From patchwork Mon Aug 1 21:12:40 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Elliot Berman X-Patchwork-Id: 594738 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 F069EC25B0E for ; Mon, 1 Aug 2022 21:14:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234307AbiHAVOG (ORCPT ); Mon, 1 Aug 2022 17:14:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41080 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235103AbiHAVOE (ORCPT ); Mon, 1 Aug 2022 17:14:04 -0400 Received: from alexa-out-sd-01.qualcomm.com (alexa-out-sd-01.qualcomm.com [199.106.114.38]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 896C83F316; Mon, 1 Aug 2022 14:14:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; i=@quicinc.com; q=dns/txt; s=qcdkim; t=1659388442; x=1690924442; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=apoLqHIFfY6O5tPy1Y3FUD9tFxQUIrkjkeX6NZD7iW0=; b=fix7eFEmC36R9fcCJMh3EHWCHM8TGWtj86ycuB3aFwlsyMjidwhfshH9 7ldcrha8av8Iz8h6R9PwrM+G9LGJcc/yHQdN/IrJw33hxaKtzEdZ3HO1I EUCHinlCc9/uUlsM59hA5+vxbXjEtt7NAnyInwarrPTZqanz01ddmvktv Q=; Received: from unknown (HELO ironmsg03-sd.qualcomm.com) ([10.53.140.143]) by alexa-out-sd-01.qualcomm.com with ESMTP; 01 Aug 2022 14:14:02 -0700 X-QCInternal: smtphost Received: from nasanex01b.na.qualcomm.com ([10.46.141.250]) by ironmsg03-sd.qualcomm.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Aug 2022 14:14:02 -0700 Received: from hu-eberman-lv.qualcomm.com (10.49.16.6) by nasanex01b.na.qualcomm.com (10.46.141.250) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.22; Mon, 1 Aug 2022 14:14:01 -0700 From: Elliot Berman To: Bjorn Andersson CC: Elliot Berman , Murali Nalajala , Trilok Soni , "Srivatsa Vaddagiri" , Carl van Schaik , Andy Gross , , Lorenzo Pieralisi , Sudeep Holla , "Marc Zyngier" , Rob Herring , "Krzysztof Kozlowski" , Jonathan Corbet , Will Deacon , Catalin Marinas , , , Subject: [PATCH v2 11/11] gunyah: Add tty console driver for RM Console Serivces Date: Mon, 1 Aug 2022 14:12:40 -0700 Message-ID: <20220801211240.597859-12-quic_eberman@quicinc.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220801211240.597859-1-quic_eberman@quicinc.com> References: <20220801211240.597859-1-quic_eberman@quicinc.com> MIME-Version: 1.0 X-Originating-IP: [10.49.16.6] X-ClientProxiedBy: nalasex01c.na.qualcomm.com (10.47.97.35) To nasanex01b.na.qualcomm.com (10.46.141.250) Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Gunyah provides a console for each VM using the VM console resource manager APIs. This driver allows console data from other VMs to be accessed via a TTY device and exports a console device to dump Linux's own logs to our console. Signed-off-by: Elliot Berman --- Documentation/virt/gunyah/index.rst | 7 + drivers/virt/gunyah/Kconfig | 10 + drivers/virt/gunyah/Makefile | 3 + drivers/virt/gunyah/rsc_mgr_console.c | 405 ++++++++++++++++++++++++++ 4 files changed, 425 insertions(+) create mode 100644 drivers/virt/gunyah/rsc_mgr_console.c diff --git a/Documentation/virt/gunyah/index.rst b/Documentation/virt/gunyah/index.rst index e7bb2b14543e..95ba9b71ab30 100644 --- a/Documentation/virt/gunyah/index.rst +++ b/Documentation/virt/gunyah/index.rst @@ -90,3 +90,10 @@ When booting a virtual machine which uses a devicetree, resource manager overlay how to communicate with resource manager, and basic description and capabilities of this VM. See Documentation/devicetree/bindings/gunyah/qcom,hypervisor.yml for a description of this node. + +Resource Manager Consoles +------------------------- +RM provides infrastructure for virtual machines to share an interactive console. This can be used to +interact with a VM which may not have access to a serial port. Linux will register a printk console: +ttyGH0. That console and other VM's consoles can be accessed via ttyGHX. +/sys/class/tty/ttyGHX/vmid will print the VM which is associated with that TTY. diff --git a/drivers/virt/gunyah/Kconfig b/drivers/virt/gunyah/Kconfig index 