root/drivers/virt/acrn/hsm.c
// SPDX-License-Identifier: GPL-2.0
/*
 * ACRN Hypervisor Service Module (HSM)
 *
 * Copyright (C) 2020 Intel Corporation. All rights reserved.
 *
 * Authors:
 *      Fengwei Yin <fengwei.yin@intel.com>
 *      Yakui Zhao <yakui.zhao@intel.com>
 */

#include <linux/cpu.h>
#include <linux/io.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/slab.h>

#include <asm/acrn.h>
#include <asm/hypervisor.h>

#include "acrn_drv.h"

/*
 * When /dev/acrn_hsm is opened, a 'struct acrn_vm' object is created to
 * represent a VM instance and continues to be associated with the opened file
 * descriptor. All ioctl operations on this file descriptor will be targeted to
 * the VM instance. Release of this file descriptor will destroy the object.
 */
static int acrn_dev_open(struct inode *inode, struct file *filp)
{
        struct acrn_vm *vm;

        vm = kzalloc_obj(*vm);
        if (!vm)
                return -ENOMEM;

        vm->vmid = ACRN_INVALID_VMID;
        filp->private_data = vm;
        return 0;
}

static int pmcmd_ioctl(u64 cmd, void __user *uptr)
{
        struct acrn_pstate_data *px_data;
        struct acrn_cstate_data *cx_data;
        u64 *pm_info;
        int ret = 0;

        switch (cmd & PMCMD_TYPE_MASK) {
        case ACRN_PMCMD_GET_PX_CNT:
        case ACRN_PMCMD_GET_CX_CNT:
                pm_info = kzalloc(sizeof(u64), GFP_KERNEL);
                if (!pm_info)
                        return -ENOMEM;

                ret = hcall_get_cpu_state(cmd, virt_to_phys(pm_info));
                if (ret < 0) {
                        kfree(pm_info);
                        break;
                }

                if (copy_to_user(uptr, pm_info, sizeof(u64)))
                        ret = -EFAULT;
                kfree(pm_info);
                break;
        case ACRN_PMCMD_GET_PX_DATA:
                px_data = kzalloc_obj(*px_data);
                if (!px_data)
                        return -ENOMEM;

                ret = hcall_get_cpu_state(cmd, virt_to_phys(px_data));
                if (ret < 0) {
                        kfree(px_data);
                        break;
                }

                if (copy_to_user(uptr, px_data, sizeof(*px_data)))
                        ret = -EFAULT;
                kfree(px_data);
                break;
        case ACRN_PMCMD_GET_CX_DATA:
                cx_data = kzalloc_obj(*cx_data);
                if (!cx_data)
                        return -ENOMEM;

                ret = hcall_get_cpu_state(cmd, virt_to_phys(cx_data));
                if (ret < 0) {
                        kfree(cx_data);
                        break;
                }

                if (copy_to_user(uptr, cx_data, sizeof(*cx_data)))
                        ret = -EFAULT;
                kfree(cx_data);
                break;
        default:
                break;
        }

        return ret;
}

/*
 * HSM relies on hypercall layer of the ACRN hypervisor to do the
 * sanity check against the input parameters.
 */
static long acrn_dev_ioctl(struct file *filp, unsigned int cmd,
                           unsigned long ioctl_param)
{
        struct acrn_vm *vm = filp->private_data;
        struct acrn_vm_creation *vm_param;
        struct acrn_vcpu_regs *cpu_regs;
        struct acrn_ioreq_notify notify;
        struct acrn_ptdev_irq *irq_info;
        struct acrn_ioeventfd ioeventfd;
        struct acrn_vm_memmap memmap;
        struct acrn_mmiodev *mmiodev;
        struct acrn_msi_entry *msi;
        struct acrn_pcidev *pcidev;
        struct acrn_irqfd irqfd;
        struct acrn_vdev *vdev;
        struct page *page;
        u64 cstate_cmd;
        int i, ret = 0;

