From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f74.google.com (mail-wm1-f74.google.com [209.85.128.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EF95F187349 for ; Wed, 11 Sep 2024 09:31:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.74 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726047073; cv=none; b=GmoP3uczQKAdloiKhhdtRz9rsseTILydkXfneUJspvUC8lryQhzK3nqcCc7m+ENoojBtnkubfEPnKrokbYqAr73w192Wc7PIgwqZXGE/Jqcu9hxG0G/jNLxz7QzOftqFXA34TC+tK465I4XkQKn5DdH7/ktX3j0eqpMjWTmVjSQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726047073; c=relaxed/simple; bh=Hp4qstVpdpGnkkfN1xgcPm4KsX6RZwEnvPl5FeeL/2Y=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=BzlKL6pCsTmt/W0AeEeuJ5+IF79cGS8H23MR1KFZUtO7oxyQPeDOLWrU75dfDgDSbEBh9kah2cDcxAi6ggBLMB8XQKzP8aY+5TPpgYlRu3kNb1BVvgkWB1iWUp/zR/yFtbiZDFX3He7WSrwqGheGBxAF+2/23gD+WtTStjdbbmI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--vdonnefort.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=OwMtYFXr; arc=none smtp.client-ip=209.85.128.74 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--vdonnefort.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="OwMtYFXr" Received: by mail-wm1-f74.google.com with SMTP id 5b1f17b1804b1-42ac185e26cso51783515e9.3 for ; Wed, 11 Sep 2024 02:31:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1726047070; x=1726651870; darn=lists.linux.dev; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=TnLSQZSAgoNi0Keo+sYtcTPVeJagPuiIv9Z2VTSsQS0=; b=OwMtYFXr70rfvoLADyMcjLYH/4bZMhy2J3mFUEK3SEd/Oi++kzd86165irI/rjqPXE e/rVa8aVADSXjFLf30CRTPE8UHIu8wtw5jAFliN0ZKCiEcCnu1XG09DOTD1OwkItRF0G hEjIN2K9xf/WYs/mWfIzpyhMM+ESVAq3vmuY7/wPUXgx1/mdXPrduuOG7Fa241bDXcbl 1ceQagCPEpxqnLasd0IX4vZI4i/uYaT9ZAt9nT8+sK0VmqgN3cc86je5kQXQ49+XB6z4 HvpykswVpslMpLlLpkr2qSGd/PBbHKkFRLAFBl+xUEU6ujugGWmIQ9fgCSVeOrU4UjLx eBwg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1726047070; x=1726651870; 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=TnLSQZSAgoNi0Keo+sYtcTPVeJagPuiIv9Z2VTSsQS0=; b=qmDbCdezmbNAnolZXRODB25koLxmJ3MTZCfU+IxCcjpLZhbGXa9uWQN9oo/XDNZaDl 5GBX2EXtPFNvK9LtHu3qbv67kgX/UN40wSxm8CgkSjdqedwTO3QITSO2SPYu/4BQ1JIM 1mJWNXvoHh1+Xn61D5Wr89eB7MQLu2tK9ONUMOOunXznbr8VYCKbmSZZ98nfWI4MGcnG OfReJ4rpUmubfUkSoHXt19wjA473/6U1LP8dxuBDfOR32gDRhx1y3B+WEaPFiW31/0M5 NI85ppQDCC/5rQRg3rAggbR2zhalBpH9xzLYj7dfv/v9mX9p3mch8oc/EK0+5Z6itQY+ BB2g== X-Gm-Message-State: AOJu0Yy6tV41UAj43odYGIBnaSCFErcbR1/zFVlUI6SZM4xG1nmOYvTY YkaWt9pGYqqc/oYBpc2/eNdojPcCLW0utszlGpb+ytoWuAWK7hcyd8w5M7KjzoeEEA0Q1otVXsK FwhBo/fmfKvEHALM1pg== X-Google-Smtp-Source: AGHT+IFBFa1ITmFWdn1hIxeejWg2oOrSElTmg674ffGcdfONVY7m5AHs9mdqHrVmIGHjb5YdccfyU5goBnO2ORC/ X-Received: from vdonnefort.c.googlers.com ([fda3:e722:ac3:cc00:28:9cb1:c0a8:2eea]) (user=vdonnefort job=sendgmr) by 2002:a05:600c:1da3:b0:42c:afd6:6896 with SMTP id 5b1f17b1804b1-42cafd6692dmr355355e9.4.1726047070522; Wed, 11 Sep 2024 02:31:10 -0700 (PDT) Date: Wed, 11 Sep 2024 10:30:27 +0100 In-Reply-To: <20240911093029.3279154-1-vdonnefort@google.com> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240911093029.3279154-1-vdonnefort@google.com> X-Mailer: git-send-email 2.46.0.598.g6f2099f65c-goog Message-ID: <20240911093029.3279154-12-vdonnefort@google.com> Subject: [PATCH 11/13] KVM: arm64: Add trace interface for hyp tracefs From: Vincent Donnefort To: rostedt@goodmis.org, mhiramat@kernel.org, linux-trace-kernel@vger.kernel.org, maz@kernel.org, oliver.upton@linux.dev Cc: kvmarm@lists.linux.dev, will@kernel.org, qperret@google.com, kernel-team@android.com, linux-kernel@vger.kernel.org, Vincent Donnefort Content-Type: text/plain; charset="UTF-8" The trace interface is solely here to reset tracing. Non-consuming read is not yet supported due to the lack of support in the ring-buffer meta page. Signed-off-by: Vincent Donnefort diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h index 96490f8c3ff2..17896e6ceca7 100644 --- a/arch/arm64/include/asm/kvm_asm.h +++ b/arch/arm64/include/asm/kvm_asm.h @@ -83,6 +83,7 @@ enum __kvm_host_smccc_func { __KVM_HOST_SMCCC_FUNC___pkvm_load_tracing, __KVM_HOST_SMCCC_FUNC___pkvm_teardown_tracing, __KVM_HOST_SMCCC_FUNC___pkvm_enable_tracing, + __KVM_HOST_SMCCC_FUNC___pkvm_reset_tracing, __KVM_HOST_SMCCC_FUNC___pkvm_swap_reader_tracing, }; diff --git a/arch/arm64/kvm/hyp/include/nvhe/trace.h b/arch/arm64/kvm/hyp/include/nvhe/trace.h index df17683a3b12..1004e1edf24f 100644 --- a/arch/arm64/kvm/hyp/include/nvhe/trace.h +++ b/arch/arm64/kvm/hyp/include/nvhe/trace.h @@ -20,6 +20,7 @@ void __pkvm_update_clock_tracing(u32 mult, u32 shift, u64 epoch_ns, u64 epoch_cy int __pkvm_load_tracing(unsigned long desc_va, size_t desc_size); void __pkvm_teardown_tracing(void); int __pkvm_enable_tracing(bool enable); +int __pkvm_reset_tracing(unsigned int cpu); int __pkvm_swap_reader_tracing(unsigned int cpu); #else static inline void *tracing_reserve_entry(unsigned long length) { return NULL; } @@ -30,6 +31,7 @@ void __pkvm_update_clock_tracing(u32 mult, u32 shift, u64 epoch_ns, u64 epoch_cy static inline int __pkvm_load_tracing(unsigned long desc_va, size_t desc_size) { return -ENODEV; } static inline void __pkvm_teardown_tracing(void) { } static inline int __pkvm_enable_tracing(bool enable) { return -ENODEV; } +static inline int __pkvm_reset_tracing(unsigned int cpu) { return -ENODEV; } static inline int __pkvm_swap_reader_tracing(unsigned int cpu) { return -ENODEV; } #endif #endif diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c index 7f5c3e888960..dc7a85922117 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c @@ -408,6 +408,13 @@ static void handle___pkvm_enable_tracing(struct kvm_cpu_context *host_ctxt) cpu_reg(host_ctxt, 1) = __pkvm_enable_tracing(enable); } +static void handle___pkvm_reset_tracing(struct kvm_cpu_context *host_ctxt) +{ + DECLARE_REG(unsigned int, cpu, host_ctxt, 1); + + cpu_reg(host_ctxt, 1) = __pkvm_reset_tracing(cpu); +} + static void handle___pkvm_swap_reader_tracing(struct kvm_cpu_context *host_ctxt) { DECLARE_REG(unsigned int, cpu, host_ctxt, 1); @@ -451,6 +458,7 @@ static const hcall_t host_hcall[] = { HANDLE_FUNC(__pkvm_load_tracing), HANDLE_FUNC(__pkvm_teardown_tracing), HANDLE_FUNC(__pkvm_enable_tracing), + HANDLE_FUNC(__pkvm_reset_tracing), HANDLE_FUNC(__pkvm_swap_reader_tracing), }; diff --git a/arch/arm64/kvm/hyp/nvhe/trace.c b/arch/arm64/kvm/hyp/nvhe/trace.c index 022fe2e24f82..6ea0f1d475bb 100644 --- a/arch/arm64/kvm/hyp/nvhe/trace.c +++ b/arch/arm64/kvm/hyp/nvhe/trace.c @@ -284,12 +284,20 @@ static int rb_page_init(struct hyp_buffer_page *bpage, unsigned long hva) return 0; } +static void rb_page_reset(struct hyp_buffer_page *bpage) +{ + bpage->write = 0; + bpage->entries = 0; + + local_set(&bpage->page->commit, 0); +} + static bool rb_cpu_loaded(struct hyp_rb_per_cpu *cpu_buffer) { return !!cpu_buffer->bpages; } -static void rb_cpu_disable_writing(struct hyp_rb_per_cpu *cpu_buffer) +static int rb_cpu_disable_writing(struct hyp_rb_per_cpu *cpu_buffer) { int prev_status; @@ -299,6 +307,8 @@ static void rb_cpu_disable_writing(struct hyp_rb_per_cpu *cpu_buffer) HYP_RB_READY, HYP_RB_UNAVAILABLE); } while (prev_status == HYP_RB_WRITING); + + return prev_status; } static int rb_cpu_enable_writing(struct hyp_rb_per_cpu *cpu_buffer) @@ -311,6 +321,38 @@ static int rb_cpu_enable_writing(struct hyp_rb_per_cpu *cpu_buffer) return 0; } +static int rb_cpu_reset(struct hyp_rb_per_cpu *cpu_buffer) +{ + struct hyp_buffer_page *bpage; + int prev_status; + + if (!rb_cpu_loaded(cpu_buffer)) + return -ENODEV; + + prev_status = rb_cpu_disable_writing(cpu_buffer); + + bpage = cpu_buffer->head_page; + do { + rb_page_reset(bpage); + bpage = rb_next_page(bpage); + } while (bpage != cpu_buffer->head_page); + + rb_page_reset(cpu_buffer->reader_page); + + cpu_buffer->meta->reader.read = 0; + cpu_buffer->meta->reader.lost_events = 0; + cpu_buffer->meta->entries = 0; + cpu_buffer->meta->overrun = 0; + cpu_buffer->meta->read = 0; + meta_pages_lost(cpu_buffer->meta) = 0; + meta_pages_touched(cpu_buffer->meta) = 0; + + if (prev_status == HYP_RB_READY) + rb_cpu_enable_writing(cpu_buffer); + + return 0; +} + static void rb_cpu_teardown(struct hyp_rb_per_cpu *cpu_buffer) { int i; @@ -602,3 +644,17 @@ int __pkvm_enable_tracing(bool enable) return ret; } + +int __pkvm_reset_tracing(unsigned int