// SPDX-License-Identifier: GPL-2.0-only
/*
 * Test edge cases and race conditions in kvm_recalculate_apic_map().
 */

#include <sys/ioctl.h>
#include <pthread.h>
#include <time.h>

#include "processor.h"
#include "test_util.h"
#include "kvm_util.h"
#include "apic.h"

#define TIMEOUT         5       /* seconds */

#define LAPIC_DISABLED  0
#define LAPIC_X2APIC    (MSR_IA32_APICBASE_ENABLE | X2APIC_ENABLE)
#define MAX_XAPIC_ID    0xff

static void *race(void *arg)
{
        struct kvm_lapic_state lapic = {};
        struct kvm_vcpu *vcpu = arg;

        while (1) {
                /* Trigger kvm_recalculate_apic_map(). */
                vcpu_ioctl(vcpu, KVM_SET_LAPIC, &lapic);
                pthread_testcancel();
        }

        return NULL;
}

int main(void)
{
        struct kvm_vcpu *vcpus[KVM_MAX_VCPUS];
        struct kvm_vcpu *vcpuN;
        struct kvm_vm *vm;
        pthread_t thread;
        time_t t;
        int i;

        kvm_static_assert(KVM_MAX_VCPUS > MAX_XAPIC_ID);

        /*
         * Create the max number of vCPUs supported by selftests so that KVM
         * has decent amount of work to do when recalculating the map, i.e. to
         * make the problematic window large enough to hit.
         */
        vm = vm_create_with_vcpus(KVM_MAX_VCPUS, NULL, vcpus);

        /*
         * Enable x2APIC on all vCPUs so that KVM doesn't bail from the recalc
         * due to vCPUs having aliased xAPIC IDs (truncated to 8 bits).
         */
        for (i = 0; i < KVM_MAX_VCPUS; i++)
                vcpu_set_msr(vcpus[i], MSR_IA32_APICBASE, LAPIC_X2APIC);

        TEST_ASSERT_EQ(pthread_create(&thread, NULL, race, vcpus[0]), 0);

        vcpuN = vcpus[KVM_MAX_VCPUS - 1];
        for (t = time(NULL) + TIMEOUT; time(NULL) < t;) {
                vcpu_set_msr(vcpuN, MSR_IA32_APICBASE, LAPIC_X2APIC);
                vcpu_set_msr(vcpuN, MSR_IA32_APICBASE, LAPIC_DISABLED);
        }

        TEST_ASSERT_EQ(pthread_cancel(thread), 0);
        TEST_ASSERT_EQ(pthread_join(thread, NULL), 0);

        kvm_vm_free(vm);

        return 0;
}