        if (vm->vmid == ACRN_INVALID_VMID && cmd != ACRN_IOCTL_CREATE_VM) {
                dev_dbg(acrn_dev.this_device,
                        "ioctl 0x%x: Invalid VM state!\n", cmd);
                return -EINVAL;
        }

        switch (cmd) {
        case ACRN_IOCTL_CREATE_VM:
                vm_param = memdup_user((void __user *)ioctl_param,
                                       sizeof(struct acrn_vm_creation));
                if (IS_ERR(vm_param))
                        return PTR_ERR(vm_param);

                if ((vm_param->reserved0 | vm_param->reserved1) != 0) {
                        kfree(vm_param);
                        return -EINVAL;
                }

                vm = acrn_vm_create(vm, vm_param);
                if (!vm) {
                        ret = -EINVAL;
                        kfree(vm_param);
                        break;
                }

                if (copy_to_user((void __user *)ioctl_param, vm_param,
                                 sizeof(struct acrn_vm_creation))) {
                        acrn_vm_destroy(vm);
                        ret = -EFAULT;
                }

                kfree(vm_param);
                break;
        case ACRN_IOCTL_START_VM:
                ret = hcall_start_vm(vm->vmid);
                if (ret < 0)
                        dev_dbg(acrn_dev.this_device,
                                "Failed to start VM %u!\n", vm->vmid);
                break;
        case ACRN_IOCTL_PAUSE_VM:
                ret = hcall_pause_vm(vm->vmid);
                if (ret < 0)
                        dev_dbg(acrn_dev.this_device,
                                "Failed to pause VM %u!\n", vm->vmid);
                break;
        case ACRN_IOCTL_RESET_VM:
                ret = hcall_reset_vm(vm->vmid);
                if (ret < 0)
                        dev_dbg(acrn_dev.this_device,
                                "Failed to restart VM %u!\n", vm->vmid);
                break;
        case ACRN_IOCTL_DESTROY_VM:
                ret = acrn_vm_destroy(vm);
                break;
        case ACRN_IOCTL_SET_VCPU_REGS:
                cpu_regs = memdup_user((void __user *)ioctl_param,
                                       sizeof(struct acrn_vcpu_regs));
                if (IS_ERR(cpu_regs))
                        return PTR_ERR(cpu_regs);

                for (i = 0; i < ARRAY_SIZE(cpu_regs->reserved); i++)
                        if (cpu_regs->reserved[i]) {
                                kfree(cpu_regs);
                                return -EINVAL;
                        }

                for (i = 0; i < ARRAY_SIZE(cpu_regs->vcpu_regs.reserved_32); i++)
                        if (cpu_regs->vcpu_regs.reserved_32[i]) {
                                kfree(cpu_regs);
                                return -EINVAL;
                        }

                for (i = 0; i < ARRAY_SIZE(cpu_regs->vcpu_regs.reserved_64); i++)
                        if (cpu_regs->vcpu_regs.reserved_64[i]) {
                                kfree(cpu_regs);
                                return -EINVAL;
                        }

                for (i = 0; i < ARRAY_SIZE(cpu_regs->vcpu_regs.gdt.reserved); i++)
                        if (cpu_regs->vcpu_regs.gdt.reserved[i] |
                            cpu_regs->vcpu_regs.idt.reserved[i]) {
                                kfree(cpu_regs);
                                return -EINVAL;
                        }

                ret = hcall_set_vcpu_regs(vm->vmid, virt_to_phys(cpu_regs));
                if (ret < 0)
                        dev_dbg(acrn_dev.this_device,
                                "Failed to set regs state of VM%u!\n",
                                vm->vmid);
                kfree(cpu_regs);
                break;
        case ACRN_IOCTL_SET_MEMSEG:
                if (copy_from_user(&memmap, (void __user *)ioctl_param,
                                   sizeof(memmap)))
                        return -EFAULT;

