Xen devel - Nov 2006 - Need help - Assigning PCI device to HVM Windows domain

Hi,

I am a newbie to Xen and I am trying to assign PCI NIC to Windows domain. I
performed below steps, with no luck.
It would be great if someone could point me to the right direction.

I did as follows:

1) I''ve got WinXP installed over Xen, and got network working with
pcnet
model
2) I''ve hidden NIC from dom0 and verified that it does not appear with
lspci
3) I''ve added interception of PCI scan from HVM domain (using
0xcf8/0xcfc
ports interception),
and when the PCI bud/dev/fun matched my physical NIC, I returned physical
vendor/device id.
4) I''ve rebuilt/reinstalled all images, but WinXP didn''t
recognize any NIC
device.

Thanks ahead,

GT


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

I forgot to mention that I allowed MMIO/IO ports access to WinXP according
to NIC''s PCI BARs.

Thanks,

GT

---------- Forwarded message ----------
From: GT <gtcharny@gmail.com>
Date: Nov 16, 2006 10:21 AM
Subject: Need help - Assigning PCI device to HVM Windows domain
To: xen-devel@lists.xensource.com

Hi,

I am a newbie to Xen and I am trying to assign PCI NIC to Windows domain. I
performed below steps, with no luck.
It would be great if someone could point me to the right direction.

I did as follows:

1) I''ve got WinXP installed over Xen, and got network working with
pcnet
model
2) I''ve hidden NIC from dom0 and verified that it does not appear with
lspci
3) I''ve added interception of PCI scan from HVM domain (using
0xcf8/0xcfc
ports interception),
and when the PCI bud/dev/fun matched my physical NIC, I returned physical
vendor/device id.
4) I''ve rebuilt/reinstalled all images, but WinXP didn''t
recognize any NIC
device.

Thanks ahead,

GT


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

On 16/11/06 8:30 am, "GT" <gtcharny@gmail.com> wrote:
> I forgot to mention that I allowed MMIO/IO ports access to WinXP according
> to NIC''s PCI BARs.
Since HVM guests are lied to about their physical memory map it is actually
not possible for the Windows guest to access the physical MMIO resources of
the NIC. You could work around this by picking up the MMIO access attempts
in qemu and forward them to/from the actual underlying physical addresses.

 -- Keir



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

This will not work!

The reason is that we tell Windows that it''s got X MB of memory,
starting at address 0, like it does in a standalone system. But in
reality, the memory actually given to the virtual machine could be ANY
location in memory (including a completely scattered selection of memory
blocks). 

Since Windows is COMPLETELY unaware of this fact, your driver will give
what it believes is the physical address, in the range of 0..X MB to the
network card when it wants to send a packet of data. This is of course
not going to work if the packet to send isn''t at the physical address
Windows thinks it is. 

Let''s take a trivial example: We give Windows a memory size of 256MB,
located in the contiguous section 256..512MB. The OS then wants to send
a packet on the network card that has the virtual address of 0x40867456
and the physical address of 0x123456 (just over 1MB), so the driver gets
the address for the packet (0x40867456). It calls the Win32 call
GetPhysicalAddress(), it will get back the address that Windows thinks
is the physical address, because it doesn''t know that we''ve
lied about
where the memory is. This means that it will get the address 0x123456.
This address should be in the 256MB..512MB range, but it isn''t,
it''s
just over 1MB. So the packet sent will be wrong (if the network card
just grabs the data and there''s no need for some extra
"stuff" around
the data-packet, in which case the card will just plain refuse to
work!). 

There are two solutions: 
1. Implement within the driver for the network card an understanding of
the fact that guest-physical memory (i.e. what your Windows OS thinks is
physical addresses) and machine physical addresses (those that are
ACTUALLY in the machine), by adding an extra layer of translation from
guest-physical to machine-physical where the driver is asking for a
physical address. Xen nows how to do this, so you should be able to use
the para-virtual driver calling mechanism to achieve this, but it does
assume that A) You are familiar with windows driver programming, B) that
you have source code for the driver(s) involved with your network card
and C) that you have a driver development kit (DDK) from MS installed on
some machine. 

