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 2E8C4C433F5 for ; Fri, 25 Feb 2022 15:00:02 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id D74854BA08; Fri, 25 Feb 2022 10:00:01 -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=@google.com 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 x79MKhPMhGzX; Fri, 25 Feb 2022 10:00:00 -0500 (EST) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 503E54BAAA; Fri, 25 Feb 2022 09:59:48 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 1539C4BB9B for ; Thu, 24 Feb 2022 22:42:55 -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 hCfYwC-W0ofn for ; Thu, 24 Feb 2022 22:42:54 -0500 (EST) Received: from mail-yw1-f201.google.com (mail-yw1-f201.google.com [209.85.128.201]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id 11B2D4BB95 for ; Thu, 24 Feb 2022 22:42:54 -0500 (EST) Received: by mail-yw1-f201.google.com with SMTP id 00721157ae682-2d07ae11467so19792207b3.12 for ; Thu, 24 Feb 2022 19:42:54 -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=TYfrDDnCDZLgsaXn4hYzYqjwtRqrff+8WzYcoEgftOI=; b=q7666YkutUkL6RKXDHN6uW1bfeRRma2VbYbkjuziO8kN3Ez+AvP99CPA+crFQIMyGM u8V98l/kcyJmZrAMYC8lp0VZdsx7hfOnk0og8Iyu8/EPTcDyOrtXaylNfruGAYrBELML 0t4kJOa3EW5NNbIbFy4ls3stZzs7gzcL6saNGB+qXhJn3B64HD/5jMrLH5g2Qj/oJRUN C3NdGCf8ofRIATki5ntXpIdGQYYOMg+4xfPq2uDJ2UMg5PbTBm+zuybq7cU5vTAp9A5R OadOj9nn2g7Sk/FRIHG0Q30twQG0Zl6SxdUGzB8zR5q1zrX1sy32E1VtmvDod4V091/Q RyvA== 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=TYfrDDnCDZLgsaXn4hYzYqjwtRqrff+8WzYcoEgftOI=; b=4Uf+P5Za0vLleoj+HB6KLOZyW7AcMmtGzeD1Xl4VgUsiWeG7/ytsE4J+4rWLLhBtLR TiEVRUqruXJPomzpZ6P7MxUNgUjRdKPpOvrwdoXsDzbzT/c0EPaylrI6d2t0UpSZAGzo AU2fR/SlJjDsg9UJsPvPicZlwF5YADX8AQKBbEATsvrhOVNk436BaqFAOeOU7kF3tCQC AGbBRkGfS1SgUTL2/cRFmwR07EOHUG8JijmLxPphdh67PQ0ReTtih/WA2YM1JUMQZlEa KigmMN79rgt4sWnJlbSMbIVn+lJ2hV9VaEjq8CfkDKte8TTk/X6NUA+cQJlfH6J4Vc6F 4dPA== X-Gm-Message-State: AOAM530U/cBfBlv5rsY93QF3gUa+ND02O0xinyFAjGUKWmoOMyGjwdYK 3A91/xDC4oK8HEfX0rq9LEDyZyvoz3vcmtRhYg== X-Google-Smtp-Source: ABdhPJyuZ08nciNdihLr0dH67Rir4ZvyzFgkAlltso3KgjJwiOs2qrT2Nw+pxsQEIBxp93gHWjAaX4W2t6yMU0pQ5Q== X-Received: from kaleshsingh.mtv.corp.google.com ([2620:15c:211:200:3a50:90b2:e6a2:9060]) (user=kaleshsingh job=sendgmr) by 2002:a25:808f:0:b0:624:a5e8:9762 with SMTP id n15-20020a25808f000000b00624a5e89762mr5469937ybk.279.1645760573552; Thu, 24 Feb 2022 19:42:53 -0800 (PST) Date: Thu, 24 Feb 2022 19:34:49 -0800 In-Reply-To: <20220225033548.1912117-1-kaleshsingh@google.com> Message-Id: <20220225033548.1912117-5-kaleshsingh@google.com> Mime-Version: 1.0 References: <20220225033548.1912117-1-kaleshsingh@google.com> X-Mailer: git-send-email 2.35.1.574.g5d30c73bfb-goog Subject: [PATCH v4 4/8] KVM: arm64: Add guard pages for pKVM (protected nVHE) hypervisor stack From: Kalesh Singh X-Mailman-Approved-At: Fri, 25 Feb 2022 09:59:45 -0500 Cc: Catalin Marinas , Kalesh Singh , will@kernel.org, kvmarm@lists.cs.columbia.edu, Andrew Walbran , maz@kernel.org, "Madhavan T. Venkataraman" , kernel-team@android.com, surenb@google.com, Mark Brown , Peter Collingbourne , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Masami Hiramatsu 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 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 --- Changes in v4: - Replace IS_ERR_OR_NULL check with IS_ERR check now that pkvm_alloc_private_va_range() returns an error for null pointer, per Fuad Changes in v3: - Handle null ptr in IS_ERR_OR_NULL checks, per Mark 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..1b69a25c1861 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(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(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; } /* -- 2.35.1.574.g5d30c73bfb-goog _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm