[Libguestfs] [PATCH] v2v: virtio-win: include *.dll too

Sun Nov 8 08:15:31 UTC 2015

> On 06 Nov 2015, at 08:51, Vadim Rozenfeld <vrozenfe at redhat.com> wrote:
> 
> On Thu, 2015-11-05 at 21:46 +0000, Richard W.M. Jones wrote:
>> On Thu, Oct 29, 2015 at 11:05:42AM +1100, Vadim Rozenfeld wrote:
>>> On Wed, 2015-10-28 at 14:53 +0300, Roman Kagan wrote:
>>>>  1) tell which devices can be configured
>>> Not sure that I fully understated your question. but if you are going to
>>> create some sort of off-line automatic virtio-win drivers update
>>> utility, then it shouldn't be too complicated. Firs of all you will need
>>> to obtain the Windows kernel version by reading the following Registry
>>> key - "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion". Let's say it
>>> 6.3, which means that it is Win8.1 or WS2012R2, parsing "BuildLabEx"
>>> string from the same hive will give you information about the platform
>>> bitness. Next you need to go through inf files, and find "DriverVer"
>>> string, like this one . taken from from vioscsi.inf
>>> 
>>> DriverVer=08/01/2015,62.72.104.10800
>>> 
>>> This string contains build time and version stamps. The version stamp
>>> looks as follow "62.72.104.10800"
>>> where 62 means a target Windows kernel version multiplied by 10. In this
>>> case it is 6.2 which means Win8 or WS2012
>>> 72 - the target host platform version multiplied bu 10 (was RHEL7.2)
>>> 104 just a magic number, but it can be changed, don't make any
>>> assumption based on this number.
>>> 10800 our internal build number (build 108) multiplied by 100
>> 
>> Hi Vadim,
>> 
>> I've almost finished implementing this, but I have a couple of
>> technical questions:
>> 
>> (1) How can we tell from the .inf file what architecture (x86 or
>> amd64) the driver is for?  There is a [Manufacturer] section which
>> looks hopeful, eg:
>> 
>>  [Manufacturer]
>>  %RHEL%   = RHEL,NTAMD64
>> 
>> but the contents are not very consistent across all the .inf files I
>> have access to.
> 
> Hi Richard,
> 
> It should be consistent. We do specify target architecture (amd64 or
> x86) when stamping inf/inx files. IIRC, qemupciserial.inf is the only
> exception, but it goes without binaries. In any case, if you are going
> to use existing distribution media, you can rely on the media layout -
> for example, if "amd64" is a part of your current path - you are in
> 64-bit directory. 
>> 
>> (2) If we have a directory containing multiple drivers, can we assume
>> that if any .inf file found matches the guest OS, then all those
>> drivers can be installed?  So far this appears to be true.  
> Yes, we will never mix 32 and 64 bit drivers into the same directory.
> I swear:) 
> 
>> If not
>> then we have to start associating drivers with .inf files, which seems
>> a bit complicated.
>> 
>> (3) You write:
>> 
>>> If you found an inf file with the matching minor OS (6 in our case)
>>> version and matching or less but close minor version number (2 vs 3)
>>> then you are in the right directory.
>> 
>> When you say "close minor version number" is there a particular
>> definition you have in mind?  eg. minor or minor-1 is OK?  Or do we
>> have to consider all .inf files in totality and choose the nearest
>> one?
> Ideally, we should try finding the exact match. If not, we have to find
> one with the same major version number and nearest minor number which is
> smaller than the target one. For example, let's say we are looking for a
> driver for Win8.1/WS2012R2, we know that both of them have kernel
> version 6.3 . So, ideally we should to find inf file with the following
> driver version string:
> 
> DriverVer=XX/YY/ZZZZ,63.AA.BBB.CCCCC
> 
> if we cannot find an inf file with such criteria, we should try finding
> another one with the OS version 62 (which means that a driver was build
> for kernel 6.2 Win8/WS2012 and technically should be compatible with
> 6.3). So, we are looking for DriverVer which looks like this one:
> DriverVer=XX/YY/ZZZZ,62.AA.BBB.CCCCC
> 
> Still no luck - decrease the target OS version to 61 and repeat.
> 
> For WDF drivers like balloon, vioserial, and rng you can go as far as
> you can trying to find an appropriate driver. 
> 
> For miniport drivers like netkvm ( Yan, please confirm ), viostor and
> vioscsi I wouldn't go too far. For example drivers designed to fork in
> specific stacks at kernel version 5.1 (WinXP) can refuse working with
> kernel 6.2 (Win8).

While NDIS miniport designed for NDIS 5.1 (XP) still can run on latest Windows, I wouldn’t do that. For NDIS 6.x (Windows 2008 and newer), we can use older drivers on new OS.
But installing a driver for a newer OS on older OS might lead to driver miss-behaviour.

> 
> However, Win10 will be a problem. At least as long as we do not release
> virtio-win drivers built for this particular OS version, and keep using 
> drivers designed for Win8/WS2012 and Win8.1/WS2012R2 platforms.
> Win10 has kernel version 10.0 (guys, who has Win10 RTM running - please
> confirm). It used to be 6.4 for RC and Beta versions, but IIRC
> Microsoft decided to change it to 10.0 for RTM and final release. 
> Microsoft promised that drivers designed for Win8/WS2012 and
> Win8.1/WS2012R2 platforms will continue working, at least for the
> nearest future.
> 
> Vadim.
> 
>> 
>> Rich.

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