2. Wait for IOMMU hardware to be available (and relevant code in Xen) to
allow the hypervisor to map the guest-physical memory to
machine-physical address translation so that the guest doesn''t need to
know the difference. 

--
Mats
> -----Original Message-----
> From: xen-devel-bounces@lists.xensource.com 
> [mailto:xen-devel-bounces@lists.xensource.com] On Behalf Of GT
> Sent: 16 November 2006 08:30
> To: xen-devel@lists.xensource.com
> Cc: gtcharny@gmail.com
> Subject: [Xen-devel] Fwd: Need help - Assigning PCI device to 
> HVM Windows domain
> 
> I forgot to mention that I allowed MMIO/IO ports access to 
> WinXP according 
> to NIC''s PCI BARs.
> 
> Thanks,
> 
> GT
> 
> ---------- Forwarded message ----------
> From: GT <gtcharny@gmail.com>
> Date: Nov 16, 2006 10:21 AM
> Subject: Need help - Assigning PCI device to HVM Windows domain
> To: xen-devel@lists.xensource.com 
> <mailto:xen-devel@lists.xensource.com> 
> 
> Hi,
> 
> I am a newbie to Xen and I am trying to assign PCI NIC to 
> Windows domain. I performed below steps, with no luck.
> It would be great if someone could point me to the right direction. 
> 
> I did as follows:
> 
> 1) I''ve got WinXP installed over Xen, and got network working 
> with pcnet model
> 2) I''ve hidden NIC from dom0 and verified that it does not 
> appear with lspci
> 3) I''ve added interception of PCI scan from HVM domain (using 
> 0xcf8/0xcfc ports interception), 
> and when the PCI bud/dev/fun matched my physical NIC, I 
> returned physical vendor/device id.
> 4) I''ve rebuilt/reinstalled all images, but WinXP didn''t 
> recognize any NIC device.
> 
> Thanks ahead,
> 
> GT
> 
> 
> 


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

Mats,

Thank you very much for detailed explanation. I understand that I won''t
be
able to get networking to work with native driver.
If I am able to produce a PV driver as you suggested in (1) I need to get
Windows to load it. PV driver would have the same vendor/device ids as
native driver. My original assumption was that during device initialization
only MMIO/IO ports are accessed, which I trap, and no DMA is performed. Even
if some DMA configuration is done during initialization, I would expect to
see a yellow bang or some other kind of error message, but in my case
Windows doesn''t seem to even try and load the driver.

Is it possible to make Windows to load native driver (even not working), or
do I need PV driver from the very beginning?

