From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yw1-f202.google.com (mail-yw1-f202.google.com [209.85.128.202]) (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 2D0E1186E4F for ; Wed, 11 Sep 2024 09:31:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726047070; cv=none; b=STRYCnnf0oSyln8cD6Fdx0CAf+BB3imP2CLmNTwzBgdMu3m23tl1+KApOQI8Q4yfHOd07BXDzzMuskxF7WUxR6EpywOnFfotfBMs61lkCjF2OddC/FaXqnPYyoAFY5j7/+CTofzQmE3SR9uxt8J6tu+/DXS7iye6dfBVdfJUBb8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726047070; c=relaxed/simple; bh=+C1Mr6Eih+8GBOgaIA5ob9ph+NaEjJpwr6bdsWTV2h4=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=kztnGNsqrpKpbKQvQZLyXX3sKaOsb9cEz5Q5PRf6tubPPr/+qaiBb676SEcN2u0ruqmigv6XaIabPO82BYaK8cs5Sku8XcPHNrK3q9UbbNnbU9RFaVGrwGTcoA7cvZJTqbocb51bpikCZfR2qbR76Q/Ix4qiZBzPr2ioUV7Zt+U= 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=BZFix/St; arc=none smtp.client-ip=209.85.128.202 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="BZFix/St" Received: by mail-yw1-f202.google.com with SMTP id 00721157ae682-6db7a8c6910so91474367b3.0 for ; Wed, 11 Sep 2024 02:31:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1726047068; x=1726651868; 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=hy3Znb+Dwqyrq2cJ7HorL7uStGBaHWkuWbAR2JZBqCQ=; b=BZFix/StczZ+mqXR7qg4uGAIGMtXggP7tvbfacMoysy7JL70hlV1oC85ur6ov8le3U vE1SAUxOci9gU9taYjXkW8AmI96XyKfToI2jNIKxPrhQJ4HprDuYjLVD1sEKWz5QrwK5 YkqVLXTWBS137GDl971S7SMgi3ETVQmraAe3ansaWgjYQVSQNqwGx5nOi9N5JdaUMtvo 96n0+OnJmkKS+LLcr5ocfHBkEReE1exe+ODueI7CGSv+if4aPyfAj5GciU977H0/lKxb bs0nbrVgH1UwbrdnEmKCwrZuVhCmbb5k+M0EpXQouG7RJV/D4Yw+IZTmNfZoRk42q087 1kcA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1726047068; x=1726651868; 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=hy3Znb+Dwqyrq2cJ7HorL7uStGBaHWkuWbAR2JZBqCQ=; b=Ps02EX5Gtw4qCi/5R1l9BKSXpERxqqVlWCOltws0QrIjN/MTK42G1D0bP24VqzvsYp 5VDbSY5YFIrHMQAPeIv2ObPypl34W8I68ksGsyjDN2aD59Ubm2E2mF9nECb9lz1+hfag CgECJOQG7OpGkgXNL0i8QBT/1WsNg+3xIhVmR8PPjzJyMq65BIp+J7Xmk13sYTfBpSaa iyGkV5+MTBh5lB5o/IQrtxBah7m2qHehGrNXIE61NXGSVSQv93sPSbiyXqgEJzJHK3Dz gG/fBszACdIkGxFUuq4KxavPwwwRGxyQRqMiRYuiaLdm9i0FQUf8stNYESlzsOSNNw31 OyXg== X-Gm-Message-State: AOJu0Yyggx2K3H7q7giDQsI5mRZ6unKWQrdQfVbypsnNBmIZCG4eETv2 1hk4Q03Iiuncdy5wDosO6/zGJ5ZzfXXr4Xivxxtgpi7GlgliEN98UNAK+AWxlTDuW6YmAkBKc4j S0QcEnS92Um2BYfMq0A== X-Google-Smtp-Source: AGHT+IFSAGx//hRZK4AAM97oklvEIfq79G7ievWf/yDgvOrEXJqZ7cy+6snJMt8gT5Wm1/gNBfGcYxIfKSWjx/Ue X-Received: from vdonnefort.c.googlers.com ([fda3:e722:ac3:cc00:28:9cb1:c0a8:2eea]) (user=vdonnefort job=sendgmr) by 2002:a05:690c:2f89:b0:6be:9d4a:f097 with SMTP id 00721157ae682-6db452739d0mr2138547b3.7.1726047068233; Wed, 11 Sep 2024 02:31:08 -0700 (PDT) Date: Wed, 11 Sep 2024 10:30:26 +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: <20240911093029.3279154-11-vdonnefort@google.com> Subject: [PATCH 10/13] KVM: arm64: Add raw 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 raw interface enables userspace tools such as trace-cmd to directly read the ring-buffer without any decoding by the kernel. Signed-off-by: Vincent Donnefort diff --git a/arch/arm64/kvm/hyp_trace.c b/arch/arm64/kvm/hyp_trace.c index 1720daeda8ae..0d0e5eada816 100644 --- a/arch/arm64/kvm/hyp_trace.c +++ b/arch/arm64/kvm/hyp_trace.c @@ -740,6 +740,86 @@ static const struct file_operations hyp_trace_pipe_fops = { .llseek = no_llseek, }; +static ssize_t +hyp_trace_raw_read(struct file *file, char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + struct ht_iterator *iter = (struct ht_iterator *)file->private_data; + size_t size; + int ret; + + if (iter->copy_leftover) + goto read; + +again: + ret = ring_buffer_read_page(iter->trace_buffer, + (struct buffer_data_read_page *)iter->spare, + cnt, iter->cpu, 0); + if (ret < 0) { + if (!ring_buffer_empty_cpu(iter->trace_buffer, iter->cpu)) + return 0; + + ret = ring_buffer_wait(iter->trace_buffer, iter->cpu, 0, NULL, + NULL); + if (ret < 0) + return ret; + + goto again; + } + + iter->copy_leftover = 0; + +read: + size = PAGE_SIZE - iter->copy_leftover; + if (size > cnt) + size = cnt; + + ret = copy_to_user(ubuf, iter->spare + PAGE_SIZE - size, size); + if (ret == size) + return -EFAULT; + + size -= ret; + *ppos += size; + iter->copy_leftover = ret; + + return size; +} + +static int hyp_trace_raw_open(struct inode *inode, struct file *file) +{ + int ret = hyp_trace_pipe_open(inode, file); + struct ht_iterator *iter; + + if (ret) + return ret; + + iter = file->private_data; + iter->spare = ring_buffer_alloc_read_page(iter->trace_buffer, iter->cpu); + if (IS_ERR(iter->spare)) { + ret = PTR_ERR(iter->spare); + iter->spare = NULL; + return ret; + } + + return 0; +} + +static int hyp_trace_raw_release(struct inode *inode, struct file *file) +{ + struct ht_iterator *iter = file->private_data; + + ring_buffer_free_read_page(iter->trace_buffer, iter->cpu, iter->spare); + + return hyp_trace_pipe_release(inode, file); +} + +static const struct file_operations hyp_trace_raw_fops = { + .open = hyp_trace_raw_open, + .read = hyp_trace_raw_read, + .release = hyp_trace_raw_release, + .llseek = no_llseek, +}; + static int hyp_trace_clock_show(struct seq_file *m, void *v) { seq_puts(m, "[boot]\n"); @@ -794,6 +874,9 @@ int hyp_trace_init_tracefs(void) tracefs_create_file("trace_pipe", TRACEFS_MODE_READ, per_cpu_dir, (void *)cpu, &hyp_trace_pipe_fops); + + tracefs_create_file("trace_pipe_raw", TRACEFS_MODE_READ, per_cpu_dir, + (void *)cpu, &hyp_trace_pipe_fops); } return 0; -- 2.46.0.598.g6f2099f65c-goog