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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C1815C43458 for ; Wed, 1 Jul 2026 20:44:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:Cc:To:From: Subject:Message-ID:References:Mime-Version:In-Reply-To:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=tzU5geEAdlGdzp5rSJKP+9OB0IsgaotJw1U5Q6pxjvc=; b=VUaO2kfP8vmX1TTDNocyVOCJBV FOAwYJynhjjA+z8vewM59nts1n0eCaF+ICBrSJ0uoyliLjGAjenRIEPeV4romp/rNyBT4+wPRVYhv MnPPyjKD5mBYx5qbhHbHYYzh2v3VlWe7jIN0SES2vMsEo39IbSvlq3mTjdh935Xkg7fDrzA0Te+me 2Xc3YjXt7hG29JNnoFLFW2kVRFp57/+VRL08e0HqQ0YxW3ptInVjT9xCwwUhcfM0eUaKICmFQgRLy 9he4R9LKS77wdfLTcwRgZyswUkn3ntk5/HVbSaMu5q9NqGxblDHZlfob341mGsVxyrcGYEwerxuI/ PNsTZdhw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wf1mg-00000002zHX-1zgJ; Wed, 01 Jul 2026 20:43:50 +0000 Received: from mail-oi1-x24a.google.com ([2607:f8b0:4864:20::24a]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wf1mc-00000002zEx-3E3S for linux-arm-kernel@lists.infradead.org; Wed, 01 Jul 2026 20:43:48 +0000 Received: by mail-oi1-x24a.google.com with SMTP id 5614622812f47-4909b046dabso1659244b6e.0 for ; Wed, 01 Jul 2026 13:43:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1782938625; x=1783543425; darn=lists.infradead.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=tzU5geEAdlGdzp5rSJKP+9OB0IsgaotJw1U5Q6pxjvc=; b=oE2Ab22b4d7sk6XVVI8e4IgRNGvV7H9zG+b1s7yuY97eABrkqNs+ivyuRkOuXlAMRM pd3ICpYOWrfmMWrAsgiCqg50Ub16yQ+qr3iSFraYsrGhACw4Z4ItPh2wiMRCZKO099J1 84ZTwZM1vX5PIF/8s1VO3RaZuhBAzzEBxAwlEzgHECZYf5S1BLUNT3s+pJvCTLtFh/Zl HKEp0SKcKeGr4Y6Rsss1U1R9/zP4+td9eFCcX4XuO1/DVVpFFwOTllw/FuDs9RZpXQRg /rxkFToyFyDDzwqiYYnvUp3G5n5+WCP82dkAt47zvQd/V53eLnVN6bFmL8/49jHxTjc8 FULw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1782938625; x=1783543425; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=tzU5geEAdlGdzp5rSJKP+9OB0IsgaotJw1U5Q6pxjvc=; b=Wr2sW1uttqxfOTfOor9FtJG4f1nyYJiBAYNBRRJCkkIiJVqAHvQs1gclYP3NT5UawZ ocJizfo5Prjkbm9w7VkekVpWr1rJNPiFqHRgdC312vdhVAMC7kFoEMXenjHMwfuzRaQQ tKnCjJB/mFU6AHj3gNuw3aCV5USBPiZ5yTiYFEXidgmkB4rBjh0IYGSidbjO9xoGa7pu CWiqxPLAWT/dd5Xte9Cl4zjtQiakmJoRHPkypR3q7g/t5bHGjGx//sVzREKNfLRLiw+x lBlN62Rx2zNSuMcz/jvzgdmFz4dqKFweQ1zNVv0FdDRMRmFcPvinSYoaTx9kwt1MCCXY JvPg== X-Forwarded-Encrypted: i=1; AFNElJ+wezrhcWkmd1iK9qiU6TSOf+suRo5ZMyGLKa1jYA3aj1XjvnU0xsoMs1hwb1x0UNsV15cypByG227h3kxC5reJ@lists.infradead.org X-Gm-Message-State: AOJu0Yx1v2Vd6ItRpxzxepDD9YsdgNVr3e7IGBNG+LlnKTDoxPis1Sfx 3+MvEWb8JyUHkbIz+/Rl8G81jDYAQf0gOuaGiTECP4iDAYFORB81MAMsmKYNR9WcFWAMWuiktk1 6howKMbpqh9d4mR8TEz44kJuKSg== X-Received: from iodr16-n1.prod.google.com ([2002:a05:6602:6c90:10b0:993:783e:f2bb]) (user=coltonlewis