Login
Username:

Password:

Remember me



Lost Password?

Register now!

Sections

Who's Online
30 user(s) are online (21 user(s) are browsing Forums)

Members: 1
Guests: 29

Maijestro, more...

Headlines

 
  Register To Post  

PCI virtio driver development
Just popping in
Just popping in


See User information
Anyone having experience writing a AOS4 driver for a pci device? I'm trying to write a virtio-... device driver.
Currently palying around with block device. So I'm setting up a simple test to write data. It seems from the
qemu monitor everything is fine. But I'm struggling with kicking of the write request to the device. From the
documentation, is should be quiet simple, just write a value to a specific address in the BAR region. I have that
address, I know the value to write. But writing to that address, nothing happens.

Is there a trick form the AmigaOS side, and is there a way to debug/monitor that from the qemu side.

Go to top
Re: PCI virtio driver development
Quite a regular
Quite a regular


See User information
@MigthyMax
As for tracing from QEMU side look at qemu/hw/virtio/trace-events for trace points that cen be enabled. You can either add -trace enable="glob pattern" (can use multiple -trace options to enable different traces) or from the QEMU monitor. Also check info pci or info qtree and check that the BARs of the device are enabled and mapped or you can also use -trace enable="pci*" to check access to PCI regs. Adding -d unimp,guest_errors may also show access to wrong memory addresses but some of those are because of not emulated hardware so may not be an error.

Now there are at least 3 people working on virtio drivers independently. Isn't it time to collaborate on a virtio.library to avoid duplicated work? Is there anybody who wants to publish their virtio access routines under an open source license to make them a standard way to access virtio devices on AmigaOS that everybody can use?

Go to top
Re: PCI virtio driver development
Just popping in
Just popping in


See User information
@balaton

The BAR mapping looks good, as long I understand everything.

I test all the options suggested. During the run of my test, no output was giving. Which makes me wonder because using "-trace enable="pci*"" only gives output during startup of the OS. But if I start my test, and it read in the pci configuration space. No additional message were written by this option.

Yeah, we should work together, but except Hans who is the third person? Any my code is just at the moment a hack done, to see how everything works.

Go to top
Re: PCI virtio driver development
Quite a regular
Quite a regular


See User information
@balatonQuote:
balaton wrote:@MigthyMax
Now there are at least 3 people working on virtio drivers independently. Isn't it time to collaborate on a virtio.library to avoid duplicated work? Is there anybody who wants to publish their virtio access routines under an open source license to make them a standard way to access virtio devices on AmigaOS that everybody can use?


It's one and the same person see...

https://www.amigans.net/modules/newbb/ ... &order=ASC&status=&mode=0

MacStudio ARM M1 Max Qemu//Pegasos2 AmigaOs4.1 FE
Go to top
Re: PCI virtio driver development
Quite a regular
Quite a regular


See User information
@MigthyMax
If you don't see access with -trace enable="pci*" when reading writing config space then it does not reach the emulated device. The pci_* trace points only show config space access, accesses to BAR aread may need enabling virtio trace points but qemu/hw/virtio/virtio-pci.c does not seem to have any. You can try to add printfs or traces to *_read/*_write functions in that file to see if they are called. Are you using the right address where it's mapped and is the correct enable bits set in the BAR? See Memory Space and IO Space bits in https://wiki.osdev.org/PCI#Command_Register (the Bus Master bit may also be needed if the device wants to write to memory with DMA). If the firmware does not know the device then it may only program the BARs but not actually enable the device so unless you enable it no access will succeed.

If you're the same person working in a virtio-net driver (you've mentioned virtio-blk above) then there may be only 2 people.

Go to top
Re: PCI virtio driver development
Home away from home
Home away from home


See User information
@Maijestro

Quote:
It's one and the same person see...

A few people have contacted me privately, so there may actually be more than three people working on virtio drivers.

@MightyMax and anyone working on virtio drivers (or considering working on)

Please try contacting A-EON about using the virtio.library. It'll take care of all the low-level stuff, so you can focus on the "blk" part.

Matthew might be a bit overloaded at the moment between work & family. So, be patient.

Hans

http://hdrlab.org.nz/ - Amiga OS 4 projects, programming articles and more.
https://keasigmadelta.com/ - more of my work
Go to top
Re: PCI virtio driver development
Home away from home
Home away from home


See User information
@Hans
Quote:

Please try contacting A-EON about using the virtio.library


Mean no open source, another sites to register to download it, another ownership who want to dictate when and how to use it. Maybe can be ok with closed source stuff, but with QEMU having developers to rely on closed source library, IMHO no way to go.

