Minor ring0 interface cleanup.

- Remove unused methods.
- Provide declaration for asm function.

PiperOrigin-RevId: 200146850
Change-Id: Ic455c96ffe0d2e78ef15f824eb65d7de705b054a

2 files changed, 7 insertions, 19 deletions

diff --git a/pkg/sentry/platform/ring0/kernel.go b/pkg/sentry/platform/ring0/kernel.go
index b0471ab9a..62e67005e 100644
--- a/pkg/sentry/platform/ring0/kernel.go
+++ b/pkg/sentry/platform/ring0/kernel.go
@@ -14,27 +14,13 @@
 
 package ring0
 
-// New creates a new kernel.
+// Init initializes a new kernel.
 //
 // N.B. that constraints on KernelOpts must be satisfied.
 //
-// Init must have been called.
-func New(opts KernelOpts) *Kernel {
-	k := new(Kernel)
+//go:nosplit
+func (k *Kernel) Init(opts KernelOpts) {
 	k.init(opts)
-	return k
-}
-
-// NewCPU creates a new CPU associated with this Kernel.
-//
-// Note that execution of the new CPU must begin at Start, with constraints as
-// documented. Initialization is not completed by this method alone.
-//
-// See also Init.
-func (k *Kernel) NewCPU() *CPU {
-	c := new(CPU)
-	c.Init(k)
-	return c
 }
 
 // Halt halts execution.
@@ -56,8 +42,7 @@ func defaultSyscall() { Halt() }
 //go:nosplit
 func defaultException(Vector) { Halt() }
 
-// Init allows the initialization of a CPU from a kernel without allocation.
-// The same constraints as NewCPU apply.
+// Init initializes a new CPU.
 //
 // Init allows embedding in other objects.
 func (c *CPU) Init(k *Kernel) {
diff --git a/pkg/sentry/platform/ring0/lib_amd64.go b/pkg/sentry/platform/ring0/lib_amd64.go
index de2842b5a..989e3e383 100644
--- a/pkg/sentry/platform/ring0/lib_amd64.go
+++ b/pkg/sentry/platform/ring0/lib_amd64.go
@@ -64,6 +64,9 @@ func wrgsmsr(addr uintptr)
 // writeCR3 writes the CR3 value.
 func writeCR3(phys uintptr)
 
+// readCR3 reads the current CR3 value.
+func readCR3() uintptr
+
 // readCR2 reads the current CR2 value.
 func readCR2() uintptr