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Porting linux network driver to Xen
Hi All, I am working on porting an existing network driver from Linux
to Xen, I understand network drivers needs netback and netfront
functionality in order to work in Xen but I am unable to nail down the
details of changes required esp. a. will the existing driver go into hypervisor or dom0? b. what changes are required in TX/RX rings for DMA in existing driver and how to incorporate them into netback/netfront,
c. handling IRQs... Any pointers to existing nic driver or pointer to a document would be really helpful.
Thanks -RK
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Re: Porting linux network driver to Xen
Native Linux drivers should work as such in Dom0. You don't have to
port them.
-Kaushik
On Nov 4, 2009, at 7:17 AM, ravi kerur wrote:
> Hi All,
>
> I am working on porting an existing network driver from Linux to
> Xen, I understand network drivers needs netback and netfront
> functionality in order to work in Xen but I am unable to nail down
> the details of changes required esp.
>
> a. will the existing driver go into hypervisor or dom0?
> b. what changes are required in TX/RX rings for DMA in existing
> driver and how to incorporate them into netback/netfront,
> c. handling IRQs...
>
> Any pointers to existing nic driver or pointer to a document would
> be really helpful.
>
> Thanks
> -RK
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@...
> http://lists.xensource.com/xen-devel_______________________________________________
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Re: Porting linux network driver to Xen
Thanks kaushik, How does netfront/netback interact with this driver? I believe I need netback functionality running in dom0 and netfront running in domU's for the existing driver. One of the documents has following explanation for Tx/Rx path.
"For transmit (TX)
requests the driver domain(dom0) uses a hypercall to map
the guest page(domU) into its
address space before sending the request through the
bridge. When the physical device driver frees the
page a callback function is automatically
invoked to return a response to netfront
which then revokes the grant.
For RX requests netfront posts I/O buffer page grants
to the RX I/O channel. When netback receives a packet from the
bridge it retrieves a posted grant from the I/O channel
and issues a grant copy hypercall to copy the
packet to the guest page(domU). Finally, netback sends a response
to the guest
via the RX channel indicating a packet is available." I am not quite sure what changes or api's I need to call such that existing Tx/Rx buffers(rings) used for DMA in the native drivers starts talking via netfront/netback.
Inputs appreciated. Thanks -RK
On Wed, Nov 4, 2009 at 8:58 AM, Kaushik Kumar Ram <kaushik@...> wrote:
Native Linux drivers should work as such in Dom0. You don't have to port them.
-Kaushik
On Nov 4, 2009, at 7:17 AM, ravi kerur wrote:
Hi All,
I am working on porting an existing network driver from Linux to Xen, I understand network drivers needs netback and netfront functionality in order to work in Xen but I am unable to nail down the details of changes required esp.
a. will the existing driver go into hypervisor or dom0?
b. what changes are required in TX/RX rings for DMA in existing driver and how to incorporate them into netback/netfront,
c. handling IRQs...
Any pointers to existing nic driver or pointer to a document would be really helpful.
Thanks
-RK
_______________________________________________
Xen-devel mailing list
Xen-devel@...
http://lists.xensource.com/xen-devel
|
|
Re: Porting linux network driver to Xen
Again, you don't have to make any changes to the driver. Netback/netfront do not interact directly with the NIC's driver.
-Kaushik On Nov 4, 2009, at 3:18 PM, ravi kerur wrote: Thanks kaushik, How does netfront/netback interact with this driver? I believe I need netback functionality running in dom0 and netfront running in domU's for the existing driver. One of the documents has following explanation for Tx/Rx path.
"For transmit (TX)
requests the driver domain(dom0) uses a hypercall to map
the guest page(domU) into its
address space before sending the request through the
bridge. When the physical device driver frees the
page a callback function is automatically
invoked to return a response to netfront
which then revokes the grant.
For RX requests netfront posts I/O buffer page grants
to the RX I/O channel. When netback receives a packet from the
bridge it retrieves a posted grant from the I/O channel
and issues a grant copy hypercall to copy the
packet to the guest page(domU). Finally, netback sends a response
to the guest
via the RX channel indicating a packet is available."
