Re: [Qemu-discuss] Add PCI Passthrough for multiple devices on same bus?

[Andrew Martin]

Tony,

I am using virt-manager, but also receive this same error when attempting
to add a second serial port through the GUI. I believe the issue is that
all 4 of the serial ports on this card appear on the same bus. Is there a
way to add more than one device that is on the same bus to the VM?

I am not familiar with the "virtual storage" method that you mention. Can
this be used with non-storage devices, such as a serial card? Do you have
any documentation on this feature?

Thanks,

Andrew

----- Original Message -----
> From: "Tony Su" <address@hidden>
> To: "Andrew Martin" <address@hidden>
> Cc: "qemu_mail" <address@hidden>
> Sent: Sunday, September 8, 2013 6:42:14 PM
> Subject: Re: [Qemu-discuss] Add PCI Passthrough for multiple devices on same 
> bus?
> 
> Since you're using virsh commands, have you also considered just
> running vm manager if you're running a graphical environment? It's
> pretty straightforward when you use vm manager if there isn't a
> conflict of some sort...
> 
> Also, just wondering if you really need to access the hardware
> directly, it's more typical to let the Host access the hardware
> directly and create virtual storage on the hardware for VM use
> instead. If you don't have a specific need, there are many benefits
> doing it the more usual virtualized storage way.
> 
> Tony
> 
> On Thu, Sep 5, 2013 at 3:15 PM, Andrew Martin <address@hidden>
> wrote:
> > Hello,
> >
> > I have a 4-port PCIe serial card that I would like to pass through
> > to a VM. The serial card has 4 serial ports on it, and I would
> > like to pass all 4 ports through. Here are the ports, as seen on
> > the host:
> > # lspci
> > 02:00.0 Serial controller: MosChip Semiconductor Technology Ltd.
> > 4-Port PCIe Serial Adapter
> > 02:00.1 Serial controller: MosChip Semiconductor Technology Ltd.
> > 4-Port PCIe Serial Adapter
> > 02:00.2 Serial controller: MosChip Semiconductor Technology Ltd.
> > 4-Port PCIe Serial Adapter
> > 02:00.3 Serial controller: MosChip Semiconductor Technology Ltd.
> > 4-Port PCIe Serial Adapter
> >
> > # virsh nodedev-list
> > pci_0000_02_00_0
> > pci_0000_02_00_1
> > pci_0000_02_00_2
> > pci_0000_02_00_3
> >
> > I have configured the first port, 02:00.0 , in my VM configuration
> > file as follows:
> > <hostdev mode='subsystem' type='pci' managed='yes'>
> >       <source>
> >         <address domain='0x0000' bus='0x02' slot='0x00'
> >         function='0x0'/>
> >       </source>
> >       <address type='pci' domain='0x0000' bus='0x00' slot='0x05'
> >       function='0x0'/>
> > </hostdev>
> >
> > If I attempt to start the VM, I get the following error:
> > error: internal error Unable to reset PCI device 0000:02:00.1:
> > internal error Active 0000:02:00.0 devices on bus with
> > 0000:02:00.1, not doing bus reset
> >
> > Running the following commands to detach the other 3 ports then
> > allows me to successfully start the VM, and I can see the serial
> > port in it:
> > # virsh nodedev-detach pci_0000_02_00_1
> > # virsh nodedev-detach pci_0000_02_00_2
> > # virsh nodedev-detach pci_0000_02_00_3
> >
> > However, when I attempt to add more than 1 of the ports to the VM
> > config, I keep getting this error:
> > error: internal error Unable to reset PCI device 0000:02:00.1:
> > internal error Active 0000:02:00.0 devices on bus with
> > 0000:02:00.1, not doing bus reset
> >
> > The second port I added (0000:02:00.1) is configured as follows in
> > the VM config:
> >     <hostdev mode='subsystem' type='pci' managed='yes'>
> >       <source>
> >         <address domain='0x0000' bus='0x02' slot='0x00'
> >         function='0x1'/>
> >       </source>
> >       <address type='pci' domain='0x0000' bus='0x00' slot='0x06'
> >       function='0x0'/>
> >     </hostdev>
> >
> > How can I add all 4 of these devices (which share the same bus) as
> > PCI passthrough to the VM?
> >
> > Thanks,
> >
> > Andrew
> >
>