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=-12.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 4D8E3C433DB for ; Fri, 8 Jan 2021 17:14:33 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id F114423884 for ; Fri, 8 Jan 2021 17:14:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F114423884 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:To:From: Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender :Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=twNd9vu0gKvjG3wHSKfQVqncfxFrPW5eyIBJCwPUx2I=; b=mCAlAleNs6Tc+/7N0bhcDgH1uP ce+fo9A+saBqs0Bxd/AP2lIe1M14cbRLI6PjDDxauqKuWEJ8KogAo6jLCtRIIG0t4v1JiYeHvmhEG 0/Ny15/EeNjGQV5WzMx5idnrILwll2KtCLkO2EaIHIZ82+08E4buIEs9iyvtHCwtcj/YdI3dBFLMG qTVAY5NzVLs1PDHRLfzl8YWfUpTY09g7DhqeKsnn79bj0wTnUqYSRi3WmPMJ9c7DyGnnlEXaIO+uw skt98uWzqGJYj1wfcHWIpwrOXFVr8H4jz2YiTjx1g7B0N0dI2GVo6kdbKUUHxtSzf8WILw4LG5L2l Q+C1fr0w==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kxvJl-00049m-6P; Fri, 08 Jan 2021 17:12:53 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kxvJM-00048o-K5 for linux-arm-kernel@lists.infradead.org; Fri, 08 Jan 2021 17:12:29 +0000 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (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 9173822E02; Fri, 8 Jan 2021 17:12:27 +0000 (UTC) Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94) (envelope-from ) id 1kxvJJ-0067u8-G4; Fri, 08 Jan 2021 17:12:25 +0000 From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu Subject: [PATCH 0/2] KVM: arm64: Work around firmware wongly advertising GICv2 compatibility Date: Fri, 8 Jan 2021 17:12:14 +0000 Message-Id: <20210108171216.2310188-1-maz@kernel.org> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, shameerali.kolothum.thodi@huawei.com, james.morse@arm.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com, ardb@kernel.org, kernel-team@android.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210108_121228_744650_733BE13A X-CRM114-Status: GOOD ( 11.14 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Suzuki K Poulose , Shameerali Kolothum Thodi , James Morse , kernel-team@android.com, Ard Biesheuvel , Julien Thierry Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org It appears that there is firmware out there that advertise GICv2 compatibility on GICv3, despite the CPUs not being able to actually do it. That's a bummer, and at best creates unexpected behaviours for the users. At worse, it will crash the machine. Awesome! In order to mitigate this issue, try and validate whether we can actually flip the CPU into supporting MMIO accesses instead of system registers. If we can't, ignore the compatibility information and shout. It's not completely foolproof, but it should cover the existing broken platforms... The workaround is much bigger than Shameer's initial proposal, but that's because I wanted to keep it localised to KVM, and not spread the horror at every level (after all, only KVM is concerned with v2 compat). Marc Zyngier (2): KVM: arm64: Rename __vgic_v3_get_ich_vtr_el2() to __vgic_v3_get_gic_config() KVM: arm64: Workaround firmware wrongly advertising GICv2-on-v3 compatibility arch/arm64/include/asm/kvm_asm.h | 4 +-- arch/arm64/kvm/hyp/nvhe/hyp-main.c | 6 ++--- arch/arm64/kvm/hyp/vgic-v3-sr.c | 39 ++++++++++++++++++++++++++++-- arch/arm64/kvm/vgic/vgic-v3.c | 12 ++++++--- 4 files changed, 51 insertions(+), 10 deletions(-) -- 2.29.2 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel