From patchwork Tue Feb 11 17:48:35 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 11376271 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1D53E14B4 for ; Tue, 11 Feb 2020 17:52:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F1B74206D7 for ; Tue, 11 Feb 2020 17:52:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581443579; bh=0Nz9UTGevazxDml65pFpWpvj0exBxapL78FXYgUMnz0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Wzy+ZbhyTO8l1xx/i4OVL6Wg3JJBoPe29VTS7dY26CUGU++CMwYp8SYJIMp7JdDsG mzxjWjBzS8JuzD6odpfGs5qU1V08z8iHCWsZp7tqT97nym366q+F3vYbHLjf8FCFK6 X3gLTeNpeeItVgPExxUYrJSo798ObyNYNDJ5hVCo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730569AbgBKRw6 (ORCPT ); Tue, 11 Feb 2020 12:52:58 -0500 Received: from mail.kernel.org ([198.145.29.99]:56192 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727911AbgBKRw5 (ORCPT ); Tue, 11 Feb 2020 12:52:57 -0500 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 09BF520661; Tue, 11 Feb 2020 17:52:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581443577; bh=0Nz9UTGevazxDml65pFpWpvj0exBxapL78FXYgUMnz0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IcFmD277CljVD6bmP3Wy7n2VaxV2vcftE3JKZII/M6aNiw0vusETXJ/mMll8RM3iJ opkauox9ZD21Jr/Q/fk6qUjJT+wAVs0olyUTGYowWGA69MI8ag4U4ixvviu16p9tt4 I14BqMlS+TphflWFD++Rq2bmdp+2ppObgLiIHPlA= 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:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1j1Zfn-004O7k-F6; Tue, 11 Feb 2020 17:50:11 +0000 From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Cc: Andre Przywara , Christoffer Dall , Dave Martin , Jintack Lim , Alexandru Elisei , James Morse , Julien Thierry , Suzuki K Poulose Subject: [PATCH v2 31/94] KVM: arm64: nv: Only toggle cache for virtual EL2 when SCTLR_EL2 changes Date: Tue, 11 Feb 2020 17:48:35 +0000 Message-Id: <20200211174938.27809-32-maz@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200211174938.27809-1-maz@kernel.org> References: <20200211174938.27809-1-maz@kernel.org> 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, kvm@vger.kernel.org, andre.przywara@arm.com, christoffer.dall@arm.com, Dave.Martin@arm.com, jintack@cs.columbia.edu, alexandru.elisei@arm.com, james.morse@arm.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Christoffer Dall So far we were flushing almost the entire universe whenever a VM would load/unload the SCTLR_EL1 and the two versions of that register had different MMU enabled settings. This turned out to be so slow that it prevented forward progress for a nested VM, because a scheduler timer tick interrupt would always be pending when we reached the nested VM. To avoid this problem, we consider the SCTLR_EL2 when evaluating if caches are on or off when entering virtual EL2 (because this is the value that we end up shadowing onto the hardware EL1 register). Signed-off-by: Christoffer Dall Signed-off-by: Jintack Lim Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/kvm_mmu.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index ee47f7637f28..ec4de0613e7c 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -88,6 +88,7 @@ alternative_cb_end #include #include #include +#include void kvm_update_va_mask(struct alt_instr *alt, __le32 *origptr, __le32 *updptr, int nr_inst); @@ -305,7 +306,10 @@ struct kvm; static inline bool vcpu_has_cache_enabled(struct kvm_vcpu *vcpu) { - return (vcpu_read_sys_reg(vcpu, SCTLR_EL1) & 0b101) == 0b101; + if (vcpu_mode_el2(vcpu)) + return (__vcpu_sys_reg(vcpu, SCTLR_EL2) & 0b101) == 0b101; + else + return (vcpu_read_sys_reg(vcpu, SCTLR_EL1) & 0b101) == 0b101; } static inline void __clean_dcache_guest_page(kvm_pfn_t pfn, unsigned long size)