Thanks a lot,

GT

On 11/16/06, Petersson, Mats <Mats.Petersson@amd.com>
wrote:
>
> This will not work!
>
> The reason is that we tell Windows that it''s got X MB of memory,
> starting at address 0, like it does in a standalone system. But in
> reality, the memory actually given to the virtual machine could be ANY
> location in memory (including a completely scattered selection of memory
> blocks).
>
> Since Windows is COMPLETELY unaware of this fact, your driver will give
> what it believes is the physical address, in the range of 0..X MB to the
> network card when it wants to send a packet of data. This is of course
> not going to work if the packet to send isn''t at the physical
address
> Windows thinks it is.
>
> Let''s take a trivial example: We give Windows a memory size of
256MB,
> located in the contiguous section 256..512MB. The OS then wants to send
> a packet on the network card that has the virtual address of 0x40867456
> and the physical address of 0x123456 (just over 1MB), so the driver gets
> the address for the packet (0x40867456). It calls the Win32 call
> GetPhysicalAddress(), it will get back the address that Windows thinks
> is the physical address, because it doesn''t know that
we''ve lied about
> where the memory is. This means that it will get the address 0x123456.
> This address should be in the 256MB..512MB range, but it isn''t,
it''s
> just over 1MB. So the packet sent will be wrong (if the network card
> just grabs the data and there''s no need for some extra
"stuff" around
> the data-packet, in which case the card will just plain refuse to
> work!).
>
> There are two solutions:
> 1. Implement within the driver for the network card an understanding of
> the fact that guest-physical memory (i.e. what your Windows OS thinks is
> physical addresses) and machine physical addresses (those that are
> ACTUALLY in the machine), by adding an extra layer of translation from
> guest-physical to machine-physical where the driver is asking for a
> physical address. Xen nows how to do this, so you should be able to use
> the para-virtual driver calling mechanism to achieve this, but it does
> assume that A) You are familiar with windows driver programming, B) that
> you have source code for the driver(s) involved with your network card
> and C) that you have a driver development kit (DDK) from MS installed on
> some machine.
>
> 2. Wait for IOMMU hardware to be available (and relevant code in Xen) to
> allow the hypervisor to map the guest-physical memory to
> machine-physical address translation so that the guest doesn''t
need to
> know the difference.
>
> --
> Mats
>
> > -----Original Message-----
> > From: xen-devel-bounces@lists.xensource.com
> > [mailto:xen-devel-bounces@lists.xensource.com] On Behalf Of GT
> > Sent: 16 November 2006 08:30
> > To: xen-devel@lists.xensource.com
> > Cc: gtcharny@gmail.com
> > Subject: [Xen-devel] Fwd: Need help - Assigning PCI device to
> > HVM Windows domain
> >
> > I forgot to mention that I allowed MMIO/IO ports access to
> > WinXP according
> > to NIC''s PCI BARs.
> >
> > Thanks,
> >
> > GT
> >
> > ---------- Forwarded message ----------
> > From: GT <gtcharny@gmail.com>
> > Date: Nov 16, 2006 10:21 AM
> > Subject: Need help - Assigning PCI device to HVM Windows domain
> > To: xen-devel@lists.xensource.com
> > <mailto:xen-devel@lists.xensource.com>
> >
> > Hi,
> >
> > I am a newbie to Xen and I am trying to assign PCI NIC to
> > Windows domain. I performed below steps, with no luck.
> > It would be great if someone could point me to the right direction.
> >
> > I did as follows:
> >
> > 1) I''ve got WinXP installed over Xen, and got network working
> > with pcnet model
> > 2) I''ve hidden NIC from dom0 and verified that it does not
> > appear with lspci
> > 3) I''ve added interception of PCI scan from HVM domain (using
> > 0xcf8/0xcfc ports interception),
> > and when the PCI bud/dev/fun matched my physical NIC, I
> > returned physical vendor/device id.
> > 4) I''ve rebuilt/reinstalled all images, but WinXP
didn''t
> > recognize any NIC device.
> >
> > Thanks ahead,
> >
> > GT
> >
> >
> >
>
>
>

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

Assumning you have a native driver and the reads of the PCI
configuration is correct, then I don''t see a reason why windows
wouldn''t
load the driver for it... However, if it loads the driver and the driver
says "I don''t know about this hardware" for some reason (for
example, it
maps the MMIO addresses for the device and tries to access it in some
way that doesn''t actually yield the result you expected, the driver
would probably bail out saying "This is something wrong, not my
device"). This is done at driver load time, and the failure may not show
up the way you expect in the device manager. 

I would start by checking that your MMIO mapping is actually mapping to
the device itself, rather than mapping to some different address in the
guest memory for DomU... 

Also, I would expect it to be a lot easier to just adopt the PV
xen-network driver and leave the hardware on Dom0. It will be a little
bit slower, but much faster than doing the qemu-dm model of device
emulation. 

