linux-kernel - Re: [Xen-devel] [PATCH] x86: Xen PV guests don't have the rtc

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <745827c24ef5e59808d725d5777b5698@eikelenboom.it>
Date:	Wed, 09 Dec 2015 16:00:21 +0100
From:	Sander Eikelenboom <linux@...elenboom.it>
To:	Jan Beulich <JBeulich@...e.com>
Cc:	Boris Ostrovsky <boris.ostrovsky@...cle.com>,
	David Vrabel <david.vrabel@...rix.com>, x86@...nel.org,
	tglx@...utronix.de, xen-devel@...ts.xenproject.org,
	mingo@...hat.com, vkuznets@...hat.com,
	linux-kernel@...r.kernel.org, stable@...r.kernel.org, hpa@...or.com
Subject: Re: [Xen-devel] [PATCH] x86: Xen PV guests don't have the
 rtc_cmos platform device

On 2015-12-09 15:42, Jan Beulich wrote:
>>>> On 09.12.15 at 15:32, <boris.ostrovsky@...cle.com> wrote:
>> --- a/arch/x86/kernel/rtc.c
>> +++ b/arch/x86/kernel/rtc.c
>> @@ -200,6 +200,9 @@ static __init int add_rtc_cmos(void)
>>  	}
>>  #endif
>> 
>> +	if (paravirt_enabled())
>> +		return -ENODEV;
> 
> What about Xen Dom0?
> 
> Jan

Checked that in my testing and that still worked:
[   16.733837] rtc_cmos 00:02: RTC can wake from S4
[   16.734030] rtc_cmos 00:02: rtc core: registered rtc_cmos as rtc0
[   16.734087] rtc_cmos 00:02: alarms up to one month, y3k, 114 bytes 
nvram
[   17.760329] rtc_cmos 00:02: setting system clock to 2015-12-09 
08:43:48 UTC (1449650628)

and /dev/rtc and /dev/rtc0 both exist.

But i don't know the nitty gritty details about why ...
--
Sander
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/