From: Paul Durrant <xadimgnik@gmail.com>
To: "'Oleksandr'" <olekstysh@gmail.com>, <xen-devel@lists.xenproject.org>
Cc: "'Kevin Tian'" <kevin.tian@intel.com>,
"'Stefano Stabellini'" <sstabellini@kernel.org>,
"'Julien Grall'" <julien@xen.org>,
"'Jun Nakajima'" <jun.nakajima@intel.com>,
"'Wei Liu'" <wl@xen.org>,
"'Andrew Cooper'" <andrew.cooper3@citrix.com>,
"'Ian Jackson'" <ian.jackson@eu.citrix.com>,
"'George Dunlap'" <george.dunlap@citrix.com>,
"'Tim Deegan'" <tim@xen.org>,
"'Oleksandr Tyshchenko'" <oleksandr_tyshchenko@epam.com>,
"'Julien Grall'" <julien.grall@arm.com>,
"'Jan Beulich'" <jbeulich@suse.com>,
"'Roger Pau Monné'" <roger.pau@citrix.com>
Subject: RE: [RFC PATCH V1 01/12] hvm/ioreq: Make x86's IOREQ feature common
Date: Tue, 4 Aug 2020 14:18:48 +0100 [thread overview]
Message-ID: <002401d66a61$ca9c2110$5fd46330$@xen.org> (raw)
In-Reply-To: <396a0833-021c-c21a-1dcf-cc8bddd1f4a9@gmail.com>
> -----Original Message-----
> From: Oleksandr <olekstysh@gmail.com>
> Sent: 04 August 2020 12:51
> To: paul@xen.org; xen-devel@lists.xenproject.org
> Cc: 'Oleksandr Tyshchenko' <oleksandr_tyshchenko@epam.com>; 'Jan Beulich' <jbeulich@suse.com>; 'Andrew
> Cooper' <andrew.cooper3@citrix.com>; 'Wei Liu' <wl@xen.org>; 'Roger Pau Monné' <roger.pau@citrix.com>;
> 'George Dunlap' <george.dunlap@citrix.com>; 'Ian Jackson' <ian.jackson@eu.citrix.com>; 'Julien Grall'
> <julien@xen.org>; 'Stefano Stabellini' <sstabellini@kernel.org>; 'Jun Nakajima'
> <jun.nakajima@intel.com>; 'Kevin Tian' <kevin.tian@intel.com>; 'Tim Deegan' <tim@xen.org>; 'Julien
> Grall' <julien.grall@arm.com>
> Subject: Re: [RFC PATCH V1 01/12] hvm/ioreq: Make x86's IOREQ feature common
>
>
> On 04.08.20 14:23, Paul Durrant wrote:
> >>
> >>> diff --git a/xen/include/xen/hvm/ioreq.h b/xen/include/xen/hvm/ioreq.h
> >>>> new file mode 100644
> >>>> index 0000000..40b7b5e
> >>>> --- /dev/null
> >>>> +++ b/xen/include/xen/hvm/ioreq.h
> >>>> @@ -0,0 +1,89 @@
> >>>> +/*
> >>>> + * hvm.h: Hardware virtual machine assist interface definitions.
> >>>> + *
> >>>> + * Copyright (c) 2016 Citrix Systems Inc.
> >>>> + *
> >>>> + * This program is free software; you can redistribute it and/or modify it
> >>>> + * under the terms and conditions of the GNU General Public License,
> >>>> + * version 2, as published by the Free Software Foundation.
> >>>> + *
> >>>> + * This program is distributed in the hope it will be useful, but WITHOUT
> >>>> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> >>>> + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
> >>>> + * more details.
> >>>> + *
> >>>> + * You should have received a copy of the GNU General Public License along with
> >>>> + * this program; If not, see <http://www.gnu.org/licenses/>.
> >>>> + */
> >>>> +
> >>>> +#ifndef __HVM_IOREQ_H__
> >>>> +#define __HVM_IOREQ_H__
> >>>> +
> >>>> +#include <xen/sched.h>
> >>>> +
> >>>> +#include <asm/hvm/ioreq.h>
> >>>> +
> >>>> +#define GET_IOREQ_SERVER(d, id) \
> >>>> + (d)->arch.hvm.ioreq_server.server[id]
> >>>> +
> >>>> +static inline struct hvm_ioreq_server *get_ioreq_server(const struct domain *d,
> >>>> + unsigned int id)
> >>>> +{
> >>>> + if ( id >= MAX_NR_IOREQ_SERVERS )
> >>>> + return NULL;
> >>>> +
> >>>> + return GET_IOREQ_SERVER(d, id);
> >>>> +}
> >>>> +
> >>>> +static inline bool hvm_ioreq_needs_completion(const ioreq_t *ioreq)
> >>>> +{
> >>>> + return ioreq->state == STATE_IOREQ_READY &&
> >>>> + !ioreq->data_is_ptr &&
> >>>> + (ioreq->type != IOREQ_TYPE_PIO || ioreq->dir != IOREQ_WRITE);
> >>>> +}
> >>> I don't think having this in common code is correct. The short-cut of not completing PIO reads
> seems
> >> somewhat x86 specific. Does ARM even have the concept of PIO?
