[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [PATCH 1/2] ns16550: reject IRQ above nr_irqs


  • To: Roger Pau Monné <roger.pau@xxxxxxxxxx>
  • From: Jan Beulich <jbeulich@xxxxxxxx>
  • Date: Thu, 10 Mar 2022 17:08:07 +0100
  • Arc-authentication-results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=suse.com; dmarc=pass action=none header.from=suse.com; dkim=pass header.d=suse.com; arc=none
  • Arc-message-signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=s2ajQbdS592gU6A5RpIAVFt/gH7Fr3CwjQ3HlwM07HU=; b=a/b0iZFk18/ixBC4sSTZoKxTTVU1jDbctbgRHbzVBJ1CBnTkYYVb273r3rbBh8TqVvNJH57/lfY9o0GXMm9wSr0bGXCpPi0a76MaU/JHINF+dMz6EXAWGoFabAGvSSN0SsCVrw85Wh9xbZtwaFgxA+VSA3eqZvB/kF6vRU4jjsR7c6VqKaVaRl2ocCMLiEOAq1xMlAxRXrP3xnKqEaORvePUVP7RUk/NHmfqmo/VPN0HwkCu2Vq1r4vBYvWZ7l6tcbFWK14FeSEMV005Iwrfh76xQ013vVTtI9FjYoHJSUGa5ogJBndAsuQPj+DGiKyfeVoBz7POzrfoT/CGJzJ5QA==
  • Arc-seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=e+N8xP/XWTcftcBsGEZNZjPtaIao/0iM8tTZqlQw9a1CtjRrknyO95XZ3py8nmFaHULZKvc71WyyjcQpmjgzczx2W7zx8Jqes70nh0vWy5Z5vUtoN0QzK0mneu8gz9afjoOQBbUt4A0fHSJXM4vBS3fxBKIt6XIZnatV2gba32kb+dqdPaMiLqx1EnZORkE3gRqqV9qxzFOZ01T/KnwSvVtNBibL+cB0+9Ig+3nUyyXqfQXPuEvp5tH098ab+b9xhzQr5z6ozU9i9v/f/T4e2Ko0LwlmgO2+c7TcROWVmrlZ+8QPVxqfgnRsbQgKQ/Fjs+EU7t8Y6Xh89IjoIQlFSw==
  • Authentication-results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=suse.com;
  • Cc: Marek Marczykowski-Górecki <marmarek@xxxxxxxxxxxxxxxxxxxxxx>, Andrew Cooper <andrew.cooper3@xxxxxxxxxx>, George Dunlap <george.dunlap@xxxxxxxxxx>, Julien Grall <julien@xxxxxxx>, Stefano Stabellini <sstabellini@xxxxxxxxxx>, Wei Liu <wl@xxxxxxx>, xen-devel@xxxxxxxxxxxxxxxxxxxx
  • Delivery-date: Thu, 10 Mar 2022 16:08:23 +0000
  • List-id: Xen developer discussion <xen-devel.lists.xenproject.org>

On 10.03.2022 16:47, Roger Pau Monné wrote:
> On Thu, Mar 10, 2022 at 04:23:00PM +0100, Jan Beulich wrote:
>> On 10.03.2022 15:34, Marek Marczykowski-Górecki wrote:
>>> --- a/xen/drivers/char/ns16550.c
>>> +++ b/xen/drivers/char/ns16550.c
>>> @@ -1221,6 +1221,9 @@ pci_uart_config(struct ns16550 *uart, bool_t 
>>> skip_amt, unsigned int idx)
>>>                              pci_conf_read8(PCI_SBDF(0, b, d, f),
>>>                                             PCI_INTERRUPT_LINE) : 0;
>>>  
>>> +                if (uart->irq >= nr_irqs)
>>> +                    uart->irq = 0;
>>
>> Don't you mean nr_irqs_gsi here? Also (nit) please add the missing blanks
>> immediately inside the parentheses.
> 
> If we use nr_irqs_gsi we will need to make the check x86 only AFAICT.

Down the road (when Arm wants to select HAS_PCI) - yes. Not necessarily
right away. After all Arm wants to have an equivalent check here then,
not merely checking against nr_irqs instead. So putting a conditional
here right away would hide the need for putting in place an Arm-specific
alternative.

Jan




 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.