From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Krowiak Subject: Re: [PATCH v4 03/15] KVM: s390: refactor crypto initialization Date: Tue, 17 Apr 2018 10:26:57 -0400 Message-ID: <2ac8b862-e2dc-843e-a0b8-906fa32b42f4@linux.vnet.ibm.com> References: <1523827345-11600-1-git-send-email-akrowiak@linux.vnet.ibm.com> <1523827345-11600-4-git-send-email-akrowiak@linux.vnet.ibm.com> <4fb50a31-1893-5cfb-0f35-fb2501c2afa8@linux.vnet.ibm.com> <20180417121044.5c8f2182.cohuck@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180417121044.5c8f2182.cohuck@redhat.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: Cornelia Huck , Harald Freudenberger Cc: Pierre Morel , alex.williamson@redhat.com, alifm@linux.vnet.ibm.com, berrange@redhat.com, bjsdjshi@linux.vnet.ibm.com, borntrae@linux.ibm.com, fiuczy@linux.vnet.ibm.com, heicars2@linux.vnet.ibm.com, jjherne@linux.vnet.ibm.com, kvm@vger.kernel.org, kwankhede@nvidia.com, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, mjrosato@linux.vnet.ibm.com, mschwid2@linux.vnet.ibm.com, pasic@linux.vnet.ibm.com, pbonzini@redhat.com, Reinhard Buendgen , thuth@redhat.com List-ID: On 04/17/2018 06:10 AM, Cornelia Huck wrote: > On Tue, 17 Apr 2018 09:49:58 +0200 > "Harald Freudenberger" wrote: > >> Didn't we say that when APXA is not available there is no Crypto support >> for KVM ? > [Going by the code, as I don't have access to the architecture] > > Current status seems to be: > - setup crycb if facility 76 is available (that's MSAX3, I guess?) The crycb is set up regardless of whether STFLE.76 (MSAX3) is installed or not. > - use format 2 if APXA is available, else use format 1 Use format 0 if MSAX3 is not available Use format 1 if MSAX3 is available but APXA is not Use format 2 if MSAX3 and APXA is available > > From Tony's patch description, the goal seems to be: > - setup crycb even if MSAX3 is not available Yes, that is true > > So my understanding is that we use APXA only to decide on the format of > the crycb, but provide it in any case? Yes, that is true > > (Not providing a crycb if APXA is not available would be loss of > functionality, I guess? Deciding not to provide vfio-ap if APXA is not > available is a different game, of course.) This would require a change to enabling the CPU model feature for AP. >