diff options
| author | Andrei Vagin <avagin@google.com> | 2021-07-20 12:04:47 -0700 |
|---|---|---|
| committer | gVisor bot <gvisor-bot@google.com> | 2021-07-20 12:07:23 -0700 |
| commit | 7ced03b3831983e35cb25ad0a9d5632ea322f9a4 (patch) | |
| tree | 4bd0c003ec35ca4d9aa5791d7ecd6b870e21aa5f | |
| parent | 5ad30cac2ede4eda318c78264e3b9810035ef27d (diff) | |
ring0: Initialize sentryXCR0 from Kernel.init()
Fixes #6300
PiperOrigin-RevId: 385840917
| -rw-r--r-- | pkg/ring0/kernel_amd64.go | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/pkg/ring0/kernel_amd64.go b/pkg/ring0/kernel_amd64.go index b5c4a39e3..a04b60b08 100644 --- a/pkg/ring0/kernel_amd64.go +++ b/pkg/ring0/kernel_amd64.go @@ -19,6 +19,7 @@ package ring0 import ( "encoding/binary" "reflect" + "sync" "gvisor.dev/gvisor/pkg/hostarch" "gvisor.dev/gvisor/pkg/sentry/arch" @@ -30,6 +31,8 @@ func HaltAndWriteFSBase(regs *arch.Registers) // init initializes architecture-specific state. func (k *Kernel) init(maxCPUs int) { + initSentryXCR0() + entrySize := reflect.TypeOf(kernelEntry{}).Size() var ( entries []kernelEntry @@ -257,7 +260,16 @@ func (c *CPU) SwitchToUser(switchOpts SwitchOpts) (vector Vector) { return } -var sentryXCR0 = xgetbv(0) +var ( + sentryXCR0 uintptr + sentryXCR0Once sync.Once +) + +// initSentryXCR0 saves a value of XCR0 in the host mode. It is used to +// initialize XCR0 of guest vCPU-s. +func initSentryXCR0() { + sentryXCR0Once.Do(func() { sentryXCR0 = xgetbv(0) }) +} // startGo is the CPU entrypoint. // |