Commit 12604092 authored by Liran Alon's avatar Liran Alon Committed by Paolo Bonzini
Browse files

target/i386: kvm: Add nested migration blocker only when kernel lacks required capabilities 



Previous commits have added support for migration of nested virtualization
workloads. This was done by utilising two new KVM capabilities:
KVM_CAP_NESTED_STATE and KVM_CAP_EXCEPTION_PAYLOAD. Both which are
required in order to correctly migrate such workloads.

Therefore, change code to add a migration blocker for vCPUs exposed with
Intel VMX or AMD SVM in case one of these kernel capabilities is
missing.

Signed-off-by: default avatarLiran Alon <liran.alon@oracle.com>
Reviewed-by: default avatarMaran Wilson <maran.wilson@oracle.com>
Message-Id: <20190619162140.133674-11-liran.alon@oracle.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent fd13f23b

target/i386/kvm.c

+7 −2
Original line number Diff line number Diff line
@@ -1640,9 +1640,14 @@ int kvm_arch_init_vcpu(CPUState *cs) 
                                  !!(c->ecx & CPUID_EXT_SMX);

    }



    if (cpu_has_nested_virt(env) && !nested_virt_mig_blocker) {

    if (cpu_has_vmx(env) && !nested_virt_mig_blocker &&

        ((kvm_max_nested_state_length() <= 0) || !has_exception_payload)) {

        error_setg(&nested_virt_mig_blocker,

                   "Nested virtualization does not support live migration yet");

                   "Kernel do not provide required capabilities for "

                   "nested virtualization migration. "

                   "(CAP_NESTED_STATE=%d, CAP_EXCEPTION_PAYLOAD=%d)",

                   kvm_max_nested_state_length() > 0,

                   has_exception_payload);

        r = migrate_add_blocker(nested_virt_mig_blocker, &local_err);

        if (local_err) {

            error_report_err(local_err);

target/i386/machine.c

+1 −1
Original line number Diff line number Diff line
@@ -233,7 +233,7 @@ static int cpu_pre_save(void *opaque) 


#ifdef CONFIG_KVM

    /* Verify we have nested virtualization state from kernel if required */

    if (cpu_has_nested_virt(env) && !env->nested_state) {

    if (kvm_enabled() && cpu_has_vmx(env) && !env->nested_state) {

        error_report("Guest enabled nested virtualization but kernel "

                "does not support saving of nested state");

        return -EINVAL;