Re: [PATCH 00/21] Fixes and lock cleanup+hardening

[Sean Christopherson]

On Wed, Mar 11, 2026, Jethro Beekman wrote:
> On 2026-03-11 00:48, Sean Christopherson wrote:
> > Fix several fatal SEV bugs, then clean up the SEV+ APIs to either document
> > that they are safe to query outside of kvm->lock, or to use lockdep-protected
> > version.  The sev_mem_enc_register_region() goof is at least the second bug
> > we've had related to checking for an SEV guest outside of kvm->lock, and in
> > general it's nearly impossible to just "eyeball" the safety of KVM's usage.
> > 
> > I included Carlos' guard() cleanups here to avoid annoying conflicts (well,
> > to solve them now instead of when applying).
> 
> I wrote a bunch of tests (see below) to check the kernel can properly handle bad userspace flows. I haven't had the chance to test them with your patch set.
> 
> test_vcpu_hotplug() triggers dump_vmcb()

FWIW, this is a non-issue, especially since SEV-ES+ guests can effectively fuzz
the VMSA at will.