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 AD9DEC43334 for ; Fri, 15 Jul 2022 06:13:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231332AbiGOGNO (ORCPT ); Fri, 15 Jul 2022 02:13:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54660 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230151AbiGOGMV (ORCPT ); Fri, 15 Jul 2022 02:12:21 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ABF187B79E for ; Thu, 14 Jul 2022 23:11:47 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id b129-20020a25e487000000b0066e1c52ac55so3292348ybh.11 for ; Thu, 14 Jul 2022 23:11:47 -0700 (PDT) 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:to :cc; bh=pCrsAtrXdQrqKS3eeA8f9GflhdYZQyxHWES6iqq1HQQ=; b=jI4zAPvvQ77ZuvgrkrRIHZRkBl0VSF8QUgVCY/1ZnqdCg0pQyYf0UuEwHeiROiTaAy FSHAtwwXH951A9lpReSW3weDPL7qdYwHOOctZaeKlz/8zfmGCk6fRs1Evv5wtDjJbTBx cksIRahdwMwL9F3qJGyjQ997TNOhcHp+H114RtKstCa99riB9yoL6l7Y4CeCyWMV/92L JuWSurazgujBJNjwdTmMGq62lprxYhEAOKVMr/bVOZY31Ft4VD0s5Xyn5gfq130hJGt6 vwzQ9VHOvkWYELkKQ1Ph3gdjt7xURPyOBYcL0IdT2MaGg5DiSqXxP2wCEE8xSsVaHn7d DJwQ== 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:to:cc; bh=pCrsAtrXdQrqKS3eeA8f9GflhdYZQyxHWES6iqq1HQQ=; b=ctGN5hLFIrmaj0v1tqSCRYN48LtTcjTr08x72VMr8OV7XpbV1aaahZ7ajiBzWy612A 2s1Iq3AZ6x+HHX1qI9X0aXUxezvKgkvwcv3oHBlkET4DDI+SMOeN/y8ni0jdL/kQ6p9x gv9GX2D6WQLF5lL9+ZmqmbV5Wecx+1PuJHxvCiAoUmTwBLXdHpoLwM8NJeh8VSRtKS// QKhUtA3lwUZI1viN3Q6v1R32vo7d7KmM0VmjcxUGVeeQSmEt4pSJefAbd5qEcCjNJfrS 9y2YvGUJELk/AKROju+FdObN+rByhfC3df9NyPYcaU3TZoHEUMNVwsL5ocDXPyaf1ljH qXgg== X-Gm-Message-State: AJIora/YRnhK/qFkMtwPCORQHZ02PVAzUWiGtKrahgCnCym44vQPXLgv OveaQ57YtQ+Q3jpUEqgtd6VqWIVLf+4EENrybA== X-Google-Smtp-Source: AGRyM1tEqC2CS+wqI7vtsUSjZ6J4A5D2uthRIAUasSZuLlJSGC81kXJwJZFzwd7qYeFr+qoAbrl5Z8/6YFdrJhWx1A== X-Received: from kaleshsingh.mtv.corp.google.com ([2620:15c:211:200:f010:455b:62ce:19e]) (user=kaleshsingh job=sendgmr) by 2002:a81:503:0:b0:317:c5d5:16fe with SMTP id 3-20020a810503000000b00317c5d516femr13830160ywf.231.1657865506980; Thu, 14 Jul 2022 23:11:46 -0700 (PDT) Date: Thu, 14 Jul 2022 23:10:26 -0700 In-Reply-To: <20220715061027.1612149-1-kaleshsingh@google.com> Message-Id: <20220715061027.1612149-18-kaleshsingh@google.com> Mime-Version: 1.0 References: <20220715061027.1612149-1-kaleshsingh@google.com> X-Mailer: git-send-email 2.37.0.170.g444d1eabd0-goog Subject: [PATCH v4 17/18] KVM: arm64: Introduce hyp_dump_backtrace() From: Kalesh Singh To: maz@kernel.org, mark.rutland@arm.com, broonie@kernel.org, madvenka@linux.microsoft.com Cc: will@kernel.org, qperret@google.com, tabba@google.com, kaleshsingh@google.com, james.morse@arm.com, alexandru.elisei@arm.com, suzuki.poulose@arm.com, catalin.marinas@arm.com, andreyknvl@gmail.com, russell.king@oracle.com, vincenzo.frascino@arm.com, mhiramat@kernel.org, ast@kernel.org, drjones@redhat.com, wangkefeng.wang@huawei.com, elver@google.com, keirf@google.com, yuzenghui@huawei.com, ardb@kernel.org, oupton@google.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, android-mm@google.com, kernel-team@android.