                ret = acrn_vm_memseg_map(vm, &memmap);
                break;
        case ACRN_IOCTL_UNSET_MEMSEG:
                if (copy_from_user(&memmap, (void __user *)ioctl_param,
                                   sizeof(memmap)))
                        return -EFAULT;

                ret = acrn_vm_memseg_unmap(vm, &memmap);
                break;
        case ACRN_IOCTL_ASSIGN_MMIODEV:
                mmiodev = memdup_user((void __user *)ioctl_param,
                                      sizeof(struct acrn_mmiodev));
                if (IS_ERR(mmiodev))
                        return PTR_ERR(mmiodev);

                ret = hcall_assign_mmiodev(vm->vmid, virt_to_phys(mmiodev));
                if (ret < 0)
                        dev_dbg(acrn_dev.this_device,
                                "Failed to assign MMIO device!\n");
                kfree(mmiodev);
                break;
        case ACRN_IOCTL_DEASSIGN_MMIODEV:
                mmiodev = memdup_user((void __user *)ioctl_param,
                                      sizeof(struct acrn_mmiodev));
                if (IS_ERR(mmiodev))
                        return PTR_ERR(mmiodev);

                ret = hcall_deassign_mmiodev(vm->vmid, virt_to_phys(mmiodev));
                if (ret < 0)
                        dev_dbg(acrn_dev.this_device,
                                "Failed to deassign MMIO device!\n");
                kfree(mmiodev);
                break;
        case ACRN_IOCTL_ASSIGN_PCIDEV:
                pcidev = memdup_user((void __user *)ioctl_param,
                                     sizeof(struct acrn_pcidev));
                if (IS_ERR(pcidev))
                        return PTR_ERR(pcidev);

                ret = hcall_assign_pcidev(vm->vmid, virt_to_phys(pcidev));
                if (ret < 0)
                        dev_dbg(acrn_dev.this_device,
                                "Failed to assign pci device!\n");
                kfree(pcidev);
                break;
        case ACRN_IOCTL_DEASSIGN_PCIDEV:
                pcidev = memdup_user((void __user *)ioctl_param,
                                     sizeof(struct acrn_pcidev));
                if (IS_ERR(pcidev))
                        return PTR_ERR(pcidev);

                ret = hcall_deassign_pcidev(vm->vmid, virt_to_phys(pcidev));
                if (ret < 0)
                        dev_dbg(acrn_dev.this_device,
                                "Failed to deassign pci device!\n");
                kfree(pcidev);
                break;
        case ACRN_IOCTL_CREATE_VDEV:
                vdev = memdup_user((void __user *)ioctl_param,
                                   sizeof(struct acrn_vdev));
                if (IS_ERR(vdev))
                        return PTR_ERR(vdev);

                ret = hcall_create_vdev(vm->vmid, virt_to_phys(vdev));
                if (ret < 0)
                        dev_dbg(acrn_dev.this_device,
                                "Failed to create virtual device!\n");
                kfree(vdev);
                break;
        case ACRN_IOCTL_DESTROY_VDEV:
                vdev = memdup_user((void __user *)ioctl_param,
                                   sizeof(struct acrn_vdev));
                if (IS_ERR(vdev))
                        return PTR_ERR(vdev);
                ret = hcall_destroy_vdev(vm->vmid, virt_to_phys(vdev));
                if (ret < 0)
                        dev_dbg(acrn_dev.this_device,
                                "Failed to destroy virtual device!\n");
                kfree(vdev);
                break;
        case ACRN_IOCTL_SET_PTDEV_INTR:
                irq_info = memdup_user((void __user *)ioctl_param,
                                       sizeof(struct acrn_ptdev_irq));
                if (IS_ERR(irq_info))
                        return PTR_ERR(irq_info);

