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=-16.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 C11DFC4338F for ; Tue, 27 Jul 2021 18:21:07 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 8F2A960D07 for ; Tue, 27 Jul 2021 18:21:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 8F2A960D07 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=j28+8UdN8qxiO//fszG4kLin7SLyTPJsj0gTJ6B9UMM=; b=xULRoCtnt7aYf1 TGbjfKZzKEU3u32vGGU8S6wxGhgly5XXmCwRF0GCR3yAhCkXpyJsjO6kLmZ8kjfiuLOQiaA+I1WLR QqFGtMAAvusm0/BF6d5oFyC4FY4u9ktB4LlTfcp5l1YlHiTPjOBduznbYiRUaSa1hHFcaOgKq766P BzjmVG4bAvYA5Jo4Cver11ZgWIUoFORwWtFOAbS+N2P+I3AIuBSUt7OOQA1GJA0fW7M7OAOTnP5Ct tUYxhavOZwqZOXcjM/Q5pk4sMlRmKfjYSKsC6lGvCmtPhuX6f3iyZEAscYeDB+2EU5jbJCMgCVGV8 Q1UVrde3N2P99plXQnug==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1m8RfQ-00Fo3D-K9; Tue, 27 Jul 2021 18:19:01 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1m8RXu-00FkY3-77 for linux-arm-kernel@lists.infradead.org; Tue, 27 Jul 2021 18:11:15 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 99D7C60E08; Tue, 27 Jul 2021 18:11:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1627409473; bh=Ur9pPprRGIm8RpSOIFYLtAZgxXBn8A4m1Hk9iN9rkZc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=e/ICnhp6aRMvqV04av0WLSCRwkFNQARS2FeYE73O8FFruDTT08mE1JSXZRCFs9oGE er58B9wzWaHOMFVXzixU1Cpzxc4HLo8nXU5ZVCbrAwtsB4WvrBLEBVg1S8Y/4UUsxT WX5J+1jZA/oiK9jV2Uy55Efn9cAKule7OT2mBjrixbZfAlr8WE7+nC4ufK1ldFNVd6 SET5afmktu2rLx5qD8oIt15eXdgWbIaBS0a7bLNSY02wrzeU0giD99SlI2+HM3hDql Z6Kb/5pXpTKND+qlOZEFh7NpLyWNuTOA1RBiDrEASbAdtd2Toti/IFGZchJnWldb2K Pzslq2gLCrdXA== Date: Tue, 27 Jul 2021 19:11:08 +0100 From: Will Deacon To: Marc Zyngier Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, qperret@google.com, dbrazdil@google.com, Srivatsa Vaddagiri , Shanker R Donthineni , James Morse , Suzuki K Poulose , Alexandru Elisei , kernel-team@android.com Subject: Re: [PATCH 04/16] KVM: arm64: Add MMIO checking infrastructure Message-ID: <20210727181107.GC19173@willie-the-truck> References: <20210715163159.1480168-1-maz@kernel.org> <20210715163159.1480168-5-maz@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210715163159.1480168-5-maz@kernel.org> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210727_111114_347402_A001B80C X-CRM114-Status: GOOD ( 23.11 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Jul 15, 2021 at 05:31:47PM +0100, Marc Zyngier wrote: > Introduce the infrastructure required to identify an IPA region > that is expected to be used as an MMIO window. > > This include mapping, unmapping and checking the regions. Nothing > calls into it yet, so no expected functional change. > > Signed-off-by: Marc Zyngier > --- > arch/arm64/include/asm/kvm_host.h | 2 + > arch/arm64/include/asm/kvm_mmu.h | 5 ++ > arch/arm64/kvm/mmu.c | 115 ++++++++++++++++++++++++++++++ > 3 files changed, 122 insertions(+) > > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > index 4add6c27251f..914c1b7bb3ad 100644 > --- a/arch/arm64/include/asm/kvm_host.h > +++ b/arch/arm64/include/asm/kvm_host.h > @@ -125,6 +125,8 @@ struct kvm_arch { > #define KVM_ARCH_FLAG_RETURN_NISV_IO_ABORT_TO_USER 0 > /* Memory Tagging Extension enabled for the guest */ > #define KVM_ARCH_FLAG_MTE_ENABLED 1 > + /* Gues has bought into the MMIO guard extension */ > +#define KVM_ARCH_FLAG_MMIO_GUARD 2 > unsigned long flags; > > /* > diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h > index b52c5c4b9a3d..f6b8fc1671b3 100644 > --- a/arch/arm64/include/asm/kvm_mmu.h > +++ b/arch/arm64/include/asm/kvm_mmu.h > @@ -170,6 +170,11 @@ phys_addr_t kvm_mmu_get_httbr(void); > phys_addr_t kvm_get_idmap_vector(void); > int kvm_mmu_init(u32 *hyp_va_bits); > > +/* MMIO guard */ > +bool kvm_install_ioguard_page(struct kvm_vcpu *vcpu, gpa_t ipa); > +bool kvm_remove_ioguard_page(struct kvm_vcpu *vcpu, gpa_t ipa); > +bool kvm_check_ioguard_page(struct kvm_vcpu *vcpu, gpa_t ipa); > + > static inline void *__kvm_vector_slot2addr(void *base, > enum arm64_hyp_spectre_vector slot) > { > diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c > index 3155c9e778f0..638827c8842b 100644 > --- a/arch/arm64/kvm/mmu.c > +++ b/arch/arm64/kvm/mmu.c > @@ -1120,6 +1120,121 @@ static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa) > kvm_set_pfn_accessed(pte_pfn(pte)); > } > > +#define MMIO_NOTE ('M' << 24 | 'M' << 16 | 'I' << 8 | '0') Although this made me smile, maybe we should carve up the bit space a bit more carefully ;) Also, you know somebody clever will "fix" that typo to 'O'! Quentin, as the other user of this stuff at the moment, how do you see the annotation space being allocated? Feels like we should have some 'type' bits which decide how to parse the rest of the entry. > + > +bool kvm_install_ioguard_page(struct kvm_vcpu *vcpu, gpa_t ipa) > +{ > + struct kvm_mmu_memory_cache *memcache; > + struct kvm_memory_slot *memslot; > + int ret, idx; > + > + if (!test_bit(KVM_ARCH_FLAG_MMIO_GUARD, &vcpu->kvm->arch.flags)) > + return false; > + > + /* Must be page-aligned */ > + if (ipa & ~PAGE_MASK) > + return false; > + > + /* > + * The page cannot be in a memslot. At some point, this will > + * have to deal with device mappings though. > + */ > + idx = srcu_read_lock(&vcpu->kvm->srcu); > + memslot = gfn_to_memslot(vcpu->kvm, ipa >> PAGE_SHIFT); > + srcu_read_unlock(&vcpu->kvm->srcu, idx); What does this memslot check achieve? A new memslot could be added after you've checked, no? > +/* Assumes mmu_lock taken */ You can use a lockdep assertion for that! Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel