On Tue, 17 Apr 2018 09:47:58 -0400 Tony Krowiak <akrow...@linux.vnet.ibm.com> wrote:
> On 04/17/2018 07:34 AM, Cornelia Huck wrote: > > On Sun, 15 Apr 2018 17:22:12 -0400 > > Tony Krowiak <akrow...@linux.vnet.ibm.com> wrote: > > > >> Introduces a new function to reset the crypto attributes for all > >> vcpus whether they are running or not. Each vcpu in KVM will > >> be removed from SIE prior to resetting the crypto attributes in its > >> SIE state description. After all vcpus have had their crypto attributes > >> reset the vcpus will be restored to SIE. > >> > >> This function will be used in a later patch to set the ECA.28 > >> bit in the SIE state description to enable interpretive execution of > >> AP instructions. It will also be incorporated into the > >> kvm_s390_vm_set_crypto(kvm) function to fix an issue whereby the crypto > >> key wrapping attributes could potentially get out of synch for running > >> vcpus. > > So, this description leads me to think it would make sense to queue > > this patch (fixing the key wrapping) independently of this series, > > wouldn't it? > I considered that because I figured there might be objections, but > since separating them would create dependency issues I didn't see > any harm in including it here. I can remove this from the explanation > above and the code below and create a separate patch for the key > wrapping if you'd prefer. Well, I think this makes sense as an individual patch, but I'll leave that to the maintainers to decide. > > > >> Signed-off-by: Tony Krowiak <akrow...@linux.vnet.ibm.com> > >> --- > >> arch/s390/kvm/kvm-s390.c | 19 +++++++++++++------ > >> arch/s390/kvm/kvm-s390.h | 14 ++++++++++++++ > >> 2 files changed, 27 insertions(+), 6 deletions(-) > >> diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h > >> index 1b5621f..76324b7 100644 > >> --- a/arch/s390/kvm/kvm-s390.h > >> +++ b/arch/s390/kvm/kvm-s390.h > >> @@ -410,4 +410,18 @@ static inline int kvm_s390_use_sca_entries(void) > >> } > >> void kvm_s390_reinject_machine_check(struct kvm_vcpu *vcpu, > >> struct mcck_volatile_info *mcck_info); > >> + > >> +/** > >> + * kvm_s390_vcpu_crypto_reset_all > >> + * > >> + * Reset the crypto attributes for each vcpu. This can be done while the > >> vcpus > >> + * are running as each vcpu will be removed from SIE before resetting the > >> crypto > >> + * attributes and restored to SIE afterward. > >> + * > >> + * Note: The kvm->lock mutex must be locked prior to calling this > >> function and > >> + * unlocked after it returns. > > "Must be called with kvm->lock held"? > Yes. The kvm->lock must be held to set the crypto attributes that will be > copied to the vcpus via the kvm_s390_vcpu_crypto_reset_all() function, > so it made sense to hold the lock across the entire operation. This was intended as a suggestion for a more compact usage note :)