                ret = hcall_set_ptdev_intr(vm->vmid, virt_to_phys(irq_info));
                if (ret < 0)
                        dev_dbg(acrn_dev.this_device,
                                "Failed to configure intr for ptdev!\n");
                kfree(irq_info);
                break;
        case ACRN_IOCTL_RESET_PTDEV_INTR:
                irq_info = memdup_user((void __user *)ioctl_param,
                                       sizeof(struct acrn_ptdev_irq));
                if (IS_ERR(irq_info))
                        return PTR_ERR(irq_info);

                ret = hcall_reset_ptdev_intr(vm->vmid, virt_to_phys(irq_info));
                if (ret < 0)
                        dev_dbg(acrn_dev.this_device,
                                "Failed to reset intr for ptdev!\n");
                kfree(irq_info);
                break;
        case ACRN_IOCTL_SET_IRQLINE:
                ret = hcall_set_irqline(vm->vmid, ioctl_param);
                if (ret < 0)
                        dev_dbg(acrn_dev.this_device,
                                "Failed to set interrupt line!\n");
                break;
        case ACRN_IOCTL_INJECT_MSI:
                msi = memdup_user((void __user *)ioctl_param,
                                  sizeof(struct acrn_msi_entry));
                if (IS_ERR(msi))
                        return PTR_ERR(msi);

                ret = hcall_inject_msi(vm->vmid, virt_to_phys(msi));
                if (ret < 0)
                        dev_dbg(acrn_dev.this_device,
                                "Failed to inject MSI!\n");
                kfree(msi);
                break;
        case ACRN_IOCTL_VM_INTR_MONITOR:
                ret = pin_user_pages_fast(ioctl_param, 1,
                                          FOLL_WRITE | FOLL_LONGTERM, &page);
                if (unlikely(ret != 1)) {
                        dev_dbg(acrn_dev.this_device,
                                "Failed to pin intr hdr buffer!\n");
                        return -EFAULT;
                }

                ret = hcall_vm_intr_monitor(vm->vmid, page_to_phys(page));
                if (ret < 0) {
                        unpin_user_page(page);
                        dev_dbg(acrn_dev.this_device,
                                "Failed to monitor intr data!\n");
                        return ret;
                }
                if (vm->monitor_page)
                        unpin_user_page(vm->monitor_page);
                vm->monitor_page = page;
                break;
        case ACRN_IOCTL_CREATE_IOREQ_CLIENT:
                if (vm->default_client)
                        return -EEXIST;
                if (!acrn_ioreq_client_create(vm, NULL, NULL, true, "acrndm"))
                        ret = -EINVAL;
                break;
        case ACRN_IOCTL_DESTROY_IOREQ_CLIENT:
                if (vm->default_client)
                        acrn_ioreq_client_destroy(vm->default_client);
                break;
        case ACRN_IOCTL_ATTACH_IOREQ_CLIENT:
                if (vm->default_client)
                        ret = acrn_ioreq_client_wait(vm->default_client);
                else
                        ret = -ENODEV;
                break;
        case ACRN_IOCTL_NOTIFY_REQUEST_FINISH:
                if (copy_from_user(&notify, (void __user *)ioctl_param,
                                   sizeof(struct acrn_ioreq_notify)))
                        return -EFAULT;

                if (notify.reserved != 0)
                        return -EINVAL;

                ret = acrn_ioreq_request_default_complete(vm, notify.vcpu);
                break;
        case ACRN_IOCTL_CLEAR_VM_IOREQ:
                acrn_ioreq_request_clear(vm);
                break;
        case ACRN_IOCTL_PM_GET_CPU_STATE:
                if (copy_from_user(&cstate_cmd, (void __user *)ioctl_param,
                                   sizeof(cstate_cmd)))
                        return -EFAULT;

                ret = pmcmd_ioctl(cstate_cmd, (void __user *)ioctl_param);
                break;
        case ACRN_IOCTL_IOEVENTFD:
                if (copy_from_user(&ioeventfd, (void __user *)ioctl_param,
                                   sizeof(ioeventfd)))
                        return -EFAULT;