--
Mats
> -----Original Message-----
> From: GT [mailto:gtcharny@gmail.com] 
> Sent: 16 November 2006 11:57
> To: Petersson, Mats
> Cc: xen-devel@lists.xensource.com; gtcharny@gmail.com
> Subject: Re: [Xen-devel] Fwd: Need help - Assigning PCI 
> device to HVM Windows domain
> 
> Mats,
> 
> Thank you very much for detailed explanation. I understand 
> that I won''t be able to get networking to work with native driver.
> If I am able to produce a PV driver as you suggested in (1) I 
> need to get Windows to load it. PV driver would have the same 
> vendor/device ids as native driver. My original assumption 
> was that during device initialization only MMIO/IO ports are 
> accessed, which I trap, and no DMA is performed. Even if some 
> DMA configuration is done during initialization, I would 
> expect to see a yellow bang or some other kind of error 
> message, but in my case Windows doesn''t seem to even try and 
> load the driver. 
> 
> Is it possible to make Windows to load native driver (even 
> not working), or do I need PV driver from the very beginning?
> 
> Thanks a lot,
> 
> GT
> 
> 
> On 11/16/06, Petersson, Mats <Mats.Petersson@amd.com> wrote:
> 
> 	This will not work!
> 	
> 	The reason is that we tell Windows that it''s got X MB of memory,
> 	starting at address 0, like it does in a standalone 
> system. But in
> 	reality, the memory actually given to the virtual 
> machine could be ANY 
> 	location in memory (including a completely scattered 
> selection of memory
> 	blocks).
> 	
> 	Since Windows is COMPLETELY unaware of this fact, your 
> driver will give
> 	what it believes is the physical address, in the range 
> of 0..X MB to the 
> 	network card when it wants to send a packet of data. 
> This is of course
> 	not going to work if the packet to send isn''t at the 
> physical address
> 	Windows thinks it is.
> 	
> 	Let''s take a trivial example: We give Windows a memory 
> size of 256MB, 
> 	located in the contiguous section 256..512MB. The OS 
> then wants to send
> 	a packet on the network card that has the virtual 
> address of 0x40867456
> 	and the physical address of 0x123456 (just over 1MB), 
> so the driver gets 
> 	the address for the packet (0x40867456). It calls the Win32 call
> 	GetPhysicalAddress(), it will get back the address that 
> Windows thinks
> 	is the physical address, because it doesn''t know that 
> we''ve lied about
> 	where the memory is. This means that it will get the 
> address 0x123456. 
> 	This address should be in the 256MB..512MB range, but 
> it isn''t, it''s
> 	just over 1MB. So the packet sent will be wrong (if the 
> network card
> 	just grabs the data and there''s no need for some extra 
> "stuff" around 
> 	the data-packet, in which case the card will just plain 
> refuse to
> 	work!).
> 	
> 	There are two solutions:
> 	1. Implement within the driver for the network card an 
> understanding of
> 	the fact that guest-physical memory ( i.e. what your 
> Windows OS thinks is
> 	physical addresses) and machine physical addresses 
> (those that are
> 	ACTUALLY in the machine), by adding an extra layer of 
> translation from
> 	guest-physical to machine-physical where the driver is 
> asking for a 
> 	physical address. Xen nows how to do this, so you 
> should be able to use
> 	the para-virtual driver calling mechanism to achieve 
> this, but it does
> 	assume that A) You are familiar with windows driver 
> programming, B) that 
> 	you have source code for the driver(s) involved with 
> your network card
> 	and C) that you have a driver development kit (DDK) 
> from MS installed on
> 	some machine.
> 	
> 	2. Wait for IOMMU hardware to be available (and 
> relevant code in Xen) to 
> 	allow the hypervisor to map the guest-physical memory to
> 	machine-physical address translation so that the guest 
> doesn''t need to
> 	know the difference.
> 	
> 	--
> 	Mats
> 	
> 	> -----Original Message-----
> 	> From: xen-devel-bounces@lists.xensource.com
> 	> [mailto:xen-devel-bounces@lists.xensource.com] On 
> Behalf Of GT 
> 	> Sent: 16 November 2006 08:30
> 	> To: xen-devel@lists.xensource.com
> 	> Cc: gtcharny@gmail.com
> 	> Subject: [Xen-devel] Fwd: Need help - Assigning PCI device to 
> 	> HVM Windows domain
> 	>
> 	> I forgot to mention that I allowed MMIO/IO ports access to
> 	> WinXP according
> 	> to NIC''s PCI BARs.
> 	>
> 	> Thanks,
> 	>
> 	> GT
> 	>
> 	> ---------- Forwarded message ---------- 
> 	> From: GT <gtcharny@gmail.com>
> 	> Date: Nov 16, 2006 10:21 AM
> 	> Subject: Need help - Assigning PCI device to HVM 
> Windows domain
> 	> To: xen-devel@lists.xensource.com 
> <mailto:xen-devel@lists.xensource.com> 
> 	> <mailto:xen-devel@lists.xensource.com>
> 	>
> 	> Hi,
> 	>
> 	> I am a newbie to Xen and I am trying to assign PCI NIC to 
> 	> Windows domain. I performed below steps, with no luck.
> 	> It would be great if someone could point me to the 
> right direction.
> 	>
> 	> I did as follows:
> 	>
> 	> 1) I''ve got WinXP installed over Xen, and got network
working
> 	> with pcnet model
> 	> 2) I''ve hidden NIC from dom0 and verified that it does not
> 	> appear with lspci
> 	> 3) I''ve added interception of PCI scan from HVM domain
(using
> 	> 0xcf8/0xcfc ports interception), 
> 	> and when the PCI bud/dev/fun matched my physical NIC, I
> 	> returned physical vendor/device id.
> 	> 4) I''ve rebuilt/reinstalled all images, but WinXP
didn''t
> 	> recognize any NIC device.
> 	>
> 	> Thanks ahead, 
> 	>
> 	> GT
> 	>
> 	>
> 	>
> 	
> 	
> 	
> 
> 
> 


