From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:33306 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2391650AbhASOY1 (ORCPT ); Tue, 19 Jan 2021 09:24:27 -0500 Subject: Re: [PATCH v1 1/4] s390/kvm: VSIE: stop leaking host addresses References: <20201218141811.310267-1-imbrenda@linux.ibm.com> <20201218141811.310267-2-imbrenda@linux.ibm.com> From: Janosch Frank Message-ID: <4265bc48-40f9-54be-8a87-bcd50c7c628a@linux.ibm.com> Date: Tue, 19 Jan 2021 15:23:35 +0100 MIME-Version: 1.0 In-Reply-To: <20201218141811.310267-2-imbrenda@linux.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit List-ID: To: Claudio Imbrenda , linux-kernel@vger.kernel.org Cc: borntraeger@de.ibm.com, david@redhat.com, kvm@vger.kernel.org, linux-s390@vger.kernel.org, stable@vger.kernel.org On 12/18/20 3:18 PM, Claudio Imbrenda wrote: > The addresses in the SIE control block of the host should not be > forwarded to the guest. They are only meaningful to the host, and > moreover it would be a clear security issue. > > Subsequent patches will actually put the right values in the guest SIE > control block. > > Fixes: a3508fbe9dc6d ("KVM: s390: vsie: initial support for nested virtualization") > Cc: stable@vger.kernel.org > Signed-off-by: Claudio Imbrenda Looks reasonable. Give me some time to have a deeper look it's a lot of architecture to read. > --- > arch/s390/kvm/vsie.c | 5 ----- > 1 file changed, 5 deletions(-) > > diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c > index 4f3cbf6003a9..ada49583e530 100644 > --- a/arch/s390/kvm/vsie.c > +++ b/arch/s390/kvm/vsie.c > @@ -416,11 +416,6 @@ static void unshadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) > memcpy((void *)((u64)scb_o + 0xc0), > (void *)((u64)scb_s + 0xc0), 0xf0 - 0xc0); > break; > - case ICPT_PARTEXEC: > - /* MVPG only */ > - memcpy((void *)((u64)scb_o + 0xc0), > - (void *)((u64)scb_s + 0xc0), 0xd0 - 0xc0); > - break; > } > > if (scb_s->ihcpu != 0xffffU) >