Files
visor/pkg/hostarch/hostarch_x86.go
Tianyu Zhou fc1afc9de5 platform: add SlimVM platform
SlimVM is a lightweight VMX-based platform for gVisor that accelerates
sentry system calls by eliminating unnecessary user/kernel context
switches.

In a traditional gVisor + KVM setup, every guest syscall triggers a
full VM exit to userspace, then re-enters the kernel via a regular
syscall:

  gr0 -> hr0 (vm_exit) -> hr3 (ioctl return) -> hr0 (re-invoke syscall)

SlimVM eliminates this overhead. When the guest executes a VMCALL, the
VM exits into VMX root mode where SlimVM directly invokes the host
kernel's syscall handler, then immediately resumes the guest:

  gr0 -> hr0 (vmcall + direct function call)

SlimVM requires a companion kernel module that provides the /dev/slimvm
device interface. See https://github.com/antgroup/slimvm for the
kernel module and full documentation.

A sentry->host getpid microbenchmark (Xeon 6982P-C, host kernel 5.10.134)
shows the effect:

            │  ns/op  │ vs base │
  base          82.5       1.0x
  slimvm       420.9       5.1x
  kvm         3566.1      43.2x

slimvm is ~8.5x faster than the kvm platform on this path. See the issue
for details.

Updates: https://github.com/google/gvisor/issues/13330

Co-developed-by: Chenggang <[email protected]>
Co-developed-by: Robin Luk <[email protected]>
Co-developed-by: Tiwei Bie <[email protected]>
Co-developed-by: Jianfeng Tan <[email protected]>
Co-developed-by: liushi.ls <[email protected]>
Co-developed-by: Yong He <[email protected]>
Co-developed-by: Aaron Lu <[email protected]>
Co-developed-by: chris.zn <[email protected]>
Co-developed-by: Lai Jiangshan <[email protected]>
Co-developed-by: Lingfu <[email protected]>
Co-developed-by: Min Le <[email protected]>
Co-developed-by: Quan Xu <[email protected]>
Co-developed-by: Zhang Haoyu <[email protected]>
Co-developed-by: Dawei Shen <[email protected]>
Signed-off-by: Tianyu Zhou <[email protected]>
2026-06-25 10:27:28 +08:00

57 lines
1.5 KiB
Go

// 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.
//go:build amd64 || 386
// +build amd64 386
package hostarch
import "encoding/binary"
const (
// PageSize is the system page size.
PageSize = 1 << PageShift
// HugePageSize is the system huge page size.
HugePageSize = 1 << HugePageShift
// JumboPageSize is the 1GB jumbo page size.
JumboPageSize = 1 << JumboPageShift
// CacheLineSize is the size of the cache line.
CacheLineSize = 1 << CacheLineShift
// PageShift is the binary log of the system page size.
PageShift = 12
// HugePageShift is the binary log of the system huge page size.
HugePageShift = 21
// JumboPageShift is the binary log of jumbo page whose size is 1GB.
JumboPageShift = 30
// CacheLineShift is the binary log of the cache line size.
CacheLineShift = 6
)
var (
// ByteOrder is the native byte order (little endian).
ByteOrder = binary.LittleEndian
)
// UntaggedUserAddr is no-op on x86.
func UntaggedUserAddr(addr Addr) Addr {
return addr
}