[PATCH] support piix PAM registers in KVM

[PATCH] support piix PAM registers in KVM

[Gleb Natapov]

Without this BIOS fails to remap 0xf0000 memory from ROM to RAM so writes
to F-segment modify ROM content instead of memory copy. Since QEMU does
not reloads ROMs during reset on next boot modified copy of BIOS is used.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
diff --git a/hw/piix_pci.c b/hw/piix_pci.c
index 933ad86..0bf435d 100644
--- a/hw/piix_pci.c
+++ b/hw/piix_pci.c
@@ -99,10 +99,6 @@ static void i440fx_update_memory_mappings(PCII440FXState *d)
     int i, r;
     uint32_t smram, addr;
 
-    if (kvm_enabled()) {
-        /* FIXME: Support remappings and protection changes. */
-        return;
-    }
     update_pam(d, 0xf0000, 0x100000, (d->dev.config[I440FX_PAM] >> 4) & 3);
     for(i = 0; i < 12; i++) {
         r = (d->dev.config[(i >> 1) + (I440FX_PAM + 1)] >> ((i & 1) * 4)) & 3;
--
			Gleb.

Re: [PATCH] support piix PAM registers in KVM

[Marcelo Tosatti]

On Tue, Sep 21, 2010 at 02:31:42PM +0200, Gleb Natapov wrote:
> Without this BIOS fails to remap 0xf0000 memory from ROM to RAM so writes
> to F-segment modify ROM content instead of memory copy. Since QEMU does
> not reloads ROMs during reset on next boot modified copy of BIOS is used.
> 
> Signed-off-by: Gleb Natapov <gleb@redhat.com>
> diff --git a/hw/piix_pci.c b/hw/piix_pci.c
> index 933ad86..0bf435d 100644
> --- a/hw/piix_pci.c
> +++ b/hw/piix_pci.c
> @@ -99,10 +99,6 @@ static void i440fx_update_memory_mappings(PCII440FXState *d)
>      int i, r;
>      uint32_t smram, addr;
>  
> -    if (kvm_enabled()) {
> -        /* FIXME: Support remappings and protection changes. */
> -        return;
> -    }
>      update_pam(d, 0xf0000, 0x100000, (d->dev.config[I440FX_PAM] >> 4) & 3);
>      for(i = 0; i < 12; i++) {
>          r = (d->dev.config[(i >> 1) + (I440FX_PAM + 1)] >> ((i & 1) * 4)) & 3;
> --
> 			Gleb.

Ugh, we should support ro slots to avoid such kind of problems...

Applied, thanks.

Re: [PATCH] support piix PAM registers in KVM

[Kevin O'Connor]

On Tue, Sep 21, 2010 at 04:06:01PM -0300, Marcelo Tosatti wrote:
> On Tue, Sep 21, 2010 at 02:31:42PM +0200, Gleb Natapov wrote:
> > Without this BIOS fails to remap 0xf0000 memory from ROM to RAM so writes
> > to F-segment modify ROM content instead of memory copy. Since QEMU does
> > not reloads ROMs during reset on next boot modified copy of BIOS is used.
> > 
> > Signed-off-by: Gleb Natapov <gleb@redhat.com>
> Applied, thanks.

Thanks.  I've committed the seabios relocation patches that depended
on this fix.

-Kevin

Re: [PATCH] support piix PAM registers in KVM

[Jason Krieg]

On 09/21/2010 02:31 PM, Gleb Natapov wrote:
> Without this BIOS fails to remap 0xf0000 memory from ROM to RAM so writes
> to F-segment modify ROM content instead of memory copy. Since QEMU does
> not reloads ROMs during reset on next boot modified copy of BIOS is used.
>
> Signed-off-by: Gleb Natapov<gleb@redhat.com>
> diff --git a/hw/piix_pci.c b/hw/piix_pci.c
> index 933ad86..0bf435d 100644
> --- a/hw/piix_pci.c
> +++ b/hw/piix_pci.c
> @@ -99,10 +99,6 @@ static void i440fx_update_memory_mappings(PCII440FXState *d)
>       int i, r;
>       uint32_t smram, addr;
>
> -    if (kvm_enabled()) {
> -        /* FIXME: Support remappings and protection changes. */
> -        return;
> -    }
>       update_pam(d, 0xf0000, 0x100000, (d->dev.config[I440FX_PAM]>>  4)&  3);
>       for(i = 0; i<  12; i++) {
>           r = (d->dev.config[(i>>  1) + (I440FX_PAM + 1)]>>  ((i&  1) * 4))&  3;
> --
> 			Gleb.
> --
> To unsubscribe from this list: send the line "unsubscribe kvm" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Hi,

While testing migration from old to new kvm ( 0.12.5 to 0.14.x ) and 
after fixing
some other problems mainly version_id probs in some of the 
VMStateDescriptions
everything was working fine until I tried to migrate Windows guests they 
would crash
after running some time. Linux guests are running stable.

So I decided to do a git bisect to identify the according commit.
Reverting this commit fixes this problem with Windows guests.

What consequences might it have not updating these memory mappings ?

Does this commit need a specific seabios version, we have seabios 0.6.0 
with qemu-kvm 0.12.5
and seabios 0.6.1.2 with qemu-kvm 0.14.1 ?

Maybe instead of reverting this commit one could check the seabios 
version in this method
and only do an update of these piix PAM registers if running with a 
newer seabios version ?

Regards,
Jason

Re: [PATCH] support piix PAM registers in KVM

[Avi Kivity]

On 06/15/2011 02:58 PM, Jason Krieg wrote:
> On 09/21/2010 02:31 PM, Gleb Natapov wrote:
>> Without this BIOS fails to remap 0xf0000 memory from ROM to RAM so 
>> writes
>> to F-segment modify ROM content instead of memory copy. Since QEMU does
>> not reloads ROMs during reset on next boot modified copy of BIOS is 
>> used.
>>
>> Signed-off-by: Gleb Natapov<gleb@redhat.com>
>> diff --git a/hw/piix_pci.c b/hw/piix_pci.c
>> index 933ad86..0bf435d 100644
>> --- a/hw/piix_pci.c
>> +++ b/hw/piix_pci.c
>> @@ -99,10 +99,6 @@ static void 
>> i440fx_update_memory_mappings(PCII440FXState *d)
>>       int i, r;
>>       uint32_t smram, addr;
>>
>> -    if (kvm_enabled()) {
>> -        /* FIXME: Support remappings and protection changes. */
>> -        return;
>> -    }
>>       update_pam(d, 0xf0000, 0x100000, (d->dev.config[I440FX_PAM]>>  
>> 4)&  3);
>>       for(i = 0; i<  12; i++) {
>>           r = (d->dev.config[(i>>  1) + (I440FX_PAM + 1)]>>  ((i&  1) 
>> * 4))&  3;
>> -- 
>>             Gleb.
>> -- 
>> To unsubscribe from this list: send the line "unsubscribe kvm" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
> Hi,
>
> While testing migration from old to new kvm ( 0.12.5 to 0.14.x ) and 
> after fixing
> some other problems mainly version_id probs in some of the 
> VMStateDescriptions
> everything was working fine until I tried to migrate Windows guests 
> they would crash
> after running some time. Linux guests are running stable.
>
> So I decided to do a git bisect to identify the according commit.
> Reverting this commit fixes this problem with Windows guests.
>
> What consequences might it have not updating these memory mappings ?
>

Resets may fail.

> Does this commit need a specific seabios version, we have seabios 
> 0.6.0 with qemu-kvm 0.12.5
> and seabios 0.6.1.2 with qemu-kvm 0.14.1 ?

IIUC newer seabios depends on this commit, but this commit does not 
depend on seabios.

>
> Maybe instead of reverting this commit one could check the seabios 
> version in this method
> and only do an update of these piix PAM registers if running with a 
> newer seabios version ?

It would be better to first understand what's going wrong.

-- 
error compiling committee.c: too many arguments to function

Re: [PATCH] support piix PAM registers in KVM

[Jason Krieg]

