Hello Paolo, On Fri, Dec 04, 2020 at 12:22:48PM +0100, Paolo Bonzini wrote: > On 05/05/20 23:22, Ashish Kalra wrote: > > From: Ashish Kalra <ashish.kalra@xxxxxxx> > > > > For source VM, live migration feature is enabled explicitly > > when the guest is booting, for the incoming VM(s) it is implied. > > This is required for handling A->B->C->... VM migrations case. > > > > Signed-off-by: Ashish Kalra <ashish.kalra@xxxxxxx> > > --- > > arch/x86/kvm/svm/sev.c | 7 +++++++ > > 1 file changed, 7 insertions(+) > > > > diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c > > index 6f69c3a47583..ba7c0ebfa1f3 100644 > > --- a/arch/x86/kvm/svm/sev.c > > +++ b/arch/x86/kvm/svm/sev.c > > @@ -1592,6 +1592,13 @@ int svm_set_page_enc_bitmap(struct kvm *kvm, > > if (ret) > > goto unlock; > > + /* > > + * For source VM, live migration feature is enabled > > + * explicitly when the guest is booting, for the > > + * incoming VM(s) it is implied. > > + */ > > + sev_update_migration_flags(kvm, KVM_SEV_LIVE_MIGRATION_ENABLED); > > + > > bitmap_copy(sev->page_enc_bmap + BIT_WORD(gfn_start), bitmap, > > (gfn_end - gfn_start)); > > > > I would prefer that userspace does this using KVM_SET_MSR instead. > > Ok. But, this is for a VM which has already been migrated based on feature support on host and guest and host negotation and enablement of the live migration support, so i am assuming that a VM which has already been migrated can have this support enabled implicitly for further migration. Thanks, Ashish
