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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 78EB7C433EF for ; Tue, 4 Jan 2022 20:01:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231550AbiADUBb (ORCPT ); Tue, 4 Jan 2022 15:01:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47064 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229962AbiADUBb (ORCPT ); Tue, 4 Jan 2022 15:01:31 -0500 Received: from mail-pj1-x1034.google.com (mail-pj1-x1034.google.com [IPv6:2607:f8b0:4864:20::1034]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 688CDC061761 for ; Tue, 4 Jan 2022 12:01:31 -0800 (PST) Received: by mail-pj1-x1034.google.com with SMTP id g11-20020a17090a7d0b00b001b2c12c7273so2269359pjl.0 for ; Tue, 04 Jan 2022 12:01:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=P38x3udDv7VccpZiXoJefyN8u/f+VmXSebvIF1IMJ9Y=; b=qw2oIUC6W97Gros4OgiOyM9i+7wnsvMfbBO23Bw18z3JsaKNq/k2XsNKJCHIs+uVhy LmQ2DH+PIflhbQyURRzOlqUVA/dYVzQ12LkZXFq45gUQaxupOlYHXeyYVsxaSjASGl3S I3smWKwTp3QwUj7mR7TBDxgbLSUUQaBE7x1YudiYEl9vOXxoPnFxMLlNGowaNoUtOsY7 oWzeA6Ag6CFEl7bhn8kaTJBmd9SsR0da/cCl2HOmLeD/c6hgdl1K8Vbn+irjyJggrDLD G7gxVyMzrcBVJdVBE13VgLzQVG1NPt9Ca/2mS6l4lsOJ1jvBpH4jMbyliEsT9CTHaVRi UB/g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=P38x3udDv7VccpZiXoJefyN8u/f+VmXSebvIF1IMJ9Y=; b=OyUKrzyaDwzDFMp1H+Q3geDpdE+NfaxMzbY7s7yNFzi4yF0GLhzkxVq6lwV2cvII+q G/qALm9ymQrH/SQ5DdvMnFrzMPpM3rL8FuOvZRg8RH7mHPbHto/9EhDN0+8CW6C1RolI nvuChWngx46ASvTu7boAE+/LoM+7rtrovSlwvQzZQJuXVqw/VHWaVEvnLjLSL/ypPqwm TcGf9dLIkFzU9QWuMgQ4yskgddfcRCxhu1ECHPoC9IanNAvfJsEfH+wmk62ndv+TE6/r tdwTytaDLXuq5QWIXjqyxzTQX7ojrj/PWy9ae0WlUgAxkvpCf3rCmIQdRguUtwc1KbWs D9NQ== X-Gm-Message-State: AOAM530lU3Xioz4OXTvRaj1fZz1+lBY4cZSXHMJYyOPy6UdNlFNfP1gB xDRmQNqBMbwwKB4W9I5AxFuNQg== X-Google-Smtp-Source: ABdhPJwBn8VJJJbQjgdjK3BL5ElqCtvbbHY3YHVoqOGEuLZPAF39gjygq4zF9vcYOMP1k5rlARtrIQ== X-Received: by 2002:a17:902:c94b:b0:149:22af:ed1c with SMTP id i11-20020a170902c94b00b0014922afed1cmr49705852pla.78.1641326490792; Tue, 04 Jan 2022 12:01:30 -0800 (PST) Received: from google.com (157.214.185.35.bc.googleusercontent.com. [35.185.214.157]) by smtp.gmail.com with ESMTPSA id nu18sm160918pjb.15.2022.01.04.12.01.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 04 Jan 2022 12:01:30 -0800 (PST) Date: Tue, 4 Jan 2022 20:01:26 +0000 From: Sean Christopherson To: Yang Zhong Cc: x86@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, pbonzini@redhat.com, corbet@lwn.net, shuah@kernel.org, jun.nakajima@intel.com, kevin.tian@intel.com, jing2.liu@linux.intel.com, jing2.liu@intel.com, guang.zeng@intel.com, wei.w.wang@intel.com Subject: Re: [PATCH v4 12/21] kvm: x86: Intercept #NM for saving IA32_XFD_ERR Message-ID: References: <20211229131328.12283-1-yang.zhong@intel.com> <20211229131328.12283-13-yang.zhong@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211229131328.12283-13-yang.zhong@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Wed, Dec 29, 2021, Yang Zhong wrote: > +static void handle_nm_fault_irqoff(struct kvm_vcpu *vcpu) > +{ > + rdmsrl(MSR_IA32_XFD_ERR, vcpu->arch.guest_fpu.xfd_err); > + kvm_queue_exception(vcpu, NM_VECTOR); This is still wrong, even though no additional supported is needed to support nested XFD. If L1 wants to intercept #NM, then KVM must not inject the #NM and must not read XFD_ERR. That this was posted multiple times is disturbing, because kvm-unit-tests has a test for exactly this, and running it against this series on a host without XFD yields: unchecked MSR access error: RDMSR from 0x1c5 at rIP: 0xffffffffa02478ee (vmx_handle_exit_irqoff+0x1de/0x240 [kvm_intel]) Call Trace: kvm_arch_vcpu_ioctl_run+0x11a0/0x1fb0 [kvm] kvm_vcpu_ioctl+0x279/0x690 [kvm] __x64_sys_ioctl+0x83/0xb0 do_syscall_64+0x3b/0xc0 entry_SYSCALL_64_after_hwframe+0x44/0xae