Re: [PATCH kernel v5 6/6] x86/sev: Do not handle #VC for DR7 read/write

[Alexey Kardashevskiy]

On 23/5/23 09:44, Sean Christopherson wrote:
> On Tue, Apr 11, 2023, Alexey Kardashevskiy wrote:
> > With MSR_AMD64_SEV_DEBUG_SWAP enabled, the guest is not expected to
> > receive a #VC for reads or writes of DR7.
> >
> > Update the SNP_FEATURES_PRESENT mask with MSR_AMD64_SNP_DEBUG_SWAP so
> > an SNP guest doesn't gracefully terminate during SNP feature negotiation
> > if MSR_AMD64_SEV_DEBUG_SWAP is enabled.
> >
> > Since a guest is not expected to receive a #VC on DR7 accesses when
> > MSR_AMD64_SEV_DEBUG_SWAP is enabled, return an error from the #VC
> > handler in this situation.
> >
> > Signed-off-by: Alexey Kardashevskiy <aik@xxxxxxx>
> > Reviewed-by: Carlos Bilbao <carlos.bilbao@xxxxxxx>
> > Reviewed-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
> > Reviewed-by: Pankaj Gupta <pankaj.gupta@xxxxxxx>
> > ---
> > Changes:
> > v4:
> > * rebased on top of SNP feature negotiation
> >
> > v2:
> > * use new bit definition
> > ---
> >   arch/x86/boot/compressed/sev.c | 2 +-
> >   arch/x86/kernel/sev.c          | 6 ++++++
> >   2 files changed, 7 insertions(+), 1 deletion(-)
>
> Can you post this separately (or bribe Boris to grab it)?  IIUC, this has no
> dependency on the KVM enabling, i.e. can/should go through the tip tree without
> waiting for the KVM patches to be applied.

I definitely can, do you mind adding yours "rb"/"ab"? Thanks!


--
Alexey