEWKk+U1xrX6aY0+w7OG2FeyKEoSI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=hm6lqGrn; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="hm6lqGrn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C540CC4AF0A; Thu, 1 Aug 2024 07:34:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1722497697; bh=4fAL4cODCnjl0NV8qGw/Qqudnit/5hoHCsZrciMhbUs=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=hm6lqGrnGLdGUt29ZxrQ9cGwGC5e/My8adr9xG8pGwOWvxzaIy2wVVZecHcsaS7MD 2vhxDp5qw6P6jWSVDdYpSlndt26lYMY/9L3hrdQVP6XL1jiOwA3de3PchwMF07I1N4 2YEHskiwTzLI1+iwXeDgxTjbuc9HN0GjQyrYNiG+t6NhVrrxrlXYCf8VJMbSS/9yNs oHiP/3JEHHEyg0SbxiUkt+heXZ9wY3Uvo6jOHCc4TGv31tTJIER/7SKgCRJbrwGHtk ninurOs1MqcQM+fogPcJEhZWkju/RfarTKElxrf4Eq/YQ9RcoW3WZjBJcrAerVNRjv rukvhfzurLf/A== X-Mailer: emacs 31.0.50 (via feedmail 11-beta-1 I) From: Aneesh Kumar K.V To: Sean Christopherson , Paolo Bonzini , Marc Zyngier , Oliver Upton , Tianrui Zhao , Bibo Mao , Huacai Chen , Michael Ellerman , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Christian Borntraeger , Janosch Frank , Claudio Imbrenda , Sean Christopherson Cc: 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 Subject: Re: [PATCH v12 02/84] KVM: arm64: Disallow copying MTE to guest memory while KVM is dirty logging In-Reply-To: <20240726235234.228822-3-seanjc@google.com> References: <20240726235234.228822-1-seanjc@google.com> <20240726235234.228822-3-seanjc@google.com> Date: Thu, 01 Aug 2024 13:04:43 +0530 Message-ID: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain Sean Christopherson writes: > Disallow copying MTE tags to guest memory while KVM is dirty logging, as > writing guest memory without marking the gfn as dirty in the memslot could > result in userspace failing to migrate the updated page. Ideally (maybe?), > KVM would simply mark the gfn as dirty, but there is no vCPU to work with, > and presumably the only use case for copy MTE tags _to_ the guest is when > restoring state on the target. > > Fixes: f0376edb1ddc ("KVM: arm64: Add ioctl to fetch/store tags in a guest") > Signed-off-by: Sean Christopherson > --- > arch/arm64/kvm/guest.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c > index e1f0ff08836a..962f985977c2 100644 > --- a/arch/arm64/kvm/guest.c > +++ b/arch/arm64/kvm/guest.c > @@ -1045,6 +1045,11 @@ int kvm_vm_ioctl_mte_copy_tags(struct kvm *kvm, > > mutex_lock(&kvm->slots_lock); > > + if (write && atomic_read(&kvm->nr_memslots_dirty_logging)) { > + ret = -EBUSY; > + goto out; > + } > + > is this equivalent to kvm_follow_pfn() with kfp->pin = 1 ? Should all those pin request fail if kvm->nr_memslots_dirty_logging != 0? > while (length > 0) { > kvm_pfn_t pfn = gfn_to_pfn_prot(kvm, gfn, write, NULL); > void *maddr; > -- > 2.46.0.rc1.232.g9752f9e123-goog