Messages in this thread | | | Date | Fri, 31 Mar 2023 09:25:59 -0500 | From | Alex Elder <> | Subject | Re: [PATCH v11 10/26] gunyah: vm_mgr: Introduce basic VM Manager |
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On 3/3/23 7:06 PM, Elliot Berman wrote: > Gunyah VM manager is a kernel moduel which exposes an interface to > Gunyah userspace to load, run, and interact with other Gunyah virtual > machines. The interface is a character device at /dev/gunyah. > > Add a basic VM manager driver. Upcoming patches will add more ioctls > into this driver. > > Co-developed-by: Prakruthi Deepak Heragu <quic_pheragu@quicinc.com> > Signed-off-by: Prakruthi Deepak Heragu <quic_pheragu@quicinc.com> > Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
One suggestion to move some code here. And a few other minor things.
-Alex
> --- > .../userspace-api/ioctl/ioctl-number.rst | 1 + > drivers/virt/gunyah/Makefile | 2 +- > drivers/virt/gunyah/rsc_mgr.c | 38 +++++- > drivers/virt/gunyah/vm_mgr.c | 116 ++++++++++++++++++ > drivers/virt/gunyah/vm_mgr.h | 23 ++++ > include/uapi/linux/gunyah.h | 23 ++++ > 6 files changed, 201 insertions(+), 2 deletions(-) > create mode 100644 drivers/virt/gunyah/vm_mgr.c > create mode 100644 drivers/virt/gunyah/vm_mgr.h > create mode 100644 include/uapi/linux/gunyah.h > > diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst > index 0a1882e296ae..2513324ae7be 100644 > --- a/Documentation/userspace-api/ioctl/ioctl-number.rst > +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst > @@ -137,6 +137,7 @@ Code Seq# Include File Comments > 'F' DD video/sstfb.h conflict! > 'G' 00-3F drivers/misc/sgi-gru/grulib.h conflict! > 'G' 00-0F xen/gntalloc.h, xen/gntdev.h conflict! > +'G' 00-0f linux/gunyah.h conflict! > 'H' 00-7F linux/hiddev.h conflict! > 'H' 00-0F linux/hidraw.h conflict! > 'H' 01 linux/mei.h conflict! > diff --git a/drivers/virt/gunyah/Makefile b/drivers/virt/gunyah/Makefile > index de29769f2f3f..03951cf82023 100644 > --- a/drivers/virt/gunyah/Makefile > +++ b/drivers/virt/gunyah/Makefile > @@ -2,5 +2,5 @@ > > obj-$(CONFIG_GUNYAH) += gunyah.o > > -gunyah_rsc_mgr-y += rsc_mgr.o rsc_mgr_rpc.o > +gunyah_rsc_mgr-y += rsc_mgr.o rsc_mgr_rpc.o vm_mgr.o > obj-$(CONFIG_GUNYAH) += gunyah_rsc_mgr.o > diff --git a/drivers/virt/gunyah/rsc_mgr.c b/drivers/virt/gunyah/rsc_mgr.c > index 67813c9a52db..d7ce692d0067 100644 > --- a/drivers/virt/gunyah/rsc_mgr.c > +++ b/drivers/virt/gunyah/rsc_mgr.c > @@ -15,8 +15,10 @@ > #include <linux/completion.h> > #include <linux/gunyah_rsc_mgr.h> > #include <linux/platform_device.h> > +#include <linux/miscdevice.h> > > #include "rsc_mgr.h" > +#include "vm_mgr.h" > > #define RM_RPC_API_VERSION_MASK GENMASK(3, 0) > #define RM_RPC_HEADER_WORDS_MASK GENMASK(7, 4) > @@ -129,6 +131,7 @@ struct gh_rm_connection { > * @cache: cache for allocating Tx messages > * @send_lock: synchronization to allow only one request to be sent at a time > * @nh: notifier chain for clients interested in RM notification messages > + * @miscdev: /dev/gunyah > */ > struct gh_rm { > struct device *dev; > @@ -145,6 +148,8 @@ struct gh_rm { > struct kmem_cache *cache; > struct mutex send_lock; > struct blocking_notifier_head nh; > + > + struct miscdevice miscdev; > }; > > /** > @@ -593,6 +598,21 @@ void gh_rm_put(struct gh_rm *rm) > } > EXPORT_SYMBOL_GPL(gh_rm_put); >
I feel like /dev/gunyah code would more appropriately be found in "vm_mgr.c". All gh_dev_ioctl() does is call the function defined there, and it's therefore a VM-oriented rather than resource-oriented device.
