At the moment if the end-user does not specify the gic-version along with KVM acceleration, v2 is set by default. However most of the systems now have GICv3 and sometimes they do not support GICv2 compatibility.
This patch keeps the default v2 selection in all cases except in the KVM accelerated mode when either - the host does not support GICv2 in-kernel emulation or - number of VCPUS exceeds 8. Those cases did not work anyway so we do not break any compatibility. Now we get v3 selected in such a case. Signed-off-by: Eric Auger <[email protected]> Reported-by: Dr. David Alan Gilbert <[email protected]> Reviewed-by: Andrew Jones <[email protected]> Reviewed-by: Richard Henderson <[email protected]> --- v2 -> v3: - add () --- hw/arm/virt.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/hw/arm/virt.c b/hw/arm/virt.c index aeb6c45e51..2d1dee50f8 100644 --- a/hw/arm/virt.c +++ b/hw/arm/virt.c @@ -1542,6 +1542,8 @@ static void virt_set_memmap(VirtMachineState *vms) */ static void finalize_gic_version(VirtMachineState *vms) { + unsigned int max_cpus = MACHINE(vms)->smp.max_cpus; + if (kvm_enabled()) { int probe_bitmap = kvm_arm_vgic_probe(); @@ -1552,7 +1554,17 @@ static void finalize_gic_version(VirtMachineState *vms) switch (vms->gic_version) { case VIRT_GIC_VERSION_NOSEL: - vms->gic_version = VIRT_GIC_VERSION_2; + if (((probe_bitmap & KVM_ARM_VGIC_V2) && max_cpus <= GIC_NCPU) || + !kvm_irqchip_in_kernel()) { + vms->gic_version = VIRT_GIC_VERSION_2; + } else { + /* + * in case the host does not support v2 in-kernel emulation or + * the end-user requested more than 8 VCPUs we now default + * to v3. In any case defaulting to v2 would be broken. + */ + vms->gic_version = VIRT_GIC_VERSION_3; + } break; case VIRT_GIC_VERSION_HOST: case VIRT_GIC_VERSION_MAX: -- 2.20.1