                if (ioeventfd.reserved != 0)
                        return -EINVAL;

                ret = acrn_ioeventfd_config(vm, &ioeventfd);
                break;
        case ACRN_IOCTL_IRQFD:
                if (copy_from_user(&irqfd, (void __user *)ioctl_param,
                                   sizeof(irqfd)))
                        return -EFAULT;
                ret = acrn_irqfd_config(vm, &irqfd);
                break;
        default:
                dev_dbg(acrn_dev.this_device, "Unknown IOCTL 0x%x!\n", cmd);
                ret = -ENOTTY;
        }

        return ret;
}

static int acrn_dev_release(struct inode *inode, struct file *filp)
{
        struct acrn_vm *vm = filp->private_data;

        acrn_vm_destroy(vm);
        kfree(vm);
        return 0;
}

static ssize_t remove_cpu_store(struct device *dev,
                                struct device_attribute *attr,
                                const char *buf, size_t count)
{
        u64 cpu, lapicid;
        int ret;

        if (kstrtoull(buf, 0, &cpu) < 0)
                return -EINVAL;

        if (cpu >= num_possible_cpus() || cpu == 0 || !cpu_is_hotpluggable(cpu))
                return -EINVAL;

        if (cpu_online(cpu))
                remove_cpu(cpu);

        lapicid = cpu_data(cpu).topo.apicid;
        dev_dbg(dev, "Try to remove cpu %lld with lapicid %lld\n", cpu, lapicid);
        ret = hcall_sos_remove_cpu(lapicid);
        if (ret < 0) {
                dev_err(dev, "Failed to remove cpu %lld!\n", cpu);
                goto fail_remove;
        }

        return count;

fail_remove:
        add_cpu(cpu);
        return ret;
}
static DEVICE_ATTR_WO(remove_cpu);

static umode_t acrn_attr_visible(struct kobject *kobj, struct attribute *a, int n)
{
       if (a == &dev_attr_remove_cpu.attr)
               return IS_ENABLED(CONFIG_HOTPLUG_CPU) ? a->mode : 0;

       return a->mode;
}

static struct attribute *acrn_attrs[] = {
        &dev_attr_remove_cpu.attr,
        NULL
};

static struct attribute_group acrn_attr_group = {
        .attrs = acrn_attrs,
        .is_visible = acrn_attr_visible,
};

static const struct attribute_group *acrn_attr_groups[] = {
        &acrn_attr_group,
        NULL
};

static const struct file_operations acrn_fops = {
        .owner          = THIS_MODULE,
        .open           = acrn_dev_open,
        .release        = acrn_dev_release,
        .unlocked_ioctl = acrn_dev_ioctl,
};

struct miscdevice acrn_dev = {
        .minor  = MISC_DYNAMIC_MINOR,
        .name   = "acrn_hsm",
        .fops   = &acrn_fops,
        .groups = acrn_attr_groups,
};

static int __init hsm_init(void)
{
        int ret;

        if (x86_hyper_type != X86_HYPER_ACRN)
                return -ENODEV;

        if (!(cpuid_eax(ACRN_CPUID_FEATURES) & ACRN_FEATURE_PRIVILEGED_VM))
                return -EPERM;

        ret = misc_register(&acrn_dev);
        if (ret) {
                pr_err("Create misc dev failed!\n");
                return ret;
        }

        ret = acrn_ioreq_intr_setup();
        if (ret) {
                pr_err("Setup I/O request handler failed!\n");
                misc_deregister(&acrn_dev);
                return ret;
        }
        return 0;
}

static void __exit hsm_exit(void)
{
        acrn_ioreq_intr_remove();
        misc_deregister(&acrn_dev);
}
module_init(hsm_init);
module_exit(hsm_exit);

MODULE_AUTHOR("Intel Corporation");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("ACRN Hypervisor Service Module (HSM)");