On Wed, May 17, 2023 at 05:59:31PM -0700, Stefano Stabellini wrote: > Hi all, > > I have run into another PVH Dom0 issue. I am trying to enable a PVH Dom0 > test with the brand new gitlab-ci runner offered by Qubes. It is an AMD > Zen3 system and we already have a few successful tests with it, see > automation/gitlab-ci/test.yaml. > > We managed to narrow down the issue to a console problem. We are > currently using console=com1 com1=115200,8n1,pci,msi as Xen command line > options, it works with PV Dom0 and it is using a PCI UART card. > > In the case of Dom0 PVH: > - it works without console=com1 > - it works with console=com1 and with the patch appended below > - it doesn't work otherwise and crashes with this error: > https://matrix-client.matrix.org/_matrix/media/r0/download/invisiblethingslab.com/uzcmldIqHptFZuxqsJtviLZK
Jan also noticed this, and we have a ticket for it in gitlab: https://gitlab.com/xen-project/xen/-/issues/85 > What is the right way to fix it? I think the right fix is to simply avoid hidden devices from being handled by vPCI, in any case such devices won't work propewrly with vPCI because they are in use by Xen, and so any cached information by vPCI is likely to become stable as Xen can modify the device without vPCI noticing. I think the chunk below should help. It's not clear to me however how hidden devices should be handled, is the intention to completely hide such devices from dom0? Roger. --- diff --git a/xen/drivers/vpci/vpci.c b/xen/drivers/vpci/vpci.c index 652807a4a454..0baef3a8d3a1 100644 --- a/xen/drivers/vpci/vpci.c +++ b/xen/drivers/vpci/vpci.c @@ -72,7 +72,12 @@ int vpci_add_handlers(struct pci_dev *pdev) unsigned int i; int rc = 0; - if ( !has_vpci(pdev->domain) ) + if ( !has_vpci(pdev->domain) || + /* + * Ignore RO and hidden devices, those are in use by Xen and vPCI + * won't work on them. + */ + pci_get_pdev(dom_xen, pdev->sbdf) ) return 0; /* We should not get here twice for the same device. */