On 06/15/2011 03:17 PM, Avi Kivity wrote:
> On 06/15/2011 02:58 PM, Jason Krieg wrote:
>> On 09/21/2010 02:31 PM, Gleb Natapov wrote:
>>> Without this BIOS fails to remap 0xf0000 memory from ROM to RAM so 
>>> writes
>>> to F-segment modify ROM content instead of memory copy. Since QEMU does
>>> not reloads ROMs during reset on next boot modified copy of BIOS is 
>>> used.
>>>
>>> Signed-off-by: Gleb Natapov<gleb@redhat.com>
>>> diff --git a/hw/piix_pci.c b/hw/piix_pci.c
>>> index 933ad86..0bf435d 100644
>>> --- a/hw/piix_pci.c
>>> +++ b/hw/piix_pci.c
>>> @@ -99,10 +99,6 @@ static void 
>>> i440fx_update_memory_mappings(PCII440FXState *d)
>>>       int i, r;
>>>       uint32_t smram, addr;
>>>
>>> -    if (kvm_enabled()) {
>>> -        /* FIXME: Support remappings and protection changes. */
>>> -        return;
>>> -    }
>>>       update_pam(d, 0xf0000, 0x100000, (d->dev.config[I440FX_PAM]>>  
>>> 4)&  3);
>>>       for(i = 0; i<  12; i++) {
>>>           r = (d->dev.config[(i>>  1) + (I440FX_PAM + 1)]>>  ((i&  
>>> 1) * 4))&  3;
>>> -- 
>>>             Gleb.
>>> -- 
>>> To unsubscribe from this list: send the line "unsubscribe kvm" in
>>> the body of a message to majordomo@vger.kernel.org
>>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>
>> Hi,
>>
>> While testing migration from old to new kvm ( 0.12.5 to 0.14.x ) and 
>> after fixing
>> some other problems mainly version_id probs in some of the 
>> VMStateDescriptions
>> everything was working fine until I tried to migrate Windows guests 
>> they would crash
>> after running some time. Linux guests are running stable.
>>
>> So I decided to do a git bisect to identify the according commit.
>> Reverting this commit fixes this problem with Windows guests.
>>
>> What consequences might it have not updating these memory mappings ?
>>
>
> Resets may fail.
>
>> Does this commit need a specific seabios version, we have seabios 
>> 0.6.0 with qemu-kvm 0.12.5
>> and seabios 0.6.1.2 with qemu-kvm 0.14.1 ?
>
> IIUC newer seabios depends on this commit, but this commit does not 
> depend on seabios.
>
>>
>> Maybe instead of reverting this commit one could check the seabios 
>> version in this method
>> and only do an update of these piix PAM registers if running with a 
>> newer seabios version ?
>
> It would be better to first understand what's going wrong.
>


I presume (just guessing) Windows wrote to F-segment modifying the ROM 
and now gets
confused if these PAM registers are updated.

Any ideas for what I could look for ?

Re: [PATCH] support piix PAM registers in KVM

[Avi Kivity]

On 06/15/2011 04:54 PM, Jason Krieg wrote:
>>
>>>
>>> Maybe instead of reverting this commit one could check the seabios 
>>> version in this method
>>> and only do an update of these piix PAM registers if running with a 
>>> newer seabios version ?
>>
>> It would be better to first understand what's going wrong.
>>
>
>
>
> I presume (just guessing) Windows wrote to F-segment modifying the ROM 
> and now gets
> confused if these PAM registers are updated.

It shouldn't, really.

>
> Any ideas for what I could look for ?
>

Try -no-tpr-opt (on both sides).

-- 
error compiling committee.c: too many arguments to function

Re: [PATCH] support piix PAM registers in KVM

[Avi Kivity]

On 06/15/2011 04:57 PM, Avi Kivity wrote:
>
>>
>> Any ideas for what I could look for ?
>>
>
> Try -no-tpr-opt (on both sides).
>

There's no such option.  Try commenting out the device_init line of 
kvm-tpr-opt.c.

-- 
error compiling committee.c: too many arguments to function

Re: [PATCH] support piix PAM registers in KVM

[Jason Krieg]

On 06/15/2011 03:59 PM, Avi Kivity wrote:
> On 06/15/2011 04:57 PM, Avi Kivity wrote:
>>
>>>
>>> Any ideas for what I could look for ?
>>>
>>
>> Try -no-tpr-opt (on both sides).
>>
>
> There's no such option.  Try commenting out the device_init line of 
> kvm-tpr-opt.c.
>

with 0.12.5 there is no device_init in kvm-tpr-opt.c
should I still try without the device_init() only with 0.14.1 ?

