nvidia-oot: add support for nvlog buffer

Using this patch we have done below changes :- - exposed buf_count, buf_size, region_size to userspace via sysfs node to read meta data related to nvlog buffers - mmap nvlog buffer to the userspace Bug 4985113 Change-Id: If5824f7199d63364847eecffd0f490213d2acda0 Signed-off-by: Manish Bhardwaj <mbhardwaj@nvidia.com> Reviewed-on: https://git-master.nvidia.com/r/c/linux-nv-oot/+/3268716 Reviewed-by: Suresh Venkatachalam <skathirampat@nvidia.com> GVS: buildbot_gerritrpt <buildbot_gerritrpt@nvidia.com> Reviewed-by: Sumeet Gupta <sumeetg@nvidia.com>
2025-12-24 02:01:36 +03:00 · 2024-12-06 17:42:41 +00:00
parent a2602b88b8
commit ed5b67aa73
2 changed files with 293 additions and 26 deletions
--- a/drivers/virt/tegra/hvc_sysfs.c
+++ b/drivers/virt/tegra/hvc_sysfs.c
@@ -1,18 +1,13 @@
 /*
- * SPDX-FileCopyrightText: Copyright (c) 2022-2024 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
- * SPDX-License-Identifier: GPL-2.0-only
+ * SPDX-FileCopyrightText: Copyright (c) 2022-2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+ * SPDX-License-Identifier: LicenseRef-NvidiaProprietary
 *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ * NVIDIA CORPORATION, its affiliates and licensors retain all intellectual
+ * property and proprietary rights in and to this material, related
+ * documentation and any modifications thereto. Any use, reproduction,
+ * disclosure or distribution of this material and related documentation
+ * without an express license agreement from NVIDIA CORPORATION or
+ * its affiliates is strictly prohibited.
 */

 #include <nvidia/conftest.h>
@@ -34,12 +29,27 @@

 /*
 * This file implements a hypervisor control driver that can be accessed
- * from user-space via the sysfs interface. Currently, the only supported
- * use case is retrieval of the HV trace log when it is available.
+ * from user-space via the sysfs interface. Currently, supported use case are
+ * retrieval of the HV trace log when it is available and mapping nvlog buffers
+ * to user space.
 */

 #define MAX_NAME_SIZE 50

+struct nvlog_shmem_info {
+	struct bin_attribute attr;
+	struct bin_attribute region_size_attr;
+	struct bin_attribute buf_size_attr;
+	struct bin_attribute buf_count_attr;
+	struct kobject *kobj;
+	char node_name[MAX_NAME_SIZE];
+	uint64_t ipa;
+	uint64_t region_size;
+	uint64_t buf_size;
+	uint64_t buf_count;
+};
+static struct nvlog_shmem_info nvlog_shmem_attrs[MAX_NVLOG_PRODUCERS];
+
 struct hyp_shared_memory_info {
 	char node_name[MAX_NAME_SIZE];
 	struct bin_attribute attr;
@@ -51,6 +61,181 @@ struct hyp_shared_memory_info {
 static struct hyp_shared_memory_info hyp_shared_memory_attrs[HYP_SHM_ID_NUM];


