From patchwork Wed Dec 18 21:55:06 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 11302269 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 11FB5139A for ; Wed, 18 Dec 2019 22:02:10 +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 C79682146E for ; Wed, 18 Dec 2019 22:02:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Y22wCx59" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C79682146E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=V25eRcRDKMvSW49u3J7YH5Q/r/bnHSclmpfajE2WxJc=; b=Y22wCx59FkzMS4 TwSLPIjD7KPyNa1XsuF37wGyn5fhfGp0h1m55vz6qQkn6m9dDp+Vu6UyOH9JGkqwedkU1uWQvb0L1 qyhniS5XeYbLGsIZRRwE4R5MGmN9pDpsl0pTWKiHIYdrTSSyfDdIE/yGxsbABZm5LBVnLcTljCffl 0bGfStlHUVUAIGE1i39sLGeXFppu0pc0sJjpC0mFMshrTI5tcMlLOMfVfBbAIJI3DQGm77VpOy1QZ 2QRHa3u13QHPpLZHvLx6uhmttW93C8iEaQEtZ8Bp/YDbCku0FDnNOEWaTdpK5wyf/Tepvp3ODSrYX VQFSKyPUJwQW9AUnn1MQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1ihhOR-0003On-VB; Wed, 18 Dec 2019 22:02:07 +0000 Received: from mga11.intel.com ([192.55.52.93]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1ihhIN-0004yV-EA for linux-arm-kernel@lists.infradead.org; Wed, 18 Dec 2019 21:55:53 +0000 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 18 Dec 2019 13:55:42 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,330,1571727600"; d="scan'208";a="222108099" Received: from sjchrist-coffee.jf.intel.com ([10.54.74.202]) by fmsmga001.fm.intel.com with ESMTP; 18 Dec 2019 13:55:41 -0800 From: Sean Christopherson To: Marc Zyngier , James Hogan , Paul Mackerras , Christian Borntraeger , Janosch Frank , Paolo Bonzini Subject: [PATCH v2 21/45] KVM: x86: Remove spurious clearing of async #PF MSR Date: Wed, 18 Dec 2019 13:55:06 -0800 Message-Id: <20191218215530.2280-22-sean.j.christopherson@intel.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20191218215530.2280-1-sean.j.christopherson@intel.com> References: <20191218215530.2280-1-sean.j.christopherson@intel.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191218_135551_557490_6AD27382 X-CRM114-Status: GOOD ( 10.53 ) X-Spam-Score: -5.0 (-----) X-Spam-Report: SpamAssassin version 3.4.2 on bombadil.infradead.org summary: Content analysis details: (-5.0 points) pts rule name description ---- ---------------------- -------------------------------------------------- -5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at https://www.dnswl.org/, high trust [192.55.52.93 listed in list.dnswl.org] -0.0 RCVD_IN_MSPIKE_H2 RBL: Average reputation (+2) [192.55.52.93 listed in wl.mailspike.net] 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.0 SPF_PASS SPF: sender matches SPF record X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kvm-ppc@vger.kernel.org, Wanpeng Li , kvm@vger.kernel.org, David Hildenbrand , Joerg Roedel , Cornelia Huck , linux-mips@vger.kernel.org, Sean Christopherson , linux-kernel@vger.kernel.org, Greg Kurz , James Morse , linux-arm-kernel@lists.infradead.org, Vitaly Kuznetsov , Suzuki K Poulose , kvmarm@lists.cs.columbia.edu, Julien Thierry , Jim Mattson Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Remove a bogus clearing of apf.msr_val from kvm_arch_vcpu_destroy(). apf.msr_val is only set to a non-zero value by kvm_pv_enable_async_pf(), which is only reachable by kvm_set_msr_common(), i.e. by writing MSR_KVM_ASYNC_PF_EN. KVM does not autonomously write said MSR, i.e. can only be written via KVM_SET_MSRS or KVM_RUN. Since KVM_SET_MSRS and KVM_RUN are vcpu ioctls, they require a valid vcpu file descriptor. kvm_arch_vcpu_destroy() is only called if KVM_CREATE_VCPU fails, and KVM declares KVM_CREATE_VCPU successful once the vcpu fd is installed and thus visible to userspace. Ergo, apf.msr_val cannot be non-zero when kvm_arch_vcpu_destroy() is called. Fixes: 344d9588a9df0 ("KVM: Add PV MSR to enable asynchronous page faults delivery.") Signed-off-by: Sean Christopherson --- arch/x86/kvm/x86.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 19c14b786255..46626b52a4da 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -9176,8 +9176,6 @@ void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu) void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu) { - vcpu->arch.apf.msr_val = 0; - kvm_arch_vcpu_free(vcpu); }