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* [PATCH] Fix PV CPUID virtualization of XSave
@ 2011-09-16  0:46 Haitao Shan
  2011-09-16  7:13 ` Jan Beulich
  0 siblings, 1 reply; 4+ messages in thread
From: Haitao Shan @ 2011-09-16  0:46 UTC (permalink / raw)
  To: Keir Fraser, xen-devel

[-- Attachment #1: Type: text/plain, Size: 1631 bytes --]

Hi, Keir,

The patch will fix XSave CPUID virtualization for PV guests. The XSave
area size returned by CPUID leaf D is changed dynamically depending on
the XCR0. Tools/libxc only assigns a static value. The fix will adjust
xsave area size during runtime.

Note: This fix is already in HVM cpuid virtualization. And Dom0 is not
affected, either.

Signed-off-by:  Shan Haitao <haitao.shan@intel.com>

Shan Haitao

diff -r 5fe770c8a8a3 xen/arch/x86/traps.c
--- a/xen/arch/x86/traps.c	Tue Sep 06 15:49:40 2011 +0100
+++ b/xen/arch/x86/traps.c	Wed Sep 07 02:09:12 2011 +0800
@@ -770,6 +770,30 @@ static void pv_cpuid(struct cpu_user_reg
     {
         if ( !cpuid_hypervisor_leaves(a, c, &a, &b, &c, &d) )
             domain_cpuid(current->domain, a, c, &a, &b, &c, &d);
+
+        switch ( a )
+        {
+        case 0xd:
+        {
+            unsigned int sub_leaf, _eax, _ebx, _ecx, _edx;
+            /* EBX value of main leaf 0 depends on enabled xsave features */
+            if ( c == 0 && current->arch.xcr0 )
+            {
+                /* reset EBX to default value first */
+                b = XSTATE_AREA_MIN_SIZE;
+                for ( sub_leaf = 2; sub_leaf < 64; sub_leaf++ )
+                {
+                    if ( !(current->arch.xcr0 & (1ULL << sub_leaf)) )
+                        continue;
+                    domain_cpuid(current->domain, a, c, &_eax, &_ebx, &_ecx,
+                                 &_edx);
+                    if ( (_eax + _ebx) > b )
+                        b = _eax + _ebx;
+                }
+            }
+        break;
+        }
+        }
         goto out;
     }

[-- Attachment #2: pv_xsave_cpuid_fix.patch --]
[-- Type: application/octet-stream, Size: 1220 bytes --]

diff -r 5fe770c8a8a3 xen/arch/x86/traps.c
--- a/xen/arch/x86/traps.c	Tue Sep 06 15:49:40 2011 +0100
+++ b/xen/arch/x86/traps.c	Wed Sep 07 02:09:12 2011 +0800
@@ -770,6 +770,30 @@ static void pv_cpuid(struct cpu_user_reg
     {
         if ( !cpuid_hypervisor_leaves(a, c, &a, &b, &c, &d) )
             domain_cpuid(current->domain, a, c, &a, &b, &c, &d);
+
+        switch ( a )
+        {
+        case 0xd:
+        {
+            unsigned int sub_leaf, _eax, _ebx, _ecx, _edx;
+            /* EBX value of main leaf 0 depends on enabled xsave features */
+            if ( c == 0 && current->arch.xcr0 )
+            {
+                /* reset EBX to default value first */
+                b = XSTATE_AREA_MIN_SIZE;
+                for ( sub_leaf = 2; sub_leaf < 64; sub_leaf++ )
+                {
+                    if ( !(current->arch.xcr0 & (1ULL << sub_leaf)) )
+                        continue;
+                    domain_cpuid(current->domain, a, c, &_eax, &_ebx, &_ecx,
+                                 &_edx);
+                    if ( (_eax + _ebx) > b )
+                        b = _eax + _ebx;
+                }
+            }
+        break;
+        }
+        }
         goto out;
     }
 

[-- Attachment #3: Type: text/plain, Size: 138 bytes --]

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

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] Fix PV CPUID virtualization of XSave
  2011-09-16  0:46 [PATCH] Fix PV CPUID virtualization of XSave Haitao Shan
@ 2011-09-16  7:13 ` Jan Beulich
  2011-09-18  9:49   ` Haitao Shan
  0 siblings, 1 reply; 4+ messages in thread
From: Jan Beulich @ 2011-09-16  7:13 UTC (permalink / raw)
  To: Haitao Shan; +Cc: xen-devel, Keir Fraser

