From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0A014C2BA83 for ; Thu, 13 Feb 2020 15:41:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D48F320661 for ; Thu, 13 Feb 2020 15:41:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581608469; bh=sMKRMxAKZmEI4l58IG+Ydcmfx5bYgtYEsOOYTnpTo20=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=X2C2fH+h4cEnouG5A/Nus4I3H9veFfgmu9wNFgmMS3mzFpBCE5K5q9HlTeVDh5Lnb Jg4H4i16KYtOQSFfc5eJPYP9qHRoasPSjAUIrfmwGNfCfPBBdSgUWhu3LcLWxhdNmJ xA6GZvtURVCbDOeIRB+gKPF/fyasmf1XGdxulrIA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387740AbgBMP2g (ORCPT ); Thu, 13 Feb 2020 10:28:36 -0500 Received: from mail.kernel.org ([198.145.29.99]:43374 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728602AbgBMP0E (ORCPT ); Thu, 13 Feb 2020 10:26:04 -0500 Received: from localhost (unknown [104.132.1.104]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8796E2469C; Thu, 13 Feb 2020 15:26:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581607562; bh=sMKRMxAKZmEI4l58IG+Ydcmfx5bYgtYEsOOYTnpTo20=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IYo68MzjpUx3/9AQC2+E4c6nmJ/BSPMTb0gdTU61GpmNU79se1TmNUKNoeuq9YTIv +2/GuJsPYm0pLp+4PNpGXp0uwA9Go9KICPrYD98HqTR9fWRm2DtEJQNCBoaTExBE8W paYy+cqPck5vNeip3xbt8V24av+gd9L/uNUuH0/k= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, stable@kernel.org, Christian Borntraeger , David Hildenbrand , Cornelia Huck , Janosch Frank , Sasha Levin Subject: [PATCH 4.14 136/173] KVM: s390: do not clobber registers during guest reset/store status Date: Thu, 13 Feb 2020 07:20:39 -0800 Message-Id: <20200213152006.212371310@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200213151931.677980430@linuxfoundation.org> References: <20200213151931.677980430@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Christian Borntraeger [ Upstream commit 55680890ea78be0df5e1384989f1be835043c084 ] The initial CPU reset clobbers the userspace fpc and the store status ioctl clobbers the guest acrs + fpr. As these calls are only done via ioctl (and not via vcpu_run), no CPU context is loaded, so we can (and must) act directly on the sync regs, not on the thread context. Cc: stable@kernel.org Fixes: e1788bb995be ("KVM: s390: handle floating point registers in the run ioctl not in vcpu_put/load") Fixes: 31d8b8d41a7e ("KVM: s390: handle access registers in the run ioctl not in vcpu_put/load") Signed-off-by: Christian Borntraeger Reviewed-by: David Hildenbrand Reviewed-by: Cornelia Huck Signed-off-by: Janosch Frank Link: https://lore.kernel.org/r/20200131100205.74720-2-frankja@linux.ibm.com Signed-off-by: Christian Borntraeger Signed-off-by: Sasha Levin --- arch/s390/kvm/kvm-s390.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 91c24e87fe10a..46fee3f4dedda 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -2384,9 +2384,7 @@ static void kvm_s390_vcpu_initial_reset(struct kvm_vcpu *vcpu) memset(vcpu->arch.sie_block->gcr, 0, 16 * sizeof(__u64)); vcpu->arch.sie_block->gcr[0] = 0xE0UL; vcpu->arch.sie_block->gcr[14] = 0xC2000000UL; - /* make sure the new fpc will be lazily loaded */ - save_fpu_regs(); - current->thread.fpu.fpc = 0; + vcpu->run->s.regs.fpc = 0; vcpu->arch.sie_block->gbea = 1; vcpu->arch.sie_block->pp = 0; vcpu->arch.sie_block->fpf &= ~FPF_BPBC; @@ -3753,7 +3751,7 @@ long kvm_arch_vcpu_ioctl(struct file *filp, } case KVM_S390_STORE_STATUS: idx = srcu_read_lock(&vcpu->kvm->srcu); - r = kvm_s390_vcpu_store_status(vcpu, arg); + r = kvm_s390_store_status_unloaded(vcpu, arg); srcu_read_unlock(&vcpu->kvm->srcu, idx); break; case KVM_S390_SET_INITIAL_PSW: { -- 2.20.1