IRQ differences with ACPI patches

gistfile1.txt

# ttyS0 interrupt present

root@cloud-hypervisor ~ # cat /proc/cmdline 
console=ttyS0 console=hvc0 root=/dev/vda3 quiet acpi=off

root@cloud-hypervisor ~ # cat /proc/interrupts 
           CPU0       
  4:          5   IO-APIC   4-edge      ttyS0
 24:          1   PCI-MSI 16384-edge      virtio0-config
 25:         50   PCI-MSI 16385-edge      virtio0-virtqueues
 26:          0   PCI-MSI 65536-edge      virtio3-config
 27:          7   PCI-MSI 65537-edge      virtio3-input
 28:          0   PCI-MSI 32768-edge      virtio1-config
 29:       2258   PCI-MSI 32769-edge      virtio1-req.0
 30:          0   PCI-MSI 49152-edge      virtio2-config
 31:          0   PCI-MSI 49153-edge      virtio2-virtqueues
NMI:          0   Non-maskable interrupts
LOC:       1126   Local timer interrupts
SPU:          0   Spurious interrupts
PMI:          0   Performance monitoring interrupts
IWI:         22   IRQ work interrupts
RTR:          0   APIC ICR read retries
RES:          0   Rescheduling interrupts
CAL:          0   Function call interrupts
TLB:          0   TLB shootdowns
ERR:          0
MIS:          0
PIN:          0   Posted-interrupt notification event
NPI:          0   Nested posted-interrupt event

root@cloud-hypervisor ~ # dmesg | grep ttyS0
[    0.000000] Command line: console=ttyS0 console=hvc0 root=/dev/vda3 quiet acpi=off
[    0.008928] Kernel command line: console=ttyS0 console=hvc0 root=/dev/vda3 quiet acpi=off
[    0.010326] printk: console [ttyS0] enabled
[    0.059083] serial8250: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a U6_16550A

# ttyS0 interrupt missing

root@cloud-hypervisor ~ # cat /proc/cmdline 
console=ttyS0 console=hvc0 root=/dev/vda3 quiet

root@cloud-hypervisor ~ # cat /proc/interrupts 
           CPU0       
  0:          1   PCI-MSI 16384-edge      virtio0-config
  1:         34   PCI-MSI 16385-edge      virtio0-virtqueues
  2:          0   PCI-MSI 65536-edge      virtio3-config
  3:          7   PCI-MSI 65537-edge      virtio3-input
  4:          0   PCI-MSI 32768-edge      virtio1-config
  5:       2249   PCI-MSI 32769-edge      virtio1-req.0
  6:          0   PCI-MSI 49152-edge      virtio2-config
  7:          0   PCI-MSI 49153-edge      virtio2-virtqueues
NMI:          0   Non-maskable interrupts
LOC:       1424   Local timer interrupts
SPU:          0   Spurious interrupts
PMI:          0   Performance monitoring interrupts
IWI:         80   IRQ work interrupts
RTR:          0   APIC ICR read retries
RES:          0   Rescheduling interrupts
CAL:          0   Function call interrupts
TLB:          0   TLB shootdowns
ERR:          0
MIS:          0
PIN:          0   Posted-interrupt notification event
NPI:          0   Nested posted-interrupt event
PIW:          0   Posted-interrupt wakeup event

root@cloud-hypervisor ~ # dmesg | grep ttyS0
[    0.000000] Command line: console=ttyS0 console=hvc0 root=/dev/vda3 quiet
[    0.011368] Kernel command line: console=ttyS0 console=hvc0 root=/dev/vda3 quiet
[    0.012802] printk: console [ttyS0] enabled
[    0.062327] serial8250: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a U6_16550A
[    0.150686] genirq: Flags mismatch irq 4. 00000000 (ttyS0) vs. 00000000 (virtio1-config)

I have the same problem described above. Does it happen to cloud-hypervisor? If it does, what's the reason?

Thank you for your kind reply.