> >>
> >> I am not 100% sure here, but it seems that doesn't have.
> >>
> >> Shall I make hvm_ioreq_needs_completion() per arch? Arm variant would
> >> have the same implementation, but without "ioreq->type !=
> >> IOREQ_TYPE_PIO" check...
> >>
> > With your series applied, does any common code actually call hvm_ioreq_needs_completion()? I suspect
> it will remain x86 specific, without any need for an Arm variant.
> Yes, it does. Please see common usage in hvm_io_assist() and
> handle_hvm_io_completion() (current patch) and usage in Arm code
> (arch/arm/io.c: io_state try_fwd_ioserv) [1]
>
>
> [1]
> https://lists.xenproject.org/archives/html/xen-devel/2020-08/msg00072.html
>
Yes, but that code is clearly not finished since, after setting io_completion it says:
/* XXX: Decide what to do */
if ( rc == IO_RETRY )
rc = IO_HANDLED;
So, it's not clear what the eventual implementation will be and whether it will need to make that call.
Paul
>
> --
> Regards,
>
> Oleksandr Tyshchenko
next prev parent reply other threads:[~2020-08-04 13:19 UTC|newest]
Thread overview: 140+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-03 18:21 [RFC PATCH V1 00/12] IOREQ feature (+ virtio-mmio) on Arm Oleksandr Tyshchenko
2020-08-03 18:21 ` [RFC PATCH V1 01/12] hvm/ioreq: Make x86's IOREQ feature common Oleksandr Tyshchenko
2020-08-04 7:45 ` Paul Durrant
2020-08-04 11:10 ` Oleksandr
2020-08-04 11:23 ` Paul Durrant
2020-08-04 11:51 ` Oleksandr
2020-08-04 13:18 ` Paul Durrant [this message]
2020-08-04 13:52 ` Julien Grall
2020-08-04 15:41 ` Jan Beulich
2020-08-04 19:11 ` Stefano Stabellini
2020-08-05 7:01 ` Jan Beulich
2020-08-06 0:37 ` Stefano Stabellini
2020-08-06 6:59 ` Jan Beulich
2020-08-06 20:32 ` Stefano Stabellini
2020-08-07 13:19 ` Oleksandr
2020-08-07 16:45 ` Oleksandr
2020-08-07 21:50 ` Stefano Stabellini
2020-08-07 22:19 ` Oleksandr
2020-08-10 13:41 ` Oleksandr
2020-08-10 23:34 ` Stefano Stabellini
2020-08-11 9:19 ` Julien Grall
2020-08-11 10:10 ` Oleksandr
2020-08-11 22:47 ` Stefano Stabellini
2020-08-12 14:35 ` Oleksandr
2020-08-12 23:08 ` Stefano Stabellini
2020-08-13 20:16 ` Julien Grall
2020-08-07 23:45 ` Oleksandr
2020-08-10 23:34 ` Stefano Stabellini
2020-08-05 8:33 ` Julien Grall
2020-08-06 0:37 ` Stefano Stabellini
2020-08-06 9:45 ` Julien Grall
2020-08-06 23:48 ` Stefano Stabellini
2020-08-10 19:20 ` Julien Grall
2020-08-10 23:34 ` Stefano Stabellini
2020-08-11 11:28 ` Julien Grall
2020-08-11 22:48 ` Stefano Stabellini
2020-08-12 8:19 ` Julien Grall
2020-08-20 19:14 ` Oleksandr
2020-08-21 0:53 ` Stefano Stabellini
2020-08-21 18:54 ` Julien Grall
2020-08-05 13:30 ` Julien Grall
2020-08-06 11:37 ` Oleksandr
2020-08-10 16:29 ` Julien Grall
2020-08-10 17:28 ` Oleksandr
2020-08-05 16:15 ` Andrew Cooper
2020-08-06 8:20 ` Oleksandr
2020-08-15 17:30 ` Julien Grall
2020-08-16 19:37 ` Oleksandr
2020-08-03 18:21 ` [RFC PATCH V1 02/12] hvm/dm: Make x86's DM " Oleksandr Tyshchenko
2020-08-03 18:21 ` [RFC PATCH V1 03/12] xen/mm: Make x86's XENMEM_resource_ioreq_server handling common Oleksandr Tyshchenko
2020-08-03 18:21 ` [RFC PATCH V1 04/12] xen/arm: Introduce arch specific bits for IOREQ/DM features Oleksandr Tyshchenko
2020-08-04 7:49 ` Paul Durrant
2020-08-04 14:01 ` Julien Grall
2020-08-04 23:22 ` Stefano Stabellini
2020-08-15 17:56 ` Julien Grall
2020-08-17 14:36 ` Oleksandr
2020-08-04 23:22 ` Stefano Stabellini
2020-08-05 7:05 ` Jan Beulich