You may know the situation already with all those AEON's classes, which you can't just download from os4depot (you need to register on some sites for), as well as of course they not open sourced, which in end leads to their usage only mostly inside of the Enhancer itself.

If ppls will be in needs to contact to the Mattew (yeah, that Mattew who answer years for simple questions), to get access to the closed source library, to sign some document or register on some site, that IMHO just crazy. Especially when it comes to the things like opensourced emulator (all the work for which done for free mostly).

I am fully up to have video driver for QEMU being closed source and for sale to cover the cost of your work, but anyone else who work for free, IMHO should not step in that mess. I'm seeing all over the places how ppls can't get simple things for aeon tracker be fixed for YEAR! Or how their sites can't be fixed to properly handle SSL things.. IMHO, if one wants to save their nervous, they shouldn't try to do any work based on the AEON's closed source stuff. It leads to the same (if not worse) issues as it was with Hyperion and whole contacting with Mattew and getting answer from him or any action, it's like talking to the black hole.

Join us to improve dopus5!
AmigaOS4 on youtube
Go to top
Re: PCI virtio driver development
Home away from home
Home away from home


See User information
@kas1e

Quote:
Mean no open source, another sites to register to download it, another ownership who want to dictate when and how to use it. Maybe can be ok with closed source stuff, but with QEMU having developers to rely on closed source library, IMHO no way to go.

This has zero effect on Qemu developers. It only matters to those writing drivers for AmigaOS.

Incidentally, Virtio isn't only for Qemu. It's also supported by other Virtual Machines (VMs).

Quote:
If ppls will be in needs to contact to the Mattew (yeah, that Mattew who answer years for simple questions), to get access to the closed source library, to sign some document or register on some site, that IMHO just crazy.

You're assuming that people will have to sign an NDA to get access. I don't remember them doing that with their classes.

The reason that I'm encouraging people to contact A-EON, is so that A-EON is aware that people want access to the library. Hopefully that'll nudge them to take action sooner rather than later. I've already encouraged them to open up access to the library.

Hans

http://hdrlab.org.nz/ - Amiga OS 4 projects, programming articles and more.
https://keasigmadelta.com/ - more of my work
Go to top
Re: PCI virtio driver development
Home away from home
Home away from home


See User information
@Hans
Quote:

You're assuming that people will have to sign an NDA to get access. I don't remember them doing that with their classes.


Not exactly NDA, but one need to wait when Mattew answer (can never happen). Or they will be in needs to register on some site (as it done with classes).


Quote:

The reason that I'm encouraging people to contact A-EON, is so that A-EON is aware that people want access to the library. Hopefully that'll nudge them to take action sooner rather than later. I've already encouraged them to open up access to the library.


If they simply upload it on os4depot for everyone's usage: then that will be very good and correct way : everyone who will be in needs can use it. All good.

But it wasn't like this with classes, and surely will not happen with this library too (i hope to be wrong). Those developers who will be in interest to use this library, will be forced to wait when Mattew will find a time to answer with putting a restriction usage on top of it :)

Do you think they can upload it to os4depot in the end for everyone's usage ? I didn't believe in, but hope to be wrong :)

Join us to improve dopus5!
AmigaOS4 on youtube
Go to top
Re: PCI virtio driver development
Just popping in
Just popping in


See User information
@hans @balaton

I don't have trouble getting the low level part setup. I have the device setup:

(qemuinfo virtio-status /machine/peripheral-anon/device[3]/virtio-backend
/machine/peripheral-anon/device[3]/virtio-backend:
  
device_name:             virtio-blk 
  device_id
:               2
  vhost_started
:           false
  bus_name
:                (null)
  
broken:                  false
  disabled
:                false
  disable_legacy_check
:    false
  started
:                 true
  use_started
:             true
  start_on_kick
:           false
  use_guest_notifier_mask
true
  vm_running
:              true
  num_vqs
:                 1
  queue_sel
:               0
  isr
:                     0
  endianness
:              big
  status
:
    
VIRTIO_CONFIG_S_ACKNOWLEDGEValid virtio device found,
    
VIRTIO_CONFIG_S_DRIVERGuest OS compatible with device,
    
VIRTIO_CONFIG_S_FEATURES_OKFeature negotiation complete,
    
VIRTIO_CONFIG_S_DRIVER_OKDriver setup and ready
  Guest features
:

  
Host features:
    
VIRTIO_RING_F_EVENT_IDXUsed availevent fields enabled,
    
VIRTIO_RING_F_INDIRECT_DESCIndirect descriptors supported,
    
VIRTIO_F_RING_RESETDriver can reset a queue individually,
    
VIRTIO_F_VERSION_1Device compliant for v1 spec (legacy),
    
VIRTIO_F_ANY_LAYOUTDevice accepts arbitrary desclayouts,
    
VIRTIO_F_NOTIFY_ON_EMPTYNotify when device runs out of availdescson VQ
    VHOST_USER_F_PROTOCOL_FEATURES
Vhost-user protocol features negotiation supported,
    
