From patchwork Fri Jan 27 11:29:12 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Price X-Patchwork-Id: 49260 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:adf:eb09:0:0:0:0:0 with SMTP id s9csp783341wrn; Fri, 27 Jan 2023 03:33:32 -0800 (PST) X-Google-Smtp-Source: AK7set8E7M4tz0dxYq2SaayI0sNxq8Fd7U8FMmxjGGRrnW4QQ3n7b1+gvmTCkadxOp/IzTYv845p X-Received: by 2002:a17:903:18c:b0:196:4624:1691 with SMTP id z12-20020a170903018c00b0019646241691mr4971381plg.54.1674819212591; Fri, 27 Jan 2023 03:33:32 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1674819212; cv=none; d=google.com; s=arc-20160816; b=TwrFKno4bPX0GsqWPzMh7KaOiU9gg+9DMIkb4iJYPExm0zPPnxeT/DwChyjA0eVBNw iyLq8auKjxtEBfC3tzDVlV48r29FKZh2amTrGcsZigMQwxyhB0mX93hS4bk35jpTPYkx itjcj+WwFOIY8nRb27eqN427b8i3+8+sjAgUPOGuhxdWSjlLbGXW2/BD2rtknRLnV2Gv OaLkuvwpgkweP7GX9oF2MISI0mZLerd+ATC6BiL3DaqYUzycVYTL4nAhbNTYNGKXoz2Z /WBLXPkHoRTlsWpYFeVmWfS5HlJ1fuVfgDV3CoNZeh3WfPyiJWz4I3VgBGbdSphX6grx Jwjg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from; bh=2I2n08TofPGijBSH9wVqYCWX98/c9uubddafT2lBccI=; b=T0X0TeZ/Zj8RREOf/7dT9fxa4V3nqTWWAihvVMpMcCxbxWP87LgJgwHWiIOCLa2Z74 P+pMU3M9Nro4UwPYoQHprcoLZP60iDTKrHQVwBCmdOTr1vf4/cIOOI2asx5uZdlt7V6y lPEM21NoPztHrDxz4ITENVBk8XmMCvsM52fFf0+S46+6sjH0lI3UnvzZ3k2H43qUk91u kTqjgD/E54gZBYCxQ94R+th3wanS+datfJsTIhKd7ZJB2jK1peH0KGdRlVw86A9E+SZr aYDol6/F18Adlu0AvxWUZkHglVXvgWx4xZ/oQsMEfj4UJKOVisUK/itcfXVergalWwFM 7SSA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=arm.com Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id w11-20020a170902d3cb00b0019488aa379asi4494527plb.181.2023.01.27.03.33.19; Fri, 27 Jan 2023 03:33:32 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=arm.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233604AbjA0Lcv (ORCPT + 99 others); Fri, 27 Jan 2023 06:32:51 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43374 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231928AbjA0LcZ (ORCPT ); Fri, 27 Jan 2023 06:32:25 -0500 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 90DB17D28F; Fri, 27 Jan 2023 03:30:56 -0800 (PST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C1A3E165C; Fri, 27 Jan 2023 03:30:45 -0800 (PST) Received: from e122027.cambridge.arm.com (e122027.cambridge.arm.com [10.1.35.16]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 912C53F64C; Fri, 27 Jan 2023 03:30:01 -0800 (PST) From: Steven Price To: kvm@vger.kernel.org, kvmarm@lists.linux.dev Cc: Steven Price , Catalin Marinas , Marc Zyngier , Will Deacon , James Morse , Oliver Upton , Suzuki K Poulose , Zenghui Yu , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Joey Gouly , Alexandru Elisei , Christoffer Dall , Fuad Tabba , linux-coco@lists.linux.dev Subject: [RFC PATCH 08/28] arm64: RME: Keep a spare page delegated to the RMM Date: Fri, 27 Jan 2023 11:29:12 +0000 Message-Id: <20230127112932.38045-9-steven.price@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230127112932.38045-1-steven.price@arm.com> References: <20230127112248.136810-1-suzuki.poulose@arm.com> <20230127112932.38045-1-steven.price@arm.com> MIME-Version: 1.0 X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_MED, SPF_HELO_NONE,SPF_NONE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1756175230358472282?= X-GMAIL-MSGID: =?utf-8?q?1756175230358472282?= Pages can only be populated/destroyed on the RMM at the 4KB granule, this requires creating the full depth of RTTs. However if the pages are going to be combined into a 4MB huge page the last RTT is only temporarily needed. Similarly when freeing memory the huge page must be temporarily split requiring temporary usage of the full depth oF RTTs. To avoid needing to perform a temporary allocation and delegation of a page for this purpose we keep a spare delegated page around. In particular this avoids the need for memory allocation while destroying the realm guest. Signed-off-by: Steven Price --- arch/arm64/include/asm/kvm_rme.h | 3 +++ arch/arm64/kvm/rme.c | 6 ++++++ 2 files changed, 9 insertions(+) diff --git a/arch/arm64/include/asm/kvm_rme.h b/arch/arm64/include/asm/kvm_rme.h index 055a22accc08..a6318af3ed11 100644 --- a/arch/arm64/include/asm/kvm_rme.h +++ b/arch/arm64/include/asm/kvm_rme.h @@ -21,6 +21,9 @@ struct realm { void *rd; struct realm_params *params; + /* A spare already delegated page */ + phys_addr_t spare_page; + unsigned long num_aux; unsigned int vmid; unsigned int ia_bits; diff --git a/arch/arm64/kvm/rme.c b/arch/arm64/kvm/rme.c index 9f8c5a91b8fc..0c9d70e4d9e6 100644 --- a/arch/arm64/kvm/rme.c +++ b/arch/arm64/kvm/rme.c @@ -148,6 +148,7 @@ static int realm_create_rd(struct kvm *kvm) } realm->rd = rd; + realm->spare_page = PHYS_ADDR_MAX; realm->ia_bits = VTCR_EL2_IPA(kvm->arch.vtcr); if (WARN_ON(rmi_rec_aux_count(rd_phys, &realm->num_aux))) { @@ -357,6 +358,11 @@ void kvm_destroy_realm(struct kvm *kvm) free_page((unsigned long)realm->rd); realm->rd = NULL; } + if (realm->spare_page != PHYS_ADDR_MAX) { + if (!WARN_ON(rmi_granule_undelegate(realm->spare_page))) + free_page((unsigned long)phys_to_virt(realm->spare_page)); + realm->spare_page = PHYS_ADDR_MAX; + } pgd_sz = kvm_pgd_pages(pgt->ia_bits, pgt->start_level); for (i = 0; i < pgd_sz; i++) {