From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-2.mimecast.com ([207.211.31.81]:36163 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726225AbgBRJi7 (ORCPT ); Tue, 18 Feb 2020 04:38:59 -0500 Subject: Re: [PATCH v2 29/42] KVM: s390: protvirt: Add diag 308 subcode 8 - 10 handling References: <20200214222658.12946-1-borntraeger@de.ibm.com> <20200214222658.12946-30-borntraeger@de.ibm.com> From: David Hildenbrand Message-ID: <9e5e7409-aaa2-47af-812f-169c2d290e18@redhat.com> Date: Tue, 18 Feb 2020 10:38:49 +0100 MIME-Version: 1.0 In-Reply-To: <20200214222658.12946-30-borntraeger@de.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-s390-owner@vger.kernel.org List-ID: To: Christian Borntraeger , Janosch Frank Cc: KVM , Cornelia Huck , Thomas Huth , Ulrich Weigand , Claudio Imbrenda , linux-s390 , Michael Mueller , Vasily Gorbik , Janosch Frank On 14.02.20 23:26, Christian Borntraeger wrote: > From: Janosch Frank > > If the host initialized the Ultravisor, we can set stfle bit 161 > (protected virtual IPL enhancements facility), which indicates that > the IPL subcodes 8, 9, and 10 are valid. These subcodes are used by a > normal guest to set/retrieve an IPL information block of type 5 (for > protected virtual machines) and transition into protected mode. > > Once in protected mode, the Ultravisor will conceal the facility bit. > Therefore each boot into protected mode has to go through > non-protected mode. There is no secure re-ipl with subcode 10 without > a previous subcode 3. > > In protected mode, there is no subcode 4 available, as the VM has no > more access to its memory from non-protected mode. I.e., only a IPL > clear is possible. > > The error cases will all be handled in userspace. > > Signed-off-by: Janosch Frank > Reviewed-by: Cornelia Huck > [borntraeger@de.ibm.com: patch merging, splitting, fixing] > Signed-off-by: Christian Borntraeger > --- > arch/s390/kvm/kvm-s390.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c > index 4a97d3b7840e..f96c1f530cc2 100644 > --- a/arch/s390/kvm/kvm-s390.c > +++ b/arch/s390/kvm/kvm-s390.c > @@ -2621,6 +2621,11 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) > if (css_general_characteristics.aiv && test_facility(65)) > set_kvm_facility(kvm->arch.model.fac_mask, 65); > > + if (is_prot_virt_host()) { > + set_kvm_facility(kvm->arch.model.fac_mask, 161); > + set_kvm_facility(kvm->arch.model.fac_list, 161); > + } > + Aren't these IPL subcodes completely emulated in QEMU? If so, rather QEMU with support should enable them when the kernel capability for PV (=== is_prot_virt_host()) is in place. -- Thanks, David / dhildenb