From patchwork Tue Aug 26 11:43:13 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoffer Dall X-Patchwork-Id: 4780651 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 1358F9F2A9 for ; Tue, 26 Aug 2014 11:47:21 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 1B66720176 for ; Tue, 26 Aug 2014 11:47:20 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 21EDE2015A for ; Tue, 26 Aug 2014 11:47:19 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1XMFAV-0007wW-V8; Tue, 26 Aug 2014 11:44:07 +0000 Received: from mail-lb0-f182.google.com ([209.85.217.182]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XMFAS-0007sB-DZ for linux-arm-kernel@lists.infradead.org; Tue, 26 Aug 2014 11:44:05 +0000 Received: by mail-lb0-f182.google.com with SMTP id n15so1211525lbi.27 for ; Tue, 26 Aug 2014 04:43:39 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=X8lVQaK6/SxLDXMiTXN5HfIzayMS1oCdT5JiuPiTWKk=; b=NDQqRSZc6utFl9U6QHs3fP9/IztBZZKAJyUMTrYp2gXyysrKdbPOftVRkA9ERnZ445 fGs7L4Axd1PtZ8Qt8BLF5Zy8OmqiwMdBKW7PCqh9dSsnFNC6X8eOMTW8y40EmovBk34t NV7F8SHoW7Nh40kl0fD19OAEI9yXAgKWramqsTZV7v8OqQwj72p0UUCJR0ZwCx69SJ/Z DKdEwS0iFRAeqzILGedfbMNc82KxqbVZRHwndvR97QwN3dmuIIiZEIgUU1uv8LTxdD+J df6rGueP8M5z+A8+bg0oeOXedzQ2p1k8dTKc6aWs31sy3/yrDWqNMUouK3PECi5+I3B3 jXvw== X-Gm-Message-State: ALoCoQk7RG/xBYXqNCSJ4GYaJQnOMnRFfVOsSHP63QWP/tZmaOhlZcXPtr/eb+4+KRYTlxUj9RLm X-Received: by 10.152.21.6 with SMTP id r6mr9250340lae.6.1409053418789; Tue, 26 Aug 2014 04:43:38 -0700 (PDT) Received: from localhost.localdomain (188-178-240-98-static.dk.customer.tdc.net. [188.178.240.98]) by mx.google.com with ESMTPSA id yx5sm4770556lbb.35.2014.08.26.04.43.36 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 26 Aug 2014 04:43:37 -0700 (PDT) From: Christoffer Dall To: kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org Subject: [PATCH v3 2/2] arm/arm64: KVM: Support KVM_CAP_READONLY_MEM Date: Tue, 26 Aug 2014 13:43:13 +0200 Message-Id: <1409053393-13768-2-git-send-email-christoffer.dall@linaro.org> X-Mailer: git-send-email 2.0.0 In-Reply-To: <1409053393-13768-1-git-send-email-christoffer.dall@linaro.org> References: <1409053393-13768-1-git-send-email-christoffer.dall@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140826_044404_639814_7A5C2456 X-CRM114-Status: GOOD ( 15.60 ) X-Spam-Score: -0.7 (/) Cc: Marc Zyngier , Peter Maydell , Christoffer Dall , Ard Biesheuvel X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP When userspace loads code and data in a read-only memory regions, KVM needs to be able to handle this on arm and arm64. Specifically this is used when running code directly from a read-only flash device; the common scenario is a UEFI blob loaded with the -bios option in QEMU. Note that the MMIO exit on writes to a read-only memory is ABI and can be used to emulate block-erase style flash devices. Cc: Ard Biesheuvel Signed-off-by: Christoffer Dall Acked-by: Marc Zyngier Tested-by: Ard Biesheuvel --- Changelog[v3]: - Remove the check for fault_status != FSC_FAULT in the I/O memory abort section, since we now do support permission faults on I/O regions. Reported-by: Ard Biesheuvel Changelog[v2]: - None arch/arm/include/uapi/asm/kvm.h | 1 + arch/arm/kvm/arm.c | 1 + arch/arm/kvm/mmu.c | 22 ++++++++-------------- arch/arm64/include/uapi/asm/kvm.h | 1 + 4 files changed, 11 insertions(+), 14 deletions(-) diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h index e6ebdd3..51257fd 100644 --- a/arch/arm/include/uapi/asm/kvm.h +++ b/arch/arm/include/uapi/asm/kvm.h @@ -25,6 +25,7 @@ #define __KVM_HAVE_GUEST_DEBUG #define __KVM_HAVE_IRQ_LINE +#define __KVM_HAVE_READONLY_MEM #define KVM_REG_SIZE(id) \ (1U << (((id) & KVM_REG_SIZE_MASK) >> KVM_REG_SIZE_SHIFT)) diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index 9f788eb..ac306b4 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -188,6 +188,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_ONE_REG: case KVM_CAP_ARM_PSCI: case KVM_CAP_ARM_PSCI_0_2: + case KVM_CAP_READONLY_MEM: r = 1; break; case KVM_CAP_COALESCED_MMIO: diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c index 16e7994..62f5642 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -747,14 +747,13 @@ static bool transparent_hugepage_adjust(pfn_t *pfnp, phys_addr_t *ipap) } static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, - struct kvm_memory_slot *memslot, + struct kvm_memory_slot *memslot, unsigned long hva, unsigned long fault_status) { int ret; bool write_fault, writable, hugetlb = false, force_pte = false; unsigned long mmu_seq; gfn_t gfn = fault_ipa >> PAGE_SHIFT; - unsigned long hva = gfn_to_hva(vcpu->kvm, gfn); struct kvm *kvm = vcpu->kvm; struct kvm_mmu_memory_cache *memcache = &vcpu->arch.mmu_page_cache; struct vm_area_struct *vma; @@ -863,7 +862,8 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run) unsigned long fault_status; phys_addr_t fault_ipa; struct kvm_memory_slot *memslot; - bool is_iabt; + unsigned long hva; + bool is_iabt, write_fault, writable; gfn_t gfn; int ret, idx; @@ -884,7 +884,10 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run) idx = srcu_read_lock(&vcpu->kvm->srcu); gfn = fault_ipa >> PAGE_SHIFT; - if (!kvm_is_visible_gfn(vcpu->kvm, gfn)) { + memslot = gfn_to_memslot(vcpu->kvm, gfn); + hva = gfn_to_hva_memslot_prot(memslot, gfn, &writable); + write_fault = kvm_is_write_fault(kvm_vcpu_get_hsr(vcpu)); + if (kvm_is_error_hva(hva) || (write_fault && !writable)) { if (is_iabt) { /* Prefetch Abort on I/O address */ kvm_inject_pabt(vcpu, kvm_vcpu_get_hfar(vcpu)); @@ -892,13 +895,6 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run) goto out_unlock; } - if (fault_status != FSC_FAULT) { - kvm_err("Unsupported fault status on io memory: %#lx\n", - fault_status); - ret = -EFAULT; - goto out_unlock; - } - /* * The IPA is reported as [MAX:12], so we need to * complement it with the bottom 12 bits from the @@ -910,9 +906,7 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run) goto out_unlock; } - memslot = gfn_to_memslot(vcpu->kvm, gfn); - - ret = user_mem_abort(vcpu, fault_ipa, memslot, fault_status); + ret = user_mem_abort(vcpu, fault_ipa, memslot, hva, fault_status); if (ret == 0) ret = 1; out_unlock: diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h index e633ff8..f4ec5a6 100644 --- a/arch/arm64/include/uapi/asm/kvm.h +++ b/arch/arm64/include/uapi/asm/kvm.h @@ -37,6 +37,7 @@ #define __KVM_HAVE_GUEST_DEBUG #define __KVM_HAVE_IRQ_LINE +#define __KVM_HAVE_READONLY_MEM #define KVM_REG_SIZE(id) \ (1U << (((id) & KVM_REG_SIZE_MASK) >> KVM_REG_SIZE_SHIFT))