Re: [PATCH] support piix PAM registers in KVM

[Jason Krieg]

On 06/15/2011 04:11 PM, Jason Krieg wrote:
> On 06/15/2011 03:59 PM, Avi Kivity wrote:
>> On 06/15/2011 04:57 PM, Avi Kivity wrote:
>>>
>>>>
>>>> Any ideas for what I could look for ?
>>>>
>>>
>>> Try -no-tpr-opt (on both sides).
>>>
>>
>> There's no such option.  Try commenting out the device_init line of 
>> kvm-tpr-opt.c.
>>
>
> with 0.12.5 there is no device_init in kvm-tpr-opt.c
> should I still try without the device_init() only with 0.14.1 ?
>
>

removing kvm_tpr_opt_setup() in qemu-kvm-x86.c is probably the 
equivalent to device_init(kvm_tpr_opt_setup)

Re: [PATCH] support piix PAM registers in KVM

[Jason Krieg]

On 06/15/2011 03:59 PM, Avi Kivity wrote:
> On 06/15/2011 04:57 PM, Avi Kivity wrote:
>>
>>>
>>> Any ideas for what I could look for ?
>>>
>>
>> Try -no-tpr-opt (on both sides).
>>
>
> There's no such option.  Try commenting out the device_init line of 
> kvm-tpr-opt.c.
>

I disabled this on both sides but still the same behaviour windows 
crashes after ~45min

Re: [PATCH] support piix PAM registers in KVM

[Avi Kivity]

On 06/15/2011 06:16 PM, Jason Krieg wrote:
> On 06/15/2011 03:59 PM, Avi Kivity wrote:
>> On 06/15/2011 04:57 PM, Avi Kivity wrote:
>>>
>>>>
>>>> Any ideas for what I could look for ?
>>>>
>>>
>>> Try -no-tpr-opt (on both sides).
>>>
>>
>> There's no such option.  Try commenting out the device_init line of 
>> kvm-tpr-opt.c.
>>
>
> I disabled this on both sides but still the same behaviour windows 
> crashes after ~45min
>

45 minutes!

Anything from the crash to indicate what's wrong?

-- 
error compiling committee.c: too many arguments to function

Re: [PATCH] support piix PAM registers in KVM

[Jason Krieg]

On 06/15/2011 05:19 PM, Avi Kivity wrote:
> On 06/15/2011 06:16 PM, Jason Krieg wrote:
>> On 06/15/2011 03:59 PM, Avi Kivity wrote:
>>> On 06/15/2011 04:57 PM, Avi Kivity wrote:
>>>>
>>>>>
>>>>> Any ideas for what I could look for ?
>>>>>
>>>>
>>>> Try -no-tpr-opt (on both sides).
>>>>
>>>
>>> There's no such option.  Try commenting out the device_init line of 
>>> kvm-tpr-opt.c.
>>>
>>
>> I disabled this on both sides but still the same behaviour windows 
>> crashes after ~45min
>>
>
> 45 minutes!
>
> Anything from the crash to indicate what's wrong?
>

debugging Windows is not really easy mostly just saying nothing.

windows runs at first normally but after some time somewhere between a 
few minutes and 1.5h
the windows kernel process goes crazy running with 100% cpu and after 
running like this for a few
more minutes windows is completely frozen.

Re: [PATCH] support piix PAM registers in KVM

[Avi Kivity]

On 06/15/2011 06:27 PM, Jason Krieg wrote:
> On 06/15/2011 05:19 PM, Avi Kivity wrote:
>> On 06/15/2011 06:16 PM, Jason Krieg wrote:
>>> On 06/15/2011 03:59 PM, Avi Kivity wrote:
>>>> On 06/15/2011 04:57 PM, Avi Kivity wrote:
>>>>>
>>>>>>
>>>>>> Any ideas for what I could look for ?
>>>>>>
>>>>>
>>>>> Try -no-tpr-opt (on both sides).
>>>>>
>>>>
>>>> There's no such option.  Try commenting out the device_init line of 
>>>> kvm-tpr-opt.c.
>>>>
>>>
>>> I disabled this on both sides but still the same behaviour windows 
>>> crashes after ~45min
>>>
>>
>> 45 minutes!
>>
>> Anything from the crash to indicate what's wrong?
>>
>
> debugging Windows is not really easy mostly just saying nothing.
>
> windows runs at first normally but after some time somewhere between a 
> few minutes and 1.5h
> the windows kernel process goes crazy running with 100% cpu and after 
> running like this for a few
> more minutes windows is completely frozen.
>

Sometimes examining the running code and registers in the qemu monitor, 
perhaps resolving symbols via WinDbg, helps in getting a clue...  it's 
not easy though.

-- 
error compiling committee.c: too many arguments to function