Re: Failed to access register with invalid access size alignment

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Wed, Apr 02, 2014 at 07:28:44PM +0000, Zytaruk, Kelly wrote:
> I have seen the subject-line error message in a few posts but I haven't yet seen a resolution for it yet.  Has anyone resolved this problem?
> 
> The full error line from the log file is;
> [00:05.0] xen_pt_pci_config_access_check: Error: Failed to access register with invalid access size alignment. (addr: 0x0e, len: 4)
> 

You could instrument QEMU to pause the guest immediately when this happens. Then
you can use xen_hvmtrace to figure the EIP and get an idea of where things are.

> Address 0x0e in PCIe config space is 2 byte aligned and can't be accessed as a 4 byte read.
> 
> I am passing an AMD graphics adapter into a guest as a secondary adapter.  I can connect with VNC and the PCI passthrough is successful as I can see the [00:05.0] device in Win7 device Manager but the device is "banged out" with the error "Windows has stopped this device because it has reported problems. (Code 43)".
> 
> The error occurs with both QEMU-upstream and QEMU-traditional.
> My configuration is Xen 4.5-unstable on Linux 3.13.4.
> 
> Thanks,
> Kelly
> 
> 
> 
> 
> 
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