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 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 76AB0C3DA78 for ; Fri, 13 Jan 2023 17:36:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:Cc :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=4cO78z/q25PSfyIaJn6IIP1PzuW3GOc/iH01Di48IGg=; b=Fbmt3+/HgjWMEg Q/lFNhjblBWTKz/uc34jZofU/Be+vcgrJpW9TV2mUBe+Ho7SIKxNTyhIAHPWfebIhQCXvKGzFe7nL KCPx9LXA3Iv5kEIY+q1rVrvOA+DiDfsXstuMEw+k1Slj8JegceMVVzfuDLzPUljplVnO1ByYVeE5c Q9EpmA+H2UHEQWEwh+Sc1A2WDRVsXKaQpYfBS+AqxwCc6VR349AldmILjPSzNiRd4MDO8htVtFUbh 20j/PJLiwuAeM+xp8dz0d3m6fSBonuqfdSLdDNMeFXnktlIT6g0NMFoMGoeqWbwsFMg4VBHNzm65m dlxtTaz83y2/CNnbsWgg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pGNy4-003oA3-EI; Fri, 13 Jan 2023 17:35:52 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1pGNo5-003iyI-Ui for linux-arm-kernel@lists.infradead.org; Fri, 13 Jan 2023 17:25:36 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 06CA5622A0; Fri, 13 Jan 2023 17:25:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 67273C433EF; Fri, 13 Jan 2023 17:25:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1673630732; bh=uBwzoDfIi5zx3t1cQvei6z7fqeSGlX0Xvp4YKJJlYBU=; h=From:To:Cc:Subject:Date:From; b=O2Q8UIRTe5brWI6BtTOkh3lNN1olC74z6oG8FjKm/81W9JYh6N+S66X9VU0Ux+yD8 VOEY2HJlTa/eJxQT9ZxwXsCjvDlakJjgDkxPDcMVZI0qdpxJE5DpUEwSh2pGIStAnA rfK8cNyfi5v5F9n09fA723l/FJ2pf/teYcqqOhpJSzb+0ejEeSkzmmYijBJXxpuKcs slthuzJRwRWItsmqRXaG2cETVBu7ncaYrVL9kITJ+z+OnnPUb9gadhgyiNywb0mVag ID2AresCQ72ExLpw3ni2pLPvjn+TTomfRZ0cHaSkJ2u+JQtrzoQ796bK7o64vtTm07 2fUmLw+R5h1kw== Received: from sofa.misterjones.org ([185.219.108.64] helo=valley-girl.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1pGNo2-001bBu-3p; Fri, 13 Jan 2023 17:25:30 +0000 From: Marc Zyngier To: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org Cc: Will Deacon , Catalin Marinas , Mark Rutland , James Morse , Suzuki K Poulose , Oliver Upton , Zenghui Yu Subject: [PATCH 0/2] KVM: arm64: Drop support for VPIPT i-cache policy Date: Fri, 13 Jan 2023 17:25:21 +0000 Message-Id: <20230113172523.2063867-1-maz@kernel.org> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, will@kernel.org, catalin.marinas@arm.com, mark.rutland@arm.com, james.morse@arm.com, suzuki.poulose@arm.com, oliver.upton@linux.dev, yuzenghui@huawei.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-20230113_092534_064103_2E299027 X-CRM114-Status: GOOD ( 13.34 ) 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: , 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 ARMv8.2 introduced support for VPIPT i-caches, the V standing for VMID-tagged. Although this looks like a reasonable idea, no implementation has ever made it into the wild. Linux has supported this for almost 6 years (amusingly, just as the architecture was dropping support for AVIVT i-caches), but we have no way to even test it, and it is likely that this code is just bit-rotting. This isn't great. Since this only impacts KVM, let's drop the support from the hypervisor. The kernel itself can still work as a guest on such a system, assuming that there is HW and a hypervisor that supports this architecture variation. On the other hand, if you are aware of such an implementation and can actively test KVM on this setup, please shout! M. Marc Zyngier (2): KVM: arm64: Disable KVM on systems with a VPIPT i-cache KVM: arm64: Remove VPIPT I-cache handling arch/arm64/include/asm/kvm_mmu.h | 3 +-- arch/arm64/kvm/arm.c | 5 +++++ arch/arm64/kvm/hyp/nvhe/tlb.c | 35 -------------------------------- arch/arm64/kvm/hyp/vhe/tlb.c | 13 ------------ 4 files changed, 6 insertions(+), 50 deletions(-) -- 2.34.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel