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 mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by smtp.lore.kernel.org (Postfix) with ESMTP id 047C4C433FE for ; Fri, 28 Jan 2022 12:20:09 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id AADC94B0F5; Fri, 28 Jan 2022 07:20:08 -0500 (EST) X-Virus-Scanned: at lists.cs.columbia.edu Authentication-Results: mm01.cs.columbia.edu (amavisd-new); dkim=softfail (fail, message has been altered) header.i=@kernel.org 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 q2m58G2wreZc; Fri, 28 Jan 2022 07:20:07 -0500 (EST) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 7E3544B0A0; Fri, 28 Jan 2022 07:20:07 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id B4BB849ED8 for ; Fri, 28 Jan 2022 07:20:05 -0500 (EST) 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 BOQtAd61vHuw for ; Fri, 28 Jan 2022 07:20:04 -0500 (EST) Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id E41CA4B120 for ; Fri, 28 Jan 2022 07:20:03 -0500 (EST) 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 0CE4CB8256B; Fri, 28 Jan 2022 12:20:03 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7471FC36AE7; Fri, 28 Jan 2022 12:20:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1643372401; bh=fD/OIdxzU/mYVdjUNkTw5RVKK8ewez/Ug1vaU47woTE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iJBzmyBk46VhEBqx6jqCroJbJ5xpZaNnOJhXSrUweIftKnc+4rM4k9+P/TQVVOfu7 M84pTmMSg9Lz9xMsUpxyvSyMU87TxNOdgVFkaxV1jieZGqfMG8ONQ+15YQQq0pq0e4 yqxnmHz0ts7E+jkdAR2dGbwE2RUmF5OdWQHjC1v4Y5YsxGdBMgr/I+Qmo0jANJ4R1o mr2zqL69ICi6Ry5Fibb25tdh6z9PDgk/T3p08xtwzjSKKVWdStO59A/Lo1WDJUTG1D eG6dA8qcTtsO4RRLA2pA+rT3ewm8U3NLeJRbRwlto6cUmYVrtBoPDIUTO9btdtX1aw muUESefv8KS4A== 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 1nDQE1-003njR-Gg; Fri, 28 Jan 2022 12:19:33 +0000 From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Subject: [PATCH v6 21/64] KVM: arm64: nv: Handle PSCI call via smc from the guest Date: Fri, 28 Jan 2022 12:18:29 +0000 Message-Id: <20220128121912.509006-22-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 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 Cc: kernel-team@android.com, Andre Przywara , Christoffer Dall , Chase Conklin , "Russell King \(Oracle\)" , mihai.carabas@oracle.com, Ganapatrao Kulkarni 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 VMs used to execute hvc #0 for the psci call if EL3 is not implemented. However, when we come to provide the virtual EL2 mode to the VM, the host OS inside the VM calls kvm_call_hyp() which is also hvc #0. So, it's hard to differentiate between them from the host hypervisor's point of view. So, let the VM execute smc instruction for the psci call. On ARMv8.3, even if EL3 is not implemented, a smc instruction executed at non-secure EL1 is trapped to EL2 if HCR_EL2.TSC==1, rather than being treated as UNDEFINED. So, the host hypervisor can handle this psci call without any confusion. Signed-off-by: Jintack Lim Signed-off-by: Marc Zyngier --- arch/arm64/kvm/handle_exit.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index 2bbeed8c9786..0cedef6e0d80 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -62,6 +62,8 @@ static int handle_hvc(struct kvm_vcpu *vcpu) static int handle_smc(struct kvm_vcpu *vcpu) { + int ret; + /* * "If an SMC instruction executed at Non-secure EL1 is * trapped to EL2 because HCR_EL2.TSC is 1, the exception is a @@ -69,10 +71,28 @@ static int handle_smc(struct kvm_vcpu *vcpu) * * We need to advance the PC after the trap, as it would * otherwise return to the same address... + * + * If imm is non-zero, it's not defined, so just skip it. + */ + if (kvm_vcpu_hvc_get_imm(vcpu)) { + vcpu_set_reg(vcpu, 0, ~0UL); + kvm_incr_pc(vcpu); + return 1; + } + + /* + * If imm is zero, it's a psci call. + * Note that on ARMv8.3, even if EL3 is not implemented, SMC executed + * at Non-secure EL1 is trapped to EL2 if HCR_EL2.TSC==1, rather than + * being treated as UNDEFINED. */ - vcpu_set_reg(vcpu, 0, ~0UL); + ret = kvm_hvc_call_handler(vcpu); + if (ret < 0) + vcpu_set_reg(vcpu, 0, ~0UL); + kvm_incr_pc(vcpu); - return 1; + + return ret; } /* -- 2.30.2 _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm