github.com/metacubex/gvisor@v0.0.0-20240320004321-933faba989ec/pkg/sentry/devices/tpuproxy/vfio.go (about)

     1  // Copyright 2024 The gVisor Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //	http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package tpuproxy
    16  
    17  import (
    18  	"fmt"
    19  
    20  	"golang.org/x/sys/unix"
    21  	"github.com/metacubex/gvisor/pkg/abi/linux"
    22  	"github.com/metacubex/gvisor/pkg/context"
    23  	"github.com/metacubex/gvisor/pkg/errors/linuxerr"
    24  	"github.com/metacubex/gvisor/pkg/fdnotifier"
    25  	"github.com/metacubex/gvisor/pkg/log"
    26  	"github.com/metacubex/gvisor/pkg/sentry/arch"
    27  	"github.com/metacubex/gvisor/pkg/sentry/kernel"
    28  	"github.com/metacubex/gvisor/pkg/sentry/vfs"
    29  	"github.com/metacubex/gvisor/pkg/usermem"
    30  	"github.com/metacubex/gvisor/pkg/waiter"
    31  )
    32  
    33  // deviceFD implements vfs.FileDescriptionImpl for /dev/vfio/vfio.
    34  type vfioFd struct {
    35  	vfsfd vfs.FileDescription
    36  	vfs.FileDescriptionDefaultImpl
    37  	vfs.DentryMetadataFileDescriptionImpl
    38  	vfs.NoLockFD
    39  
    40  	hostFd     int32
    41  	device     *vfioDevice
    42  	queue      waiter.Queue
    43  	memmapFile vfioFDMemmapFile
    44  }
    45  
    46  // Release implements vfs.FileDescriptionImpl.Release.
    47  func (fd *vfioFd) Release(context.Context) {
    48  	fdnotifier.RemoveFD(fd.hostFd)
    49  	fd.queue.Notify(waiter.EventHUp)
    50  	unix.Close(int(fd.hostFd))
    51  }
    52  
    53  // EventRegister implements waiter.Waitable.EventRegister.
    54  func (fd *vfioFd) EventRegister(e *waiter.Entry) error {
    55  	fd.queue.EventRegister(e)
    56  	if err := fdnotifier.UpdateFD(fd.hostFd); err != nil {
    57  		fd.queue.EventUnregister(e)
    58  		return err
    59  	}
    60  	return nil
    61  }
    62  
    63  // EventUnregister implements waiter.Waitable.EventUnregister.
    64  func (fd *vfioFd) EventUnregister(e *waiter.Entry) {
    65  	fd.queue.EventUnregister(e)
    66  	if err := fdnotifier.UpdateFD(fd.hostFd); err != nil {
    67  		panic(fmt.Sprint("UpdateFD:", err))
    68  	}
    69  }
    70  
    71  // Readiness implements waiter.Waitable.Readiness.
    72  func (fd *vfioFd) Readiness(mask waiter.EventMask) waiter.EventMask {
    73  	return fdnotifier.NonBlockingPoll(fd.hostFd, mask)
    74  }
    75  
    76  // Epollable implements vfs.FileDescriptionImpl.Epollable.
    77  func (fd *vfioFd) Epollable() bool {
    78  	return true
    79  }
    80  
    81  // Ioctl implements vfs.FileDescriptionImpl.Ioctl.
    82  func (fd *vfioFd) Ioctl(ctx context.Context, uio usermem.IO, sysno uintptr, args arch.SyscallArguments) (uintptr, error) {
    83  	cmd := args[1].Uint()
    84  	t := kernel.TaskFromContext(ctx)
    85  	if t == nil {
    86  		panic("Ioctl should be called from a task context")
    87  	}
    88  	switch cmd {
    89  	case linux.VFIO_CHECK_EXTENSION:
    90  		return fd.checkExtension(extension(args[2].Int()))
    91  	case linux.VFIO_SET_IOMMU:
    92  		return fd.setIOMMU(extension(args[2].Int()))
    93  	}
    94  	return 0, linuxerr.ENOSYS
    95  }
    96  
    97  // checkExtension returns a positive integer when the given VFIO extension
    98  // is supported, otherwise, it returns 0.
    99  func (fd *vfioFd) checkExtension(ext extension) (uintptr, error) {
   100  	switch ext {
   101  	case linux.VFIO_TYPE1_IOMMU, linux.VFIO_SPAPR_TCE_IOMMU, linux.VFIO_TYPE1v2_IOMMU:
   102  		ret, err := ioctlInvoke[int32](fd.hostFd, linux.VFIO_CHECK_EXTENSION, int32(ext))
   103  		if err != nil {
   104  			log.Warningf("check VFIO extension %s: %v", ext, err)
   105  			return 0, err
   106  		}
   107  		return ret, nil
   108  	}
   109  	return 0, linuxerr.EINVAL
   110  }
   111  
   112  // Set the iommu to the given type.  The type must be supported by an iommu
   113  // driver as verified by calling VFIO_CHECK_EXTENSION using the same type.
   114  func (fd *vfioFd) setIOMMU(ext extension) (uintptr, error) {
   115  	switch ext {
   116  	case linux.VFIO_TYPE1_IOMMU, linux.VFIO_SPAPR_TCE_IOMMU, linux.VFIO_TYPE1v2_IOMMU:
   117  		ret, err := ioctlInvoke[int32](fd.hostFd, linux.VFIO_SET_IOMMU, int32(ext))
   118  		if err != nil {
   119  			log.Warningf("set the IOMMU group to %s: %v", ext, err)
   120  			return 0, err
   121  		}
   122  		return ret, nil
   123  	}
   124  	return 0, linuxerr.EINVAL
   125  }
   126  
   127  // VFIO extension.
   128  type extension int32
   129  
   130  // String implements fmt.Stringer for VFIO extension string representation.
   131  func (e extension) String() string {
   132  	switch e {
   133  	case linux.VFIO_TYPE1_IOMMU:
   134  		return "VFIO_TYPE1_IOMMU"
   135  	case linux.VFIO_SPAPR_TCE_IOMMU:
   136  		return "VFIO_SPAPR_TCE_IOMMU"
   137  	case linux.VFIO_TYPE1v2_IOMMU:
   138  		return "VFIO_TYPE1v2_IOMMU"
   139  	}
   140  	return ""
   141  }