+/* Map the HV trace buffer to the calling user process */
+static int nvlog_buffer_mmap(struct file *fp, struct kobject *ko,
+	struct bin_attribute *attr, struct vm_area_struct *vma)
+{
+	struct nvlog_shmem_info *info = container_of(attr, struct nvlog_shmem_info, attr);
+
+	if ((info->ipa == 0) || (info->region_size == 0))
+		return -EINVAL;
+
+
+	if ((vma->vm_end - vma->vm_start) != attr->size)
+		return -EINVAL;
+
+	return remap_pfn_range(
+		vma, vma->vm_start,
+		info->ipa >> PAGE_SHIFT,
+		info->region_size, vma->vm_page_prot);
+}
+
+static ssize_t nvlog_region_size_read(struct file *fp, struct kobject *ko,
+	struct bin_attribute *attr, char *buf, loff_t pos, size_t size)
+{
+	struct nvlog_shmem_info *info = container_of(attr, struct nvlog_shmem_info, region_size_attr);
+
+	snprintf(buf, size, "%llu\n", info->region_size);
+	return size;
+}
+
+static ssize_t nvlog_buffer_size_read(struct file *fp, struct kobject *ko,
+	struct bin_attribute *attr, char *buf, loff_t pos, size_t size)
+{
+	struct nvlog_shmem_info *info = container_of(attr, struct nvlog_shmem_info, buf_size_attr);
+
+	snprintf(buf, size, "%llu\n", info->buf_size);
+	return size;
+}
+
+static ssize_t nvlog_buffer_count_read(struct file *fp, struct kobject *ko,
+	struct bin_attribute *attr, char *buf, loff_t pos, size_t size)
+{
+	struct nvlog_shmem_info *info = container_of(attr, struct nvlog_shmem_info, buf_count_attr);
+
+	snprintf(buf, size, "%llu\n", info->buf_count);
+	return size;
+}
+
+static int nvlog_create_sysfs_nodes(struct nvlog_shmem_info *info)
+{
+	int ret = 0;
+
+	if (info == NULL)
+		return -EINVAL;
+
+	sysfs_bin_attr_init((struct bin_attribute *)&info->attr);
+	info->attr.attr.name = info->node_name;
+	info->attr.attr.mode = 0600;
+	info->attr.size = info->region_size;
+	info->attr.mmap = nvlog_buffer_mmap;
+	ret = sysfs_create_bin_file(info->kobj, &info->attr);
+	if (ret != 0)
+		goto fail;
+
+	sysfs_bin_attr_init((struct bin_attribute *)&info->region_size_attr);
+	info->region_size_attr.attr.name = "region_size";
+	info->region_size_attr.attr.mode = 0444;
+	info->region_size_attr.size = 16u;
+	info->region_size_attr.read = nvlog_region_size_read;
+	ret = sysfs_create_bin_file(info->kobj, &info->region_size_attr);
+	if (ret != 0)
+		goto del_attr;
+
+	sysfs_bin_attr_init((struct bin_attribute *)&info->buf_size_attr);
+	info->buf_size_attr.attr.name = "buf_size";
+	info->buf_size_attr.attr.mode = 0444;
+	info->buf_size_attr.size = 16u;
+	info->buf_size_attr.read = nvlog_buffer_size_read;
+	ret = sysfs_create_bin_file(info->kobj, &info->buf_size_attr);
+	if (ret != 0)
+		goto del_region_size;
+
+	sysfs_bin_attr_init((struct bin_attribute *)&info->buf_count_attr);
+	info->buf_count_attr.attr.name = "buf_count";
+	info->buf_count_attr.attr.mode = 0444;
+	info->buf_count_attr.size = 16u;
+	info->buf_count_attr.read = nvlog_buffer_count_read;
+	ret = sysfs_create_bin_file(info->kobj, &info->buf_count_attr);
+	if (ret != 0)
+		goto del_buf_size;
+
+	return 0;
+
+del_buf_size:
+	sysfs_remove_bin_file(info->kobj, &info->buf_size_attr);
+del_region_size:
+	sysfs_remove_bin_file(info->kobj, &info->region_size_attr);
+del_attr:
+	sysfs_remove_bin_file(info->kobj, &info->attr);
+fail:
+	return ret;
+}
+
+static int hyp_nvlog_buffer_init(void)
+{
+	struct vm_info_region *info;
+	struct kobject *parent;
+	uint64_t ipa, cntr;
+	char dir_name[MAX_NAME_SIZE];
+	int ret;
+
+	parent = kobject_create_and_add("nvlog", NULL);
+	if (parent == NULL) {
+		TEGRA_HV_INFO("failed to add kobject\n");
+		return -ENOMEM;
+	}
+
+	if (hyp_read_vm_info(&ipa) != 0) {
+		ret = -EINVAL;
+		goto fail;
+	}
+
+	info = (__force struct vm_info_region *)ioremap(ipa, sizeof(*info));
+	if (info == NULL) {
+		ret = -EFAULT;
+		goto fail;
+	}
+
+	for (cntr = 0; cntr < MAX_NVLOG_PRODUCERS; cntr++) {
+		if (info->nvlog_producers[cntr].ipa != 0U
+					&& info->nvlog_producers[cntr].region_size != 0U) {
+			nvlog_shmem_attrs[cntr].ipa = info->nvlog_producers[cntr].ipa;
+			nvlog_shmem_attrs[cntr].region_size = info->nvlog_producers[cntr].region_size;
+			nvlog_shmem_attrs[cntr].buf_size = info->nvlog_producers[cntr].buf_size;
+			nvlog_shmem_attrs[cntr].buf_count = info->nvlog_producers[cntr].buf_count;
+
+			ret = snprintf(nvlog_shmem_attrs[cntr].node_name, MAX_NAME_SIZE, "%s",
+								info->nvlog_producers[cntr].name);
+			if (ret > 0U) {
+				nvlog_shmem_attrs[cntr].node_name[ret] = '\0';
+			} else {
+				TEGRA_HV_INFO("snprintf failure - %s\n",
+							info->nvlog_producers[cntr].name);
+				iounmap((void __iomem *)info);
+				ret = -EFAULT;
+				goto fail;
+			}
+
+			strncpy(dir_name, nvlog_shmem_attrs[cntr].node_name, MAX_NAME_SIZE);
+			strncat(dir_name, "_dir", 4);
+			nvlog_shmem_attrs[cntr].kobj = kobject_create_and_add(dir_name, parent);
+			if (nvlog_shmem_attrs[cntr].kobj == NULL) {
+				TEGRA_HV_INFO("failed to add kobject\n");
+				ret = -ENOMEM;
+				goto fail;
+			}
+
+			ret = nvlog_create_sysfs_nodes(&nvlog_shmem_attrs[cntr]);
+			if (ret != 0)
+				goto fail;
+		}
+	}
+
+	iounmap((void __iomem *)info);
+	return 0;
+
+fail:
+	for (cntr = 0; cntr < MAX_NVLOG_PRODUCERS; cntr++) {
+		if (nvlog_shmem_attrs[cntr].kobj)
+			kobject_del(nvlog_shmem_attrs[cntr].kobj);
+	}
+
+	if (parent)
+		kobject_del(parent);
+
+	return ret;
+}

