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 <bin.lu@arm.com>
COPYBARA_INTEGRATE_REVIEW=https://github.com/google/gvisor/pull/919 from lubinszARM:pr_kvm eedea52db451bf62722759009a9f14c54a69c55f
PiperOrigin-RevId: 285501256

1 files changed, 9 insertions, 0 deletions

diff --git a/pkg/sentry/platform/kvm/kvm_amd64.go b/pkg/sentry/platform/kvm/kvm_amd64.go
index 5d8ef4761..c5a6f9c7d 100644
--- a/pkg/sentry/platform/kvm/kvm_amd64.go
+++ b/pkg/sentry/platform/kvm/kvm_amd64.go
@@ -17,6 +17,7 @@
 package kvm
 
 import (
+	"gvisor.dev/gvisor/pkg/cpuid"
 	"gvisor.dev/gvisor/pkg/sentry/platform/ring0"
 )
 
@@ -211,3 +212,11 @@ type cpuidEntries struct {
 	_       uint32
 	entries [_KVM_NR_CPUID_ENTRIES]cpuidEntry
 }
+
+// updateGlobalOnce does global initialization. It has to be called only once.
+func updateGlobalOnce(fd int) error {
+	physicalInit()
+	err := updateSystemValues(int(fd))
+	ring0.Init(cpuid.HostFeatureSet())
+	return err
+}