On Fri, Feb 01, 2019 at 12:37:16PM +0000, Andre Przywara wrote: > At the moment kvmtool always tries to instantiate a virtual GICv2 for > the guest, and fails with some scary error message if that doesn't work. > The user has then to manually specify "--irqchip=gicv3", which is not > really obvious. > With the advent of more GICv3-only machines, let's try to be more > clever and implement some auto-detection of the GIC type needed: > We try gicv3-its, gicv3, gicv2m and gicv2, in that order. That first one > succeeding wins. > For GICv2 machines the first two will always fail. For GICv2-backwards > compatible GICv3 machines GICv3 is probably the better choice these days. > > This algorithm is in effect is there is no explicit --irqchip parameter > on the command line. We still allow the GIC type to be set explicitly. > > Signed-off-by: Andre Przywara <[email protected]> > --- > arm/gic.c | 25 +++++++++++++++++++++++++ > arm/include/arm-common/gic.h | 1 + > 2 files changed, 26 insertions(+) > > diff --git a/arm/gic.c b/arm/gic.c > index abcbcc09..a86da20e 100644 > --- a/arm/gic.c > +++ b/arm/gic.c > @@ -182,6 +182,8 @@ static int gic__create_device(struct kvm *kvm, enum > irqchip_type type) > gic_device.type = KVM_DEV_TYPE_ARM_VGIC_V3; > dist_attr.attr = KVM_VGIC_V3_ADDR_TYPE_DIST; > break; > + case IRQCHIP_AUTO: > + return -ENODEV; > } > > err = ioctl(kvm->vm_fd, KVM_CREATE_DEVICE, &gic_device); > @@ -199,6 +201,8 @@ static int gic__create_device(struct kvm *kvm, enum > irqchip_type type) > case IRQCHIP_GICV3: > err = ioctl(gic_fd, KVM_SET_DEVICE_ATTR, &redist_attr); > break; > + case IRQCHIP_AUTO: > + return -ENODEV; > } > if (err) > goto out_err; > @@ -249,9 +253,30 @@ static int gic__create_irqchip(struct kvm *kvm) > > int gic__create(struct kvm *kvm, enum irqchip_type type) > { > + enum irqchip_type try; > int err; > > switch (type) { > + case IRQCHIP_AUTO: > + try = IRQCHIP_GICV3_ITS; > + err = gic__create(kvm, try); > + if (err) { > + try = IRQCHIP_GICV3; > + err = gic__create(kvm, try); > + } > + if (err) { > + try = IRQCHIP_GICV2M; > + err = gic__create(kvm, try); > + } > + if (err) { > + try = IRQCHIP_GICV2; > + err = gic__create(kvm, try); > + } > + if (err) > + return err;
Easier to write this as a descending loop over the irqchip_type enum? Will _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
