From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Reply-To: pmorel@linux.ibm.com Subject: Re: [PATCH RFC 2/2] KVM: s390: introduce and use KVM_REQ_VSIE_RESTART References: <20180807125131.3606-1-david@redhat.com> <20180807125131.3606-3-david@redhat.com> From: Pierre Morel Date: Tue, 7 Aug 2018 19:06:26 +0200 MIME-Version: 1.0 In-Reply-To: <20180807125131.3606-3-david@redhat.com> Content-Type: text/plain; charset="utf-8"; format="flowed" Content-Transfer-Encoding: 8bit Content-Language: en-US Message-Id: Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: David Hildenbrand , linux-kernel@vger.kernel.org Cc: linux-s390@vger.kernel.org, Heiko Carstens , Martin Schwidefsky , Cornelia Huck , Janosch Frank , Christian Borntraeger List-ID: On 07/08/2018 14:51, David Hildenbrand wrote: > When we change the crycb (or execution controls), we also have to make sure > that the vSIE shadow datastructures properly consider the changed > values before rerunning the vSIE. We can achieve that by simply using a > VCPU request now. > > This has to be a synchronous request (== handled before entering the > (v)SIE again). > > The request will make sure that the vSIE handler is left, and that the > request will be processed (NOP), therefore forcing a reload of all > vSIE data (including rebuilding the crycb) when re-entering the vSIE > interception handler the next time. > > Signed-off-by: David Hildenbrand > --- > arch/s390/include/asm/kvm_host.h | 1 + > arch/s390/kvm/kvm-s390.c | 7 ++++++- > 2 files changed, 7 insertions(+), 1 deletion(-) > > diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h > index 29c940bf8506..75d39628f21d 100644 > --- a/arch/s390/include/asm/kvm_host.h > +++ b/arch/s390/include/asm/kvm_host.h > @@ -44,6 +44,7 @@ > #define KVM_REQ_ICPT_OPEREXC KVM_ARCH_REQ(2) > #define KVM_REQ_START_MIGRATION KVM_ARCH_REQ(3) > #define KVM_REQ_STOP_MIGRATION KVM_ARCH_REQ(4) > +#define KVM_REQ_VSIE_RESTART KVM_ARCH_REQ(5) > > #define SIGP_CTRL_C 0x80 > #define SIGP_CTRL_SCN_MASK 0x3f > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c > index c87734a31fdb..2fdc017d91f0 100644 > --- a/arch/s390/kvm/kvm-s390.c > +++ b/arch/s390/kvm/kvm-s390.c > @@ -842,8 +842,11 @@ void kvm_s390_vcpu_crypto_reset_all(struct kvm *kvm) > > kvm_s390_vcpu_block_all(kvm); > > - kvm_for_each_vcpu(i, vcpu, kvm) > + kvm_for_each_vcpu(i, vcpu, kvm) { > kvm_s390_vcpu_crypto_setup(vcpu); > + /* recreate the shadow crycb by leaving the VSIE handler */ > + kvm_s390_sync_request(KVM_REQ_VSIE_RESTART, vcpu); > + } > > kvm_s390_vcpu_unblock_all(kvm); > } > @@ -3201,6 +3204,8 @@ static int kvm_s390_handle_requests(struct kvm_vcpu *vcpu) > > /* nothing to do, just clear the request */ > kvm_clear_request(KVM_REQ_UNHALT, vcpu); > + /* we left the vsie handler, nothing to do, just clear the request */ > + kvm_clear_request(KVM_REQ_VSIE_RESTART, vcpu); > > return 0; > } Reviewed-by: Pierre Morel Tested-by: Pierre Morel -- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany