Re: [RFC 0/2] [RFC] Honor PCI prefetchable attributes for a virtual machine on ARM64

From: Christoph Hellwig
Date: Mon May 03 2021 - 03:02:28 EST


On Thu, Apr 29, 2021 at 11:29:04AM -0500, Shanker Donthineni wrote:
> Problem statement: Virtual machine crashes when NVIDIA GPU driver access a prefetchable BAR space due to the unaligned reads/writes for pass-through devices. The same binary works fine as expected in the host kernel. Only one BAR has control & status registers (CSR) and other PCI BARs are marked as prefetchable. NVIDIA GPU driver uses the write-combine feature for mapping the prefetchable BARs to improve performance. This problem applies to all other drivers which want to enable WC.

Unless you mean the noveau drivers this simply does not matter. Please
don't spam the kernel lists with issues with your broken and license
violating drivers.