From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752046AbdDJGHo (ORCPT ); Mon, 10 Apr 2017 02:07:44 -0400 Received: from mx2.suse.de ([195.135.220.15]:56666 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751007AbdDJGHn (ORCPT ); Mon, 10 Apr 2017 02:07:43 -0400 Subject: Re: [For Linux 4/4] xen/displif: add ABI for para-virtual display To: Oleksandr Andrushchenko , Julien Grall , xen-devel@lists.xenproject.org References: <1491553840-5180-1-git-send-email-andr2000@gmail.com> <1491553840-5180-5-git-send-email-andr2000@gmail.com> <82ade2ce-93e0-d817-b289-ca09fa1bb66e@arm.com> <9ae3da7e-069a-f93c-c1ef-800a46c7e067@gmail.com> <397a9a62-8128-d6b4-0f87-2219ec0cba48@suse.com> <6f8fae9b-82fa-ec98-e381-25e60733fe22@gmail.com> Cc: joculator@gmail.com, al1img@gmail.com, vlad.babchuk@gmail.com, andrii.anisov@gmail.com, olekstysh@gmail.com, konrad.wilk@oracle.com, lars.kurth@citrix.com, sstabellini@kernel.org, linux-kernel@vger.kernel.org, Oleksandr Andrushchenko , Oleksandr Grytsov From: Juergen Gross Message-ID: Date: Mon, 10 Apr 2017 08:07:39 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: <6f8fae9b-82fa-ec98-e381-25e60733fe22@gmail.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/04/17 08:06, Oleksandr Andrushchenko wrote: > On 04/10/2017 09:03 AM, Juergen Gross wrote: >> On 07/04/17 16:02, Oleksandr Andrushchenko wrote: >>> Hi, Julien! >>> >>> On 04/07/2017 04:50 PM, Julien Grall wrote: >>>> Hi Oleksandr, >>>> >>>> On 07/04/17 09:30, Oleksandr Andrushchenko wrote: >>>>> +/* >>>>> + >>>>> ****************************************************************************** >>>>> >>>>> >>>>> + * Back to front events delivery >>>>> + >>>>> ****************************************************************************** >>>>> >>>>> >>>>> + * In order to deliver asynchronous events from back to front a >>>>> shared page is >>>>> + * allocated by front and its granted reference propagated to back >>>>> via >>>>> + * XenStore entries (evt-ring-ref/evt-event-channel). >>>>> + * This page has a common header used by both front and back to >>>>> synchronize >>>>> + * access and control event's ring buffer, while back being a >>>>> producer of the >>>>> + * events and front being a consumer. The rest of the page after the >>>>> header >>>>> + * is used for event packets. >>>>> + * >>>>> + * Upon reception of an event(s) front may confirm its reception >>>>> + * for either each event, group of events or none. >>>>> + */ >>>>> + >>>>> +struct xendispl_event_page { >>>>> + uint32_t in_cons; >>>>> + uint32_t in_prod; >>>>> + uint8_t reserved[56]; >>>>> +}; >>>>> + >>>>> +#define XENDISPL_EVENT_PAGE_SIZE 4096 >>>> This will be always the size of a grant (e.g xen page size), right? If >>>> so, I would prefer if you use XEN_PAGE_SIZE to so we can easily update >>>> Linux in the case Xen is using a different page size. >>>> >>>> Note that the Front-end, Backend and Xen may use different page size, >>>> so your drivers would need to cope with that. The current approach is >>>> to always use the page granularity of Xen. >>>> >>> Will the following satisfy the requirement? >>> #define XENDISPL_EVENT_PAGE_SIZE XEN_PAGE_SIZE >>> >>>>> +#define XENDISPL_IN_RING_OFFS (sizeof(struct xendispl_event_page)) >>>>> +#define XENDISPL_IN_RING_SIZE (XENDISPL_EVENT_PAGE_SIZE - >>>>> XENDISPL_IN_RING_OFFS) >>>>> +#define XENDISPL_IN_RING_LEN (XENDISPL_IN_RING_SIZE / sizeof(struct >>>>> xendispl_evt)) >>>>> +#define XENDISPL_IN_RING(page) \ >>>>> + ((struct xendispl_evt *)((char *)(page) + XENDISPL_IN_RING_OFFS)) >>>>> +#define XENDISPL_IN_RING_REF(page, idx) \ >>>>> + (XENDISPL_IN_RING((page))[(idx) % XENDISPL_IN_RING_LEN]) >>>>> + >>>>> +#endif /* __XEN_PUBLIC_IO_DISPLIF_H__ */ >>>>> + >>>>> +/* >>>>> + * Local variables: >>>>> + * mode: C >>>>> + * c-file-style: "BSD" >>>>> + * c-basic-offset: 4 >>>>> + * tab-width: 4 >>>>> + * indent-tabs-mode: nil >>>>> + * End: >>>>> + */ >> I believe you'll send V2 due to the XEN_PAGE_SIZE usage? > yes >> >> Can you then please remove the editor mode settings block in each >> header, too? Those are disliked in the Linux tree. > sure, I will >> >> >> Juergen > Do you mind if I keep your acks for V2 with these changes? You can keep them, of course. Juergen