Hi Joerg Roedel, > From: [email protected] [mailto:[email protected]] > Yes, that is true. But the messages are harmless and you are safe to ignore > them in your usecase. > We only care about the kdump case when copying the old IR and DMAR tables > into the new kernel, > because in the kdump case the old kernel crashed and left devices in an > undefined state, so that > they might still send DMA and IRQ requests to the new kernel, corrupting data > or causing spurious/blocked irqs. > Blocked IRQs or DMA requests might even break devices so that the new kernel > can't initialize them anymore. ... > That is why we want to make sure, that no spurious IRQ or DMA requests are > blocked when the new > kernel initializes the IOMMU. In the non-kdump case we can assume that the > old kernel put the devices > into a defined state where they are not sending spurious requests.
Thanks so much for your detail and clear comments, get it now. Send you a patch " Don't print the failure message when booting non-kdump kernel" to make it less alarming or misleading. Please review it, thanks! BR qiuxu _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
