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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 B344DC3A5A2 for ; Tue, 3 Sep 2019 16:31:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8971623431 for ; Tue, 3 Sep 2019 16:31:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567528272; bh=FkGpRU1yy9aEz6Lo31CjpS1AI9j+y3Elk0LzZ2y+ofY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=E8nH34m20wXv2zgZMSYA4LqQLH/AAkqWZbh5WlYazcGT1NaiNENafTJOV4RelWxut 2Bpf9C6JhlbqjzJnIH7wHAfomtu92AXIQt74JTCKK0beqb6MUrfq6Q0mtJ7SDUSI5h 31XfYf6l+mhVrAH8iKLF6Z+/9yFkSwTA7cGjcbbo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729936AbfICQ2e (ORCPT ); Tue, 3 Sep 2019 12:28:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:50572 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727107AbfICQ2d (ORCPT ); Tue, 3 Sep 2019 12:28:33 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E3129215EA; Tue, 3 Sep 2019 16:28:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567528111; bh=FkGpRU1yy9aEz6Lo31CjpS1AI9j+y3Elk0LzZ2y+ofY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=amPuOO3ARIp3oBp2Rjhy7U0gnQcX7TpkPYBoYJBu2+9WaNSSoNw92sOhUTXZM41S0 3hWBwE8f3gv2Oy2GPL1ci3/xLtbZubmvSGkNtkTYYYp8rlNgEX2pB+igEyYHxdaQef FH2twAkeoDVXjmiBvoUGVJrI251GbfxLVoZGV+zQ= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Peter Xu , Paolo Bonzini , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , Alex Williamson , Eduardo Habkost , Sasha Levin , kvm@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 115/167] kvm: Check irqchip mode before assign irqfd Date: Tue, 3 Sep 2019 12:24:27 -0400 Message-Id: <20190903162519.7136-115-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190903162519.7136-1-sashal@kernel.org> References: <20190903162519.7136-1-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Peter Xu [ Upstream commit 654f1f13ea56b92bacade8ce2725aea0457f91c0 ] When assigning kvm irqfd we didn't check the irqchip mode but we allow KVM_IRQFD to succeed with all the irqchip modes. However it does not make much sense to create irqfd even without the kernel chips. Let's provide a arch-dependent helper to check whether a specific irqfd is allowed by the arch. At least for x86, it should make sense to check: - when irqchip mode is NONE, all irqfds should be disallowed, and, - when irqchip mode is SPLIT, irqfds that are with resamplefd should be disallowed. For either of the case, previously we'll silently ignore the irq or the irq ack event if the irqchip mode is incorrect. However that can cause misterious guest behaviors and it can be hard to triage. Let's fail KVM_IRQFD even earlier to detect these incorrect configurations. CC: Paolo Bonzini CC: Radim Krčmář CC: Alex Williamson CC: Eduardo Habkost Signed-off-by: Peter Xu Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini Signed-off-by: Sasha Levin --- arch/x86/kvm/irq.c | 7 +++++++ arch/x86/kvm/irq.h | 1 + virt/kvm/eventfd.c | 9 +++++++++ 3 files changed, 17 insertions(+) diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c index faa264822cee3..007bc654f928a 100644 --- a/arch/x86/kvm/irq.c +++ b/arch/x86/kvm/irq.c @@ -172,3 +172,10 @@ void __kvm_migrate_timers(struct kvm_vcpu *vcpu) __kvm_migrate_apic_timer(vcpu); __kvm_migrate_pit_timer(vcpu); } + +bool kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args) +{ + bool resample = args->flags & KVM_IRQFD_FLAG_RESAMPLE; + + return resample ? irqchip_kernel(kvm) : irqchip_in_kernel(kvm); +} diff --git a/arch/x86/kvm/irq.h b/arch/x86/kvm/irq.h index d5005cc265217..fd210cdd49839 100644 --- a/arch/x86/kvm/irq.h +++ b/arch/x86/kvm/irq.h @@ -114,6 +114,7 @@ static inline int irqchip_in_kernel(struct kvm *kvm) return mode != KVM_IRQCHIP_NONE; } +bool kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args); void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu); void kvm_inject_apic_timer_irqs(struct kvm_vcpu *vcpu); void kvm_apic_nmi_wd_deliver(struct kvm_vcpu *vcpu); diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c index b20b751286fc6..757a17f5ebdeb 100644 --- a/virt/kvm/eventfd.c +++ b/virt/kvm/eventfd.c @@ -44,6 +44,12 @@ static struct workqueue_struct *irqfd_cleanup_wq; +bool __attribute__((weak)) +kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args) +{ + return true; +} + static void irqfd_inject(struct work_struct *work) { @@ -297,6 +303,9 @@ kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd *args) if (!kvm_arch_intc_initialized(kvm)) return -EAGAIN; + if (!kvm_arch_irqfd_allowed(kvm, args)) + return -EINVAL; + irqfd = kzalloc(sizeof(*irqfd), GFP_KERNEL); if (!irqfd) return -ENOMEM; -- 2.20.1