[Xen-devel] Re: [PATCH] xen: mask XSAVE in cpuid since we don't allow guests to use it

[Keir Fraser <keir.fraser@xxxxxxxxxxxxx>]

If you¹re using a recent xen-unstable then you might try again with the
current tip. A couple of changes went in recently (including one fix today).

 -- Keir

On 09/03/2009 11:18, "Boris Derzhavets" <bderzhavets@xxxxxxxxx> wrote:

> I was able to go through creating PV DomUs images via corresponding pygrub's
> profiles for F10,CentOS 5.2,SNV_106 (64-bit all).
> However, only Solaris Nevada PV DomU gets loaded via standard
> pygrub profile. 
> 
> Attempt to load F10 PV:-
> 
> [2009-03-09 05:33:38 6351] DEBUG (XendDomainInfo:92)
> XendDomainInfo.create(['vm', ['name', 'F10PV'], ['memory', 2048],
> ['on_reboot', 'restart'], ['on_crash', 'restart'], ['vcpus', 1],
> ['on_xend_start', 'ignore'], ['on_xend_stop', 'ignore'], ['bootloader',
> '/usr/bin/pygrub'], ['bootloader_args', '-q'], ['image', ['linux',
> ['videoram', 4]]], ['device', ['vbd', ['uname', 'phy:/dev/sdb5'], ['dev',
> 'xvda'], ['mode', 'w']]], ['device', ['vif', ['bridge', 'eth0']]], ['device',
> ['vkbd']], ['device', ['vfb', ['vncunused', '1'], ['type', 'vnc'],
> ['xauthority', '/root/.Xauthority']]]])
> [2009-03-09 05:33:38 6351] DEBUG (XendDomainInfo:2183)
> XendDomainInfo.constructDomain
> [2009-03-09 05:33:38 6351] DEBUG (balloon:166) Balloon: 7239368 KiB free; need
> 2048; done.
> [2009-03-09 05:33:38 6351] DEBUG (XendDomain:452) Adding Domain: 8
> [2009-03-09 05:33:38 6351] DEBUG (XendDomainInfo:2362)
> XendDomainInfo.initDomain: 8 256
> [2009-03-09 05:33:38 12975] DEBUG (XendBootloader:113) Launching bootloader as
> ['/usr/bin/pygrub', '--output=/var/run/xend/boot/xenbl.29001', '-q',
> '/dev/sdb5'].
> [2009-03-09 05:33:39 6351] ERROR (XendBootloader:213) Boot loader didn't
> return any data!
> [2009-03-09 05:33:39 6351] ERROR (XendDomainInfo:472) VM start failed
> Traceback (most recent call last):
>   File "//usr/lib64/python/xen/xend/XendDomainInfo.py", line 452, in start
>     XendTask.log_progress(31, 60, self._initDomain)
>   File "//usr/lib64/python/xen/xend/XendTask.py", line 209, in log_progress
>     retval = func(*args, **kwds)
>   File "//usr/lib64/python/xen/xend/XendDomainInfo.py", line 2364, in
> _initDomain
>     self._configureBootloader()
>   File "//usr/lib64/python/xen/xend/XendDomainInfo.py", line 2765, in
> _configureBootloader
>     bootloader_args, kernel, ramdisk, args)
>   File "//usr/lib64/python/xen/xend/XendBootloader.py", line 214, in
> bootloader
>     raise VmError, msg
> 
> Attempt to load CentOS 5.2 PV:-
> 
> [2009-03-09 06:45:39 6351] DEBUG (XendDomainInfo:92)
> XendDomainInfo.create(['vm', ['name', 'RHEL52PV'], ['memory', 2048], ['vcpus',
> 1], ['on_xend_start', 'ignore'], ['on_xend_stop', 'ignore'], ['image',
> ['linux', ['videoram', 4]]], ['device', ['vbd', ['uname', 'phy:/dev/sdb5'],
> ['dev', 'xvda'], ['mode', 'w']]], ['device', ['vif', ['bridge', 'eth0']]]])
> [2009-03-09 06:45:39 6351] DEBUG (XendDomainInfo:2183)
> XendDomainInfo.constructDomain
> [2009-03-09 06:45:39 6351] DEBUG (balloon:166) Balloon: 7239368 KiB free; need
> 2048; done.
> [2009-03-09 06:45:39 6351] DEBUG (XendDomain:452) Adding Domain: 12
> [2009-03-09 06:45:39 6351] DEBUG (XendDomainInfo:2362)
