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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 6123FC55193 for ; Thu, 23 Apr 2020 17:39:15 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id 20E5D20736 for ; Thu, 23 Apr 2020 17:39:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 20E5D20736 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvmarm-bounces@lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id CF1354B19E; Thu, 23 Apr 2020 13:39:14 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id vA06+5FpCZkT; Thu, 23 Apr 2020 13:39:13 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id A4E504B1B7; Thu, 23 Apr 2020 13:39:13 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 5D2EC4B194 for ; Thu, 23 Apr 2020 13:39:10 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id bQCNUZ9qJ3r5 for ; Thu, 23 Apr 2020 13:39:09 -0400 (EDT) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 49D0F4B19C for ; Thu, 23 Apr 2020 13:39:09 -0400 (EDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id F346D11B3; Thu, 23 Apr 2020 10:39:08 -0700 (PDT) Received: from localhost.localdomain (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8E9A53F68F; Thu, 23 Apr 2020 10:39:07 -0700 (PDT) From: Andre Przywara To: Will Deacon , Julien Thierry Subject: [PATCH kvmtool v4 4/5] memslot: Add support for READONLY mappings Date: Thu, 23 Apr 2020 18:38:43 +0100 Message-Id: <20200423173844.24220-5-andre.przywara@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200423173844.24220-1-andre.przywara@arm.com> References: <20200423173844.24220-1-andre.przywara@arm.com> Cc: kvm@vger.kernel.org, Ard Biesheuvel , Raphael Gault , Sami Mujawar , kvmarm@lists.cs.columbia.edu X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu A KVM memslot has a flags field, which allows to mark a region as read-only. Add another memory type bit to allow kvmtool-internal users to map a write-protected region. Write access would trap and can be handled by the MMIO emulation, which should register on the same guest address region. Signed-off-by: Andre Przywara --- include/kvm/kvm.h | 12 ++++++++---- kvm.c | 5 +++++ 2 files changed, 13 insertions(+), 4 deletions(-) diff --git a/include/kvm/kvm.h b/include/kvm/kvm.h index 9428f57a..53373b08 100644 --- a/include/kvm/kvm.h +++ b/include/kvm/kvm.h @@ -40,10 +40,12 @@ enum kvm_mem_type { KVM_MEM_TYPE_RAM = 1 << 0, KVM_MEM_TYPE_DEVICE = 1 << 1, KVM_MEM_TYPE_RESERVED = 1 << 2, + KVM_MEM_TYPE_READONLY = 1 << 3, KVM_MEM_TYPE_ALL = KVM_MEM_TYPE_RAM | KVM_MEM_TYPE_DEVICE | KVM_MEM_TYPE_RESERVED + | KVM_MEM_TYPE_READONLY }; struct kvm_ext { @@ -158,17 +160,19 @@ u64 host_to_guest_flat(struct kvm *kvm, void *ptr); bool kvm__arch_load_kernel_image(struct kvm *kvm, int fd_kernel, int fd_initrd, const char *kernel_cmdline); +#define add_read_only(type, str) \ + (((type) & KVM_MEM_TYPE_READONLY) ? str " (read-only)" : str) static inline const char *kvm_mem_type_to_string(enum kvm_mem_type type) { - switch (type) { + switch (type & ~KVM_MEM_TYPE_READONLY) { case KVM_MEM_TYPE_ALL: return "(all)"; case KVM_MEM_TYPE_RAM: - return "RAM"; + return add_read_only(type, "RAM"); case KVM_MEM_TYPE_DEVICE: - return "device"; + return add_read_only(type, "device"); case KVM_MEM_TYPE_RESERVED: - return "reserved"; + return add_read_only(type, "reserved"); } return "???"; diff --git a/kvm.c b/kvm.c index 26f6b9bc..e327541d 100644 --- a/kvm.c +++ b/kvm.c @@ -242,6 +242,7 @@ int kvm__register_mem(struct kvm *kvm, u64 guest_phys, u64 size, struct kvm_mem_bank *bank; struct list_head *prev_entry; u32 slot; + u32 flags = 0; int ret; mutex_lock(&kvm->mem_banks_lock); @@ -313,9 +314,13 @@ int kvm__register_mem(struct kvm *kvm, u64 guest_phys, u64 size, bank->type = type; bank->slot = slot; + if (type & KVM_MEM_TYPE_READONLY) + flags |= KVM_MEM_READONLY; + if (type != KVM_MEM_TYPE_RESERVED) { mem = (struct kvm_userspace_memory_region) { .slot = slot, + .flags = flags, .guest_phys_addr = guest_phys, .memory_size = size, .userspace_addr = (unsigned long)userspace_addr, -- 2.17.1 _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm