Messages in this thread | | | Date | Wed, 18 Oct 2023 14:11:20 +0200 | From | Greg Kroah-Hartman <> | Subject | Re: [PATCH 0/5] mlx5 ConnectX diagnostic misc driver |
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On Wed, Oct 18, 2023 at 09:00:25AM -0300, Jason Gunthorpe wrote: > On Wed, Oct 18, 2023 at 10:31:23AM +0200, Greg Kroah-Hartman wrote: > > On Wed, Oct 18, 2023 at 01:19:36AM -0700, Saeed Mahameed wrote: > > > Historically a userspace program was used that accessed the PCI register > > > and config space directly through /sys/bus/pci/.../XXX and could operate > > > these debugging interfaces in parallel with the running driver. > > > This approach is incompatible with secure boot and kernel lockdown so this > > > driver provides a secure and restricted interface to that. > > > > Why not just write a UIO driver for this hardware then? > > The old mechanism relied on direct config space and sometimes mmio > access to the PCI device. We did a security analysis and concluded > that approach could not provide the required security for what our > customers want from the secure boot and lockdown modes. We cannot > allow a lockdown userspace direct access to those device registers. > > So, it was redesigned to be RPC driven instead of having direct HW > access. The RPCs allow the device to provide the required level of > security. > > This new misc driver does not expose any HW registers or interrupts to > userspace, so it does not seem like a fit for UIO.
Ok, I'll not complain, I always like "real" drivers instead of UIO ones, nice to see this happen!
thanks,
greg k-h
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