> XendDomainInfo.initDomain: 12 256
> [2009-03-09 06:45:39 16739] DEBUG (XendBootloader:113) Launching bootloader as
> ['/usr/bin/pygrub', '--output=/var/run/xend/boot/xenbl.15023', '/dev/sdb5'].
> [2009-03-09 06:45:44 6351] ERROR (XendBootloader:213) Boot loader didn't
> return any data!
> [2009-03-09 06:45:44 6351] ERROR (XendDomainInfo:472) VM start failed
> Traceback (most recent call last):
>   File "//usr/lib64/python/xen/xend/XendDomainInfo.py", line 452, in start
>     XendTask.log_progress(31, 60, self._initDomain)
>   File "//usr/lib64/python/xen/xend/XendTask.py", line 209, in log_progress
>     retval = func(*args, **kwds)
>   File "//usr/lib64/python/xen/xend/XendDomainInfo.py", line 2364, in
> _initDomain
>     self._configureBootloader()
>   File "//usr/lib64/python/xen/xend/XendDomainInfo.py", line 2765, in
> _configureBootloader
>     bootloader_args, kernel, ramdisk, args)
>   File "//usr/lib64/python/xen/xend/XendBootloader.py", line 214, in
> bootloader
>     raise VmError, msg
> VmError: Boot loader didn't return any data!
> 
> 
> 
> 
> 
> 
> 
> 
> 
> --- On Sun, 3/8/09, Jeremy Fitzhardinge <jeremy@xxxxxxxx> wrote:
>> From: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
>> Subject: [PATCH] xen: mask XSAVE in cpuid since we don't allow guests to use
>> it
>> To: "Keir Fraser" <keir.fraser@xxxxxxxxxxxxx>
>> Cc: "Xen-devel" <xen-devel@xxxxxxxxxxxxxxxxxxx>, "Marc - A. Dahlhaus [
>> Administration | Westermann GmbH ]" <mad@xxxxxx>, "Boris Derzhavets"
>> <bderzhavets@xxxxxxxxx>
>> Date: Sunday, March 8, 2009, 12:31 AM
>> 
>> Mask X86_FEATURE_XSAVE in cpuid leaf 1, ecx, as we don't allow guests to
>> use it (by setting cr4.OSXSAVE).
>> 
>> This prevents crashes in pvops dom0 kernels, as new versions of Linux try
>> to use this feature.
>> 
>> (This patch deals with dom0 cpuid; I'm not sure where the right place to
>> set up the default mask for domU is.)
>> 
>> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
>> 
>> diff -r 7f573cb76db4 xen/arch/x86/traps.c
>> --- a/xen/arch/x86/traps.c Tue Mar 03 13:22:28 2009 +0000
>> +++ b/xen/arch/x86/traps.c Sat Mar 07 17:02:03 2009 -0800
>> @@ -757,6 +757,7 @@
>>         __clear_bit(X86_FEATURE_XTPR % 32, &c);
>>         __clear_bit(X86_FEATURE_PDCM % 32, &c);
>>         __clear_bit(X86_FEATURE_DCA % 32, &c);
>> +        __clear_bit(X86_FEATURE_XSAVE % 32, &c);
>>         if ( !cpu_has_apic )
>>           
>>  __clear_bit(X86_FEATURE_X2APIC % 32, &c);
>>         __set_bit(X86_FEATURE_HYPERVISOR % 32, &c);
>> diff -r 7f573cb76db4 xen/include/asm-x86/cpufeature.h
>> --- a/xen/include/asm-x86/cpufeature.h Tue Mar 03 13:22:28 2009 +0000
>> +++ b/xen/include/asm-x86/cpufeature.h Sat Mar 07 17:02:03 2009 -0800
>> @@ -95,6 +95,7 @@
>> #define X86_FEATURE_SSE4_2 (4*32+20) /* Streaming SIMD Extensions 4.2 */
>> #define X86_FEATURE_X2APIC (4*32+21) /* Extended xAPIC */
>> #define X86_FEATURE_POPCNT (4*32+23) /* POPCNT instruction */
>> +#define X86_FEATURE_XSAVE (4*32+26) /* XSAVE/XRSTOR/XSETBV/XGETBV */
>> #define X86_FEATURE_HYPERVISOR (4*32+31) /* Running under some hypervisor */
>> 
>> /* VIA/Cyrix/Centaur-defined CPU features, CPUID level 0xC0000001, word 5 */
>> 
>> 
> 
>  



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