I am not quite sure what changes or api's I need to call such that existing Tx/Rx buffers(rings) used for DMA in the native drivers starts talking via netfront/netback.
Inputs appreciated.
Thanks
-RK
On Wed, Nov 4, 2009 at 8:58 AM, Kaushik Kumar Ram <kaushik@...> wrote:
Native Linux drivers should work as such in Dom0. You don't have to port them.
-Kaushik
On Nov 4, 2009, at 7:17 AM, ravi kerur wrote:
Hi All,
I am working on porting an existing network driver from Linux to Xen, I understand network drivers needs netback and netfront functionality in order to work in Xen but I am unable to nail down the details of changes required esp.
a. will the existing driver go into hypervisor or dom0?
b. what changes are required in TX/RX rings for DMA in existing driver and how to incorporate them into netback/netfront,
c. handling IRQs...
Any pointers to existing nic driver or pointer to a document would be really helpful.
Thanks
-RK
_______________________________________________
Xen-devel mailing list
Xen-devel@...
http://lists.xensource.com/xen-devel
_______________________________________________
Xen-devel mailing list
Xen-devel@...
http://lists.xensource.com/xen-devel
|
|
Re: Porting linux network driver to Xen
I am confused now, probably I should ask what changes are needed such that I can access NIC from guest domains(domUs) for Tx and Rx? i.e if I compile native linux driver and run on dom0, how can I access it from domU's
are the changes just the configuration such that path is setup from domU/netfront -> dom0/netback->Bridge->NIC? Inputs appreciated. Thanks -Ravi On Wed, Nov 4, 2009 at 1:47 PM, Kaushik Kumar Ram <kaushik@...> wrote:
Again, you don't have to make any changes to the driver. Netback/netfront do not interact directly with the
NIC's driver.
-Kaushik On Nov 4, 2009, at 3:18 PM, ravi kerur wrote: Thanks kaushik, How does netfront/netback interact with this driver? I believe I need netback functionality running in dom0 and netfront running in domU's for the existing driver. One of the documents has following explanation for Tx/Rx path.
"For transmit (TX)
requests the driver domain(dom0) uses a hypercall to map
the guest page(domU) into its
address space before sending the request through the
bridge. When the physical device driver frees the
page a callback function is automatically
invoked to return a response to netfront
which then revokes the grant.
For RX requests netfront posts I/O buffer page grants
to the RX I/O channel. When netback receives a packet from the
bridge it retrieves a posted grant from the I/O channel
and issues a grant copy hypercall to copy the
packet to the guest page(domU). Finally, netback sends a response
to the guest
via the RX channel indicating a packet is available."
I am not quite sure what changes or api's I need to call such that existing Tx/Rx buffers(rings) used for DMA in the native drivers starts talking via netfront/netback.
Inputs appreciated.
Thanks
-RK
On Wed, Nov 4, 2009 at 8:58 AM, Kaushik Kumar Ram <kaushik@...> wrote:
Native Linux drivers should work as such in Dom0. You don't have to port them.
-Kaushik
On Nov 4, 2009, at 7:17 AM, ravi kerur wrote:
Hi All,
I am working on porting an existing network driver from Linux to Xen, I understand network drivers needs netback and netfront functionality in order to work in Xen but I am unable to nail down the details of changes required esp.
a. will the existing driver go into hypervisor or dom0?
b. what changes are required in TX/RX rings for DMA in existing driver and how to incorporate them into netback/netfront,
c. handling IRQs...
Any pointers to existing nic driver or pointer to a document would be really helpful.
Thanks
-RK
_______________________________________________
Xen-devel mailing list
Xen-devel@...
http://lists.xensource.com/xen-devel
_______________________________________________
Xen-devel mailing list
Xen-devel@...
http://lists.xensource.com/xen-devel
|
|
Re: Porting linux network driver to Xen
I am confused now, probably I should ask what changes are needed such that I can access NIC from guest domains(domUs) for Tx and Rx? i.e if I compile native linux driver and run on dom0, how can I access it from domU's
are the changes just the configuration such that path is setup from domU/netfront -> dom0/netback->Bridge->NIC?
Yes. Just make sure the NIC corresponding to this driver is attached to the bridge. If this NIC is not your default interface you may need to tweak the configuration.
-Kaushik
On Wed, Nov 4, 2009 at 1:47 PM, Kaushik Kumar Ram <kaushik@...> wrote:
Again, you don't have to make any changes to the driver. Netback/netfront do not interact directly with the
NIC's driver.
-Kaushik On Nov 4, 2009, at 3:18 PM, ravi kerur wrote: Thanks kaushik, How does netfront/netback interact with this driver? I believe I need netback functionality running in dom0 and netfront running in domU's for the existing driver. One of the documents has following explanation for Tx/Rx path.
"For transmit (TX)
requests the driver domain(dom0) uses a hypercall to map
the guest page(domU) into its
address space before sending the request through the
bridge. When the physical device driver frees the
page a callback function is automatically
invoked to return a response to netfront
which then revokes the grant.
For RX requests netfront posts I/O buffer page grants
to the RX I/O channel. When netback receives a packet from the
bridge it retrieves a posted grant from the I/O channel
and issues a grant copy hypercall to copy the
packet to the guest page(domU). Finally, netback sends a response
to the guest
via the RX channel indicating a packet is available."
I am not quite sure what changes or api's I need to call such that existing Tx/Rx buffers(rings) used for DMA in the native drivers starts talking via netfront/netback.
Inputs appreciated.
Thanks
-RK
_______________________________________________
Xen-devel mailing list
Xen-devel@...
http://lists.xensource.com/xen-devel
|
|
Re: Porting linux network driver to Xen
Thank you Kaushik for your help. Very much appreciated. Thanks -RK On Wed, Nov 4, 2009 at 3:07 PM, Kaushik Kumar Ram <kaushik@...> wrote:
I am confused now, probably I should ask what changes are needed such that I can access NIC from guest domains(domUs) for Tx and Rx? i.e if I compile native linux driver and run on dom0, how can I access it from domU's
are the changes just the configuration such that path is setup from domU/netfront -> dom0/netback->Bridge->NIC?
Yes. Just make sure the NIC corresponding to this driver is attached to the bridge. If this NIC is not your default interface you may need to tweak the configuration.
-Kaushik
On Wed, Nov 4, 2009 at 1:47 PM, Kaushik Kumar Ram <kaushik@...> wrote:
Again, you don't have to make any changes to the driver. Netback/netfront do not interact directly with the
NIC's driver.
-Kaushik On Nov 4, 2009, at 3:18 PM, ravi kerur wrote: Thanks kaushik, How does netfront/netback interact with this driver? I believe I need netback functionality running in dom0 and netfront running in domU's for the existing driver. One of the documents has following explanation for Tx/Rx path.
"For transmit (TX)
requests the driver domain(dom0) uses a hypercall to map
the guest page(domU) into its
address space before sending the request through the
bridge. When the physical device driver frees the
page a callback function is automatically
invoked to return a response to netfront
which then revokes the grant.
For RX requests netfront posts I/O buffer page grants
to the RX I/O channel. When netback receives a packet from the
bridge it retrieves a posted grant from the I/O channel
and issues a grant copy hypercall to copy the
packet to the guest page(domU). Finally, netback sends a response
to the guest
via the RX channel indicating a packet is available."
I am not quite sure what changes or api's I need to call such that existing Tx/Rx buffers(rings) used for DMA in the native drivers starts talking via netfront/netback.
Inputs appreciated.
Thanks
-RK
_______________________________________________
Xen-devel mailing list
Xen-devel@...
http://lists.xensource.com/xen-devel
|
|
Re: Porting linux network driver to Xen
Hi Kaushik, An additional Q, as long as the configuration is correct, I should be able to access network(i.e ftp, ssh and other apps) from dom0 via the usual path mentioned earlier. Please confirm. Thanks
RK On Wed, Nov 4, 2009 at 3:33 PM, ravi kerur <rkerur@...> wrote:
Thank you Kaushik for your help. Very much appreciated.
