While trying to use a SCSI disk on the LSI controller with an
older version of Fedora (25), I'm getting:

 qemu: warning: Blocked re-entrant IO on MemoryRegion: lsi-mmio at addr: 0x34

and the SCSI controller is not usable. Seems like we have to
disable the reentrancy checker for the MMIO region, too, to
get this working again.

The problem could be reproduced it like this:

./qemu-system-x86_64 -accel kvm -m 2G -machine q35 \
 -device lsi53c810,id=lsi1 -device scsi-hd,drive=d0 \
 -drive if=none,id=d0,file=.../somedisk.qcow2 \
 -cdrom Fedora-Everything-netinst-i386-25-1.3.iso

Where somedisk.qcow2 is an image that contains already some partitions
and file systems.

In the boot menu of Fedora, go to
"Troubleshooting" -> "Rescue a Fedora system" -> "3) Skip to shell"

Then check "dmesg | grep -i 53c" for failure messages, and try to mount
a partition from somedisk.qcow2.

Message-Id: <20230516090556.553813-1-th...@redhat.com>
Signed-off-by: Thomas Huth <th...@redhat.com>
---
 hw/scsi/lsi53c895a.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/hw/scsi/lsi53c895a.c b/hw/scsi/lsi53c895a.c
index db27872963..048436352b 100644
--- a/hw/scsi/lsi53c895a.c
+++ b/hw/scsi/lsi53c895a.c
@@ -2307,6 +2307,7 @@ static void lsi_scsi_realize(PCIDevice *dev, Error **errp)
      * re-entrancy guard.
      */
     s->ram_io.disable_reentrancy_guard = true;
+    s->mmio_io.disable_reentrancy_guard = true;
 
     address_space_init(&s->pci_io_as, pci_address_space_io(dev), "lsi-pci-io");
     qdev_init_gpio_out(d, &s->ext_irq, 1);
-- 
2.31.1


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