0adb6efd4848..ba7bd058e959 100644 --- a/drivers/virt/gunyah/Kconfig +++ b/drivers/virt/gunyah/Kconfig @@ -12,3 +12,13 @@ config GUNYAH Say Y here to enable the drivers needed to interact in a Gunyah virtual environment. + +if GUNYAH +config GUNYAH_RESOURCE_MANAGER_CONSOLE + tristate "Gunyah Resource Manager Consoles" + depends on TTY + help + This enables support for console output using Gunyah's Resource Manager RPC. + This is normally used when a secondary VM which does not have exclusive access + to a real serial device and virtio-console is unavailable. +endif diff --git a/drivers/virt/gunyah/Makefile b/drivers/virt/gunyah/Makefile index b3f15c052297..001cf1630c03 100644 --- a/drivers/virt/gunyah/Makefile +++ b/drivers/virt/gunyah/Makefile @@ -3,3 +3,6 @@ gunyah-y += sysfs.o device.o msgq.o gunyah-y += rsc_mgr.o rsc_mgr_rpc.o obj-$(CONFIG_GUNYAH) += gunyah.o + +gunyah_console-y += rsc_mgr_console.o +obj-$(CONFIG_GUNYAH_RESOURCE_MANAGER_CONSOLE) += gunyah_console.o diff --git a/drivers/virt/gunyah/rsc_mgr_console.c b/drivers/virt/gunyah/rsc_mgr_console.c new file mode 100644 index 000000000000..eda25100314f --- /dev/null +++ b/drivers/virt/gunyah/rsc_mgr_console.c @@ -0,0 +1,405 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved. + */ + +#define pr_fmt(fmt) "gh_rsc_mgr_console: " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * The Linux TTY code does not support dynamic addition of tty derived devices so we need to know + * how many tty devices we might need when space is allocated for the tty device. Since VMs might be + * added/removed dynamically, we need to make sure we have enough allocated. + */ +#define RSC_MGR_TTY_ADAPTERS 16 + +/* # of payload bytes that can fit in a 1-fragment CONSOLE_WRITE message */ +#define RM_CONS_WRITE_MSG_SIZE ((1 * (GH_MSGQ_MAX_MSG_SIZE - 8)) - 4) + +struct rm_cons_port { + struct tty_port port; + gh_vmid_t vmid; + bool open; + unsigned int index; + + DECLARE_KFIFO(put_fifo, char, 1024); + spinlock_t fifo_lock; + struct work_struct put_work; + + struct rm_cons_data *cons_data; +}; + +struct rm_cons_data { + struct tty_driver *tty_driver; + struct device *dev; + + spinlock_t ports_lock; + struct rm_cons_port *ports[RSC_MGR_TTY_ADAPTERS]; + + struct notifier_block rsc_mgr_notif; + struct console console; +}; + +static void put_work_fn(struct work_struct *ws) +{ + char buf[RM_CONS_WRITE_MSG_SIZE]; + int count, ret; + struct rm_cons_port *port = container_of(ws, struct rm_cons_port, put_work); + + while (!kfifo_is_empty(&port->put_fifo)) { + count = kfifo_out_spinlocked(&port->put_fifo, buf, sizeof(buf), &port->fifo_lock); + if (count <= 0) + continue; + + ret = gh_rm_console_write(port->vmid, buf, count); + if (ret) { + pr_warn_once("failed to send characters: %d\n", ret); + break; + } + } +} + +static int rsc_mgr_console_notif(struct notifier_block *nb, unsigned long cmd, void *data) +{ + int count, i; + struct rm_cons_port *rm_port; + struct tty_port *tty_port = NULL; + struct rm_cons_data *cons_data = container_of(nb, struct rm_cons_data, rsc_mgr_notif); + const struct gh_rm_notification *notif = data; + struct gh_rm_notif_vm_console_chars const * const msg = notif->buff; + + if (cmd != GH_RM_NOTIF_VM_CONSOLE_CHARS || + notif->size < sizeof(*msg)) + return NOTIFY_DONE; + + spin_lock(&cons_data->ports_lock); + for (i = 0; i < RSC_MGR_TTY_ADAPTERS; i++) { + if (!cons_data->ports[i]) + continue; + if (cons_data->ports[i]->vmid == msg->vmid) { + rm_port = cons_data->ports[i]; + break; + } + } + if (rm_port) + tty_port = tty_port_get(&rm_port->port); + spin_unlock(&cons_data->ports_lock); + + if (!rm_port) + pr_warn("Received unexpected console characters for VMID %u\n", msg->vmid); + if (!tty_port) + return NOTIFY_DONE; + + count = tty_buffer_request_room(tty_port, msg->num_bytes); + tty_insert_flip_string(tty_port, msg->bytes, count); + tty_flip_buffer_push(tty_port); + + tty_port_put(tty_port); + return NOTIFY_OK; +} + +static ssize_t