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

I found the issue. My NIC physically resides on bus 1 which is what I was
telling Windows, but in qemu model there is no such creature, neither
PCI-to-PCI bridge. I tricked Windows to think that it resides on bus 0
(using free device id), and it started to install the driver. The
installation crashed the domain though ;)

Thanks a lot,

GT

On 11/16/06, Petersson, Mats <Mats.Petersson@amd.com>
wrote:
>
> Assumning you have a native driver and the reads of the PCI
> configuration is correct, then I don''t see a reason why windows
wouldn''t
> load the driver for it... However, if it loads the driver and the driver
> says "I don''t know about this hardware" for some reason
(for example, it
> maps the MMIO addresses for the device and tries to access it in some
> way that doesn''t actually yield the result you expected, the
driver
> would probably bail out saying "This is something wrong, not my
> device"). This is done at driver load time, and the failure may not
show
> up the way you expect in the device manager.
>
> I would start by checking that your MMIO mapping is actually mapping to
> the device itself, rather than mapping to some different address in the
> guest memory for DomU...
>
> Also, I would expect it to be a lot easier to just adopt the PV
> xen-network driver and leave the hardware on Dom0. It will be a little
> bit slower, but much faster than doing the qemu-dm model of device
> emulation.
>
> --
> Mats
>
> > -----Original Message-----
> > From: GT [mailto:gtcharny@gmail.com]
> > Sent: 16 November 2006 11:57
> > To: Petersson, Mats
> > Cc: xen-devel@lists.xensource.com; gtcharny@gmail.com
> > Subject: Re: [Xen-devel] Fwd: Need help - Assigning PCI
> > device to HVM Windows domain
> >
> > Mats,
> >
> > Thank you very much for detailed explanation. I understand
> > that I won''t be able to get networking to work with native
driver.
> > If I am able to produce a PV driver as you suggested in (1) I
> > need to get Windows to load it. PV driver would have the same
> > vendor/device ids as native driver. My original assumption
> > was that during device initialization only MMIO/IO ports are
> > accessed, which I trap, and no DMA is performed. Even if some
> > DMA configuration is done during initialization, I would
> > expect to see a yellow bang or some other kind of error
> > message, but in my case Windows doesn''t seem to even try and
> > load the driver.
> >
> > Is it possible to make Windows to load native driver (even
> > not working), or do I need PV driver from the very beginning?
> >
> > Thanks a lot,
> >
> > GT
> >
> >
> > On 11/16/06, Petersson, Mats <Mats.Petersson@amd.com> wrote:
> >
> >       This will not work!
> >
> >       The reason is that we tell Windows that it''s got X MB
of memory,
> >       starting at address 0, like it does in a standalone
> > system. But in
> >       reality, the memory actually given to the virtual
> > machine could be ANY
> >       location in memory (including a completely scattered
> > selection of memory
> >       blocks).
> >
> >       Since Windows is COMPLETELY unaware of this fact, your
> > driver will give
> >       what it believes is the physical address, in the range
> > of 0..X MB to the
> >       network card when it wants to send a packet of data.
> > This is of course
> >       not going to work if the packet to send isn''t at the
> > physical address
> >       Windows thinks it is.
> >
> >       Let''s take a trivial example: We give Windows a memory
> > size of 256MB,
> >       located in the contiguous section 256..512MB. The OS
> > then wants to send
> >       a packet on the network card that has the virtual
> > address of 0x40867456
> >       and the physical address of 0x123456 (just over 1MB),
> > so the driver gets
> >       the address for the packet (0x40867456). It calls the Win32 call
