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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0AC92C433F5 for ; Fri, 28 Jan 2022 12:20:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348436AbiA1MUH (ORCPT ); Fri, 28 Jan 2022 07:20:07 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:55604 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348437AbiA1MUG (ORCPT ); Fri, 28 Jan 2022 07:20:06 -0500 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 ams.source.kernel.org (Postfix) with ESMTPS id 61785B82569 for ; Fri, 28 Jan 2022 12:20:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1FE26C340E0; Fri, 28 Jan 2022 12:20:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1643372404; bh=F0WDPTujzh01Sq2s/H4RolAuXeFIrVC3Zcaf5EdNwW0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aYKUh28AyglCuRrCGavmXM+QKo+pT+WTNFagUtlGrCNLh2Pidy8bYlXyjPc21H8tY vIdQO84Py1i+BYViLCGDvPHhWLIJUeeJycFa/CQfsS69Dl5mdajvR+7RJBhvS2OIFB o8oib1bsQQfVOsIbdzeNwNFqNcvK/y2HTVWnkH833lvLQU2T9LcaMzQYOVp9W1rgeU XVpz6Fa18LwEWogvnIDZMlNP5PrB/rmElloQ7qeJnnXqYnKU8FiN4CfrVTxR/iHFCt iHP0RHiK6Sd1EzU0egisOiSgnrQnmLs8E/K/vAV/fFAC9bcmHAd9SDD9ZXUUUi+fkk sOHdATHs1AHfg== Received: from sofa.misterjones.org ([185.219.108.64] helo=why.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1nDQDx-003njR-Iu; Fri, 28 Jan 2022 12:19:29 +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 , Jintack Lim , Haibo Xu , Ganapatrao Kulkarni , Chase Conklin , "Russell King (Oracle)" , James Morse , Suzuki K Poulose , Alexandru Elisei , karl.heubaum@oracle.com, mihai.carabas@oracle.com, miguel.luis@oracle.com, kernel-team@android.com Subject: [PATCH v6 15/64] KVM: arm64: nv: Handle HCR_EL2.E2H specially Date: Fri, 28 Jan 2022 12:18:23 +0000 Message-Id: <20220128121912.509006-16-maz@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220128121912.509006-1-maz@kernel.org> References: <20220128121912.509006-1-maz@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 185.219.108.64 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, jintack@cs.columbia.edu, haibo.xu@linaro.org, gankulkarni@os.amperecomputing.com, chase.conklin@arm.com, linux@armlinux.org.uk, james.morse@arm.com, suzuki.poulose@arm.com, alexandru.elisei@arm.com, karl.heubaum@oracle.com, mihai.carabas@oracle.com, miguel.luis@oracle.com, 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 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org HCR_EL2.E2H is nasty, as a flip of this bit completely changes the way we deal with a lot of the state. So when the guest flips this bit (sysregs are live), do the put/load dance so that we have a consistent state. Yes, this is slow. Don't do it. Suggested-by: Alexandru Elisei Signed-off-by: Marc Zyngier --- arch/arm64/kvm/sys_regs.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index ace4a54caef9..102bc4906723 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -183,9 +183,24 @@ void vcpu_write_sys_reg(struct kvm_vcpu *vcpu, u64 val, int reg) goto memory_write; if (unlikely(get_el2_to_el1_mapping(reg, &el1r, &xlate))) { + bool need_put_load; + if (!is_hyp_ctxt(vcpu)) goto memory_write; + /* + * HCR_EL2.E2H is nasty: it changes the way we interpret a + * lot of the EL2 state, so treat is as a full state + * transition. + */ + need_put_load = ((reg == HCR_EL2) && + vcpu_el2_e2h_is_set(vcpu) != !!(val & HCR_E2H)); + + if (need_put_load) { + preempt_disable(); + kvm_arch_vcpu_put(vcpu); + } + /* * Always store a copy of the write to memory to avoid having * to reverse-translate virtual EL2 system registers for a @@ -193,6 +208,11 @@ void vcpu_write_sys_reg(struct kvm_vcpu *vcpu, u64 val, int reg) */ __vcpu_sys_reg(vcpu, reg) = val; + if (need_put_load) { + kvm_arch_vcpu_load(vcpu, smp_processor_id()); + preempt_enable(); + } + switch (reg) { case ELR_EL2: write_sysreg_el1(val, SYS_ELR); -- 2.30.2