RE: [Xen-devel] [PATCH] fix the time issue on x86_64

["Li, Xin B" <xin.b.li@xxxxxxxxx>]

Ian Pratt wrote:
>  > For x86_64, we must have a RTC driver compiled in
> kernel. 
>> I compiled a native x86_64 Linux kernel without any RTC
>> driver support, and the native Linux kernel also has the
>> same 
>> time issue.
>> If we run hwclock, we get
>>      Cannot access the Hardware Clock via any known method.
>>      Use the --debug option to see the details of our search
>> for an access method.
>> If this command fails, /etc/rc.d/rc.sysinit can not set
>> kernel time (by calling syscall settimeofday())
>> correctly. 
>> 
>> And after adding CONFIG_RTC to xeno64 default config
>> file, 
>> the time issue is gone.
>> But for i386, this is not a must, for it has some other
>> way 
>> to get the RTC time.
> 
> This will only work for privileged guests -- unprivileged
> guests can not and should not be able to access the RTC
> directly. 
> 
> The options are to either have our own /dev/rtc driver,
> or to emulate reading the rtc in Xen for unprivilged
> guests (which is dead easy). 
> 
> Ian

So, do we need this patch? I think it should be OK for xen0.
-Xin


> 
> 
>> Following is the patch:
>> 
>> # This is a BitKeeper generated diff -Nru style patch. #
>> # ChangeSet
>> #   2005/06/08 23:59:01-07:00 xin@xxxxxxxxxxxxxxxxxxxxxx
>> #   fix time issue bug on x86_64
>> #   Signed-off-by: Li B Xin <li.b.xin@xxxxxxxxx>
>> #   Signed-off-by: Jun Nakajima <jun.nakajima@xxxxxxxxx>
>> # #
>> linux-2.6.11-xen-sparse/arch/xen/configs/xen0_defconfig_x86_64
>> #   2005/06/08 23:59:00-07:00 xin@xxxxxxxxxxxxxxxxxxxxxx
>> +1 -1 #   fix time issue bug by adding RTC driver
>> support. #   x86_64 must have a RTC driver support, or
>> we can not run hwclock successfully, so we can not set a
>> correct time to kernel. #   Signed-off-by: Li B Xin
>> <li.b.xin@xxxxxxxxx> #   Signed-off-by: Jun Nakajima
>> <jun.nakajima@xxxxxxxxx> #  
>> diff -Nru
>> a/linux-2.6.11-xen-sparse/arch/xen/configs/xen0_defconfig_x86_64
>> b/linux-2.6.11-xen-sparse/arch/xen/configs/xen0_defconfig_x86_64
>> ---
>> a/linux-2.6.11-xen-sparse/arch/xen/configs/xen0_defconfig_x86_64
>> 2005-06-09 00:02:32 -07:00 +++
>>  b/linux-2.6.11-xen-sparse/arch/xen/configs/xen0_defconfig_x86_64
>>  2005-06-09 00:02:32 -07:00 @@ -701,7 +701,7 @@ #
>>  CONFIG_WATCHDOG is not set # CONFIG_HW_RANDOM is not
>> set # CONFIG_NVRAM is not set -# CONFIG_RTC is not set
>> +CONFIG_RTC=y
>>  # CONFIG_GEN_RTC is not set
>>  # CONFIG_DTLK is not set
>>  # CONFIG_R3964 is not set
>> 
>> 
>> thanks
>> -Xin
>> 
>> _______________________________________________
>> Xen-devel mailing list
>> Xen-devel@xxxxxxxxxxxxxxxxxxx
>> http://lists.xensource.com/xen-devel

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel