From patchwork Mon Jan 4 13:49:59 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 11996843 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=-17.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 554BEC433E9 for ; Mon, 4 Jan 2021 13:52:34 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 16F0F207BC for ; Mon, 4 Jan 2021 13:52:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 16F0F207BC Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=YRLABgVSItmpxAhZVbwVaMNiP3l554o2oMCQrff0n6g=; b=Ab5DbRBPoPncecmL2CQDy79hn Y7fQ3gHpRoPAyf7NSBGYESyHISG2s2+t5EHgzAi9aQkeFre/qYfdqdtAcXgpCgciG3MHxYxnQPtxw e1quJZQPS9TV6kH/RylvS6Pj6rCMq0cLRtDohMmNX/veGyIPOVQ52+kEYlcMP0goxBfSiGFekasiP ZgAMdht1zMIyxPOq7dni0mH1bd77M8zOe1otjnlInKeHmZDl2mefZZ8YxLE7MHYmg7rD5SO/jDRaB r0rM97kgOzgCWezBUhHzxj7v8b482u6gy3V0EWtHkpO7WZh34q846ZLbmYwBGt6fj+T/hor1Eg+eU 8IpTd1sIw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kwQGE-00048a-5E; Mon, 04 Jan 2021 13:51:02 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kwQFv-00041a-Li for linux-arm-kernel@lists.infradead.org; Mon, 04 Jan 2021 13:50:46 +0000 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 EC76C221F9; Mon, 4 Jan 2021 13:50:42 +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) (envelope-from ) id 1kwQFt-005E24-6q; Mon, 04 Jan 2021 13:50:41 +0000 From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu Subject: [PATCH v2 05/17] arm64: Initialise as nVHE before switching to VHE Date: Mon, 4 Jan 2021 13:49:59 +0000 Message-Id: <20210104135011.2063104-6-maz@kernel.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210104135011.2063104-1-maz@kernel.org> References: <20210104135011.2063104-1-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, catalin.marinas@arm.com, will@kernel.org, mark.rutland@arm.com, dbrazdil@google.com, alexandru.elisei@arm.com, ardb@kernel.org, james.morse@arm.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210104_085043_880185_D00EE654 X-CRM114-Status: GOOD ( 18.94 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , kernel-team@android.com, Suzuki K Poulose , Catalin Marinas , Alexandru Elisei , James Morse , David Brazdil , Will Deacon , Ard Biesheuvel , Julien Thierry Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org As we are aiming to be able to control whether we enable VHE or not, let's always drop down to EL1 first, and only then upgrade to VHE if at all possible. This means that if the kernel is booted at EL2, we always start with a nVHE init, drop to EL1 to initialise the the kernel, and only then upgrade the kernel EL to EL2 if possible (the process is obviously shortened for secondary CPUs). The resume path is handled similarly to a secondary CPU boot. Signed-off-by: Marc Zyngier --- arch/arm64/kernel/head.S | 38 ++---------------------------------- arch/arm64/kernel/hyp-stub.S | 24 +++++++++++++++++++++++ arch/arm64/kernel/sleep.S | 1 + 3 files changed, 27 insertions(+), 36 deletions(-) diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index 28e9735302df..07445fd976ef 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -433,6 +433,7 @@ SYM_FUNC_START_LOCAL(__primary_switched) bl __pi_memset dsb ishst // Make zero page visible to PTW + bl switch_to_vhe #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) bl kasan_early_init #endif @@ -493,42 +494,6 @@ SYM_INNER_LABEL(init_el1, SYM_L_LOCAL) eret SYM_INNER_LABEL(init_el2, SYM_L_LOCAL) -#ifdef CONFIG_ARM64_VHE - /* - * Check for VHE being present. x2 being non-zero indicates that we - * do have VHE, and that the kernel is intended to run at EL2. - */ - mrs x2, id_aa64mmfr1_el1 - ubfx x2, x2, #ID_AA64MMFR1_VHE_SHIFT, #4 -#else - mov x2, xzr -#endif - cbz x2, init_el2_nvhe - - /* - * When VHE _is_ in use, EL1 will not be used in the host and - * requires no configuration, and all non-hyp-specific EL2 setup - * will be done via the _EL1 system register aliases in __cpu_setup. - */ - mov_q x0, HCR_HOST_VHE_FLAGS - msr hcr_el2, x0 - isb - - init_el2_state vhe - - isb - - mov_q x0, INIT_PSTATE_EL2 - msr spsr_el2, x0 - msr elr_el2, lr - mov w0, #BOOT_CPU_MODE_EL2 - eret - -SYM_INNER_LABEL(init_el2_nvhe, SYM_L_LOCAL) - /* - * When VHE is not in use, early init of EL2 and EL1 needs to be - * done here. - */ mov_q x0, INIT_SCTLR_EL1_MMU_OFF msr sctlr_el1, x0 @@ -623,6 +588,7 @@ SYM_FUNC_START_LOCAL(secondary_startup) /* * Common entry point for secondary CPUs. */ + bl switch_to_vhe bl __cpu_secondary_check52bitva bl __cpu_setup // initialise processor adrp x1, swapper_pg_dir diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S index 6ffdc1f7778b..b727848bd0ec 100644 --- a/arch/arm64/kernel/hyp-stub.S +++ b/arch/arm64/kernel/hyp-stub.S @@ -184,3 +184,27 @@ SYM_FUNC_START(__hyp_reset_vectors) hvc #0 ret SYM_FUNC_END(__hyp_reset_vectors) + +/* + * Entry point to switch to VHE if deemed capable + */ +SYM_FUNC_START(switch_to_vhe) +#ifdef CONFIG_ARM64_VHE + // Need to have booted at EL2 + adr_l x1, __boot_cpu_mode + ldr w0, [x1] + cmp w0, #BOOT_CPU_MODE_EL2 + b.ne 1f + + // and still be at EL1 + mrs x0, CurrentEL + cmp x0, #CurrentEL_EL1 + b.ne 1f + + // Turn the world upside down + mov x0, #HVC_VHE_RESTART + hvc #0 +1: +#endif + ret +SYM_FUNC_END(switch_to_vhe) diff --git a/arch/arm64/kernel/sleep.S b/arch/arm64/kernel/sleep.S index 6bdef7362c0e..5bfd9b87f85d 100644 --- a/arch/arm64/kernel/sleep.S +++ b/arch/arm64/kernel/sleep.S @@ -100,6 +100,7 @@ SYM_FUNC_END(__cpu_suspend_enter) .pushsection ".idmap.text", "awx" SYM_CODE_START(cpu_resume) bl init_kernel_el + bl switch_to_vhe bl __cpu_setup /* enable the MMU early - so we can access sleep_save_stash by va */ adrp x1, swapper_pg_dir