>>> On 16.09.11 at 02:46, Haitao Shan <maillists.shan@gmail.com> wrote:
> Hi, Keir,
> 
> The patch will fix XSave CPUID virtualization for PV guests. The XSave
> area size returned by CPUID leaf D is changed dynamically depending on
> the XCR0. Tools/libxc only assigns a static value. The fix will adjust
> xsave area size during runtime.
> 
> Note: This fix is already in HVM cpuid virtualization. And Dom0 is not
> affected, either.
> 
> Signed-off-by:  Shan Haitao <haitao.shan@intel.com>
> 
> Shan Haitao
> 
> diff -r 5fe770c8a8a3 xen/arch/x86/traps.c
> --- a/xen/arch/x86/traps.c	Tue Sep 06 15:49:40 2011 +0100
> +++ b/xen/arch/x86/traps.c	Wed Sep 07 02:09:12 2011 +0800
> @@ -770,6 +770,30 @@ static void pv_cpuid(struct cpu_user_reg
>      {
>          if ( !cpuid_hypervisor_leaves(a, c, &a, &b, &c, &d) )
>              domain_cpuid(current->domain, a, c, &a, &b, &c, &d);
> +
> +        switch ( a )
> +        {
> +        case 0xd:
> +        {
> +            unsigned int sub_leaf, _eax, _ebx, _ecx, _edx;
> +            /* EBX value of main leaf 0 depends on enabled xsave features 
> */
> +            if ( c == 0 && current->arch.xcr0 )
> +            {
> +                /* reset EBX to default value first */
> +                b = XSTATE_AREA_MIN_SIZE;
> +                for ( sub_leaf = 2; sub_leaf < 64; sub_leaf++ )

Shouldn't the upper bound be 63 here (as bit 63 serves a different
purpose, and if that bit was set code changes would be required in
various other places)?

Jan

> +                {
> +                    if ( !(current->arch.xcr0 & (1ULL << sub_leaf)) )
> +                        continue;
> +                    domain_cpuid(current->domain, a, c, &_eax, &_ebx, &_ecx,
> +                                 &_edx);
> +                    if ( (_eax + _ebx) > b )
> +                        b = _eax + _ebx;
> +                }
> +            }
> +        break;
> +        }
> +        }
>          goto out;
>      }

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] Fix PV CPUID virtualization of XSave
  2011-09-16  7:13 ` Jan Beulich
@ 2011-09-18  9:49   ` Haitao Shan
  2011-09-19 13:37     ` Haitao Shan
  0 siblings, 1 reply; 4+ messages in thread
From: Haitao Shan @ 2011-09-18  9:49 UTC (permalink / raw)
  To: Jan Beulich; +Cc: xen-devel, Keir Fraser

2011/9/16 Jan Beulich <JBeulich@suse.com>:
>>>> On 16.09.11 at 02:46, Haitao Shan <maillists.shan@gmail.com> wrote:
>> Hi, Keir,
>>
>> The patch will fix XSave CPUID virtualization for PV guests. The XSave
>> area size returned by CPUID leaf D is changed dynamically depending on
>> the XCR0. Tools/libxc only assigns a static value. The fix will adjust
>> xsave area size during runtime.
>>
>> Note: This fix is already in HVM cpuid virtualization. And Dom0 is not
>> affected, either.
>>
>> Signed-off-by:  Shan Haitao <haitao.shan@intel.com>
>>
>> Shan Haitao
>>
>> diff -r 5fe770c8a8a3 xen/arch/x86/traps.c
>> --- a/xen/arch/x86/traps.c    Tue Sep 06 15:49:40 2011 +0100
>> +++ b/xen/arch/x86/traps.c    Wed Sep 07 02:09:12 2011 +0800
>> @@ -770,6 +770,30 @@ static void pv_cpuid(struct cpu_user_reg
>>      {
>>          if ( !cpuid_hypervisor_leaves(a, c, &a, &b, &c, &d) )
>>              domain_cpuid(current->domain, a, c, &a, &b, &c, &d);
>> +
>> +        switch ( a )
>> +        {
>> +        case 0xd:
>> +        {
>> +            unsigned int sub_leaf, _eax, _ebx, _ecx, _edx;
>> +            /* EBX value of main leaf 0 depends on enabled xsave features
>> */
>> +            if ( c == 0 && current->arch.xcr0 )
>> +            {
>> +                /* reset EBX to default value first */
>> +                b = XSTATE_AREA_MIN_SIZE;
>> +                for ( sub_leaf = 2; sub_leaf < 64; sub_leaf++ )
>
> Shouldn't the upper bound be 63 here (as bit 63 serves a different
> purpose, and if that bit was set code changes would be required in
> various other places)?
>
> Jan
Nice catch! I will update the patch. The same piece of code is
borrowed from hvm_cpuid(), where I can change the value from 64 to 63,
too.

Shan Haitao

>
>> +                {
>> +                    if ( !(current->arch.xcr0 & (1ULL << sub_leaf)) )
>> +                        continue;
>> +                    domain_cpuid(current->domain, a, c, &_eax, &_ebx, &_ecx,
>> +                                 &_edx);
>> +                    if ( (_eax + _ebx) > b )
>> +                        b = _eax + _ebx;
>> +                }
>> +            }
>> +        break;
>> +        }
>> +        }
>>          goto out;
>>      }
>
>
>
>

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] Fix PV CPUID virtualization of XSave
  2011-09-18  9:49   ` Haitao Shan
@ 2011-09-19 13:37     ` Haitao Shan
  0 siblings, 0 replies; 4+ messages in thread
From: Haitao Shan @ 2011-09-19 13:37 UTC (permalink / raw)
  To: Jan Beulich; +Cc: xen-devel, Keir Fraser

[-- Attachment #1: Type: text/plain, Size: 4694 bytes --]

Jan, Keir,

Updated patch is attached.

The patch will fix XSave CPUID virtualization for PV guests. The XSave
area size returned by CPUID leaf D is changed dynamically depending on
the XCR0. Tools/libxc only assigns a static value. The fix will adjust
xsave area size during runtime.

Note: This fix is already in HVM cpuid virtualization. And Dom0 is not
affected, either.

Signed-off-by:  Shan Haitao <haitao.shan@intel.com>

diff -r e90438f6e6d1 xen/arch/x86/hvm/hvm.c
--- a/xen/arch/x86/hvm/hvm.c	Wed Sep 14 11:38:13 2011 +0100
+++ b/xen/arch/x86/hvm/hvm.c	Mon Sep 19 14:34:15 2011 +0800
@@ -2426,7 +2426,7 @@ void hvm_cpuid(unsigned int input, unsig
         {
             /* reset EBX to default value first */
             *ebx = XSTATE_AREA_MIN_SIZE;
-            for ( sub_leaf = 2; sub_leaf < 64; sub_leaf++ )
+            for ( sub_leaf = 2; sub_leaf < 63; sub_leaf++ )
             {
                 if ( !(v->arch.xcr0 & (1ULL << sub_leaf)) )
                     continue;
diff -r e90438f6e6d1 xen/arch/x86/traps.c
--- a/xen/arch/x86/traps.c	Wed Sep 14 11:38:13 2011 +0100
+++ b/xen/arch/x86/traps.c	Mon Sep 19 14:34:15 2011 +0800
@@ -770,6 +770,30 @@ static void pv_cpuid(struct cpu_user_reg
     {
         if ( !cpuid_hypervisor_leaves(a, c, &a, &b, &c, &d) )
             domain_cpuid(current->domain, a, c, &a, &b, &c, &d);
+
+        switch ( a )
+        {
+        case 0xd:
+        {
+            unsigned int sub_leaf, _eax, _ebx, _ecx, _edx;
+            /* EBX value of main leaf 0 depends on enabled xsave features */
+            if ( c == 0 && current->arch.xcr0 )
+            {
+                /* reset EBX to default value first */
+                b = XSTATE_AREA_MIN_SIZE;
+                for ( sub_leaf = 2; sub_leaf < 63; sub_leaf++ )
+                {
+                    if ( !(current->arch.xcr0 & (1ULL << sub_leaf)) )
+                        continue;
+                    domain_cpuid(current->domain, a, c, &_eax, &_ebx, &_ecx,
+                                 &_edx);
+                    if ( (_eax + _ebx) > b )
+                        b = _eax + _ebx;
+                }
+            }
+        break;
+        }
+        }
         goto out;
     }



