github.com/metacubex/gvisor@v0.0.0-20240320004321-933faba989ec/pkg/sentry/platform/kvm/kvm_arm64_unsafe.go (about)

     1  // Copyright 2019 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  //go:build arm64
    16  // +build arm64
    17  
    18  package kvm
    19  
    20  import (
    21  	"fmt"
    22  
    23  	"golang.org/x/sys/unix"
    24  )
    25  
    26  var (
    27  	runDataSize  int
    28  	hasGuestPCID bool
    29  )
    30  
    31  func updateSystemValues(fd int) error {
    32  	// Extract the mmap size.
    33  	sz, _, errno := unix.RawSyscall(unix.SYS_IOCTL, uintptr(fd), KVM_GET_VCPU_MMAP_SIZE, 0)
    34  	if errno != 0 {
    35  		return fmt.Errorf("getting VCPU mmap size: %v", errno)
    36  	}
    37  	// Save the data.
    38  	runDataSize = int(sz)
    39  	hasGuestPCID = true
    40  
    41  	// Success.
    42  	return nil
    43  }