On Wednesday, August 4, 2021 8:00 PM, Ashish Kalra wrote:
> +/*
> + * Currently this exit is only used by SEV guests for
> + * MSR_KVM_MIGRATION_CONTROL to indicate if the guest
> + * is ready for migration.
> + */
> +static int kvm_handle_x86_msr(X86CPU *cpu, struct kvm_run *run) {
> + static uint64_t msr_kvm_migration_control;
> +
> + if (run->msr.index != MSR_KVM_MIGRATION_CONTROL) {
> + run->msr.error = -EINVAL;
> + return -1;
> + }
> +
> + switch (run->exit_reason) {
> + case KVM_EXIT_X86_RDMSR:
> + run->msr.error = 0;
> + run->msr.data = msr_kvm_migration_control;
> + break;
> + case KVM_EXIT_X86_WRMSR:
> + msr_kvm_migration_control = run->msr.data;
> + if (run->msr.data == KVM_MIGRATION_READY) {
> + sev_del_migrate_blocker();
It seems this is enabled/disabled by the guest, which means that the guest can
always refuse to be migrated?
Best,
Wei
