From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752072AbdBBQ3L convert rfc822-to-8bit (ORCPT ); Thu, 2 Feb 2017 11:29:11 -0500 Received: from aserp1040.oracle.com ([141.146.126.69]:48001 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751045AbdBBQ3I (ORCPT ); Thu, 2 Feb 2017 11:29:08 -0500 Subject: Re: [PATCH v2 5/9] xen/pvh: Prevent PVH guests from using PIC, RTC and IOAPIC To: =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= References: <1485459692-23961-1-git-send-email-boris.ostrovsky@oracle.com> <1485459692-23961-6-git-send-email-boris.ostrovsky@oracle.com> <20170202153515.a3hznbofx4u4b3az@dhcp-3-221.uk.xensource.com> Cc: JGross@suse.com, xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org From: Boris Ostrovsky Message-ID: Date: Thu, 2 Feb 2017 11:30:19 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.6.0 MIME-Version: 1.0 In-Reply-To: <20170202153515.a3hznbofx4u4b3az@dhcp-3-221.uk.xensource.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8BIT X-Source-IP: aserv0021.oracle.com [141.146.126.233] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/02/2017 10:35 AM, Roger Pau Monné wrote: > On Thu, Jan 26, 2017 at 02:41:28PM -0500, Boris Ostrovsky wrote: >> Make sure they don't use these devices since they are not emulated >> for unprivileged PVH guest. > This description seems weird for what it's actually done. AFAICT you are not > really preventing the guest from using the PIC or the IO APIC, because this is > fetched from the MADT table (or should be fetched from there in any case). This was meant to say that we don't want to use ACPI_IRQ_MODEL_[IOA]PIC since we don't support SCI (which is expected on x86 to be one of the two). I'll re-word it. > > See below for the RTC... > > [...] >> @@ -1892,6 +1900,9 @@ static void __init xen_hvm_guest_init(void) >> >> init_hvm_pv_info(); >> >> + if (xen_pvh_domain()) >> + x86_platform.legacy.rtc = 0; > Can't you fetch that from the FADT boot flags field? (See "5.2.9.3 IA-PC Boot > Architecture Flags" in ACPI 6.1 spec). Good point. In fact, I can drop this altogether because acpi_parse_fadt() will do this for us. -boris