Currently, the Q35 supports up to 4096 vCPUs (since v9.0), but for TCG
cases, if x2APIC is not actively enabled to boot more than 255 vCPUs (
e.g., qemu-system-i386 -M pc-q35-9.0 -smp 666), the following error is
reported:
Unexpected error in apic_common_set_id() at ../hw/intc/apic_common.c:449:
qemu-system-i386: APIC ID 255 requires x2APIC feature in CPU
Aborted (core dumped)
This error can be resolved by setting x2apic=on in -cpu. In order to
better help users deal with this scenario, add the error hint to
instruct users on how to enable the x2apic feature. Then, the error
report becomes the following:
Unexpected error in apic_common_set_id() at ../hw/intc/apic_common.c:448:
qemu-system-i386: APIC ID 255 requires x2APIC feature in CPU
Try x2apic=on in -cpu.
Aborted (core dumped)
Note since @errp is &error_abort, error_append_hint() can't be applied
on @errp. And in order to separate the exact error message from the
(perhaps effectively) hint, adding a hint via error_append_hint() is
also necessary. Therefore, introduce @local_error in
apic_common_set_id() to handle both the error message and the error
hint.
Suggested-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Message-Id: <20240606140858.2157106-1-zhao1.liu@intel.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>