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In non-protected nVHE mode, unwinds and dumps the hypervisor backtrace from EL1. This is possible beacuase the host can directly access the hypervisor stack pages in non-proteced mode. Signed-off-by: Kalesh Singh --- arch/arm64/include/asm/stacktrace/nvhe.h | 64 +++++++++++++++++++++--- 1 file changed, 56 insertions(+), 8 deletions(-) diff --git a/arch/arm64/include/asm/stacktrace/nvhe.h b/arch/arm64/include/asm/stacktrace/nvhe.h index ec1a4ee21c21..c322ac95b256 100644 --- a/arch/arm64/include/asm/stacktrace/nvhe.h +++ b/arch/arm64/include/asm/stacktrace/nvhe.h @@ -190,6 +190,56 @@ static int notrace unwind_next(struct unwind_state *state) } NOKPROBE_SYMBOL(unwind_next); +/** + * kvm_nvhe_print_backtrace_entry - Symbolizes and prints the HYP stack address + */ +static inline void kvm_nvhe_print_backtrace_entry(unsigned long addr, + unsigned long hyp_offset) +{ + unsigned long va_mask = GENMASK_ULL(vabits_actual - 1, 0); + + /* Mask tags and convert to kern addr */ + addr = (addr & va_mask) + hyp_offset; + kvm_err(" [<%016lx>] %pB\n", addr, (void *)addr); +} + +/** + * hyp_backtrace_entry - Dump an entry of the non-protected nVHE HYP stacktrace + * + * @arg : the hypervisor offset, used for address translation + * @where : the program counter corresponding to the stack frame + */ +static inline bool hyp_dump_backtrace_entry(void *arg, unsigned long where) +{ + kvm_nvhe_print_backtrace_entry(where, (unsigned long)arg); + + return true; +} + +/** + * hyp_dump_backtrace - Dump the non-proteced nVHE HYP backtrace. + * + * @hyp_offset: hypervisor offset, used for address translation. + * + * The host can directly access HYP stack pages in non-protected + * mode, so the unwinding is done directly from EL1. This removes + * the need for shared buffers between host and hypervisor for + * the stacktrace. + */ +static inline void hyp_dump_backtrace(unsigned long hyp_offset) +{ + struct kvm_nvhe_stacktrace_info *stacktrace_info; + struct unwind_state state; + + stacktrace_info = this_cpu_ptr_nvhe_sym(kvm_stacktrace_info); + + kvm_nvhe_unwind_init(&state, stacktrace_info->fp, stacktrace_info->pc); + + kvm_err("Non-protected nVHE HYP call trace:\n"); + unwind(&state, hyp_dump_backtrace_entry, (void *)hyp_offset); + kvm_err("---- End of Non-protected nVHE HYP call trace ----\n"); +} + #ifdef CONFIG_PROTECTED_NVHE_STACKTRACE DECLARE_KVM_NVHE_PER_CPU(unsigned long [NVHE_STACKTRACE_SIZE/sizeof(long)], pkvm_stacktrace); @@ -206,22 +256,18 @@ DECLARE_KVM_NVHE_PER_CPU(unsigned long [NVHE_STACKTRACE_SIZE/sizeof(long)], pkvm static inline void pkvm_dump_backtrace(unsigned long hyp_offset) { unsigned long *stacktrace_pos; - unsigned long va_mask, pc; stacktrace_pos = (unsigned long *)this_cpu_ptr_nvhe_sym(pkvm_stacktrace); - va_mask = GENMASK_ULL(vabits_actual - 1, 0); kvm_err("Protected nVHE HYP call trace:\n"); - /* The stack trace is terminated by a null entry */ - for (; *stacktrace_pos; stacktrace_pos++) { - /* Mask tags and convert to kern addr */ - pc = (*stacktrace_pos & va_mask) + hyp_offset; - kvm_err(" [<%016lx>] %pB\n", pc, (void *)pc); - } + /* The saved stacktrace is terminated by a null entry */ + for (; *stacktrace_pos; stacktrace_pos++) + kvm_nvhe_print_backtrace_entry(*stacktrace_pos, hyp_offset); kvm_err("---- End of Protected nVHE HYP call trace ----\n"); } + #else /* !CONFIG_PROTECTED_NVHE_STACKTRACE */ static inline void pkvm_dump_backtrace(unsigned long hyp_offset) { @@ -238,6 +284,8 @@ static inline void kvm_nvhe_dump_backtrace(unsigned long hyp_offset) { if (is_protected_kvm_enabled()) pkvm_dump_backtrace(hyp_offset); + else + hyp_dump_backtrace(hyp_offset); } #endif /* __KVM_NVHE_HYPERVISOR__ */ #endif /* __ASM_STACKTRACE_NVHE_H */ -- 2.37.0.170.g444d1eabd0-goog