191 lines
4.2 KiB
Go
191 lines
4.2 KiB
Go
// Copyright 2018 The gVisor Authors.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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// +build amd64
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package kvm
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import (
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"gvisor.dev/gvisor/pkg/cpuid"
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"gvisor.dev/gvisor/pkg/sentry/platform/ring0"
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)
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// userRegs represents KVM user registers.
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//
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// This mirrors kvm_regs.
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type userRegs struct {
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RAX uint64
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RBX uint64
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RCX uint64
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RDX uint64
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RSI uint64
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RDI uint64
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RSP uint64
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RBP uint64
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R8 uint64
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R9 uint64
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R10 uint64
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R11 uint64
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R12 uint64
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R13 uint64
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R14 uint64
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R15 uint64
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RIP uint64
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RFLAGS uint64
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}
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// systemRegs represents KVM system registers.
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//
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// This mirrors kvm_sregs.
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type systemRegs struct {
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CS segment
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DS segment
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ES segment
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FS segment
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GS segment
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SS segment
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TR segment
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LDT segment
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GDT descriptor
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IDT descriptor
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CR0 uint64
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CR2 uint64
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CR3 uint64
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CR4 uint64
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CR8 uint64
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EFER uint64
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apicBase uint64
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interruptBitmap [(_KVM_NR_INTERRUPTS + 63) / 64]uint64
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}
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// segment is the expanded form of a segment register.
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//
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// This mirrors kvm_segment.
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type segment struct {
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base uint64
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limit uint32
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selector uint16
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typ uint8
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present uint8
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DPL uint8
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DB uint8
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S uint8
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L uint8
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G uint8
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AVL uint8
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unusable uint8
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_ uint8
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}
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// Clear clears the segment and marks it unusable.
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func (s *segment) Clear() {
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*s = segment{unusable: 1}
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}
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// selector is a segment selector.
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type selector uint16
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// tobool is a simple helper.
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func tobool(x ring0.SegmentDescriptorFlags) uint8 {
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if x != 0 {
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return 1
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}
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return 0
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}
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// Load loads the segment described by d into the segment s.
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//
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// The argument sel is recorded as the segment selector index.
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func (s *segment) Load(d *ring0.SegmentDescriptor, sel ring0.Selector) {
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flag := d.Flags()
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if flag&ring0.SegmentDescriptorPresent == 0 {
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s.Clear()
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return
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}
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s.base = uint64(d.Base())
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s.limit = d.Limit()
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s.typ = uint8((flag>>8)&0xF) | 1
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s.S = tobool(flag & ring0.SegmentDescriptorSystem)
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s.DPL = uint8(d.DPL())
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s.present = tobool(flag & ring0.SegmentDescriptorPresent)
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s.AVL = tobool(flag & ring0.SegmentDescriptorAVL)
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s.L = tobool(flag & ring0.SegmentDescriptorLong)
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s.DB = tobool(flag & ring0.SegmentDescriptorDB)
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s.G = tobool(flag & ring0.SegmentDescriptorG)
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if s.L != 0 {
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s.limit = 0xffffffff
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}
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s.unusable = 0
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s.selector = uint16(sel)
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}
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// descriptor describes a region of physical memory.
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//
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// It corresponds to the pseudo-descriptor used in the x86 LGDT and LIDT
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// instructions, and mirrors kvm_dtable.
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type descriptor struct {
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base uint64
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limit uint16
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_ [3]uint16
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}
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// modelControlRegister is an MSR entry.
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//
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// This mirrors kvm_msr_entry.
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type modelControlRegister struct {
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index uint32
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_ uint32
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data uint64
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}
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// modelControlRegisers is a collection of MSRs.
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//
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// This mirrors kvm_msrs.
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type modelControlRegisters struct {
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nmsrs uint32
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_ uint32
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entries [16]modelControlRegister
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}
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// cpuidEntry is a single CPUID entry.
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//
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// This mirrors kvm_cpuid_entry2.
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type cpuidEntry struct {
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function uint32
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index uint32
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flags uint32
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eax uint32
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ebx uint32
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ecx uint32
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edx uint32
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_ [3]uint32
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}
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// cpuidEntries is a collection of CPUID entries.
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//
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// This mirrors kvm_cpuid2.
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type cpuidEntries struct {
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nr uint32
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_ uint32
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entries [_KVM_NR_CPUID_ENTRIES]cpuidEntry
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}
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// updateGlobalOnce does global initialization. It has to be called only once.
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func updateGlobalOnce(fd int) error {
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physicalInit()
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err := updateSystemValues(int(fd))
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ring0.Init(cpuid.HostFeatureSet())
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return err
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}
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