Go 1.18 support for the KVM platform

It is similar with 36a17a814b ("Go 1.17 support for the KVM platform") that
fixed the same problem for x86. Go 1.18 adds the support of the register-based
calling convention on aarch64.

Signed-off-by: Andrei Vagin <avagin@gmail.com>

pkg/ring0/entry_arm64.go

@@ -47,12 +47,14 @@ func El0_irq_invalid()
 func El0_fiq_invalid()
 func El0_error_invalid()
 
-func Vectors()
+func vectors()
+func AddrOfVectors() uintptr
 
-// Start is the CPU entrypoint.
+// start is the CPU entrypoint.
 //
 // The CPU state will be set to c.Registers().
-func Start()
+func start()
+func AddrOfStart() uintptr
 func kernelExitToEl1()
 
 func kernelExitToEl0()

pkg/ring0/entry_arm64.s

@@ -611,8 +611,8 @@ TEXT ·kernelExitToEl1(SB),NOSPLIT,$0
 
 	ERET()
 
-// Start is the CPU entrypoint.
-TEXT ·Start(SB),NOSPLIT,$0
+// start is the CPU entrypoint.
+TEXT ·start(SB),NOSPLIT,$0
 	// Init.
 	WORD $0xd508871f    // __tlbi(vmalle1)
 	DSB $7          // dsb(nsh)
@@ -646,6 +646,12 @@ TEXT ·Start(SB),NOSPLIT,$0
 
 	B ·kernelExitToEl1(SB)
 
+// func AddrOfStart() uintptr
+TEXT ·AddrOfStart(SB), $0-8
+	MOVD	$·start(SB), R0
+	MOVD	R0, ret+0(FP)
+	RET
+
 // El1_sync_invalid is the handler for an invalid EL1_sync.
 TEXT ·El1_sync_invalid(SB),NOSPLIT,$0
 	B ·Shutdown(SB)
@@ -839,12 +845,12 @@ TEXT ·El0_fiq_invalid(SB),NOSPLIT,$0
 TEXT ·El0_error_invalid(SB),NOSPLIT,$0
 	B ·Shutdown(SB)
 
-// Vectors implements exception vector table.
+// vectors implements exception vector table.
 // The start address of exception vector table should be 11-bits aligned.
 // For detail, please refer to arm developer document:
 // https://developer.arm.com/documentation/100933/0100/AArch64-exception-vector-table
 // Also can refer to the code in linux kernel: arch/arm64/kernel/entry.S
-TEXT ·Vectors(SB),NOSPLIT,$0
+TEXT ·vectors(SB),NOSPLIT,$0
 	PCALIGN $2048
 	B ·El1_sync_invalid(SB)
 	PCALIGN $128
@@ -880,3 +886,9 @@ TEXT ·Vectors(SB),NOSPLIT,$0
 	B ·El0_fiq_invalid(SB)
 	PCALIGN $128
 	B ·El0_error_invalid(SB)
+
+// func AddrOfVectors() uintptr
+TEXT ·AddrOfVectors(SB), $0-8
+       MOVD    $·vectors(SB), R0
+       MOVD    R0, ret+0(FP)
+       RET

pkg/sentry/platform/kvm/machine_arm64_unsafe.go

@@ -122,7 +122,7 @@ func (c *vCPU) initArchState() error {
 
 	// pc
 	reg.id = _KVM_ARM64_REGS_PC
-	data = uint64(reflect.ValueOf(ring0.Start).Pointer())
+	data = uint64(ring0.AddrOfStart())
 	if err := c.setOneRegister(&reg); err != nil {
 		return err
 	}
@@ -136,7 +136,7 @@ func (c *vCPU) initArchState() error {
 
