From patchwork Fri Jun 28 06:04:51 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shaoqin Huang X-Patchwork-Id: 13715495 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E2CEAC2BBCA for ; Fri, 28 Jun 2024 06:05:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=I9zn2i4ef/uuSlInb0x78J+Hjt4S8lkHLb69/zw01pU=; b=bTV3JfNdpk6pLa/h6SY4uPFsrM X7TdU+By0DsufjQw0EoRt6pxf39FjaHu9kTCgbokGsgeK8z6cJxluYL41rk6eZ9Hr72vrN14IeAD7 TEjSIMhuSBLuZWFOIttFi36eNc2KP5aiCeBgmGmQaqKmKQYZm1YwcVuVlKmwi9NatWwiykL1iGUwz raf0YTluxzXiV4DSHA7rOpb8UcC0EmAbPTriDKAmcjK92bj6oMUem/y7PabVLf/zA9VfgeOCUHgOO u1UGvx2lRAHpsE5BVUEgFaBBjoYWA0Y8F62mEDOvM9g7eYHCT7yh2Ej0ZeL7UczTxmuJwl8E5/OBn QiWsD+xA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sN4ji-0000000ChaF-0VRs; Fri, 28 Jun 2024 06:05:30 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sN4jT-0000000ChU6-3Huk for linux-arm-kernel@lists.infradead.org; Fri, 28 Jun 2024 06:05:17 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1719554714; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=I9zn2i4ef/uuSlInb0x78J+Hjt4S8lkHLb69/zw01pU=; b=e9f8V+/RcksgoTIfwO1UL3a0FNiVbwIFxNmd33S1pLsLaxwyPfWHlYr/KOASf9CIkWj/bD Z+4DmFpRU0+1zoUiuisLu2eesTAX9OSmSGrS/egPX/Betxe4E7IZT1STmk/5RBDaVM7qSG Of3YfFlgIwx4ir7tTTwuzS3pWzv2W9A= Received: from mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-85-vNQFQkwvPM233aWf-atBog-1; Fri, 28 Jun 2024 02:05:07 -0400 X-MC-Unique: vNQFQkwvPM233aWf-atBog-1 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id B601119560B1; Fri, 28 Jun 2024 06:05:05 +0000 (UTC) Received: from virt-mtcollins-01.lab.eng.rdu2.redhat.com (virt-mtcollins-01.lab.eng.rdu2.redhat.com [10.8.1.196]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id C26321945CB1; Fri, 28 Jun 2024 06:05:03 +0000 (UTC) From: Shaoqin Huang To: Oliver Upton , Marc Zyngier , kvmarm@lists.linux.dev Cc: Shaoqin Huang , James Morse , Suzuki K Poulose , Zenghui Yu , Catalin Marinas , Will Deacon , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 1/2] KVM: arm64: Allow userspace to change ID_AA64PFR1_EL1 Date: Fri, 28 Jun 2024 02:04:51 -0400 Message-Id: <20240628060454.1936886-2-shahuang@redhat.com> In-Reply-To: <20240628060454.1936886-1-shahuang@redhat.com> References: <20240628060454.1936886-1-shahuang@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240627_230515_921594_24881DA9 X-CRM114-Status: GOOD ( 14.84 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Allow userspace to change the guest-visible value of the register with some severe limitation: - No changes to features not virtualized by KVM (MPAM_frac, RAS_frac, SME, RNDP_trap). - No changes to features (CSV2_frac, NMI, MTE_frac, GCS, THE, MTEX, DF2, PFAR) which haven't been added into the ftr_id_aa64pfr1[]. Because the struct arm64_ftr_bits definition for each feature in the ftr_id_aa64pfr1[] is used by arm64_check_features. If they're not existing in the ftr_id_aa64pfr1[], the for loop won't check the if the new_val is safe for those features. --- arch/arm64/kvm/sys_regs.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 22b45a15d068..159cded22357 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -2306,7 +2306,9 @@ static const struct sys_reg_desc sys_reg_descs[] = { ID_AA64PFR0_EL1_GIC | ID_AA64PFR0_EL1_AdvSIMD | ID_AA64PFR0_EL1_FP), }, - ID_SANITISED(ID_AA64PFR1_EL1), + ID_WRITABLE(ID_AA64PFR1_EL1, ID_AA64PFR1_EL1_MTE | + ID_AA64PFR1_EL1_SSBS | + ID_AA64PFR1_EL1_BT), ID_UNALLOCATED(4,2), ID_UNALLOCATED(4,3), ID_WRITABLE(ID_AA64ZFR0_EL1, ~ID_AA64ZFR0_EL1_RES0),