Re: "swiotlb buffer is full" in DomU with PCI passthrough is caused by low memory in Dom0

[zithro <slack@xxxxxxxxx>]

On 25 Apr 2023 22:30, Paul Leiber wrote:
> Hi,
Hi,

> I can't rule out that there actually is a log entry in Dom0 for this 
> situation, and my Xen and/or linux knowledge was not good enough to let 
> me find it. If this is the case, I'd appreciate some pointers.
Then why not posting your logs ?

Did you add "loglvl=all" and/or "guest_loglvl=all" to Xen cmdline ?
What logs did you read: "dmesg", "xl dmesg" or logs in /var/log/xen ?

From the (few) posts I've read, this problems happens on 
non-virtualized systems, so maybe it's not related to Xen at all.
Maybe it's a driver problem.
(Search query used: "swiotlb buffer is full").

Also I found pointers related to the *domU* kernel command line option 
"swiotlb", like using "swiotlb=1" or "swiotlb=65536"
PS: I'm not an expert, just a Xen user ;)