 /* Map the HV trace buffer to the calling user process */
 static int hvc_sysfs_mmap(struct file *fp, struct kobject *ko,
@@ -128,8 +313,7 @@ static int create_log_mask_node(struct kobject *kobj)
 	return sysfs_create_bin_file(kobj, &log_mask_attr);
 }

-/* Set up all relevant hypervisor control nodes */
-static int __init hvc_sysfs_register(void)
+static int hyp_trace_buffer_init(void)
 {
 	struct kobject *kobj;
 	int ret;
@@ -139,13 +323,6 @@ static int __init hvc_sysfs_register(void)
 	struct trace_buf *buffs;
 	uint16_t i, count;

-	if (is_tegra_hypervisor_mode() == false) {
-		TEGRA_HV_INFO("hypervisor is not present\n");
-		/*retunring success in case of native kernel otherwise
-		  systemd-modules-load service will failed.*/
-		return 0;
-	}
-
 	kobj = kobject_create_and_add("hvc", NULL);
 	if (kobj == NULL) {
 		TEGRA_HV_INFO("failed to add kobject\n");
@@ -233,6 +410,34 @@ fail:
 	return ret;
 }

+/* Set up all relevant hypervisor control nodes */
+static int __init hvc_sysfs_register(void)
+{
+	int ret;
+
+	if (is_tegra_hypervisor_mode() == false) {
+		TEGRA_HV_INFO("hypervisor is not present\n");
+		/* retunring success in case of native kernel otherwise
+		 * systemd-modules-load service will failed.
+		 */
+		return 0;
+	}
+
+	ret = hyp_trace_buffer_init();
+	if (ret != 0)
+		TEGRA_HV_ERR("Error: Hypervisor trace buffer init failed\n");
+	else
+		TEGRA_HV_INFO("Hypervisor trace buffer initialized successfully\n");
+
+	ret = hyp_nvlog_buffer_init();
+	if (ret != 0)
+		TEGRA_HV_ERR("Error: Hypervisor nvlog buffer init failed\n");
+	else
+		TEGRA_HV_INFO("Hypervisor nvlog buffer initialized successfully\n");
+
+	return 0;
+}
+
 late_initcall(hvc_sysfs_register);

