Re: [Xen-devel] ARM64: PCIe in DOM0

[Bharat Bhushan <bharat.bhushan@xxxxxxx>]

Hi,

> -----Original Message-----
> From: Julien Grall <julien.grall@xxxxxxx>
> Sent: Friday, October 5, 2018 6:51 PM
> To: Bharat Bhushan <bharat.bhushan@xxxxxxx>; Xen-
> devel@xxxxxxxxxxxxxxxxxxxx
> Subject: Re: [Xen-devel] ARM64: PCIe in DOM0
> 
> Hi,
> 
> On 05/10/2018 12:06, Bharat Bhushan wrote:
> > Further update:
> > If I change Kconfig to enable this default
> 
> CONFIG_HAS_ITS is in tech preview. For having access to it, you need to pass
> XEN_CONFIG_EXPERT on *all* the make command line.

I tried with this and I can see "its" node in Dom0 device-tree
My compilation steps are:
I am cross-compiling, so set toolchain path.

make dist-xen XEN_TARGET_ARCH=arm64 XEN_CONFIG_EXPERT=y 
CONFIG_EARLY_PRINTK=8250,0x21c0600,0
mkimage -A arm64 -T kernel -a 0x80000000 -e 0x80000000 -C none -d ./xen/xen 
xen4.11-uImage

> 
> > Then DOM0 Linux Boots but MSIs are not still working,
> >
> > Getting below error:
> >    - pci 0001:00:00.0: Failed to add - passthrough or MSI/MSI-X might fail!
> 
> This is a red-herring. This lines happen because PHYSDEVOP_pci_device_add
> is not implemented on Xen Arm.

I assume PCI device will still be working on ARM64 based platforms

> 
> >
> > Any help is very useful,!!
> 
> Can you please provide the full log?

Please find attached logs.
I have one UART of a DUART working, So at a time I am not able to provide same 
to XEN or DOM0.
So for you will see two set of log, one when console provided to XEN and 
another same console provided to DOM0 while used for early-prints of XEN.

I am new to XEN so might be doing something wrong.

Thanks
-Bharat

> 
> >>> -----Original Message-----
> >>> From: Bharat Bhushan
> >>> Sent: Friday, October 5, 2018 2:09 PM
> >>> To: Xen-devel@xxxxxxxxxxxxxxxxxxxx
> >>> Subject: ARM64: PCIe in DOM0
> >>>
> >>> Hi All,
> >>>
> >>> I am booting XEN for the first time on my platform and observing
> >>> that PCIe are not working.
> >>>
> >>> Here are my observations on this.
> >>>
> >>> 1) "git-its" node (below) from device tree is not available in DOM0
> >>> device tree.
> >>>
> >>>                  its: gic-its@6020000 {
> >>>                          compatible = "arm,gic-v3-its";
> >>>                          msi-controller;
> >>>                          reg = <0x0 0x6020000 0 0x20000>;
> >>>                  };
> >>>
> >>>    We have "msi-parent" property in PCIe controller node which
> >>> provides phandle of above mentioned node.
> >>>    Linux (DOM0) error out if it does find a valid msi-parent.
> >>>
> >>> First question I have is, What is the reason for removing gic-its node?
> 
> If CONFIG_HAS_ITS is disabled, then the virtual ITS is not built.
> Therefore the node is removed to prevent Dom0 using ITS.
> 
> >>> 2) Use Legacy interrupts rather than MSI
> >>>
> >>>    Used "pci=nomsi" in DOM0 bootargs to move away from MSIs,
> >>>
> >>>   Legacy interrupts are also not received and see netdev-watchdog.
> 
> Did you check whether legacy interrupts are routed to Dom0?
> 
> Cheers,
> 
> --
> Julien Grall

Attachment: Boot-log1.txt
Description: Boot-log1.txt

Attachment: Xen-log.txt
Description: Xen-log.txt

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