72 lines
2.0 KiB
Go
72 lines
2.0 KiB
Go
// Copyright 2019 The gVisor Authors.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
package pagetables
|
|
|
|
// Address constraints.
|
|
//
|
|
// The lowerTop and upperBottom currently apply to four-level pagetables;
|
|
// additional refactoring would be necessary to support five-level pagetables.
|
|
const (
|
|
lowerTop = 0x0000ffffffffffff
|
|
upperBottom = 0xffff000000000000
|
|
pteShift = 12
|
|
pmdShift = 21
|
|
pudShift = 30
|
|
pgdShift = 39
|
|
|
|
pteMask = 0x1ff << pteShift
|
|
pmdMask = 0x1ff << pmdShift
|
|
pudMask = 0x1ff << pudShift
|
|
pgdMask = 0x1ff << pgdShift
|
|
|
|
pteSize = 1 << pteShift
|
|
pmdSize = 1 << pmdShift
|
|
pudSize = 1 << pudShift
|
|
pgdSize = 1 << pgdShift
|
|
|
|
ttbrASIDOffset = 48
|
|
ttbrASIDMask = 0xff
|
|
|
|
entriesPerPage = 512
|
|
)
|
|
|
|
// InitArch does some additional initialization related to the architecture.
|
|
//
|
|
// +checkescape:hard,stack
|
|
//go:nosplit
|
|
func (p *PageTables) InitArch(allocator Allocator) {
|
|
if p.upperSharedPageTables != nil {
|
|
p.cloneUpperShared()
|
|
} else {
|
|
p.archPageTables.root = p.Allocator.NewPTEs()
|
|
p.archPageTables.rootPhysical = p.Allocator.PhysicalFor(p.archPageTables.root)
|
|
}
|
|
}
|
|
|
|
// cloneUpperShared clone the upper from the upper shared page tables.
|
|
//
|
|
//go:nosplit
|
|
func (p *PageTables) cloneUpperShared() {
|
|
if p.upperStart != upperBottom {
|
|
panic("upperStart should be the same as upperBottom")
|
|
}
|
|
|
|
p.archPageTables.root = p.upperSharedPageTables.archPageTables.root
|
|
p.archPageTables.rootPhysical = p.upperSharedPageTables.archPageTables.rootPhysical
|
|
}
|
|
|
|
// PTEs is a collection of entries.
|
|
type PTEs [entriesPerPage]PTE
|