> >       GetPhysicalAddress(), it will get back the address that
> > Windows thinks
> >       is the physical address, because it doesn''t know that
> > we''ve lied about
> >       where the memory is. This means that it will get the
> > address 0x123456.
> >       This address should be in the 256MB..512MB range, but
> > it isn''t, it''s
> >       just over 1MB. So the packet sent will be wrong (if the
> > network card
> >       just grabs the data and there''s no need for some extra
> > "stuff" around
> >       the data-packet, in which case the card will just plain
> > refuse to
> >       work!).
> >
> >       There are two solutions:
> >       1. Implement within the driver for the network card an
> > understanding of
> >       the fact that guest-physical memory ( i.e. what your
> > Windows OS thinks is
> >       physical addresses) and machine physical addresses
> > (those that are
> >       ACTUALLY in the machine), by adding an extra layer of
> > translation from
> >       guest-physical to machine-physical where the driver is
> > asking for a
> >       physical address. Xen nows how to do this, so you
> > should be able to use
> >       the para-virtual driver calling mechanism to achieve
> > this, but it does
> >       assume that A) You are familiar with windows driver
> > programming, B) that
> >       you have source code for the driver(s) involved with
> > your network card
> >       and C) that you have a driver development kit (DDK)
> > from MS installed on
> >       some machine.
> >
> >       2. Wait for IOMMU hardware to be available (and
> > relevant code in Xen) to
> >       allow the hypervisor to map the guest-physical memory to
> >       machine-physical address translation so that the guest
> > doesn''t need to
> >       know the difference.
> >
> >       --
> >       Mats
> >
> >       > -----Original Message-----
> >       > From: xen-devel-bounces@lists.xensource.com
> >       > [mailto:xen-devel-bounces@lists.xensource.com] On
> > Behalf Of GT
> >       > Sent: 16 November 2006 08:30
> >       > To: xen-devel@lists.xensource.com
> >       > Cc: gtcharny@gmail.com
> >       > Subject: [Xen-devel] Fwd: Need help - Assigning PCI device
to
> >       > HVM Windows domain
> >       >
> >       > I forgot to mention that I allowed MMIO/IO ports access to
> >       > WinXP according
> >       > to NIC''s PCI BARs.
> >       >
> >       > Thanks,
> >       >
> >       > GT
> >       >
> >       > ---------- Forwarded message ----------
> >       > From: GT <gtcharny@gmail.com>
> >       > Date: Nov 16, 2006 10:21 AM
> >       > Subject: Need help - Assigning PCI device to HVM
> > Windows domain
> >       > To: xen-devel@lists.xensource.com
> > <mailto:xen-devel@lists.xensource.com>
> >       > <mailto:xen-devel@lists.xensource.com>
> >       >
> >       > Hi,
> >       >
> >       > I am a newbie to Xen and I am trying to assign PCI NIC to
> >       > Windows domain. I performed below steps, with no luck.
> >       > It would be great if someone could point me to the
> > right direction.
> >       >
> >       > I did as follows:
> >       >
> >       > 1) I''ve got WinXP installed over Xen, and got
network working
> >       > with pcnet model
> >       > 2) I''ve hidden NIC from dom0 and verified that it
does not
> >       > appear with lspci
> >       > 3) I''ve added interception of PCI scan from HVM
domain (using
> >       > 0xcf8/0xcfc ports interception),
> >       > and when the PCI bud/dev/fun matched my physical NIC, I
> >       > returned physical vendor/device id.
> >       > 4) I''ve rebuilt/reinstalled all images, but WinXP
didn''t
> >       > recognize any NIC device.
> >       >
> >       > Thanks ahead,
> >       >
> >       > GT
> >       >
> >       >
> >       >
> >
> >
> >
> >
> >
> >
>
>
>

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