Commit 4ca1238e authored by @zhanghailiang's avatar @zhanghailiang Committed by zhuyanting
Browse files

migration: Compat virtual timer adjust for v4.0.1 and v4.1.0 



Vtimer adjust is used in openEuler qemu-4.0.1, however kvm_adjvtime
is introduced in openEuler qemu-4.1.0. To maintain the compatibility
and enable cross version migration, let's enable vtimer adjust only
if kvm_adjvtime is not enabled, otherwise there may be conflicts
between vtimer adjust and kvm_adjvtime.

After this modification:
1: openEuler qemu-4.0.1 use vtimer as the default virtual timer
2: openEuler qemu-4.1.0 use kvm_adjvtime as the defaut virtual timer

Migration from openEuler qemu-4.0.1 to openEuler qemu-4.1.0 will
be ok, but migration path from upstream qemu-4.0.1 to openEuler
qemu-4..0.1 will be broken.

Since openEuler qemu-4.1.0, kvm_adjvtime is used as the default
virtual timer. So please upgrade to openEuler qemu-4.1.0 and
use the virt-4.1 machine.

Signed-off-by: default avatarYing Fang <fangying1@huawei.com>
parent 3a71cb4c

cpus.c

+18 −2
Original line number Diff line number Diff line
@@ -1067,6 +1067,12 @@ void cpu_synchronize_all_pre_loadvm(void) 
}



#ifdef __aarch64__

static bool kvm_adjvtime_enabled(CPUState *cs)

{

    ARMCPU *cpu = ARM_CPU(cs);

    return cpu->kvm_adjvtime == true;

}



static void get_vcpu_timer_tick(CPUState *cs)

{

    CPUARMState *env = &ARM_CPU(cs)->env;
@@ -1096,7 +1102,13 @@ static int do_vm_stop(RunState state, bool send_stop) 
        cpu_disable_ticks();

        pause_all_vcpus();

#ifdef __aarch64__

        if (first_cpu) {

        /* vtimer adjust is used in openEuler qemu-4.0.1, however kvm_adjvtime

         * is introduced in openEuler qemu-4.1.0. To maintain the compatibility

         * and enable cross version migration, let's enable vtimer adjust only

         * if kvm_adjvtime is not enabled, otherwise there may be conflicts

         * between vtimer adjust and kvm_adjvtime.

         */

        if (first_cpu && !kvm_adjvtime_enabled(first_cpu)) {

            get_vcpu_timer_tick(first_cpu);

        }

#endif
@@ -1946,6 +1958,7 @@ void cpu_resume(CPUState *cpu) 
}



#ifdef __aarch64__



static void set_vcpu_timer_tick(CPUState *cs)

{

    CPUARMState *env = &ARM_CPU(cs)->env;
@@ -1977,7 +1990,10 @@ void resume_all_vcpus(void) 


    qemu_clock_enable(QEMU_CLOCK_VIRTUAL, true);

#ifdef __aarch64__

    if (first_cpu) {

    /* Enable vtimer adjust only if kvm_adjvtime is not enabled, otherwise

     * there may be conflicts between vtimer adjust and kvm_adjvtime.

     */

    if (first_cpu && !kvm_adjvtime_enabled(first_cpu)) {

        set_vcpu_timer_tick(first_cpu);

    }

#endif