All of lore.kernel.org
 help / color / mirror / Atom feed
From: Julien Grall <julien@xen.org>
To: Jan Beulich <jbeulich@suse.com>,
	"xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>
Cc: Stefano Stabellini <sstabellini@kernel.org>, Wei Liu <wl@xen.org>,
	Konrad Wilk <konrad.wilk@oracle.com>,
	George Dunlap <George.Dunlap@eu.citrix.com>,
	Andrew Cooper <andrew.cooper3@citrix.com>,
	Ian Jackson <ian.jackson@citrix.com>
Subject: Re: [Xen-devel] [PATCH] IRQ: u16 is too narrow for an event channel number
Date: Tue, 14 Jan 2020 10:16:00 +0000	[thread overview]
Message-ID: <09fa90a8-b58a-04e9-ccae-702b3b092c4a@xen.org> (raw)
In-Reply-To: <cb84362c-d175-7a71-89cc-17ce0c523b09@suse.com>

Hi Jan,

On 14/01/2020 10:02, Jan Beulich wrote:
> FIFO event channels allow ports up to 2^17, so we need to use a wider
> field in struct pirq. Move "masked" such that it may share the 8-byte
> slot with struct arch_pirq on 64-bit arches, rather than leaving a
> 7-byte hole in all cases.
> 
> Take the opportunity and also add a comment regarding "arch" placement
> within the structure.
> 
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> 
> --- a/xen/include/xen/irq.h
> +++ b/xen/include/xen/irq.h
> @@ -127,9 +127,10 @@ struct vcpu;
>   
>   struct pirq {
>       int pirq;
> -    u16 evtchn;
> -    bool_t masked;
> +    evtchn_port_t evtchn;
>       struct rcu_head rcu_head;
> +    bool masked;
> +    /* Architectures may require this field to be last. */

I orginally planned to add a comment in struct pirq, but I am not in 
favor to continue to encourage quirkiness in the code. I sent a series 
(see [1]) that drop this requirements from x86 and therefore remove the 
need of this comment.

>       struct arch_pirq arch;
>   };
>   
> 

Cheers,

[1] 
https://lists.xenproject.org/archives/html/xen-devel/2020-01/msg00924.html

-- 
Julien Grall

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel

  reply	other threads:[~2020-01-14 10:16 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-14 10:02 [Xen-devel] [PATCH] IRQ: u16 is too narrow for an event channel number Jan Beulich
2020-01-14 10:16 ` Julien Grall [this message]
2020-01-14 10:23   ` Jan Beulich
2020-01-14 10:39     ` Julien Grall
2020-01-14 10:41 ` Andrew Cooper

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=09fa90a8-b58a-04e9-ccae-702b3b092c4a@xen.org \
    --to=julien@xen.org \
    --cc=George.Dunlap@eu.citrix.com \
    --cc=andrew.cooper3@citrix.com \
    --cc=ian.jackson@citrix.com \
    --cc=jbeulich@suse.com \
    --cc=konrad.wilk@oracle.com \
    --cc=sstabellini@kernel.org \
    --cc=wl@xen.org \
    --cc=xen-devel@lists.xenproject.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.