vmid_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct rm_cons_port *rm_port = dev_get_drvdata(dev); + + if (rm_port->vmid == GH_VMID_SELF) + return sysfs_emit(buf, "self\n"); + + return sysfs_emit(buf, "%u\n", rm_port->vmid); +} + +static DEVICE_ATTR_RO(vmid); + +static struct attribute *rsc_mgr_tty_dev_attrs[] = { + &dev_attr_vmid.attr, + NULL +}; + +static const struct attribute_group rsc_mgr_tty_dev_attr_group = { + .attrs = rsc_mgr_tty_dev_attrs, +}; + +static const struct attribute_group *rsc_mgr_tty_dev_attr_groups[] = { + &rsc_mgr_tty_dev_attr_group, + NULL +}; + +static int rsc_mgr_tty_open(struct tty_struct *tty, struct file *filp) +{ + int ret; + struct rm_cons_port *rm_port = dev_get_drvdata(tty->dev); + + if (!rm_port->open) { + ret = gh_rm_console_open(rm_port->vmid); + if (ret) { + pr_err("Failed to open RM console for vmid %x: %d\n", rm_port->vmid, ret); + return ret; + } + rm_port->open = true; + } + + return tty_port_open(&rm_port->port, tty, filp); +} + +static void rsc_mgr_tty_close(struct tty_struct *tty, struct file *filp) +{ + int ret; + struct rm_cons_port *rm_port = dev_get_drvdata(tty->dev); + + if (rm_port->open) { + if (rm_port->vmid != GH_VMID_SELF) { + ret = gh_rm_console_close(rm_port->vmid); + if (ret) + pr_warn("Failed to close RM console for vmid %d: %d\n", + rm_port->vmid, ret); + } + rm_port->open = false; + + tty_port_close(&rm_port->port, tty, filp); + } + +} + +static int rsc_mgr_tty_write(struct tty_struct *tty, const unsigned char *buf, int count) +{ + struct rm_cons_port *rm_port = dev_get_drvdata(tty->dev); + int ret; + + ret = kfifo_in_spinlocked(&rm_port->put_fifo, buf, count, &rm_port->fifo_lock); + if (ret > 0) + schedule_work(&rm_port->put_work); + + return ret; +} + +static unsigned int rsc_mgr_mgr_tty_write_room(struct tty_struct *tty) +{ + struct rm_cons_port *rm_port = dev_get_drvdata(tty->dev); + + return kfifo_avail(&rm_port->put_fifo); +} + +static void rsc_mgr_console_write(struct console *co, const char *buf, unsigned count) +{ + struct rm_cons_port *rm_port = co->data; + int ret; + + ret = kfifo_in_spinlocked(&rm_port->put_fifo, buf, count, &rm_port->fifo_lock); + if (ret > 0) + schedule_work(&rm_port->put_work); +} + +static struct tty_driver *rsc_mgr_console_device(struct console *co, int *index) +{ + struct rm_cons_port *rm_port = co->data; + + *index = rm_port->index; + return rm_port->port.tty->driver; +} + +static int rsc_mgr_console_setup(struct console *co, char *unused) +{ + int ret; + struct rm_cons_port *rm_port = co->data; + + if (!rm_port->open) { + ret = gh_rm_console_open(rm_port->vmid); + if (ret) { + pr_err("Failed to open RM console for vmid %x: %d\n", rm_port->vmid, ret); + return ret; + } + rm_port->open = true; + } + + return 0; +} + +static int rsc_mgr_console_exit(struct console *co) +{ + int ret; + struct rm_cons_port *rm_port = co->data; + + if (rm_port->open) { + ret = gh_rm_console_close(rm_port->vmid); + if (ret) { + pr_err("Failed to close RM console for vmid %x: %d\n", rm_port->vmid, ret); + return ret; + } + rm_port->open = false; + } + + return 0; +} + +static const struct tty_operations rsc_mgr_tty_ops = { + .open = rsc_mgr_tty_open, + .close = rsc_mgr_tty_close, + .write = rsc_mgr_tty_write, + .write_room = rsc_mgr_mgr_tty_write_room, +}; + +static void rsc_mgr_port_destruct(struct tty_port *port) +{ + struct rm_cons_port *rm_port = container_of(port, struct rm_cons_port, port); + struct rm_cons_data *cons_data = rm_port->cons_data; + + spin_lock(&cons_data->ports_lock); + WARN_ON(cons_data->ports[rm_port->index] != rm_port); + cons_data->ports[rm_port->index] = NULL; + spin_unlock(&cons_data->ports_lock); + kfree(rm_port); +} + +static const struct tty_port_operations rsc_mgr_port_ops = { + .destruct = rsc_mgr_port_destruct, +}; + +static struct rm_cons_port *rsc_mgr_port_create(struct rm_cons_data *cons_data, gh_vmid_t vmid) +{ + struct rm_cons_port *rm_port; + struct device *ttydev; + unsigned int index; + int ret; + + rm_port = kzalloc(sizeof(*rm_port), GFP_KERNEL); + rm_port->vmid = vmid; + INIT_KFIFO(rm_port->put_fifo); + spin_lock_init(&rm_port->fifo_lock); + INIT_WORK(&rm_port->put_work, put_work_fn); + tty_port_init(&rm_port->port); + rm_port->port.ops = &rsc_mgr_port_ops; + + spin_lock(&cons_data->ports_lock); + for (index = 0; index < RSC_MGR_TTY_ADAPTERS; index++) { + if (!cons_data->ports[index]) { + cons_data->ports[index] = rm_port; + rm_port->index = index; + break; + } + } + spin_unlock(&cons_data->ports_lock); + if (index >= RSC_MGR_TTY_ADAPTERS) { + ret = -ENOSPC; + goto err_put_port; + } + + ttydev = tty_port_register_device_attr(&rm_port->port, cons_data->tty_driver, index, + cons_data->dev, rm_port, rsc_mgr_tty_dev_attr_groups); + if (IS_ERR(ttydev)) { + ret = PTR_ERR(ttydev); + goto err_put_port; + } + + return rm_port; +err_put_port: + tty_port_put(&rm_port->port); + return ERR_PTR(ret); +} + +static int rsc_mgr_console_probe(struct auxiliary_device *auxdev, + const struct auxiliary_device_id *aux_dev_id) +{ + struct rm_cons_data *cons_data; + struct rm_cons_port *rm_port; + int ret; + gh_vmid_t vmid; + + cons_data = devm_kzalloc(&auxdev->dev, sizeof(*cons_data), GFP_KERNEL); + if (!cons_data) + return -ENOMEM; + dev_set_drvdata(&auxdev->dev, cons_data); + cons_data->dev = &auxdev->dev; + + cons_data->tty_driver = tty_alloc_driver(RSC_MGR_TTY_ADAPTERS, + TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV); + if (IS_ERR(cons_data->tty_driver)) + return PTR_ERR(cons_data->tty_driver); + + cons_data->tty_driver->driver_name = "gh"; + cons_data->tty_driver->name = "ttyGH"; + cons_data->tty_driver->type = TTY_DRIVER_TYPE_SYSTEM; + cons_data->tty_driver->init_termios = tty_std_termios; + tty_set_operations(cons_data->tty_driver, &rsc_mgr_tty_ops); + + ret = tty_register_driver(cons_data->tty_driver); + if (ret) { + dev_err(&auxdev->dev, "Could not register tty driver: %d\n", ret); + goto err_put_tty; + } + + spin_lock_init(&cons_data->ports_lock); + + cons_data->rsc_mgr_notif.notifier_call = rsc_mgr_console_notif; + ret = gh_rm_register_notifier(&cons_data->rsc_mgr_notif); + if (ret) { + dev_err(&auxdev->dev, "Could not register for resource manager notifications: %d\n", + ret); + goto err_put_tty; + } + + rm_port = rsc_mgr_port_create(cons_data, GH_VMID_SELF); + if (IS_ERR(rm_port)) { + ret = PTR_ERR(rm_port); + dev_err(&auxdev->dev, "Could not create own console: %d\n", ret); + goto err_unreg_notif; + } + + strncpy(cons_data->console.name, "ttyGH", sizeof(cons_data->console.name)); + cons_data->console.write = rsc_mgr_console_write; + cons_data->console.device = rsc_mgr_console_device; + cons_data->console.setup = rsc_mgr_console_setup; + cons_data->console.exit = rsc_mgr_console_exit; + cons_data->console.index = rm_port->index; + cons_data->console.data = rm_port; + register_console(&cons_data->console); + + ret = gh_rm_get_vmid(&vmid); + if (!ret) + rsc_mgr_port_create(cons_data, vmid); + else + pr_warn("Failed to get this VM's VMID: %d. Not creating loop-back console\n", ret); + + return 0; +err_unreg_notif: + gh_rm_unregister_notifier(&cons_data->rsc_mgr_notif); +err_put_tty: + tty_driver_kref_put(cons_data->tty_driver); + return ret; +} + +static void rsc_mgr_console_remove(struct auxiliary_device *auxdev) +{ + struct rm_cons_data *cons_data = dev_get_drvdata(&auxdev->dev); + + unregister_console(&cons_data->console); + gh_rm_unregister_notifier(&cons_data->rsc_mgr_notif); + tty_driver_kref_put(cons_data->tty_driver); +} + +static struct auxiliary_device_id rsc_mgr_console_ids[] = { + { .name = "gunyah.console" }, + {} +}; +MODULE_DEVICE_TABLE(auxiliary, rsc_mgr_console_ids); + +static struct auxiliary_driver rsc_mgr_console_drv = { + .probe = rsc_mgr_console_probe, + .remove = rsc_mgr_console_remove, + .id_table = rsc_mgr_console_ids, +}; +module_auxiliary_driver(rsc_mgr_console_drv); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Gunyah Console");