1 files changed, 15 insertions, 87 deletions

diff --git a/tools/testing/selftests/kvm/lib/aarch64/ucall.c b/tools/testing/selftests/kvm/lib/aarch64/ucall.c
index ed237b744690..562c16dfbb00 100644
--- a/tools/testing/selftests/kvm/lib/aarch64/ucall.c
+++ b/tools/testing/selftests/kvm/lib/aarch64/ucall.c
@@ -6,108 +6,36 @@
  */
 #include "kvm_util.h"
 
+/*
+ * ucall_exit_mmio_addr holds per-VM values (global data is duplicated by each
+ * VM), it must not be accessed from host code.
+ */
 static vm_vaddr_t *ucall_exit_mmio_addr;
 
-static bool ucall_mmio_init(struct kvm_vm *vm, vm_paddr_t gpa)
-{
-	if (kvm_userspace_memory_region_find(vm, gpa, gpa + 1))
-		return false;
-
-	virt_pg_map(vm, gpa, gpa);
-
-	ucall_exit_mmio_addr = (vm_vaddr_t *)gpa;
-	sync_global_to_guest(vm, ucall_exit_mmio_addr);
-
-	return true;
-}
-
-void ucall_init(struct kvm_vm *vm, void *arg)
+void ucall_arch_init(struct kvm_vm *vm, vm_paddr_t mmio_gpa)
 {
-	vm_paddr_t gpa, start, end, step, offset;
-	unsigned int bits;
-	bool ret;
+	virt_pg_map(vm, mmio_gpa, mmio_gpa);
 
-	if (arg) {
-		gpa = (vm_paddr_t)arg;
-		ret = ucall_mmio_init(vm, gpa);
-		TEST_ASSERT(ret, "Can't set ucall mmio address to %lx", gpa);
-		return;
-	}
+	vm->ucall_mmio_addr = mmio_gpa;
 
-	/*
-	 * Find an address within the allowed physical and virtual address
-	 * spaces, that does _not_ have a KVM memory region associated with
-	 * it. Identity mapping an address like this allows the guest to
-	 * access it, but as KVM doesn't know what to do with it, it
-	 * will assume it's something userspace handles and exit with
-	 * KVM_EXIT_MMIO. Well, at least that's how it works for AArch64.
-	 * Here we start with a guess that the addresses around 5/8th
-	 * of the allowed space are unmapped and then work both down and
-	 * up from there in 1/16th allowed space sized steps.
-	 *
-	 * Note, we need to use VA-bits - 1 when calculating the allowed
-	 * virtual address space for an identity mapping because the upper
-	 * half of the virtual address space is the two's complement of the
-	 * lower and won't match physical addresses.
-	 */
-	bits = vm->va_bits - 1;
-	bits = min(vm->pa_bits, bits);
-	end = 1ul << bits;
-	start = end * 5 / 8;
-	step = end / 16;
-	for (offset = 0; offset < end - start; offset += step) {
-		if (ucall_mmio_init(vm, start - offset))
-			return;
-		if (ucall_mmio_init(vm, start + offset))
-			return;
-	}
-	TEST_FAIL("Can't find a ucall mmio address");
+	write_guest_global(vm, ucall_exit_mmio_addr, (vm_vaddr_t *)mmio_gpa);
 }
 
-void ucall_uninit(struct kvm_vm *vm)
+void ucall_arch_do_ucall(vm_vaddr_t uc)
 {
-	ucall_exit_mmio_addr = 0;
-	sync_global_to_guest(vm, ucall_exit_mmio_addr);
+	WRITE_ONCE(*ucall_exit_mmio_addr, uc);
 }
 
-void ucall(uint64_t cmd, int nargs, ...)
-{
-	struct ucall uc = {};
-	va_list va;
-	int i;
-
-	WRITE_ONCE(uc.cmd, cmd);
-	nargs = min(nargs, UCALL_MAX_ARGS);
-
-	va_start(va, nargs);
-	for (i = 0; i < nargs; ++i)
-		WRITE_ONCE(uc.args[i], va_arg(va, uint64_t));
-	va_end(va);
-
-	WRITE_ONCE(*ucall_exit_mmio_addr, (vm_vaddr_t)&uc);
-}
-
-uint64_t get_ucall(struct kvm_vcpu *vcpu, struct ucall *uc)
+void *ucall_arch_get_ucall(struct kvm_vcpu *vcpu)
 {
 	struct kvm_run *run = vcpu->run;
-	struct ucall ucall = {};
-
-	if (uc)
-		memset(uc, 0, sizeof(*uc));
 
 	if (run->exit_reason == KVM_EXIT_MMIO &&
-	    run->mmio.phys_addr == (uint64_t)ucall_exit_mmio_addr) {
-		vm_vaddr_t gva;
-
-		TEST_ASSERT(run->mmio.is_write && run->mmio.len == 8,
+	    run->mmio.phys_addr == vcpu->vm->ucall_mmio_addr) {
+		TEST_ASSERT(run->mmio.is_write && run->mmio.len == sizeof(uint64_t),
 			    "Unexpected ucall exit mmio address access");
-		memcpy(&gva, run->mmio.data, sizeof(gva));
-		memcpy(&ucall, addr_gva2hva(vcpu->vm, gva), sizeof(ucall));
-
-		vcpu_run_complete_io(vcpu);
-		if (uc)
-			memcpy(uc, &ucall, sizeof(ucall));
+		return (void *)(*((uint64_t *)run->mmio.data));
 	}
 
-	return ucall.cmd;
+	return NULL;
 }