Commit 97b4c918 authored by Eric Auger's avatar Eric Auger Committed by Peter Maydell
Browse files

hw/arm/virt: kvm: Restructure finalize_gic_version() 



Restructure the finalize_gic_version with switch cases and
clearly separate the following cases:

- KVM mode / in-kernel irqchip
- KVM mode / userspace irqchip
- TCG mode

In KVM mode / in-kernel irqchip , we explictly check whether
the chosen version is supported by the host. If the end-user
explicitly sets v2/v3 and this is not supported by the host,
then the user gets an explicit error message. Note that for
old kernels where the CREATE_DEVICE ioctl doesn't exist then
we will now fail if the user specifically asked for gicv2,
where previously we (probably) would have succeeded.

In KVM mode / userspace irqchip we immediatly output an error
in case the end-user explicitly selected v3. Also we warn the
end-user about the unexpected usage of gic-version=host in
that case as only userspace GICv2 is supported.

Signed-off-by: default avatarEric Auger <eric.auger@redhat.com>
Reviewed-by: default avatarAndrew Jones <drjones@redhat.com>
Message-id: 20200311131618.7187-6-eric.auger@redhat.com
Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
parent d45efe47

hw/arm/virt.c

+66 −20
Original line number Diff line number Diff line
@@ -1543,33 +1543,79 @@ static void virt_set_memmap(VirtMachineState *vms) 
 */

static void finalize_gic_version(VirtMachineState *vms)

{

    if (vms->gic_version == VIRT_GIC_VERSION_HOST ||

        vms->gic_version == VIRT_GIC_VERSION_MAX) {

        if (!kvm_enabled()) {

            if (vms->gic_version == VIRT_GIC_VERSION_HOST) {

                error_report("gic-version=host requires KVM");

    if (kvm_enabled()) {

        int probe_bitmap;



        if (!kvm_irqchip_in_kernel()) {

            switch (vms->gic_version) {

            case VIRT_GIC_VERSION_HOST:

                warn_report(

                    "gic-version=host not relevant with kernel-irqchip=off "

                     "as only userspace GICv2 is supported. Using v2 ...");

                return;

            case VIRT_GIC_VERSION_MAX:

            case VIRT_GIC_VERSION_NOSEL:

                vms->gic_version = VIRT_GIC_VERSION_2;

                return;

            case VIRT_GIC_VERSION_2:

                return;

            case VIRT_GIC_VERSION_3:

                error_report(

                    "gic-version=3 is not supported with kernel-irqchip=off");

                exit(1);

            } else {

                /* "max": currently means 3 for TCG */

                vms->gic_version = VIRT_GIC_VERSION_3;

            }

        } else {

            int probe_bitmap = kvm_arm_vgic_probe();

        }



        probe_bitmap = kvm_arm_vgic_probe();

        if (!probe_bitmap) {

                error_report(

                    "Unable to determine GIC version supported by host");

            error_report("Unable to determine GIC version supported by host");

            exit(1);

            } else {

        }



        switch (vms->gic_version) {

        case VIRT_GIC_VERSION_HOST:

        case VIRT_GIC_VERSION_MAX:

            if (probe_bitmap & KVM_ARM_VGIC_V3) {

                vms->gic_version = VIRT_GIC_VERSION_3;

            } else {

                vms->gic_version = VIRT_GIC_VERSION_2;

            }

            return;

        case VIRT_GIC_VERSION_NOSEL:

            vms->gic_version = VIRT_GIC_VERSION_2;

            break;

        case VIRT_GIC_VERSION_2:

        case VIRT_GIC_VERSION_3:

            break;

        }



        /* Check chosen version is effectively supported by the host */

        if (vms->gic_version == VIRT_GIC_VERSION_2 &&

            !(probe_bitmap & KVM_ARM_VGIC_V2)) {

            error_report("host does not support in-kernel GICv2 emulation");

            exit(1);

        } else if (vms->gic_version == VIRT_GIC_VERSION_3 &&

                   !(probe_bitmap & KVM_ARM_VGIC_V3)) {

            error_report("host does not support in-kernel GICv3 emulation");

            exit(1);

        }

    } else if (vms->gic_version == VIRT_GIC_VERSION_NOSEL) {

        return;

    }



    /* TCG mode */

    switch (vms->gic_version) {

    case VIRT_GIC_VERSION_NOSEL:

        vms->gic_version = VIRT_GIC_VERSION_2;

        break;

    case VIRT_GIC_VERSION_MAX:

        vms->gic_version = VIRT_GIC_VERSION_3;

        break;

    case VIRT_GIC_VERSION_HOST:

        error_report("gic-version=host requires KVM");

        exit(1);

    case VIRT_GIC_VERSION_2:

    case VIRT_GIC_VERSION_3:

        break;

    }

}