From 6b424530397e5100b08628efe8f6c62178daa70b Mon Sep 17 00:00:00 2001 From: lubinszARM <34124929+lubinszARM@users.noreply.github.com> Date: Fri, 13 Dec 2019 17:09:55 -0800 Subject: enable kvm to support arm64 There are 4 jobs were finished in this package: 1, Virtual machine initialization. 2, Bluepill implementation. 3, Move ring0.Vectors() into the address with 11-bits alignment. 4, Basic support for "SwitchToUser". Signed-off-by: Bin Lu COPYBARA_INTEGRATE_REVIEW=https://github.com/google/gvisor/pull/919 from lubinszARM:pr_kvm eedea52db451bf62722759009a9f14c54a69c55f PiperOrigin-RevId: 285501256 --- pkg/sentry/platform/kvm/bluepill.go | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) (limited to 'pkg/sentry/platform/kvm/bluepill.go') diff --git a/pkg/sentry/platform/kvm/bluepill.go b/pkg/sentry/platform/kvm/bluepill.go index 043de51b3..30dbb74d6 100644 --- a/pkg/sentry/platform/kvm/bluepill.go +++ b/pkg/sentry/platform/kvm/bluepill.go @@ -20,6 +20,7 @@ import ( "syscall" "gvisor.dev/gvisor/pkg/sentry/arch" + "gvisor.dev/gvisor/pkg/sentry/platform/ring0" "gvisor.dev/gvisor/pkg/sentry/platform/safecopy" ) @@ -36,6 +37,18 @@ func sighandler() func dieTrampoline() var ( + // bounceSignal is the signal used for bouncing KVM. + // + // We use SIGCHLD because it is not masked by the runtime, and + // it will be ignored properly by other parts of the kernel. + bounceSignal = syscall.SIGCHLD + + // bounceSignalMask has only bounceSignal set. + bounceSignalMask = uint64(1 << (uint64(bounceSignal) - 1)) + + // bounce is the interrupt vector used to return to the kernel. + bounce = uint32(ring0.VirtualizationException) + // savedHandler is a pointer to the previous handler. // // This is called by bluepillHandler. @@ -45,6 +58,13 @@ var ( dieTrampolineAddr uintptr ) +// redpill invokes a syscall with -1. +// +//go:nosplit +func redpill() { + syscall.RawSyscall(^uintptr(0), 0, 0, 0) +} + // dieHandler is called by dieTrampoline. // //go:nosplit @@ -73,8 +93,8 @@ func (c *vCPU) die(context *arch.SignalContext64, msg string) { func init() { // Install the handler. - if err := safecopy.ReplaceSignalHandler(syscall.SIGSEGV, reflect.ValueOf(sighandler).Pointer(), &savedHandler); err != nil { - panic(fmt.Sprintf("Unable to set handler for signal %d: %v", syscall.SIGSEGV, err)) + if err := safecopy.ReplaceSignalHandler(bluepillSignal, reflect.ValueOf(sighandler).Pointer(), &savedHandler); err != nil { + panic(fmt.Sprintf("Unable to set handler for signal %d: %v", bluepillSignal, err)) } // Extract the address for the trampoline. -- cgit v1.2.3