linux/tools/testing/selftests/kvm/lib/loongarch/ucall.c
Bibo Mao 304b93b1a0 KVM: selftests: Add ucall test support for LoongArch
Add ucall test support for LoongArch, ucall method on LoongArch uses
undefined mmio area. It will cause vCPU exiting to hypervisor so that
hypervisor can communicate with vCPU.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2025-05-20 20:20:26 +08:00

38 lines
970 B
C

// SPDX-License-Identifier: GPL-2.0
/*
* ucall support. A ucall is a "hypercall to userspace".
*
*/
#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.
*/
vm_vaddr_t *ucall_exit_mmio_addr;
void ucall_arch_init(struct kvm_vm *vm, vm_paddr_t mmio_gpa)
{
vm_vaddr_t mmio_gva = vm_vaddr_unused_gap(vm, vm->page_size, KVM_UTIL_MIN_VADDR);
virt_map(vm, mmio_gva, mmio_gpa, 1);
vm->ucall_mmio_addr = mmio_gpa;
write_guest_global(vm, ucall_exit_mmio_addr, (vm_vaddr_t *)mmio_gva);
}
void *ucall_arch_get_ucall(struct kvm_vcpu *vcpu)
{
struct kvm_run *run = vcpu->run;
if (run->exit_reason == KVM_EXIT_MMIO &&
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");
return (void *)(*((uint64_t *)run->mmio.data));
}
return NULL;
}