cpu) +{ + int ret = 0; + + if (cpu >= hyp_nr_cpus) + return -EINVAL; + + hyp_spin_lock(&trace_rb_lock); + ret = rb_cpu_reset(per_cpu_ptr(&trace_rb, cpu)); + hyp_spin_unlock(&trace_rb_lock); + + return ret; +} diff --git a/arch/arm64/kvm/hyp_trace.c b/arch/arm64/kvm/hyp_trace.c index 0d0e5eada816..8ac8f9763cbd 100644 --- a/arch/arm64/kvm/hyp_trace.c +++ b/arch/arm64/kvm/hyp_trace.c @@ -196,6 +196,11 @@ static int __get_reader_page(int cpu) return kvm_call_hyp_nvhe(__pkvm_swap_reader_tracing, cpu); } +static int __reset(int cpu) +{ + return kvm_call_hyp_nvhe(__pkvm_reset_tracing, cpu); +} + static void hyp_trace_free_pages(struct hyp_trace_desc *desc) { struct rb_page_desc *rb_desc; @@ -354,6 +359,7 @@ static int hyp_trace_buffer_load(struct hyp_trace_buffer *hyp_buffer, size_t siz hyp_buffer->writer.pdesc = &desc->page_desc; hyp_buffer->writer.get_reader_page = __get_reader_page; + hyp_buffer->writer.reset = __reset; hyp_buffer->trace_buffer = ring_buffer_reader(&hyp_buffer->writer); if (!hyp_buffer->trace_buffer) { ret = -ENOMEM; @@ -820,6 +826,49 @@ static const struct file_operations hyp_trace_raw_fops = { .llseek = no_llseek, }; +static void hyp_trace_reset(int cpu) +{ + struct hyp_trace_buffer *hyp_buffer = &hyp_trace_buffer; + + mutex_lock(&hyp_buffer->lock); + + if (!hyp_trace_buffer_loaded(hyp_buffer)) + goto out; + + if (cpu == RING_BUFFER_ALL_CPUS) + ring_buffer_reset(hyp_buffer->trace_buffer); + else + ring_buffer_reset_cpu(hyp_buffer->trace_buffer, cpu); + +out: + mutex_unlock(&hyp_buffer->lock); +} + +static int hyp_trace_open(struct inode *inode, struct file *file) +{ + int cpu = (s64)inode->i_private; + + if (file->f_mode & FMODE_WRITE) { + hyp_trace_reset(cpu); + + return 0; + } + + return -EPERM; +} + +static ssize_t hyp_trace_write(struct file *filp, const char __user *ubuf, + size_t count, loff_t *ppos) +{ + return count; +} + +static const struct file_operations hyp_trace_fops = { + .open = hyp_trace_open, + .write = hyp_trace_write, + .release = NULL, +}; + static int hyp_trace_clock_show(struct seq_file *m, void *v) { seq_puts(m, "[boot]\n"); @@ -852,6 +901,9 @@ int hyp_trace_init_tracefs(void) tracefs_create_file("trace_pipe", TRACEFS_MODE_WRITE, root, (void *)RING_BUFFER_ALL_CPUS, &hyp_trace_pipe_fops); + tracefs_create_file("trace", TRACEFS_MODE_WRITE, root, + (void *)RING_BUFFER_ALL_CPUS, &hyp_trace_fops); + tracefs_create_file("trace_clock", TRACEFS_MODE_READ, root, NULL, &hyp_trace_clock_fops); @@ -877,6 +929,9 @@ int hyp_trace_init_tracefs(void) tracefs_create_file("trace_pipe_raw", TRACEFS_MODE_READ, per_cpu_dir, (void *)cpu, &hyp_trace_pipe_fops); + + tracefs_create_file("trace", TRACEFS_MODE_READ, per_cpu_dir, + (void *)cpu, &hyp_trace_fops); } return 0; -- 2.46.0.598.g6f2099f65c-goog