Mike Larkin <mlar...@nested.page> writes:
> On Mon, Jan 09, 2023 at 06:51:27PM -0500, Dave Voutila wrote: >> >> This ok with folks? Had OK's for the original diff but double checking >> before I commit. >> > > This is only half of what you need to do to stop guests from using > unwanted/unsupported instructions. Removing the CPUID feature flag bit > only lets the guest know "don't use this instruction" but if they ignore > that and use it anyway, well... shrug. > > If you want to remove support for WAITPKG, we'll need to enable > TPAUSE/UMWAIT exiting, and then inject #UD if we ever exit for that > reason. I think there are a few examples of this in vmm.c already. > I'm pretty sure the cpu does that for us as the original details from the user reporting the issue shows the linux kernel puking with: [ 0.052602] invalid opcode: 0000 [#1] SMP PTI I'll double check the SDM but I think if we don't tell VMX to support it, it should be handling the exception for us. But, it's Intel VMX, so who knows! -dv
