From 0660a7a6994db0db9f6d0b84f6345aa06dc61761 Mon Sep 17 00:00:00 2001
From: Jon Maloy <jmaloy@redhat.com>
Date: Mon, 29 May 2023 14:21:08 -0400
Subject: [PATCH 16/21] lsi53c895a: disable reentrancy detection for MMIO
region, too
RH-Author: Jon Maloy <jmaloy@redhat.com>
RH-MergeRequest: 165: memory: prevent dma-reentracy issues
RH-Jira: RHEL-516
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
RH-Commit: [12/13] fb9da8b68cdf0dc0b0bd8fb8540849c944d0bf20 (jmaloy/jmaloy-qemu-kvm-2)
Jira: https://issues.redhat.com/browse/RHEL-516
Upstream: Merged
CVE: CVE-2023-2680
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 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);
--
2.39.3