job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6808:5088:b0:487:6930:d50 with SMTP id 5614622812f47-4960efba909mr1932765b6e.35.1782938625160; Wed, 01 Jul 2026 13:43:45 -0700 (PDT) Date: Wed, 1 Jul 2026 20:43:39 +0000 In-Reply-To: <20260701204342.2654385-1-coltonlewis@google.com> Mime-Version: 1.0 References: <20260701204342.2654385-1-coltonlewis@google.com> X-Mailer: git-send-email 2.55.0.rc2.803.g1fd1e6609c-goog Message-ID: <20260701204342.2654385-3-coltonlewis@google.com> Subject: [PATCH 2/5] arm64: Treat HCR_EL2.E2H as RES1 when ID_AA64MMFR4_EL1.E2H0 is negative From: Colton Lewis To: stable@vger.kernel.org Cc: Catalin Marinas , Will Deacon , Marc Zyngier , Oliver Upton , James Morse , Suzuki K Poulose , Zenghui Yu , Mingwei Zhang , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260701_134346_812812_FF63CEE1 X-CRM114-Status: GOOD ( 13.25 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Marc Zyngier [ Upstream commit 3944382fa6f22b54bc3624c9657b98ec34b5ba59 ] For CPUs that have ID_AA64MMFR4_EL1.E2H0 as negative, it is important to avoid the boot path that sets HCR_EL2.E2H=0. Fortunately, we already have this path to cope with fruity CPUs. Tweak init_el2 to look at ID_AA64MMFR4_EL1.E2H0 first. Reviewed-by: Suzuki K Poulose Signed-off-by: Marc Zyngier Reviewed-by: Catalin Marinas Link: https://lore.kernel.org/r/20240122181344.258974-8-maz@kernel.org Signed-off-by: Oliver Upton --- arch/arm64/kernel/head.S | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index 6517bf2644a08..e32c8dd0b17a7 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -589,25 +589,32 @@ SYM_INNER_LABEL(init_el2, SYM_L_LOCAL) mov_q x1, INIT_SCTLR_EL1_MMU_OFF /* - * Fruity CPUs seem to have HCR_EL2.E2H set to RES1, - * making it impossible to start in nVHE mode. Is that - * compliant with the architecture? Absolutely not! + * Compliant CPUs advertise their VHE-onlyness with + * ID_AA64MMFR4_EL1.E2H0 < 0. HCR_EL2.E2H can be + * RES1 in that case. + * + * Fruity CPUs seem to have HCR_EL2.E2H set to RES1, but + * don't advertise it (they predate this relaxation). */ + mrs_s x0, SYS_ID_AA64MMFR4_EL1 + ubfx x0, x0, #ID_AA64MMFR4_EL1_E2H0_SHIFT, #ID_AA64MMFR4_EL1_E2H0_WIDTH + tbnz x0, #(ID_AA64MMFR4_EL1_E2H0_SHIFT + ID_AA64MMFR4_EL1_E2H0_WIDTH - 1), 1f + mrs x0, hcr_el2 and x0, x0, #HCR_E2H - cbz x0, 1f - + cbz x0, 2f +1: /* Set a sane SCTLR_EL1, the VHE way */ pre_disable_mmu_workaround msr_s SYS_SCTLR_EL12, x1 mov x2, #BOOT_CPU_FLAG_E2H - b 2f + b 3f -1: +2: pre_disable_mmu_workaround msr sctlr_el1, x1 mov x2, xzr -2: +3: __init_el2_nvhe_prepare_eret mov w0, #BOOT_CPU_MODE_EL2 -- 2.55.0.rc2.803.g1fd1e6609c-goog