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=-8.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 1932FC433DF for ; Wed, 15 Jul 2020 10:09:01 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 DC89F206D5 for ; Wed, 15 Jul 2020 10:09:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DC89F206D5 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jveLD-0006Im-Rn; Wed, 15 Jul 2020 10:08:43 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jveLD-0006Ih-6k for xen-devel@lists.xenproject.org; Wed, 15 Jul 2020 10:08:43 +0000 X-Inumbo-ID: 292587d0-c683-11ea-bb8b-bc764e2007e4 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 292587d0-c683-11ea-bb8b-bc764e2007e4; Wed, 15 Jul 2020 10:08:42 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id ECED0B6D9; Wed, 15 Jul 2020 10:08:44 +0000 (UTC) Subject: Re: [PATCH v2 1/2] x86: restore pv_rtc_handler() invocation To: paul@xen.org References: <416ac9b1-93d1-81a2-be19-d58d509fdfec@suse.com> <59f26856-d23d-bb69-0403-39e77acbf85c@suse.com> <001301d65a8e$e10e1260$a32a3720$@xen.org> From: Jan Beulich Message-ID: Date: Wed, 15 Jul 2020 12:08:42 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <001301d65a8e$e10e1260$a32a3720$@xen.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: xen-devel@lists.xenproject.org, =?UTF-8?B?J1JvZ2VyIFBhdSBNb25uw6kn?= , 'Wei Liu' , 'Andrew Cooper' Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" On 15.07.2020 12:01, Paul Durrant wrote: >> -----Original Message----- >> From: Jan Beulich >> Sent: 15 July 2020 10:47 >> To: xen-devel@lists.xenproject.org >> Cc: Andrew Cooper ; Paul Durrant ; Wei Liu ; >> Roger Pau Monné >> Subject: [PATCH v2 1/2] x86: restore pv_rtc_handler() invocation >> >> This was lost when making the logic accessible to PVH Dom0. >> >> Fixes: 835d8d69d96a ("x86/rtc: provide mediated access to RTC for PVH dom0") >> Signed-off-by: Jan Beulich >> >> --- a/xen/arch/x86/time.c >> +++ b/xen/arch/x86/time.c >> @@ -1160,6 +1160,10 @@ void rtc_guest_write(unsigned int port, >> case RTC_PORT(1): >> if ( !ioports_access_permitted(currd, RTC_PORT(0), RTC_PORT(1)) ) >> break; >> + >> + if ( pv_rtc_handler ) >> + pv_rtc_handler(currd->arch.cmos_idx & 0x7f, data); >> + > > This appears to be semantically slightly different to the old code in that it is only done for a write to RC_PORT(1), whereas it would have been done on a write to either RTC_POR(0) or RTC_PORT(1) before. Is that of any concern? The old code was (quoting plain 4.13.1) else if ( port == RTC_PORT(0) ) { currd->arch.cmos_idx = data; } else if ( (port == RTC_PORT(1)) && ioports_access_permitted(currd, RTC_PORT(0), RTC_PORT(1)) ) { unsigned long flags; if ( pv_rtc_handler ) pv_rtc_handler(currd->arch.cmos_idx & 0x7f, data); spin_lock_irqsave(&rtc_lock, flags); outb(currd->arch.cmos_idx & 0x7f, RTC_PORT(0)); outb(data, RTC_PORT(1)); spin_unlock_irqrestore(&rtc_lock, flags); } which I think similarly invoked the hook for RTC_PORT(1) only. Jan