2020-08-05 16:41 ` Stefano Stabellini
2020-08-05 19:45 ` Oleksandr
2020-08-05 9:32 ` Julien Grall
2020-08-05 15:41 ` Oleksandr
2020-08-06 10:19 ` Julien Grall
2020-08-10 18:09 ` Oleksandr
2020-08-10 18:21 ` Oleksandr
2020-08-10 19:00 ` Julien Grall
2020-08-10 20:29 ` Oleksandr
2020-08-10 22:37 ` Julien Grall
2020-08-11 6:13 ` Oleksandr
2020-08-12 15:08 ` Oleksandr
2020-08-11 17:09 ` Oleksandr
2020-08-11 17:50 ` Julien Grall
2020-08-13 18:41 ` Oleksandr
2020-08-13 20:36 ` Julien Grall
2020-08-13 21:49 ` Oleksandr
2020-08-13 20:39 ` Oleksandr Tyshchenko
2020-08-13 22:14 ` Julien Grall
2020-08-14 12:08 ` Oleksandr
2020-08-05 14:12 ` Julien Grall
2020-08-05 14:45 ` Jan Beulich
2020-08-05 19:30 ` Oleksandr
2020-08-06 11:08 ` Julien Grall
2020-08-06 11:29 ` Jan Beulich
2020-08-20 18:30 ` Oleksandr
2020-08-21 6:16 ` Jan Beulich
2020-08-21 11:13 ` Oleksandr
2020-08-06 13:27 ` Oleksandr
2020-08-10 18:25 ` Julien Grall
2020-08-10 19:58 ` Oleksandr
2020-08-05 16:13 ` Jan Beulich
2020-08-05 19:47 ` Oleksandr
2020-08-03 18:21 ` [RFC PATCH V1 05/12] hvm/dm: Introduce xendevicemodel_set_irq_level DM op Oleksandr Tyshchenko
2020-08-04 23:22 ` Stefano Stabellini
2020-08-05 9:39 ` Julien Grall
2020-08-06 0:37 ` Stefano Stabellini
2020-08-06 11:32 ` Julien Grall
2020-08-06 23:49 ` Stefano Stabellini
2020-08-07 8:43 ` Jan Beulich
2020-08-07 21:50 ` Stefano Stabellini
2020-08-08 9:27 ` Julien Grall
2020-08-08 9:28 ` Julien Grall
2020-08-10 23:34 ` Stefano Stabellini
2020-08-11 13:04 ` Julien Grall
2020-08-11 22:48 ` Stefano Stabellini
2020-08-18 9:31 ` Julien Grall
2020-08-21 0:53 ` Stefano Stabellini
2020-08-17 15:23 ` Jan Beulich
2020-08-17 22:56 ` Stefano Stabellini
2020-08-18 8:03 ` Jan Beulich
2020-08-05 16:15 ` Jan Beulich
2020-08-05 22:12 ` Oleksandr
2020-08-03 18:21 ` [RFC PATCH V1 06/12] libxl: Introduce basic virtio-mmio support on Arm Oleksandr Tyshchenko
2020-08-03 18:21 ` [RFC PATCH V1 07/12] A collection of tweaks to be able to run emulator in driver domain Oleksandr Tyshchenko
2020-08-05 16:19 ` Jan Beulich
2020-08-05 16:40 ` Paul Durrant
2020-08-06 9:22 ` Oleksandr
2020-08-06 9:27 ` Jan Beulich
2020-08-14 16:30 ` Oleksandr
2020-08-16 15:36 ` Julien Grall
2020-08-17 15:07 ` Oleksandr
2020-08-03 18:21 ` [RFC PATCH V1 08/12] xen/arm: Invalidate qemu mapcache on XENMEM_decrease_reservation Oleksandr Tyshchenko
2020-08-05 16:21 ` Jan Beulich
2020-08-06 11:35 ` Julien Grall
2020-08-06 11:50 ` Jan Beulich
2020-08-06 14:28 ` Oleksandr
2020-08-06 16:33 ` Jan Beulich
2020-08-06 16:57 ` Oleksandr
2020-08-03 18:21 ` [RFC PATCH V1 09/12] libxl: Handle virtio-mmio irq in more correct way Oleksandr Tyshchenko
2020-08-04 23:22 ` Stefano Stabellini
2020-08-05 20:51 ` Oleksandr
2020-08-03 18:21 ` [RFC PATCH V1 10/12] libxl: Add support for virtio-disk configuration Oleksandr Tyshchenko
2020-08-04 23:23 ` Stefano Stabellini
2020-08-05 21:12 ` Oleksandr
2020-08-06 0:37 ` Stefano Stabellini
2020-08-03 18:21 ` [RFC PATCH V1 11/12] libxl: Insert "dma-coherent" property into virtio-mmio device node Oleksandr Tyshchenko
2020-08-04 23:23 ` Stefano Stabellini
2020-08-05 20:35 ` Oleksandr
2020-08-03 18:21 ` [RFC PATCH V1 12/12] libxl: Fix duplicate memory node in DT Oleksandr Tyshchenko
2020-08-15 17:24 ` [RFC PATCH V1 00/12] IOREQ feature (+ virtio-mmio) on Arm Julien Grall
2020-08-16 19:34 ` Oleksandr
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