2011/9/18 Haitao Shan <maillists.shan@gmail.com>:
> 2011/9/16 Jan Beulich <JBeulich@suse.com>:
>>>>> On 16.09.11 at 02:46, Haitao Shan <maillists.shan@gmail.com> wrote:
>>> Hi, Keir,
>>>
>>> The patch will fix XSave CPUID virtualization for PV guests. The XSave
>>> area size returned by CPUID leaf D is changed dynamically depending on
>>> the XCR0. Tools/libxc only assigns a static value. The fix will adjust
>>> xsave area size during runtime.
>>>
>>> Note: This fix is already in HVM cpuid virtualization. And Dom0 is not
>>> affected, either.
>>>
>>> Signed-off-by:  Shan Haitao <haitao.shan@intel.com>
>>>
>>> Shan Haitao
>>>
>>> diff -r 5fe770c8a8a3 xen/arch/x86/traps.c
>>> --- a/xen/arch/x86/traps.c    Tue Sep 06 15:49:40 2011 +0100
>>> +++ b/xen/arch/x86/traps.c    Wed Sep 07 02:09:12 2011 +0800
>>> @@ -770,6 +770,30 @@ static void pv_cpuid(struct cpu_user_reg
>>>      {
>>>          if ( !cpuid_hypervisor_leaves(a, c, &a, &b, &c, &d) )
>>>              domain_cpuid(current->domain, a, c, &a, &b, &c, &d);
>>> +
>>> +        switch ( a )
>>> +        {
>>> +        case 0xd:
>>> +        {
>>> +            unsigned int sub_leaf, _eax, _ebx, _ecx, _edx;
>>> +            /* EBX value of main leaf 0 depends on enabled xsave features
>>> */
>>> +            if ( c == 0 && current->arch.xcr0 )
>>> +            {
>>> +                /* reset EBX to default value first */
>>> +                b = XSTATE_AREA_MIN_SIZE;
>>> +                for ( sub_leaf = 2; sub_leaf < 64; sub_leaf++ )
>>
>> Shouldn't the upper bound be 63 here (as bit 63 serves a different
>> purpose, and if that bit was set code changes would be required in
>> various other places)?
>>
>> Jan
> Nice catch! I will update the patch. The same piece of code is
> borrowed from hvm_cpuid(), where I can change the value from 64 to 63,
> too.
>
> Shan Haitao
>
>>
>>> +                {
>>> +                    if ( !(current->arch.xcr0 & (1ULL << sub_leaf)) )
>>> +                        continue;
>>> +                    domain_cpuid(current->domain, a, c, &_eax, &_ebx, &_ecx,
>>> +                                 &_edx);
>>> +                    if ( (_eax + _ebx) > b )
>>> +                        b = _eax + _ebx;
>>> +                }
>>> +            }
>>> +        break;
>>> +        }
>>> +        }
>>>          goto out;
>>>      }
>>
>>
>>
>>
>

[-- Attachment #2: pv_xsave_cpuid_fix.patch --]
[-- Type: application/octet-stream, Size: 1782 bytes --]

diff -r e90438f6e6d1 xen/arch/x86/hvm/hvm.c
--- a/xen/arch/x86/hvm/hvm.c	Wed Sep 14 11:38:13 2011 +0100
+++ b/xen/arch/x86/hvm/hvm.c	Mon Sep 19 14:34:15 2011 +0800
@@ -2426,7 +2426,7 @@ void hvm_cpuid(unsigned int input, unsig
         {
             /* reset EBX to default value first */
             *ebx = XSTATE_AREA_MIN_SIZE; 
-            for ( sub_leaf = 2; sub_leaf < 64; sub_leaf++ )
+            for ( sub_leaf = 2; sub_leaf < 63; sub_leaf++ )
             {
                 if ( !(v->arch.xcr0 & (1ULL << sub_leaf)) )
                     continue;
diff -r e90438f6e6d1 xen/arch/x86/traps.c
--- a/xen/arch/x86/traps.c	Wed Sep 14 11:38:13 2011 +0100
+++ b/xen/arch/x86/traps.c	Mon Sep 19 14:34:15 2011 +0800
@@ -770,6 +770,30 @@ static void pv_cpuid(struct cpu_user_reg
     {
         if ( !cpuid_hypervisor_leaves(a, c, &a, &b, &c, &d) )
             domain_cpuid(current->domain, a, c, &a, &b, &c, &d);
+
+        switch ( a )
+        {
+        case 0xd:
+        {
+            unsigned int sub_leaf, _eax, _ebx, _ecx, _edx;
+            /* EBX value of main leaf 0 depends on enabled xsave features */
+            if ( c == 0 && current->arch.xcr0 )
+            {
+                /* reset EBX to default value first */
+                b = XSTATE_AREA_MIN_SIZE;
+                for ( sub_leaf = 2; sub_leaf < 63; sub_leaf++ )
+                {
+                    if ( !(current->arch.xcr0 & (1ULL << sub_leaf)) )
+                        continue;
+                    domain_cpuid(current->domain, a, c, &_eax, &_ebx, &_ecx,
+                                 &_edx);
+                    if ( (_eax + _ebx) > b )
+                        b = _eax + _ebx;
+                }
+            }
+        break;
+        }
+        }
         goto out;
     }
 

[-- Attachment #3: Type: text/plain, Size: 138 bytes --]

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

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2011-09-19 13:37 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2011-09-16  0:46 [PATCH] Fix PV CPUID virtualization of XSave Haitao Shan
2011-09-16  7:13 ` Jan Beulich
2011-09-18  9:49   ` Haitao Shan
2011-09-19 13:37     ` Haitao Shan

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