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 1612BC433F5 for ; Tue, 22 Feb 2022 16:57:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234422AbiBVQ5k (ORCPT ); Tue, 22 Feb 2022 11:57:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43388 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233144AbiBVQ5i (ORCPT ); Tue, 22 Feb 2022 11:57:38 -0500 Received: from mail-yw1-x1149.google.com (mail-yw1-x1149.google.com [IPv6:2607:f8b0:4864:20::1149]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DC00716BFAD for ; Tue, 22 Feb 2022 08:57:11 -0800 (PST) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-2d07ae11460so145910127b3.7 for ; Tue, 22 Feb 2022 08:57:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:cc; bh=knnzmuohJ2ih2y2NTiUEzUxj92qYLV4FmoYUekHSvUw=; b=tazhhxtdUk3rQttzgDm+V0n+dY4v2ZnB4i8xG8ax2HZdSoHAffJo42UTzU3IHvzAqj CzDDQtHudJDmOpjvt+NTOxsHiMMcd5AR1KeV4KZ04Anj9Hvg2wo5WdkKx0uhJOAuX1UG DMG5h+1UR544FLvyjxNA1/VvkZavi0pxiwKfoHP3qdoBAJ8849pS8kTNoGD5QX5f9/Px 48yknJpXBRw8xvBSwtZigYe1MGyv8eQBBWwjuMT8BSujAmFufVqRsnYE2LCmZqywZs8i wJddWj0UZSrpFMMQpEijc1j/Xch9CqJ1J2YUynBS8lvvuY7OGu4etP9u4qE8wqmUHhIw yLwg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:cc; bh=knnzmuohJ2ih2y2NTiUEzUxj92qYLV4FmoYUekHSvUw=; b=Xe91ktN0nz4w2p6o9pV1v0wApCbo6UaLaeuPYe45EQbzSk64vQZvT72LAB9FO9RrmX xN5Wg8mZ4aBISVHiinRGGt5aYR5PpjCCM40Zl/0+mwECR581bifkJyipKWhc2dZ4RNL6 kvpoz2aXJbfrXoguQ4ynICHKbbZ3xNv5kdigDG5vE82x1Qj7MawXuufXgpHG2X+jk+17 j+Wpnt9zwM9+0lpFs5dhtiT3W2h9ZjwbVSXUZHTnncr0RCGmQjLoeoY8ljVa6lgbciA8 tdSSdwDokx577mWJZ+sFc4ipEXCP56AVkN3QJZGPtE5l0QRMZP1sMIYa0TqfFfPpjHQ6 c9Tw== X-Gm-Message-State: AOAM533n76ItwTRSOBBPIpeh+7FaW4OiC4J7NMks7qREoj/z04nSlB16 OZMv4ni8o3w57ntUAI41J0IBjqRWNd3WoztbZg== X-Google-Smtp-Source: ABdhPJxsM9h50TZI3B0JLyBOhiXv0umcrv6dsBugtZNBeZtlKN8O9HTo3L2ie+qpRSFxA92HD2CPBV8kKYkIX9PJAQ== X-Received: from kaleshsingh.mtv.corp.google.com ([2620:15c:211:200:5db7:1235:b3dd:cfcb]) (user=kaleshsingh job=sendgmr) by 2002:a25:4cc1:0:b0:623:ca02:c1e5 with SMTP id z184-20020a254cc1000000b00623ca02c1e5mr22952503yba.95.1645549030879; Tue, 22 Feb 2022 08:57:10 -0800 (PST) Date: Tue, 22 Feb 2022 08:51:05 -0800 In-Reply-To: <20220222165212.2005066-1-kaleshsingh@google.com> Message-Id: <20220222165212.2005066-5-kaleshsingh@google.com> Mime-Version: 1.0 References: <20220222165212.2005066-1-kaleshsingh@google.com> X-Mailer: git-send-email 2.35.1.473.g83b2b277ed-goog Subject: [PATCH v2 4/9] KVM: arm64: Add guard pages for pKVM (protected nVHE) hypervisor stack From: Kalesh Singh Cc: will@kernel.org, maz@kernel.org, qperret@google.com, tabba@google.com, surenb@google.com, kernel-team@android.com, Kalesh Singh , Catalin Marinas , James Morse , Alexandru Elisei , Suzuki K Poulose , Ard Biesheuvel , Mark Rutland , Pasha Tatashin , Joey Gouly , Peter Collingbourne , Andrew Scull , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kvmarm@lists.cs.columbia.edu Content-Type: text/plain; charset="UTF-8" To: unlisted-recipients:; (no To-header on input) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Maps the stack pages in the flexible private VA range and allocates guard pages below the stack as unbacked VA space. The stack is aligned to twice its size to aid overflow detection (implemented in a subsequent patch in the series). Signed-off-by: Kalesh Singh --- arch/arm64/kvm/hyp/nvhe/setup.c | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-) diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c index 27af337f9fea..69df21320b09 100644 --- a/arch/arm64/kvm/hyp/nvhe/setup.c +++ b/arch/arm64/kvm/hyp/nvhe/setup.c @@ -105,11 +105,28 @@ static int recreate_hyp_mappings(phys_addr_t phys, unsigned long size, if (ret) return ret; - end = (void *)per_cpu_ptr(&kvm_init_params, i)->stack_hyp_va; + /* + * Private mappings are allocated upwards from __io_map_base + * so allocate the guard page first then the stack. + */ + start = (void *)pkvm_alloc_private_va_range(PAGE_SIZE, PAGE_SIZE); + if (IS_ERR_OR_NULL(start)) + return PTR_ERR(start); + + /* + * The stack is aligned to twice its size to facilitate overflow + * detection. + */ + end = (void *)per_cpu_ptr(&kvm_init_params, i)->stack_pa; start = end - PAGE_SIZE; - ret = pkvm_create_mappings(start, end, PAGE_HYP); - if (ret) - return ret; + start = (void *)__pkvm_create_private_mapping((phys_addr_t)start, + PAGE_SIZE, PAGE_SIZE * 2, PAGE_HYP); + if (IS_ERR_OR_NULL(start)) + return PTR_ERR(start); + end = start + PAGE_SIZE; + + /* Update stack_hyp_va to end of the stack's private VA range */ + per_cpu_ptr(&kvm_init_params, i)->stack_hyp_va = (unsigned long) end; } /* -- 2.35.1.473.g83b2b277ed-goog