On 1/26/21 12:54 PM, Peter Gonda wrote: > sev_pin_memory assumes that callers hold the kvm->lock. This was true for > all callers except svm_register_enc_region since it does not originate > from svm_mem_enc_op. Also added lockdep annotation to help prevent > future regressions.
I'm not exactly sure what the problem is that your fixing? What is the symptom that you're seeing? > > Tested: Booted SEV enabled VM on host. > > Cc: Thomas Gleixner <[email protected]> > Cc: Ingo Molnar <[email protected]> > Cc: "H. Peter Anvin" <[email protected]> > Cc: Paolo Bonzini <[email protected]> > Cc: Joerg Roedel <[email protected]> > Cc: Tom Lendacky <[email protected]> > Cc: Brijesh Singh <[email protected]> > Cc: Sean Christopherson <[email protected]> > Cc: [email protected] > Cc: [email protected] > Cc: [email protected] > Cc: [email protected] > Fixes: 116a2214c5173 (KVM: SVM: Pin guest memory when SEV is active) I can't find this commit. The Linux and KVM trees have it as: 1e80fdc09d12 ("KVM: SVM: Pin guest memory when SEV is active") > Signed-off-by: Peter Gonda <[email protected]> > > --- > arch/x86/kvm/svm.c | 16 +++++++++------- This patch won't apply, as it has already been a few releases since svm.c was moved to the arch/x86/kvm/svm directory and this function now lives in sev.c. Thanks, Tom > 1 file changed, 9 insertions(+), 7 deletions(-) > > diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c > index afdc5b44fe9f..9884e57f3d0f 100644 > --- a/arch/x86/kvm/svm.c > +++ b/arch/x86/kvm/svm.c > @@ -1699,6 +1699,8 @@ static struct page **sev_pin_memory(struct kvm *kvm, > unsigned long uaddr, > struct page **pages; > unsigned long first, last; > > + lockdep_assert_held(&kvm->lock); > + > if (ulen == 0 || uaddr + ulen < uaddr) > return NULL; > > @@ -7228,12 +7230,19 @@ static int svm_register_enc_region(struct kvm *kvm, > if (!region) > return -ENOMEM; > > + mutex_lock(&kvm->lock); > region->pages = sev_pin_memory(kvm, range->addr, range->size, > ®ion->npages, 1); > if (!region->pages) { > ret = -ENOMEM; > goto e_free; > } > > + region->uaddr = range->addr; > + region->size = range->size; > + > + list_add_tail(®ion->list, &sev->regions_list); > + mutex_unlock(&kvm->lock); > + > /* > * The guest may change the memory encryption attribute from C=0 -> C=1 > * or vice versa for this memory range. Lets make sure caches are > @@ -7242,13 +7251,6 @@ static int svm_register_enc_region(struct kvm *kvm, > */ > sev_clflush_pages(region->pages, region->npages); > > - region->uaddr = range->addr; > - region->size = range->size; > - > - mutex_lock(&kvm->lock); > - list_add_tail(®ion->list, &sev->regions_list); > - mutex_unlock(&kvm->lock); > - > return ret; > > e_free: >
