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=-17.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 8A5EDC43460 for ; Mon, 10 May 2021 17:27:55 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id 182F961494 for ; Mon, 10 May 2021 17:27:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 182F961494 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvmarm-bounces@lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id A79D74B833; Mon, 10 May 2021 13:27:54 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Rj1Ph-bOD-YY; Mon, 10 May 2021 13:27:53 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 0CE2A4B83B; Mon, 10 May 2021 13:27:53 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id A03B94B2E6 for ; Mon, 10 May 2021 13:27:51 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id cUfu6BPsp6xy for ; Mon, 10 May 2021 13:27:50 -0400 (EDT) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id 37B154B2BD for ; Mon, 10 May 2021 13:27:50 -0400 (EDT) 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 6A65461480; Mon, 10 May 2021 17:27:49 +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 4.94.2) (envelope-from ) id 1lg9GR-000Uqg-EW; Mon, 10 May 2021 18:00:16 +0100 From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Subject: [PATCH v4 29/66] KVM: arm64: nv: Configure HCR_EL2 for nested virtualization Date: Mon, 10 May 2021 17:58:43 +0100 Message-Id: <20210510165920.1913477-30-maz@kernel.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210510165920.1913477-1-maz@kernel.org> References: <20210510165920.1913477-1-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, jintack@cs.columbia.edu, haibo.xu@linaro.org, james.morse@arm.com, suzuki.poulose@arm.com, alexandru.elisei@arm.com, kernel-team@android.com, jintack.lim@linaro.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Cc: kernel-team@android.com, Andre Przywara , Jintack Lim X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu From: Jintack Lim We enable nested virtualization by setting the HCR NV and NV1 bit. When the virtual E2H bit is set, we can support EL2 register accesses via EL1 registers from the virtual EL2 by doing trap-and-emulate. A better alternative, however, is to allow the virtual EL2 to access EL2 register states without trap. This can be easily achieved by not traping EL1 registers since those registers already have EL2 register states. Signed-off-by: Jintack Lim Signed-off-by: Marc Zyngier --- arch/arm64/kvm/hyp/vhe/switch.c | 36 ++++++++++++++++++++++++++++++--- 1 file changed, 33 insertions(+), 3 deletions(-) diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c index a238f52955c5..79789850639b 100644 --- a/arch/arm64/kvm/hyp/vhe/switch.c +++ b/arch/arm64/kvm/hyp/vhe/switch.c @@ -37,9 +37,39 @@ static void __activate_traps(struct kvm_vcpu *vcpu) u64 hcr = vcpu->arch.hcr_el2; u64 val; - /* Trap VM sysreg accesses if an EL2 guest is not using VHE. */ - if (vcpu_mode_el2(vcpu) && !vcpu_el2_e2h_is_set(vcpu)) - hcr |= HCR_TVM | HCR_TRVM; + if (is_hyp_ctxt(vcpu)) { + hcr |= HCR_NV; + + if (!vcpu_el2_e2h_is_set(vcpu)) { + /* + * For a guest hypervisor on v8.0, trap and emulate + * the EL1 virtual memory control register accesses. + */ + hcr |= HCR_TVM | HCR_TRVM | HCR_NV1; + } else { + /* + * For a guest hypervisor on v8.1 (VHE), allow to + * access the EL1 virtual memory control registers + * natively. These accesses are to access EL2 register + * states. + * Note that we still need to respect the virtual + * HCR_EL2 state. + */ + u64 vhcr_el2 = __vcpu_sys_reg(vcpu, HCR_EL2); + + /* + * We already set TVM to handle set/way cache maint + * ops traps, this somewhat collides with the nested + * virt trapping for nVHE. So turn this off for now + * here, in the hope that VHE guests won't ever do this. + * TODO: find out whether it's worth to support both + * cases at the same time. + */ + hcr &= ~HCR_TVM; + + hcr |= vhcr_el2 & (HCR_TVM | HCR_TRVM); + } + } ___activate_traps(vcpu, hcr); -- 2.29.2 _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm