On Fri, Mar 04, 2022 at 12:36:17PM -0500, Boris Ostrovsky wrote: >>> I bisected it to "x86: remove the IOMMU table infrastructure" but haven't actually looked at the code yet. >> That looks like the swiotlb buffer did not get initialized at all, but I >> can't really explain why. >> >> Can you stick in a printk and see if xen_swiotlb_init_early gets called >> at all? > > > > Actually, that's the only thing I did do so far and yes, it does get called. So, specifically for "x86: remove the IOMMU table infrastructure" I think we need the one-liner below so that swiotlb_exit doesn't get called for the Xen case. But that should have been fixed up by the next patch already. diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c index 2ac0ef9c2fb76..1173aa282ab27 100644 --- a/arch/x86/kernel/pci-dma.c +++ b/arch/x86/kernel/pci-dma.c @@ -70,7 +70,7 @@ static void __init pci_xen_swiotlb_init(void) if (!xen_initial_domain() && !x86_swiotlb_enable && swiotlb_force != SWIOTLB_FORCE) return; - x86_swiotlb_enable = false; + x86_swiotlb_enable = true; xen_swiotlb = true; xen_swiotlb_init_early(); dma_ops = &xen_swiotlb_dma_ops;
