Re: CVS commit: src/sys/dev/nvmm

[Reinoud Zandijk <reinoud%NetBSD.org@localhost>]

Hi Taylor,

Thanks for updating NVMM! Would it be a good idea to sync our code with
DragonBSDs? AFAICS they kept the code compiling for NetBSD too. To have a
common code base?

With regards,
Reinoud

On Tue, Sep 13, 2022 at 08:10:04PM +0000, Taylor R Campbell wrote:
> Module Name:	src
> Committed By:	riastradh
> Date:		Tue Sep 13 20:10:04 UTC 2022
> 
> Modified Files:
> 	src/sys/dev/nvmm: nvmm.c nvmm_internal.h
> 	src/sys/dev/nvmm/x86: nvmm_x86_vmx.c
> 
> Log Message:
> nvmm(4): Add suspend/resume support.
> 
> New MD nvmm_impl callbacks:
> 
> - .suspend_interrupt forces all VMs on all physical CPUs to exit.
> - .vcpu_suspend suspends an individual vCPU on a machine.
> - .machine_suspend suspends an individual machine.
> - .suspend suspends the whole system.
> - .resume resumes the whole system.
> - .machine_resume resumes an individual machine.
> - .vcpu_resume resumes an indidivudal vCPU on a machine.
> 
> Suspending nvmm:
> 
> 1. causes new VM operations (ioctl and close) to block until resumed,
> 2. uses .suspend_interrupt to interrupt any concurrent and force them
>    to return early, and then
> 3. uses the various suspend callbacks to suspend all vCPUs, machines,
>    and the whole system -- all vCPUs before the machine they're on,
>    and all machines before the system.
> 
> Resuming nvmm does the reverse of (3) -- resume system, resume each
> machine and then the vCPUs on that machine -- and then unblocks
> operations.
> 
> Implemented only for x86-vmx for now:
> 
> - suspend_interrupt triggers a TLB IPI to cause VM exits;
> - vcpu_suspend issues VMCLEAR to force any in-CPU state to be written
>   to memory;
> - machine_suspend does nothing;
> - suspend does VMXOFF on all CPUs;
> - resume does VMXON on all CPUs;
> - machine_resume does nothing; and
> - vcpu_resume just marks each vCPU as valid but inactive so
>   subsequent use will clear it and load it with vmptrld.
> 
> x86-svm left as an exercise for the reader.
> 
> 
> To generate a diff of this commit:
> cvs rdiff -u -r1.46 -r1.47 src/sys/dev/nvmm/nvmm.c
> cvs rdiff -u -r1.20 -r1.21 src/sys/dev/nvmm/nvmm_internal.h
> cvs rdiff -u -r1.84 -r1.85 src/sys/dev/nvmm/x86/nvmm_x86_vmx.c
> 
> Please note that diffs are not public domain; they are subject to the
> copyright notices on the relevant files.