From 8f19df61a101c1e57a1bce8adddb57a4a7123a77 Mon Sep 17 00:00:00 2001
From: Thomas Huth <thuth@redhat.com>
Date: Tue, 16 May 2023 11:05:56 +0200
Subject: [PATCH 11/15] lsi53c895a: disable reentrancy detection for MMIO
 region, too

RH-Author: Jon Maloy <jmaloy@redhat.com>
RH-MergeRequest: 277: memory: prevent dma-reentracy issues
RH-Bugzilla: 1999236
RH-Acked-by: Thomas Huth <thuth@redhat.com>
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
RH-Commit: [11/12] 8016c86f8432f5ea06c831d1181e87e6d45a6a50 (redhat/rhel/src/qemu-kvm/jons-qemu-kvm-2)

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1999236
Upstream: Merged
CVE: CVE-2021-3750

commit d139fe9ad8a27bcc50b4ead77d2f97d191a0e95e
Author: Thomas Huth <thuth@redhat.com>
Date:   Tue May 16 11:05:56 2023 +0200

    lsi53c895a: disable reentrancy detection for MMIO region, too

    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-thuth@redhat.com>
    Signed-off-by: Thomas Huth <thuth@redhat.com>

Signed-off-by: Jon Maloy <jmaloy@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 1e15e13fbf..2b9cb2ac5d 100644
--- a/hw/scsi/lsi53c895a.c
+++ b/hw/scsi/lsi53c895a.c
@@ -2306,6 +2306,7 @@ 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);
-- 
2.37.3