/*
 * KVM_GET/SET_* tests
 *
 * Copyright (C) 2018, Red Hat, Inc.
 *
 * This work is licensed under the terms of the GNU GPL, version 2.
 *
 * Tests for vCPU state save/restore, including nested guest state.
 */
#define _GNU_SOURCE /* for program_invocation_short_name */
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>

#include "test_util.h"

#include "kvm_util.h"
#include "processor.h"
#include "vmx.h"

#define VCPU_ID         5

static bool have_nested_state;

void l2_guest_code(void)
{
        GUEST_SYNC(6);

        /* Exit to L1 */
        vmcall();

        /* L1 has now set up a shadow VMCS for us.  */
        GUEST_ASSERT(vmreadz(GUEST_RIP) == 0xc0ffee);
        GUEST_SYNC(10);
        GUEST_ASSERT(vmreadz(GUEST_RIP) == 0xc0ffee);
        GUEST_ASSERT(!vmwrite(GUEST_RIP, 0xc0fffee));
        GUEST_SYNC(11);
        GUEST_ASSERT(vmreadz(GUEST_RIP) == 0xc0fffee);
        GUEST_ASSERT(!vmwrite(GUEST_RIP, 0xc0ffffee));
        GUEST_SYNC(12);

        /* Done, exit to L1 and never come back.  */
        vmcall();
}

void l1_guest_code(struct vmx_pages *vmx_pages)
{
#define L2_GUEST_STACK_SIZE 64
        unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];

        GUEST_ASSERT(vmx_pages->vmcs_gpa);
        GUEST_ASSERT(prepare_for_vmx_operation(vmx_pages));
        GUEST_SYNC(3);
        GUEST_ASSERT(load_vmcs(vmx_pages));
        GUEST_ASSERT(vmptrstz() == vmx_pages->vmcs_gpa);

        GUEST_SYNC(4);
        GUEST_ASSERT(vmptrstz() == vmx_pages->vmcs_gpa);

        prepare_vmcs(vmx_pages, l2_guest_code,
                     &l2_guest_stack[L2_GUEST_STACK_SIZE]);

        GUEST_SYNC(5);
        GUEST_ASSERT(vmptrstz() == vmx_pages->vmcs_gpa);
        GUEST_ASSERT(!vmlaunch());
        GUEST_ASSERT(vmptrstz() == vmx_pages->vmcs_gpa);
        GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);

        /* Check that the launched state is preserved.  */
        GUEST_ASSERT(vmlaunch());

        GUEST_ASSERT(!vmresume());
        GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);

        GUEST_SYNC(7);
        GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);

        GUEST_ASSERT(!vmresume());
        GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);

        vmwrite(GUEST_RIP, vmreadz(GUEST_RIP) + 3);

        vmwrite(SECONDARY_VM_EXEC_CONTROL, SECONDARY_EXEC_SHADOW_VMCS);
        vmwrite(VMCS_LINK_POINTER, vmx_pages->shadow_vmcs_gpa);

        GUEST_ASSERT(!vmptrld(vmx_pages->shadow_vmcs_gpa));
        GUEST_ASSERT(vmlaunch());
        GUEST_SYNC(8);
        GUEST_ASSERT(vmlaunch());
        GUEST_ASSERT(vmresume());

        vmwrite(GUEST_RIP, 0xc0ffee);
        GUEST_SYNC(9);
        GUEST_ASSERT(vmreadz(GUEST_RIP) == 0xc0ffee);

        GUEST_ASSERT(!vmptrld(vmx_pages->vmcs_gpa));
        GUEST_ASSERT(!vmresume());
        GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);

        GUEST_ASSERT(!vmptrld(vmx_pages->shadow_vmcs_gpa));
        GUEST_ASSERT(vmreadz(GUEST_RIP) == 0xc0ffffee);
        GUEST_ASSERT(vmlaunch());
        GUEST_ASSERT(vmresume());
        GUEST_SYNC(13);
        GUEST_ASSERT(vmreadz(GUEST_RIP) == 0xc0ffffee);
        GUEST_ASSERT(vmlaunch());
        GUEST_ASSERT(vmresume());
}

void guest_code(struct vmx_pages *vmx_pages)
{
        GUEST_SYNC(1);
        GUEST_SYNC(2);

        if (vmx_pages)
                l1_guest_code(vmx_pages);

        GUEST_DONE();
}

int main(int argc, char *argv[])
{
        struct vmx_pages *vmx_pages = NULL;
        vm_vaddr_t vmx_pages_gva = 0;

        struct kvm_regs regs1, regs2;
        struct kvm_vm *vm;
        struct kvm_run *run;
        struct kvm_x86_state *state;
        struct ucall uc;
        int stage;

        struct kvm_cpuid_entry2 *entry = kvm_get_supported_cpuid_entry(1);

        /* Create VM */
        vm = vm_create_default(VCPU_ID, 0, guest_code);
        vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
        run = vcpu_state(vm, VCPU_ID);

        vcpu_regs_get(vm, VCPU_ID, &regs1);

        if (kvm_check_cap(KVM_CAP_NESTED_STATE)) {
                vmx_pages = vcpu_alloc_vmx(vm, &vmx_pages_gva);
                vcpu_args_set(vm, VCPU_ID, 1, vmx_pages_gva);
        } else {
                printf("will skip nested state checks\n");
                vcpu_args_set(vm, VCPU_ID, 1, 0);
        }

        for (stage = 1;; stage++) {
                _vcpu_run(vm, VCPU_ID);
                TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
                            "Stage %d: unexpected exit reason: %u (%s),\n",
                            stage, run->exit_reason,
                            exit_reason_str(run->exit_reason));

                memset(&regs1, 0, sizeof(regs1));
                vcpu_regs_get(vm, VCPU_ID, &regs1);
                switch (get_ucall(vm, VCPU_ID, &uc)) {
                case UCALL_ABORT:
                        TEST_ASSERT(false, "%s at %s:%d", (const char *)uc.args[0],
                                    __FILE__, uc.args[1]);
                        /* NOT REACHED */
                case UCALL_SYNC:
                        break;
                case UCALL_DONE:
                        goto done;
                default:
                        TEST_ASSERT(false, "Unknown ucall 0x%x.", uc.cmd);
                }

                /* UCALL_SYNC is handled here.  */
                TEST_ASSERT(!strcmp((const char *)uc.args[0], "hello") &&
                            uc.args[1] == stage, "Unexpected register values vmexit #%lx, got %lx",
                            stage, (ulong)uc.args[1]);

                state = vcpu_save_state(vm, VCPU_ID);
                kvm_vm_release(vm);

                /* Restore state in a new VM.  */
                kvm_vm_restart(vm, O_RDWR);
                vm_vcpu_add(vm, VCPU_ID, 0, 0);
                vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
                vcpu_load_state(vm, VCPU_ID, state);
                run = vcpu_state(vm, VCPU_ID);
                free(state);

                memset(&regs2, 0, sizeof(regs2));
                vcpu_regs_get(vm, VCPU_ID, &regs2);
                TEST_ASSERT(!memcmp(&regs1, &regs2, sizeof(regs2)),
                            "Unexpected register values after vcpu_load_state; rdi: %lx rsi: %lx",
                            (ulong) regs2.rdi, (ulong) regs2.rsi);
        }

done:
        kvm_vm_free(vm);
}