 MODULE_LICENSE("GPL");
--- a/include/soc/tegra/virt/syscalls.h
+++ b/include/soc/tegra/virt/syscalls.h
@@ -1,6 +1,13 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
 /*
- * Copyright (c) 2022, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+ * SPDX-FileCopyrightText: Copyright (c) 2022-2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+ * SPDX-License-Identifier: LicenseRef-NvidiaProprietary
+ *
+ * NVIDIA CORPORATION, its affiliates and licensors retain all intellectual
+ * property and proprietary rights in and to this material, related
+ * documentation and any modifications thereto. Any use, reproduction,
+ * disclosure or distribution of this material and related documentation
+ * without an express license agreement from NVIDIA CORPORATION or
+ * its affiliates is strictly prohibited.
 */

 #ifndef __TEGRA_SYSCALLS_H__
@@ -18,11 +25,13 @@
 #define HVC_NR_READ_HYP_INFO		9
 #define HVC_NR_GUEST_RESET		10
 #define HVC_NR_SYSINFO_IPA		13
+#define HVC_NR_READ_VM_INFO		16
 #define HVC_NR_TRACE_GET_EVENT_MASK		0x8003U
 #define HVC_NR_TRACE_SET_EVENT_MASK		0x8004U

 #define GUEST_PRIMARY		0
 #define GUEST_IVC_SERVER	0
+#define MAX_NVLOG_PRODUCERS	32U
 #define HVC_NR_CPU_FREQ		0xC6000022

 #define NGUESTS_MAX 16
@@ -33,6 +42,45 @@
 #include <linux/types.h>
 #endif

+/*
+ * @brief Structure describing a single NvLog producer. A producer can have
+ * multiple buffers (if it has multiple threads) and the buffers are stored
+ * contiguously in memory as an array. This structure provides the base
+ * address, stride, and length of the array so that the consumer can locate all
+ * of the buffers belonging to the producer.
+ */
+struct nvlog_producer {
+	/* Base IPA of an array of NvLog buffers belonging to the producer. */
+	uint64_t ipa;
+	/* Size of the IPA region containing the NvLog buffer array. */
+	uint64_t region_size;
+	/* Size of a single NvLog buffer. This is the stride of the array of
+	 * NvLog buffers belonging to the producer.
+	 */
+	uint64_t buf_size;
+	/* Number of NvLog buffers belonging to the producer. */
+	uint64_t buf_count;
+	/* Name of the NvLog producer. */
+	char name[32];
+};
+
+/*
+ * Data structure for the VM Information Region.
+ *
+ * The Intermediate Physical Address (IPA) of this structure is returned by the
+ * hyp_read_vm_info Hypercall.
+ */
+struct vm_info_region {
+	/*
+	 * Table of NvLog producers.
+	 *
+	 * This table is only populated for VMs that have the 'log_access' PCT flag
+	 * set. Valid entries in the table have non-zero 'region_ipa', 'buf_size',
+	 * and buf_count' fields.
+	 */
+	struct nvlog_producer nvlog_producers[MAX_NVLOG_PRODUCERS];
+};
+
 struct tegra_hv_queue_data {
 	uint32_t	id;	/* IVC id */
 	uint32_t	peers[2];
@@ -212,6 +260,20 @@ __attribute__((no_sanitize_address)) static inline int hyp_read_nguests(unsigned
 	return (int)r0;
 }

+__attribute__((no_sanitize_address)) static inline int hyp_read_vm_info(uint64_t *vm_info_region_pa)
+{
+	register uint64_t r0 asm("x0");
+	register uint64_t r1 asm("x1");
+
+	asm("hvc %2"
+		: "=r"(r0), "=r"(r1)
+		: "i"(HVC_NR_READ_VM_INFO)
+		: "x2", "x3", _X4_X17);
+
+	*vm_info_region_pa = r1;
+	return (int)r0;
+}
+
 __attribute__((no_sanitize_address)) static inline int hyp_read_ivc_info(uint64_t *ivc_info_page_pa)
 {
 	register uint64_t r0 asm("x0");