VIRTIO_BLK_F_CONFIG_WCECache writeback and writethrough modes supported,
    
VIRTIO_BLK_F_FLUSHFlush command supported,
    
VIRTIO_BLK_F_WRITE_ZEROESWrite zeroes command supported,
    
VIRTIO_BLK_F_DISCARDDiscard command supported,
    
VIRTIO_BLK_F_TOPOLOGYTopology information available,
    
VIRTIO_BLK_F_BLK_SIZEBlock size of disk available,
    
VIRTIO_BLK_F_GEOMETRYLegacy geometry available,
    
VIRTIO_BLK_F_SEG_MAXMax segments in a request is seg_max
  Backend features
:


And I even setup a request in the queue:

(qemuinfo virtio-queue-element /machine/peripheral-anon/device[3]/virtio-backend 0 0
Desc next is 768
/machine/peripheral-anon/device[3]/virtio-backend:
  
device_namevirtio-blk
  index
:   0
  desc
:
    
descs:
        
addr 0x471ad70 len 1 (writenext),
        
addr 0x4709ca0 len 7 (next),
        
addr 0x471ad60 len 16 (next)
  
avail:
    
flags0
    idx
:   0
    ring
:  0
  used
:
    
flags0
    idx
:   256
(qemu)


The "only" thing is, I cannot signal the device like described in chapter 4.1.4.4.1. I calculate the address, but writing any kind of value into that address location, results in nothing. No error message from qemu, no processing of the virtqueue entries. And yes the PCI command register has bit 2 set.

So that's is where I need help, or least some kind of debug output telling my what qemu thinks is wrong.

And yes I will contact Matthew. But I already had my code, a long time before the virtio.library was made public known.

Go to top
Re: PCI virtio driver development
Not too shy to talk
Not too shy to talk


See User information
@kas1eQuote:
If they simply upload it on os4depot for everyone's usage: then that will be very good and correct way : everyone who will be in needs can use it. All good.

But it wasn't like this with classes, and surely will not happen with this library too (i hope to be wrong). Those developers who will be in interest to use this library, will be forced to wait when Mattew will find a time to answer with putting a restriction usage on top of it :)

Do you think they can upload it to os4depot in the end for everyone's usage ? I didn't believe in, but hope to be wrong :)


You have made me curious. As I understood it. E.g. an ordinary person who would like to do something with VAAPI for AOS4 has to ask @ for an API, register somewhere, sign something ?
VAAPI is only for A-EON products ?

Go to top
Re: PCI virtio driver development
Not too shy to talk
Not too shy to talk


See User information
@smarkusgQuote:
smarkusg wrote:@kas1eQuote:
If they simply upload it on os4depot for everyone's usage: then that will be very good and correct way : everyone who will be in needs can use it. All good.

But it wasn't like this with classes, and surely will not happen with this library too (i hope to be wrong). Those developers who will be in interest to use this library, will be forced to wait when Mattew will find a time to answer with putting a restriction usage on top of it :)

Do you think they can upload it to os4depot in the end for everyone's usage ? I didn't believe in, but hope to be wrong :)


You have made me curious. As I understood it. E.g. an ordinary person who would like to do something with VAAPI for AOS4 has to ask @ for an API, register somewhere, sign something ?
VAAPI is only for A-EON products ?


Im assuming they are talking about the Enhancer Software Core 2 pack (link here) as that requires an Amisphere login to download the pack for free.

My own opinion is it doesnt matter what website you get it from, as its still free and Matthew will still have the same limited time to do things. There are much better things to spend time on.

Go to top
Re: PCI virtio driver development
Quite a regular
Quite a regular


See User information
@MigthyMax
It's hard to know what you're doing without a lot of details or seeing the code so it's hard to help. I don't know what's happening but if you think writes don't reach QEMU you could add additional logging in the virtio-pci as I said before to see what values reach there.

Other than that, maybe check if addresses written in the queue are correct. I'm not sure but I think virtio devices need physical addresses as they don't know about the CPU virtual addresses so unless you have a one to one mapping you may need to translate addresses to physical memory locations that you tell the device to operate on.

Also you can try -trace enable="virtqueue*" to see changes to queue. See other trace entries in qemu/hw/virtio/trace-events.

Go to top

  Register To Post

 




Currently Active Users Viewing This Thread: 1 ( 0 members and 1 Anonymous Users )




Powered by XOOPS 2.0 © 2001-2023 The XOOPS Project