From patchwork Mon Dec 9 11:53:08 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shameerali Kolothum Thodi X-Patchwork-Id: 13899413 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 BCC92E7717D for ; Mon, 9 Dec 2024 11:57:36 +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-Type:MIME-Version: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=H6T1jf9AjvCD4xrOeMK/zAuKY/nr6KMimt+D0cQm2C8=; b=C0c3QASc7fP1MZ8JsL94ic4Wvp SAJtf0zdSEidS3ufHF5TgdvF/DYJvBek1ZtlwUSij4oUIMjY2HRNgTxHa8XzVfvzOjz3MYW3EXfvS zm+FoiG9vFJFLuhA9nosZYTNcmuYbSRNPjFzcd0QTWdIZgXTxkRV38Fw5JDL6LBSUZtSSfmtMT85t 6oyFK90lG1y1BNfcNq5+iql2vfLHyWEbt6xNsZrHwpxILFmYqDV7IWeiavCdizc3GRYz2E58H6oU9 /X5GKD5igTSbzhrVew0vjd89JaTsRB92iu8nArMqibklh/4yj4F4gKGnWVnR+B0wwq9uT+2f32btI Ct5FBCuQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tKcOC-00000007aZV-1cxt; Mon, 09 Dec 2024 11:57:24 +0000 Received: from frasgout.his.huawei.com ([185.176.79.56]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tKcKZ-00000007ZYN-0yEq for linux-arm-kernel@lists.infradead.org; Mon, 09 Dec 2024 11:53:40 +0000 Received: from mail.maildlp.com (unknown [172.18.186.231]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4Y6Krq3fC4z6GC3Q; Mon, 9 Dec 2024 19:48:59 +0800 (CST) Received: from frapeml500008.china.huawei.com (unknown [7.182.85.71]) by mail.maildlp.com (Postfix) with ESMTPS id 5A73C140A30; Mon, 9 Dec 2024 19:53:30 +0800 (CST) Received: from A2303104131.china.huawei.com (10.203.177.241) by frapeml500008.china.huawei.com (7.182.85.71) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.39; Mon, 9 Dec 2024 12:53:23 +0100 From: Shameer Kolothum To: , , CC: , , , , , , , , , , , Subject: [PATCH v3 0/3] KVM: arm64: Errata management for VM Live migration Date: Mon, 9 Dec 2024 11:53:08 +0000 Message-ID: <20241209115311.40496-1-shameerali.kolothum.thodi@huawei.com> X-Mailer: git-send-email 2.12.0.windows.1 MIME-Version: 1.0 X-Originating-IP: [10.203.177.241] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To frapeml500008.china.huawei.com (7.182.85.71) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241209_035339_413772_7155B490 X-CRM114-Status: GOOD ( 12.02 ) 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 Hi, Changes from RFC v2[1]: -Addressed comments from Oliver(Thanks!). -Using implementation CPUs MIDR/REVIDR when it is set for _midr_range() functions(Patch 1 & 3) -New hypercall for retrieving implementation CPUs(Patch #2). -Dropped RFC. Sanity tested on a HiSilicon ARM64 platform using a hacked Qemu that can handle the above hypercall. Thanks, Shameer [1] https://lore.kernel.org/kvmarm/20241024094012.29452-1-shameerali.kolothum.thodi@huawei.com/ Changes from RFC v1: https://lore.kernel.org/kvmarm/20241011075053.80540-1-shameerali.kolothum.thodi@huawei.com/ -Introduced hypercalls to retrieve target CPUs info from user space VMM. see patch #1 for details. -Patch #2 uses the hypercall to retrieve the target CPU info if any. -Use the target CPUs MIDR/REVIDR in errata enablement. See patch #3. Background from v1: On ARM64 platforms most of the errata workarounds are based on CPU MIDR/REVIDR values and a number of these workarounds need to be implemented by the Guest kernel as well. This creates a problem when Guest needs to be migrated to a platform that differs in these MIDR/REVIDR values even if the VMM can come up with a common minimum feature list for the Guest using the recently introduced "Writable ID registers" support. (This is roughly based on a discussion I had with Marc and Oliver at KVM forum. Marc outlined his idea for a solution and this is an attempt to implement it. Thanks to both and I take all the blame if this is nowhere near what is intended/required) Shameer Kolothum (3): arm64: Modify _midr_range() functions to read MIDR/REVIDR internally KVM: arm64: Introduce hypercall support for retrieving target implementations arm64: paravirt: Enable errata based on implementation CPUs Documentation/virt/kvm/arm/hypercalls.rst | 30 +++++++++++++ arch/arm64/include/asm/cputype.h | 51 ++++++++++++++++------- arch/arm64/include/asm/mmu.h | 3 +- arch/arm64/include/asm/paravirt.h | 3 ++ arch/arm64/kernel/cpu_errata.c | 37 +++++++++++----- arch/arm64/kernel/cpufeature.c | 8 ++-- arch/arm64/kernel/image-vars.h | 2 + arch/arm64/kernel/paravirt.c | 31 ++++++++++++++ arch/arm64/kernel/proton-pack.c | 17 ++++---- arch/arm64/kvm/vgic/vgic-v3.c | 2 +- drivers/clocksource/arm_arch_timer.c | 2 +- include/linux/arm-smccc.h | 7 ++++ 12 files changed, 152 insertions(+), 41 deletions(-)