> +static long gh_dev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) > +{ > + struct miscdevice *miscdev = filp->private_data; > + struct gh_rm *rm = container_of(miscdev, struct gh_rm, miscdev); > + > + return gh_dev_vm_mgr_ioctl(rm, cmd, arg); > +} > + > +static const struct file_operations gh_dev_fops = { > + .owner = THIS_MODULE, > + .unlocked_ioctl = gh_dev_ioctl, > + .compat_ioctl = compat_ptr_ioctl, > + .llseek = noop_llseek, > +}; > + > static int gh_msgq_platform_probe_direction(struct platform_device *pdev, bool tx, > struct gh_resource *ghrsc) > { > @@ -651,7 +671,22 @@ static int gh_rm_drv_probe(struct platform_device *pdev) > rm->msgq_client.rx_callback = gh_rm_msgq_rx_data; > rm->msgq_client.tx_done = gh_rm_msgq_tx_done; > > - return gh_msgq_init(&pdev->dev, &rm->msgq, &rm->msgq_client, &rm->tx_ghrsc, &rm->rx_ghrsc); > + ret = gh_msgq_init(&pdev->dev, &rm->msgq, &rm->msgq_client, &rm->tx_ghrsc, &rm->rx_ghrsc); > + if (ret) > + goto err_cache; > + > + rm->miscdev.name = "gunyah"; > + rm->miscdev.minor = MISC_DYNAMIC_MINOR; > + rm->miscdev.fops = &gh_dev_fops; > + > + ret = misc_register(&rm->miscdev); > + if (ret) > + goto err_msgq; > + > + return 0; > +err_msgq: > + mbox_free_channel(gh_msgq_chan(&rm->msgq)); > + gh_msgq_remove(&rm->msgq); > err_cache: > kmem_cache_destroy(rm->cache); > return ret; > @@ -661,6 +696,7 @@ static int gh_rm_drv_remove(struct platform_device *pdev) > { > struct gh_rm *rm = platform_get_drvdata(pdev); > > + misc_deregister(&rm->miscdev); > mbox_free_channel(gh_msgq_chan(&rm->msgq)); > gh_msgq_remove(&rm->msgq); > kmem_cache_destroy(rm->cache); > diff --git a/drivers/virt/gunyah/vm_mgr.c b/drivers/virt/gunyah/vm_mgr.c > new file mode 100644 > index 000000000000..dbacf36af72d > --- /dev/null > +++ b/drivers/virt/gunyah/vm_mgr.c > @@ -0,0 +1,116 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved. > + */ > + > +#define pr_fmt(fmt) "gh_vm_mgr: " fmt > + > +#include <linux/anon_inodes.h> > +#include <linux/file.h> > +#include <linux/gunyah_rsc_mgr.h> > +#include <linux/miscdevice.h> > +#include <linux/module.h> > + > +#include <uapi/linux/gunyah.h> > + > +#include "vm_mgr.h" > + > +static void gh_vm_free(struct work_struct *work) > +{ > + struct gh_vm *ghvm = container_of(work, struct gh_vm, free_work); > + int ret; > + > + ret = gh_rm_dealloc_vmid(ghvm->rm, ghvm->vmid); > + if (ret) > + pr_warn("Failed to deallocate vmid: %d\n", ret); > + > + put_gh_rm(ghvm->rm); > + kfree(ghvm); > +} > + > +static __must_check struct gh_vm *gh_vm_alloc(struct gh_rm *rm) > +{ > + struct gh_vm *ghvm; > + int vmid; > + > + vmid = gh_rm_alloc_vmid(rm, 0); > + if (vmid < 0) > + return ERR_PTR(vmid); > + > + ghvm = kzalloc(sizeof(*ghvm), GFP_KERNEL); > + if (!ghvm) { > + gh_rm_dealloc_vmid(rm, vmid); > + return ERR_PTR(-ENOMEM); > + } > + > + ghvm->parent = gh_rm_get(rm); > + ghvm->vmid = vmid; > + ghvm->rm = rm; > + > + INIT_WORK(&ghvm->free_work, gh_vm_free); > + > + return ghvm; > +} > + > +static int gh_vm_release(struct inode *inode, struct file *filp) > +{ > + struct gh_vm *ghvm = filp->private_data; > + > + /* VM will be reset and make RM calls which can interruptible sleep. > + * Defer to a work so this thread can receive signal. > + */ > + schedule_work(&ghvm->free_work); > + return 0; > +} > + > +static const struct file_operations gh_vm_fops = { > + .release = gh_vm_release, > + .llseek = noop_llseek, > +}; > + > +static long gh_dev_ioctl_create_vm(struct gh_rm *rm, unsigned long arg) > +{ > + struct gh_vm *ghvm; > + struct file *file; > + int fd, err; > + > + /* arg reserved for future use. */
Do you have a clear idea of how this might be used in the future?
I was thinking you could silently ignore the argument value, but I suppose if it *does* get used in the future, you want the caller to know it's being ignored. (Is that right?)
> + if (arg) > + return -EINVAL; > + > + ghvm = gh_vm_alloc(rm); > + if (IS_ERR(ghvm)) > + return PTR_ERR(ghvm); > + > + fd = get_unused_fd_flags(O_CLOEXEC); > + if (fd < 0) { > + err = fd; > + goto err_destroy_vm; > + } > + > + file = anon_inode_getfile("gunyah-vm", &gh_vm_fops, ghvm, O_RDWR); > + if (IS_ERR(file)) { > + err = PTR_ERR(file); > + goto err_put_fd; > + } > + > + fd_install(fd, file); > + > + return fd; > + > +err_put_fd: > + put_unused_fd(fd); > +err_destroy_vm: > + gh_vm_free(&ghvm->free_work); > + return err; > +} > + > +long gh_dev_vm_mgr_ioctl(struct gh_rm *rm, unsigned int cmd, unsigned long arg) > +{ > + switch (cmd) { > + case GH_CREATE_VM: > + return gh_dev_ioctl_create_vm(rm, arg); > + default: > + return -ENOIOCTLCMD; > + } > +} > diff --git a/drivers/virt/gunyah/vm_mgr.h b/drivers/virt/gunyah/vm_mgr.h > new file mode 100644 > index 000000000000..4b22fbcac91c > --- /dev/null > +++ b/drivers/virt/gunyah/vm_mgr.h > @@ -0,0 +1,23 @@ > +/* SPDX-License-Identifier: GPL-2.0-only */ > +/* > + * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved. > + */ > + > +#ifndef _GH_PRIV_VM_MGR_H > +#define _GH_PRIV_VM_MGR_H
Maybe _GH_VM_MGR_H?
> + > +#include <linux/gunyah_rsc_mgr.h> > + > +#include <uapi/linux/gunyah.h> > + > +long gh_dev_vm_mgr_ioctl(struct gh_rm *rm, unsigned int cmd, unsigned long arg); > + > +struct gh_vm { > + u16 vmid; > + struct gh_rm *rm; > + struct device *parent; > + > + struct work_struct free_work; > +}; > + > +#endif > diff --git a/include/uapi/linux/gunyah.h b/include/uapi/linux/gunyah.h > new file mode 100644 > index 000000000000..10ba32d2b0a6 > --- /dev/null > +++ b/include/uapi/linux/gunyah.h > @@ -0,0 +1,23 @@ > +/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note */ > +/* > + * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved. > + */ > + > +#ifndef _UAPI_LINUX_GUNYAH > +#define _UAPI_LINUX_GUNYAH
Use _UAPI_LINUX_GUNYAH_H
> + > +/* > + * Userspace interface for /dev/gunyah - gunyah based virtual machine > + */ > + > +#include <linux/types.h> > +#include <linux/ioctl.h> > + > +#define GH_IOCTL_TYPE 'G' > + > +/* > + * ioctls for /dev/gunyah fds: > + */ > +#define GH_CREATE_VM _IO(GH_IOCTL_TYPE, 0x0) /* Returns a Gunyah VM fd */ > + > +#endif
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