From patchwork Thu Feb 24 05:13:35 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kalesh Singh X-Patchwork-Id: 12757840 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 B1B4AC433EF for ; Thu, 24 Feb 2022 05:16:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Cc:From:Subject:Mime-Version:Message-Id :Date:Reply-To:To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=Q3s/IneIwiCQGR+nx0sDPDZjCXgQyBjE10nXLxjhy8k=; b=Pd/5I13lfxfmvQ CcAD7KC07XHYw17tBX5eAF/SKpfR+qRjjhhpjuvczyQ+kJv18VEgKo67Ve4eHH0t3aDzBXDYgn4QK SKhjfOJnqY3RDme9Ta8QGxmTg0qCkUgPnbQrIIlWXDc8+UTSXzqxHhzVO1cJUGq9FuRdbvOoe+o7z DDxDl0jvZlLTV3pAb1uaGSrbo54wOi2oW5DGR4XlE8HrdGfSy43g2CA5/rjkCPFnofbcnxHO2Nd2f helFDq08xOEb8YbdsgsZ4241BMm6aSIPyM15VKCXTRlZNY018A0jbCsTqZvUCqcMWzFycMBJBWOyH sxoRYOSGJOoLvGbAej5g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nN6T9-00GpcZ-Kv; Thu, 24 Feb 2022 05:15:11 +0000 Received: from mail-yw1-x114a.google.com ([2607:f8b0:4864:20::114a]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nN6T5-00GpcA-Lb for linux-arm-kernel@lists.infradead.org; Thu, 24 Feb 2022 05:15:09 +0000 Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-2d7b96d74f8so11314807b3.16 for ; Wed, 23 Feb 2022 21:15:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:message-id:mime-version:subject:from:cc; bh=VRP10WDdbxuQYIT1IOcNI0rSS6aawIOMCBB1XLSQkxI=; b=GYT8cVdbYGZDyroDPEZvq6vJikNTwDBW1778+5mVN+VE1nqSYZIh3zBtI83Ini4jgj 756Ky/3UCYmLes/d/U5KVFihtRdDfmjziMCEDEW2f0ku69+YeHsb2HHkDW+Ub28RVl+b LPICnhLLfMZ+IE/PRhN971A35YNNuZveHt7YymqK2bKa2yQFiE+nz3uvxOU2r7dNnEs7 4rCXezH2cYkWAseacLrlJvEyKcScR3ulZ9xGrp23Tjpl1P879Fp2acRPbsobDt33gqrw B2bwgZpivDYzkoqwZlhFKWDNZse6ucvzS5pVORIELgIbiIZHbMosGBhcb8hRxmuNaRVE y+lg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:message-id:mime-version:subject:from:cc; bh=VRP10WDdbxuQYIT1IOcNI0rSS6aawIOMCBB1XLSQkxI=; b=zCQjwG1zo9j1c8G+1+Txr9ecncnuhKkihg8V0NjkgeRTHVyAlH6MbtogbpG+Ew0qxW +ZOiFVpiUg9fr9lngIox+KJrmUxd/0Ad4fvwZlU9na/N7EgJbqnkiRG7DsatNqknWXke OuMMI7csVKHDbKirADoK1QyIEU37F1j4YDfQc6qaE8jG4mbCgq87awQWUmsKdfFL1ls2 MZYaFfv4BMOT1uJgPT1RSlvngmB9exzqhq3jF0C63Fsrdbb7KpBoLJ5aRFq9sN3vwWwn gnQUmrMmS6N9TLzH3fqL2B74fCqwlORKZSuOcZyoWUjnZVfmD/I02l3rsRK3vsuB3kaZ HOzA== X-Gm-Message-State: AOAM531r76to21as6xKCTm1DyMX2SjInA5qvstlzanCsAg+Zb8reMryi uJoqtHNAqWpvXJPLf9PZen3oPgAhRtpvcEPe/g== X-Google-Smtp-Source: ABdhPJzUArkTDX/M4vDb37UTwphM2NOQLwma1KWAfIVP/V2aK4dx/IvxUZwMhGnxk0KxU4+1OmIAS8k+ilwciBnuXw== X-Received: from kaleshsingh.mtv.corp.google.com ([2620:15c:211:200:415c:9be0:c461:440a]) (user=kaleshsingh job=sendgmr) by 2002:a25:ab74:0:b0:624:41d4:c4f0 with SMTP id u107-20020a25ab74000000b0062441d4c4f0mr1008577ybi.277.1645679705804; Wed, 23 Feb 2022 21:15:05 -0800 (PST) Date: Wed, 23 Feb 2022 21:13:35 -0800 Message-Id: <20220224051439.640768-1-kaleshsingh@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.35.1.473.g83b2b277ed-goog Subject: [PATCH v3 0/8] KVM: arm64: Hypervisor stack enhancements 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 , James Morse , Alexandru Elisei , Suzuki K Poulose , Catalin Marinas , Mark Rutland , Mark Brown , Masami Hiramatsu , Peter Collingbourne , "Madhavan T. Venkataraman" , Andrew Walbran , Andrew Scull , Paolo Bonzini , Zenghui Yu , Ard Biesheuvel , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220223_211507_748112_BAEA1BE5 X-CRM114-Status: GOOD ( 17.03 ) 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 Hi all, This is v3 of the nVHE hypervisor stack enhancements. Previous versions