Re: [PATCH] target/i386: SEV: do not assume machine->cgs is SEV

[Paolo Bonzini <pbonzini@redhat.com>]

On Thu, Jun 6, 2024 at 6:07 PM Xiaoyao Li <xiaoyao.li@intel.com> wrote:
>
> On 6/6/2024 6:44 AM, Paolo Bonzini wrote:
> > There can be other confidential computing classes that are not derived
> > from sev-common.  Avoid aborting when encountering them.
>
> I hit it today when rebasing TDX patches to latest QEMU master, which
> has the SEV-SNP series merged. (I didn't get time to review it between
> it gets merged.)
>
> my approach is to guard with sev_enabled() when calling
> sev_es_set_reset_vector() in kvm_arch_reset_vcpu(), because calling sev*
> specific function in generic kvm code doesn't look reasonable to me.

On the other hand I would like to avoid too many sev/tdx conditionals
in common code.  Neither choice is great.

Another possibility is to make this a X86ConfidentialGuest method, if
the TDX code has anything similar.

Feel free to keep this patch, or anything that replaces it, in your TDX series.

Apart from this issue, I could rebase the previous TDX patches on top
of SEV-SNP without any problems.

Paolo