Re: git: 76887e84be97 - main - cpuset: increase userland maximum size to 1024

On Tue, 2023-05-09 at 09:43 +0200, Corvin Köhne wrote:
> On Tue, 2023-05-09 at 08:59 +0200, Corvin Köhne wrote:
> > On Mon, 2023-05-08 at 18:26 +0000, Ed Maste wrote:
> > > The branch main has been updated by emaste:
> > > 
> > > URL:
> > > https://cgit.FreeBSD.org/src/commit/?id=76887e84be975698b14699d7d0dfb157d73e9990
> > > 
> > > commit 76887e84be975698b14699d7d0dfb157d73e9990
> > > Author:     Ed Maste <emaste@FreeBSD.org>
> > > AuthorDate: 2023-05-02 20:57:12 +0000
> > > Commit:     Ed Maste <emaste@FreeBSD.org>
> > > CommitDate: 2023-05-08 18:25:15 +0000
> > > 
> > >     cpuset: increase userland maximum size to 1024
> > >     
> > >     Hardware with more than 256 CPU cores is now available and
> > > will
> > > become
> > >     increasingly common.  Bump CPU_MAXSIZE (used for userland
> > > cpuset_t
> > >     sizing) to 1024 to define the ABI for FreeBSD 14.
> > >     
> > >     PR:             269572, 271213 [exp-run]
> > >     Reviewed by:    mjg, jhb
> > >     Relnotes:       yes
> > >     Sponsored by:   The FreeBSD Foundation
> > >     Differential Revision: https://reviews.freebsd.org/D39941
> > > ---
> > >  sys/sys/_cpuset.h | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > 
> > > diff --git a/sys/sys/_cpuset.h b/sys/sys/_cpuset.h
> > > index b75ee595da3c..676f9855f384 100644
> > > --- a/sys/sys/_cpuset.h
> > > +++ b/sys/sys/_cpuset.h
> > > @@ -40,7 +40,7 @@
> > >  #define        CPU_SETSIZE     MAXCPU
> > >  #endif
> > >  
> > > -#define        CPU_MAXSIZE     256
> > > +#define        CPU_MAXSIZE     1024
> > >  
> > >  #ifndef        CPU_SETSIZE
> > >  #define        CPU_SETSIZE     CPU_MAXSIZE
> > 
> > Hi Ed,
> > 
> > this somehow breaks bhyve on my system. It immediately exits with
> > "vm_run error -1" on startup.
> > 
> > 
> 
> Setting MAXCPU [1] to 1024 as well, solves the issue. Not sure if
> it's
> a regression of your commit or a bhyve bug.
> 
> [1]
> https://github.com/freebsd/freebsd-src/blob/20d8d9809a8c0a3ddd1d0156e77ec53a1ed95747/sys/amd64/include/param.h#L68
> 
> 

vmm kernel module and bhyve userland are sharing a cpuset_t. So, this
commit introduces a mismatch in the ioctl signature of VM_RUN. Any
advice how to fix this properly, would be appreciated.

[1]
https://github.com/freebsd/freebsd-src/blob/c543e09f1f8ef98f201f7dd3f34ae023d61dfa83/sys/amd64/include/vmm.h#L759



-- 
Kind regards,
Corvin