can be found at: v2: https://lore.kernel.org/r/20220222165212.2005066-1-kaleshsingh@google.com/ v1: https://lore.kernel.org/r/20220210224220.4076151-1-kaleshsingh@google.com/ The main update in this version is that the unwinder now uses the core logic from the regular kernel stack unwinder to avoid duplicate code, per Mark; along with fixes for the other issues identified in v2. The previous cover letter (with updated call trace) has been copied below. Thanks, Kalesh ----- This series is based on 5.17-rc5 and adds the following stack features to the KVM nVHE hypervisor: == Hyp Stack Guard Pages == Based on the technique used by arm64 VMAP_STACK to detect overflow. i.e. the stack is aligned to twice its size which ensure that the 'stack shift' bit of any valid SP is 0. The 'stack shift' bit can be tested in the exception entry to detect overflow without corrupting GPRs. == Hyp Stack Unwinder == Based on the arm64 kernel stack unwinder (See: arch/arm64/kernel/stacktrace.c) The unwinding and dumping of the hyp stack is not enabled by default and depends on CONFIG_NVHE_EL2_DEBUG to avoid potential information leaks. When CONFIG_NVHE_EL2_DEBUG is enabled the host stage 2 protection is disabled, allowing the host to read the hypervisor stack pages and unwind the stack from EL1. This allows us to print the hypervisor stacktrace before panicking the host; as shown below. Example call trace: [ 98.916444][ T426] kvm [426]: nVHE hyp panic at: [] __kvm_nvhe_overflow_stack+0x8/0x34! [ 98.918360][ T426] nVHE HYP call trace: [ 98.918692][ T426] kvm [426]: [] __kvm_nvhe_cpu_prepare_nvhe_panic_info+0x4c/0x68 [ 98.919545][ T426] kvm [426]: [] __kvm_nvhe_hyp_panic+0x2c/0xe8 [ 98.920107][ T426] kvm [426]: [] __kvm_nvhe_hyp_panic_bad_stack+0x10/0x10 [ 98.920665][ T426] kvm [426]: [] __kvm_nvhe___kvm_hyp_host_vector+0x24c/0x794 [ 98.921292][ T426] kvm [426]: [] __kvm_nvhe_overflow_stack+0x24/0x34 . . . [ 98.973382][ T426] kvm [426]: [] __kvm_nvhe_overflow_stack+0x24/0x34 [ 98.973816][ T426] kvm [426]: [] __kvm_nvhe___kvm_vcpu_run+0x38/0x438 [ 98.974255][ T426] kvm [426]: [] __kvm_nvhe_handle___kvm_vcpu_run+0x1c4/0x364 [ 98.974719][ T426] kvm [426]: [] __kvm_nvhe_handle_trap+0xa8/0x130 [ 98.975152][ T426] kvm [426]: [] __kvm_nvhe___host_exit+0x64/0x64 [ 98.975588][ T426] ---- end of nVHE HYP call trace ---- Kalesh Singh (8): KVM: arm64: Introduce hyp_alloc_private_va_range() KVM: arm64: Introduce pkvm_alloc_private_va_range() KVM: arm64: Add guard pages for KVM nVHE hypervisor stack KVM: arm64: Add guard pages for pKVM (protected nVHE) hypervisor stack KVM: arm64: Detect and handle hypervisor stack overflows KVM: arm64: Add hypervisor overflow stack KVM: arm64: Unwind and dump nVHE HYP stacktrace KVM: arm64: Symbolize the nVHE HYP backtrace arch/arm64/include/asm/kvm_asm.h | 20 +++ arch/arm64/include/asm/kvm_mmu.h | 4 + arch/arm64/include/asm/stacktrace.h | 12 ++ arch/arm64/kernel/stacktrace.c | 210 ++++++++++++++++++++++++--- arch/arm64/kvm/Kconfig | 5 +- arch/arm64/kvm/arm.c | 34 ++++- arch/arm64/kvm/handle_exit.c | 16 +- arch/arm64/kvm/hyp/include/nvhe/mm.h | 3 +- arch/arm64/kvm/hyp/nvhe/host.S | 29 ++++ arch/arm64/kvm/hyp/nvhe/hyp-main.c | 5 +- arch/arm64/kvm/hyp/nvhe/mm.c | 51 ++++--- arch/arm64/kvm/hyp/nvhe/setup.c | 25 +++- arch/arm64/kvm/hyp/nvhe/switch.c | 30 +++- arch/arm64/kvm/mmu.c | 62 +++++--- scripts/kallsyms.c | 2 +- 15 files changed, 422 insertions(+), 86 deletions(-) base-commit: cfb92440ee71adcc2105b0890bb01ac3cddb8507