 	// vbar_el1
 	reg.id = _KVM_ARM64_REGS_VBAR_EL1
-	vectorLocation := reflect.ValueOf(ring0.Vectors).Pointer()
+	vectorLocation := ring0.AddrOfVectors()
 	data = uint64(ring0.KernelStartAddress | vectorLocation)
 	if err := c.setOneRegister(&reg); err != nil {
 		return err

pkg/sentry/platform/kvm/testutil/testutil_arm64.s

@@ -33,7 +33,7 @@ TEXT ·AddrOfGetpid(SB),NOSPLIT,$0-8
 	MOVD R0, ret+0(FP)
 	RET
 
-TEXT ·Touch(SB),NOSPLIT,$0
+TEXT ·touch(SB),NOSPLIT,$0
 start:
 	MOVD 0(R8), R1
 	MOVD $SYS_GETPID, R8   // getpid
@@ -41,37 +41,37 @@ start:
 	B start
 
 TEXT ·AddrOfTouch(SB),NOSPLIT,$0-8
-	MOVD $·Touch(SB), R0
+	MOVD $·touch(SB), R0
 	MOVD R0, ret+0(FP)
 	RET
 
-TEXT ·HaltLoop(SB),NOSPLIT,$0
+TEXT ·haltLoop(SB),NOSPLIT,$0
 start:
 	HLT
 	B start
 
 TEXT ·AddOfHaltLoop(SB),NOSPLIT,$0-8
-	MOVD $·HaltLoop(SB), R0
+	MOVD $·haltLoop(SB), R0
 	MOVD R0, ret+0(FP)
 	RET
 
 // This function simulates a loop of syscall.
-TEXT ·SyscallLoop(SB),NOSPLIT,$0
+TEXT ·syscallLoop(SB),NOSPLIT,$0
 start:
 	SVC
 	B start
 
 TEXT ·AddrOfSyscallLoop(SB),NOSPLIT,$0-8
-	MOVD $·SyscallLoop(SB), R0
+	MOVD $·syscallLoop(SB), R0
 	MOVD R0, ret+0(FP)
 	RET
 
-TEXT ·SpinLoop(SB),NOSPLIT,$0
+TEXT ·spinLoop(SB),NOSPLIT,$0
 start:
 	B start
 
 TEXT ·AddrOfSpinLoop(SB),NOSPLIT,$0-8
-	MOVD $·SpinLoop(SB), R0
+	MOVD $·spinLoop(SB), R0
 	MOVD R0, ret+0(FP)
 	RET
 
@@ -143,7 +143,7 @@ isNaN:
         MVN R29, R29; \
         MVN R30, R30;
 
-TEXT ·TwiddleRegsSyscall(SB),NOSPLIT,$0
+TEXT ·twiddleRegsSyscall(SB),NOSPLIT,$0
 	TWIDDLE_REGS()
 	MSR R10, TPIDR_EL0
 	// Trapped in el0_svc.
@@ -151,11 +151,11 @@ TEXT ·TwiddleRegsSyscall(SB),NOSPLIT,$0
 	RET // never reached
 
 TEXT ·AddrOfTwiddleRegsSyscall(SB),NOSPLIT,$0-8
-	MOVD $·TwiddleRegsSyscall(SB), R0
+	MOVD $·twiddleRegsSyscall(SB), R0
 	MOVD R0, ret+0(FP)
 	RET
 
-TEXT ·TwiddleRegsFault(SB),NOSPLIT,$0
+TEXT ·twiddleRegsFault(SB),NOSPLIT,$0
 	TWIDDLE_REGS()
 	MSR R10, TPIDR_EL0
 	// Trapped in el0_ia.
@@ -164,6 +164,6 @@ TEXT ·TwiddleRegsFault(SB),NOSPLIT,$0
 	RET // never reached
 
 TEXT ·AddrOfTwiddleRegsFault(SB),NOSPLIT,$0-8
-	MOVD $·TwiddleRegsFault(SB), R0
+	MOVD $·twiddleRegsFault(SB), R0
 	MOVD R0, ret+0(FP)
 	RET