Re: [x86 pmap changes] CVS commit: src/sys/arch

[Andrew Doran <ad%netbsd.org@localhost>]

On Thu, Jan 09, 2020 at 05:46:13PM +0100, Maxime Villard wrote:

> This FPU issue should be fixed in the latest nvmm_x86_vmx.c, we still have
> STTS/CLTS (not needed but for debugging) as part of context switches, and
> when overhauling the FPU code I overlooked that VMX needs special CR0_TS
> care that SVM doesn't need.
> 
> Note that dropping STTS/CLTS would probably increase cswitch performance,
> because updating cr0 is costly.
> 
> Having said that, I am still hitting a KASSERT related to pmap:
> 
> 	kernel diagnostic assertion "ptp->wire_count == 1" failed file
> 		".../x86/x86/pmap.c", line 1969
> 	pmap_freepages
> 	pmap_ept_free_ptp
> 	pmap_ept_remove
> 	pmap_remove
> 	uvm_unmap_remove
> 	uvmspace_free
> 	nvmm_ioctl
> 	sys_ioctl

Taking a look.  I think it's probably related to the changes I made to
further defer freeing PTPs (ugly but necessary for yamt-pagecache).  I think
I see a more elegant way to handle that.

Andrew