KVM: selftests: Drop now-unnecessary ucall_uninit()

Drop ucall_uninit() and ucall_arch_uninit() now that ARM doesn't modify
the host's copy of ucall_exit_mmio_addr, i.e. now that there's no need to
reset the pointer before potentially creating a new VM.  The few calls to
ucall_uninit() are all immediately followed by kvm_vm_free(), and that is
likely always going to hold true, i.e. it's extremely unlikely a test
will want to effectively disable ucall in the middle of a test.

Reviewed-by: Andrew Jones <andrew.jones@linux.dev>
Tested-by: Peter Gonda <pgonda@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221006003409.649993-7-seanjc@google.com

tools/testing/selftests/kvm/aarch64/aarch32_id_regs.c

@@ -162,6 +162,5 @@ int main(void)
 	test_user_raz_invariant(vcpu);
 	test_guest_raz(vcpu);
 
-	ucall_uninit(vm);
 	kvm_vm_free(vm);
 }

tools/testing/selftests/kvm/dirty_log_test.c

@@ -811,7 +811,6 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 
 	free(bmap);
 	free(host_bmap_track);
-	ucall_uninit(vm);
 	kvm_vm_free(vm);
 }
 

tools/testing/selftests/kvm/include/ucall_common.h

@@ -25,7 +25,6 @@ struct ucall {
 };
 
 void ucall_arch_init(struct kvm_vm *vm, vm_paddr_t mmio_gpa);
-void ucall_arch_uninit(struct kvm_vm *vm);
 void ucall_arch_do_ucall(vm_vaddr_t uc);
 void *ucall_arch_get_ucall(struct kvm_vcpu *vcpu);
 
@@ -37,11 +36,6 @@ static inline void ucall_init(struct kvm_vm *vm, vm_paddr_t mmio_gpa)
 	ucall_arch_init(vm, mmio_gpa);
 }
 
-static inline void ucall_uninit(struct kvm_vm *vm)
-{
-	ucall_arch_uninit(vm);
-}
-
 #define GUEST_SYNC_ARGS(stage, arg1, arg2, arg3, arg4)	\
 				ucall(UCALL_SYNC, 6, "hello", stage, arg1, arg2, arg3, arg4)
 #define GUEST_SYNC(stage)	ucall(UCALL_SYNC, 2, "hello", stage)

tools/testing/selftests/kvm/kvm_page_table_test.c

@@ -416,7 +416,6 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	TEST_ASSERT(ret == 0, "Error in sem_destroy");
 
 	free(vcpu_threads);
-	ucall_uninit(vm);
 	kvm_vm_free(vm);
 }
 

tools/testing/selftests/kvm/lib/aarch64/ucall.c

@@ -12,23 +12,13 @@
  */
 static vm_vaddr_t *ucall_exit_mmio_addr;
 
-static void ucall_set_mmio_addr(struct kvm_vm *vm, vm_paddr_t mmio_gpa)
-{
-	vm->ucall_mmio_addr = mmio_gpa;
-
-	write_guest_global(vm, ucall_exit_mmio_addr, (vm_vaddr_t *)mmio_gpa);
-}
-
 void ucall_arch_init(struct kvm_vm *vm, vm_paddr_t mmio_gpa)
 {
 	virt_pg_map(vm, mmio_gpa, mmio_gpa);
 
-	ucall_set_mmio_addr(vm, mmio_gpa);
-}
+	vm->ucall_mmio_addr = mmio_gpa;
 
-void ucall_arch_uninit(struct kvm_vm *vm)
-{
-	ucall_set_mmio_addr(vm, (vm_paddr_t)NULL);
+	write_guest_global(vm, ucall_exit_mmio_addr, (vm_vaddr_t *)mmio_gpa);
 }
 
 void ucall_arch_do_ucall(vm_vaddr_t uc)

tools/testing/selftests/kvm/lib/memstress.c

@@ -229,7 +229,6 @@ struct kvm_vm *memstress_create_vm(enum vm_guest_mode mode, int nr_vcpus,
 
 void memstress_destroy_vm(struct kvm_vm *vm)
 {
-	ucall_uninit(vm);
 	kvm_vm_free(vm);
 }
 

tools/testing/selftests/kvm/lib/riscv/ucall.c

@@ -14,10 +14,6 @@ void ucall_arch_init(struct kvm_vm *vm, vm_paddr_t mmio_gpa)
 {
 }
 
-void ucall_arch_uninit(struct kvm_vm *vm)
-{
-}
-
 struct sbiret sbi_ecall(int ext, int fid, unsigned long arg0,
 			unsigned long arg1, unsigned long arg2,
 			unsigned long arg3, unsigned long arg4,

tools/testing/selftests/kvm/lib/s390x/ucall.c

@@ -10,10 +10,6 @@ void ucall_arch_init(struct kvm_vm *vm, vm_paddr_t mmio_gpa)
 {
 }
 
-void ucall_arch_uninit(struct kvm_vm *vm)
-{
-}
-
 void ucall_arch_do_ucall(vm_vaddr_t uc)
 {
 	/* Exit via DIAGNOSE 0x501 (normally used for breakpoints) */

tools/testing/selftests/kvm/lib/x86_64/ucall.c

@@ -12,10 +12,6 @@ void ucall_arch_init(struct kvm_vm *vm, vm_paddr_t mmio_gpa)
 {
 }
 
-void ucall_arch_uninit(struct kvm_vm *vm)
-{
-}
-
 void ucall_arch_do_ucall(vm_vaddr_t uc)
 {
 	asm volatile("in %[port], %%al"