Introduce a barebones module file for the mshv API. Introduce CONFIG_HYPERV_ROOT_API for controlling compilation of mshv. Co-developed-by: Lillian Grassin-Drake <ligrassi@xxxxxxxxxxxxx> Signed-off-by: Lillian Grassin-Drake <ligrassi@xxxxxxxxxxxxx> Signed-off-by: Nuno Das Neves <nunodasneves@xxxxxxxxxxxxxxxxxxx> --- arch/x86/Kconfig | 2 ++ arch/x86/hyperv/Kconfig | 22 +++++++++++++ arch/x86/hyperv/Makefile | 4 +++ virt/mshv/mshv_main.c | 70 ++++++++++++++++++++++++++++++++++++++++ 4 files changed, 98 insertions(+) create mode 100644 arch/x86/hyperv/Kconfig create mode 100644 virt/mshv/mshv_main.c diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index f6946b81f74a..8d3848eea358 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -2901,3 +2901,5 @@ source "drivers/firmware/Kconfig" source "arch/x86/kvm/Kconfig" source "arch/x86/Kconfig.assembler" + +source "arch/x86/hyperv/Kconfig" diff --git a/arch/x86/hyperv/Kconfig b/arch/x86/hyperv/Kconfig new file mode 100644 index 000000000000..81e783ab3514 --- /dev/null +++ b/arch/x86/hyperv/Kconfig @@ -0,0 +1,22 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# HYPERV_ROOT_API configuration +# + +config HYPERV_ROOT_API + tristate "Microsoft Hypervisor root partition interfaces: /dev/mshv" + depends on HYPERV + help + Provides access to interfaces for managing guest virtual machines + running under the Microsoft Hypervisor. + + These interfaces will only work when Linux is running as root + partition on the Microsoft Hypervisor. + + The interfaces are provided via a device named /dev/mshv. + + To compile this as a module, choose M here: the module + will be called mshv. + + If unsure, say N. + diff --git a/arch/x86/hyperv/Makefile b/arch/x86/hyperv/Makefile index 2ebcf3969121..86f6dc1c5118 100644 --- a/arch/x86/hyperv/Makefile +++ b/arch/x86/hyperv/Makefile @@ -5,3 +5,7 @@ obj-$(CONFIG_X86_64) += hv_apic.o hv_proc.o irqdomain.o ifdef CONFIG_X86_64 obj-$(CONFIG_PARAVIRT_SPINLOCKS) += hv_spinlock.o endif + +MSHV := ../../../virt/mshv +mshv-y += $(MSHV)/mshv_main.o +obj-$(CONFIG_HYPERV_ROOT_API) += mshv.o diff --git a/virt/mshv/mshv_main.c b/virt/mshv/mshv_main.c new file mode 100644 index 000000000000..ecb9089761fe --- /dev/null +++ b/virt/mshv/mshv_main.c @@ -0,0 +1,70 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2020, Microsoft Corporation. + * + * Authors: + * Nuno Das Neves <nudasnev@xxxxxxxxxxxxx> + * Lillian Grassin-Drake <ligrassi@xxxxxxxxxxxxx> + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/fs.h> +#include <linux/miscdevice.h> + +MODULE_AUTHOR("Microsoft"); +MODULE_LICENSE("GPL"); + +static long +mshv_dev_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) +{ + return -ENOTTY; +} + +static int +mshv_dev_open(struct inode *inode, struct file *filp) +{ + return 0; +} + +static int +mshv_dev_release(struct inode *inode, struct file *filp) +{ + return 0; +} + +static const struct file_operations mshv_dev_fops = { + .owner = THIS_MODULE, + .open = mshv_dev_open, + .release = mshv_dev_release, + .unlocked_ioctl = mshv_dev_ioctl, + .llseek = noop_llseek, +}; + +static struct miscdevice mshv_dev = { + .minor = MISC_DYNAMIC_MINOR, + .name = "mshv", + .fops = &mshv_dev_fops, + .mode = 600, +}; + +static int +__init mshv_init(void) +{ + int r; + + r = misc_register(&mshv_dev); + if (r) + pr_err("%s: misc device register failed\n", __func__); + + return r; +} + +static void +__exit mshv_exit(void) +{ + misc_deregister(&mshv_dev); +} + +module_init(mshv_init); +module_exit(mshv_exit); -- 2.25.1