Thanks
-RK
On Wed, Nov 4, 2009 at 3:07 PM, Kaushik Kumar Ram <kaushik@...> wrote:
I am confused now, probably I should ask what changes are needed such that I can access NIC from guest domains(domUs) for Tx and Rx? i.e if I compile native linux driver and run on dom0, how can I access it from domU's
are the changes just the configuration such that path is setup from domU/netfront -> dom0/netback->Bridge->NIC?
Yes. Just make sure the NIC corresponding to this driver is attached to the bridge. If this NIC is not your default interface you may need to tweak the configuration.
-Kaushik
On Wed, Nov 4, 2009 at 1:47 PM, Kaushik Kumar Ram <kaushik@...> wrote:
Again, you don't have to make any changes to the driver. Netback/netfront do not interact directly with the
NIC's driver.
-Kaushik On Nov 4, 2009, at 3:18 PM, ravi kerur wrote: Thanks kaushik, How does netfront/netback interact with this driver? I believe I need netback functionality running in dom0 and netfront running in domU's for the existing driver. One of the documents has following explanation for Tx/Rx path.
"For transmit (TX)
requests the driver domain(dom0) uses a hypercall to map
the guest page(domU) into its
address space before sending the request through the
bridge. When the physical device driver frees the
page a callback function is automatically
invoked to return a response to netfront
which then revokes the grant.
For RX requests netfront posts I/O buffer page grants
to the RX I/O channel. When netback receives a packet from the
bridge it retrieves a posted grant from the I/O channel
and issues a grant copy hypercall to copy the
packet to the guest page(domU). Finally, netback sends a response
to the guest
via the RX channel indicating a packet is available."
I am not quite sure what changes or api's I need to call such that existing Tx/Rx buffers(rings) used for DMA in the native drivers starts talking via netfront/netback.
Inputs appreciated.
Thanks
-RK
_______________________________________________
Xen-devel mailing list
Xen-devel@...
http://lists.xensource.com/xen-devel
|
|
Re: Porting linux network driver to Xen
An additional Q, as long as the configuration is correct, I should be able to access network(i.e ftp, ssh and other apps) from dom0 via the usual path mentioned earlier. Please confirm.
Yes.
-Kaushik
On Wed, Nov 4, 2009 at 3:07 PM, Kaushik Kumar Ram <kaushik@...> wrote:
I am confused now, probably I should ask what changes are needed such that I can access NIC from guest domains(domUs) for Tx and Rx? i.e if I compile native linux driver and run on dom0, how can I access it from domU's
are the changes just the configuration such that path is setup from domU/netfront -> dom0/netback->Bridge->NIC?
Yes. Just make sure the NIC corresponding to this driver is attached to the bridge. If this NIC is not your default interface you may need to tweak the configuration.
-Kaushik
On Wed, Nov 4, 2009 at 1:47 PM, Kaushik Kumar Ram <kaushik@...> wrote:
Again, you don't have to make any changes to the driver. Netback/netfront do not interact directly with the
NIC's driver.
-Kaushik On Nov 4, 2009, at 3:18 PM, ravi kerur wrote: Thanks kaushik, How does netfront/netback interact with this driver? I believe I need netback functionality running in dom0 and netfront running in domU's for the existing driver. One of the documents has following explanation for Tx/Rx path.
"For transmit (TX)
requests the driver domain(dom0) uses a hypercall to map
the guest page(domU) into its
address space before sending the request through the
bridge. When the physical device driver frees the
page a callback function is automatically
invoked to return a response to netfront
which then revokes the grant.
For RX requests netfront posts I/O buffer page grants
to the RX I/O channel. When netback receives a packet from the
bridge it retrieves a posted grant from the I/O channel
and issues a grant copy hypercall to copy the
packet to the guest page(domU). Finally, netback sends a response
to the guest
via the RX channel indicating a packet is available."
I am not quite sure what changes or api's I need to call such that existing Tx/Rx buffers(rings) used for DMA in the native drivers starts talking via netfront/netback.
Inputs appreciated.
Thanks
-RK
_______________________________________________
Xen-devel mailing list
Xen-devel@...
http://lists.xensource.com/xen-devel
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