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Diffstat (limited to 'pkg/ring0/defs.go')
| -rw-r--r-- | pkg/ring0/defs.go | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/pkg/ring0/defs.go b/pkg/ring0/defs.go new file mode 100644 index 000000000..e2561e4c2 --- /dev/null +++ b/pkg/ring0/defs.go @@ -0,0 +1,112 @@ +// Copyright 2018 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 ring0 + +import ( + "gvisor.dev/gvisor/pkg/ring0/pagetables" + "gvisor.dev/gvisor/pkg/sentry/arch" +) + +// Kernel is a global kernel object. +// +// This contains global state, shared by multiple CPUs. +type Kernel struct { + // PageTables are the kernel pagetables; this must be provided. + PageTables *pagetables.PageTables + + KernelArchState +} + +// Hooks are hooks for kernel functions. +type Hooks interface { + // KernelSyscall is called for kernel system calls. + // + // Return from this call will restore registers and return to the kernel: the + // registers must be modified directly. + // + // If this function is not provided, a kernel exception results in halt. + // + // This must be go:nosplit, as this will be on the interrupt stack. + // Closures are permitted, as the pointer to the closure frame is not + // passed on the stack. + KernelSyscall() + + // KernelException handles an exception during kernel execution. + // + // Return from this call will restore registers and return to the kernel: the + // registers must be modified directly. + // + // If this function is not provided, a kernel exception results in halt. + // + // This must be go:nosplit, as this will be on the interrupt stack. + // Closures are permitted, as the pointer to the closure frame is not + // passed on the stack. + KernelException(Vector) +} + +// CPU is the per-CPU struct. +type CPU struct { + // self is a self reference. + // + // This is always guaranteed to be at offset zero. + self *CPU + + // kernel is reference to the kernel that this CPU was initialized + // with. This reference is kept for garbage collection purposes: CPU + // registers may refer to objects within the Kernel object that cannot + // be safely freed. + kernel *Kernel + + // CPUArchState is architecture-specific state. + CPUArchState + + // registers is a set of registers; these may be used on kernel system + // calls and exceptions via the Registers function. + registers arch.Registers + + // hooks are kernel hooks. + hooks Hooks +} + +// Registers returns a modifiable-copy of the kernel registers. +// +// This is explicitly safe to call during KernelException and KernelSyscall. +// +//go:nosplit +func (c *CPU) Registers() *arch.Registers { + return &c.registers +} + +// SwitchOpts are passed to the Switch function. +type SwitchOpts struct { + // Registers are the user register state. + Registers *arch.Registers + + // FloatingPointState is a byte pointer where floating point state is + // saved and restored. + FloatingPointState *byte + + // PageTables are the application page tables. + PageTables *pagetables.PageTables + + // Flush indicates that a TLB flush should be forced on switch. + Flush bool + + // FullRestore indicates that an iret-based restore should be used. + FullRestore bool + + // SwitchArchOpts are architecture-specific options. + SwitchArchOpts +} |