device: 0.935
graphic: 0.929
peripherals: 0.761
boot: 0.646
vnc: 0.616
architecture: 0.593
semantic: 0.588
performance: 0.585
debug: 0.546
register: 0.528
permissions: 0.524
mistranslation: 0.520
hypervisor: 0.484
socket: 0.471
PID: 0.469
kernel: 0.440
risc-v: 0.369
ppc: 0.361
network: 0.346
x86: 0.340
files: 0.337
VMM: 0.330
user-level: 0.256
arm: 0.222
i386: 0.208
assembly: 0.175
virtual: 0.144
TCG: 0.140
KVM: 0.031

QEMU fails with duplicate SaveStateEntry when using two legacy virtio input devices
Description of problem:
QEMU bails out when it is started with two virtio-input devices running in legacy virtio mode, using two different transports (like PCI and CCW on s390x).
Steps to reproduce:
```
qemu-system-s390x -M s390-ccw-virtio-2.6 -cpu max -nographic -device virtio-multitouch-pci -device virtio-tablet-ccw
```
fails with:
```
qemu-system-s390x: -device virtio-tablet-ccw: savevm_state_handler_insert: Detected duplicate SaveStateEntry: id=virtio-input, instance_id=0x0
```
Additional information:
The problem does *not* occur if using modern virtio devices (which automatically happens for -M s390-ccw-virtio-2.7 and newer) or if using virtio-input devices with the same transport (e.g. two PCI devices instead of one PCI and one CCW).

Also note that the problem only occurs since QEMU 8.1 since older versions did not check for duplicate SaveStateEntries (see commit caa91b3c44cdb2d2921e25 ).