From c5cb3e97098834f9cf12b6c5260d9b43d68d64eb Mon Sep 17 00:00:00 2001
From: Jon Maloy <jmaloy@redhat.com>
Date: Tue, 9 May 2023 10:29:03 -0400
Subject: [PATCH 07/15] raven: disable reentrancy detection for iomem

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: [7/12] f41983390acba68043d386be090172dd17a5e58c (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 6dad5a6810d9c60ca320d01276f6133bbcfa1fc7
Author: Alexander Bulekov <alxndr@bu.edu>
Date:   Thu Apr 27 17:10:12 2023 -0400

    raven: disable reentrancy detection for iomem

    As the code is designed for re-entrant calls from raven_io_ops to
    pci-conf, mark raven_io_ops as reentrancy-safe.

    Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
    Message-Id: <20230427211013.2994127-8-alxndr@bu.edu>
    Signed-off-by: Thomas Huth <thuth@redhat.com>

Signed-off-by: Jon Maloy <jmaloy@redhat.com>
---
 hw/pci-host/raven.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/hw/pci-host/raven.c b/hw/pci-host/raven.c
index 6e514f75eb..245b1653e4 100644
--- a/hw/pci-host/raven.c
+++ b/hw/pci-host/raven.c
@@ -294,6 +294,13 @@ static void raven_pcihost_initfn(Object *obj)
     memory_region_init(&s->pci_memory, obj, "pci-memory", 0x3f000000);
     address_space_init(&s->pci_io_as, &s->pci_io, "raven-io");
 
+    /*
+     * Raven's raven_io_ops use the address-space API to access pci-conf-idx
+     * (which is also owned by the raven device). As such, mark the
+     * pci_io_non_contiguous as re-entrancy safe.
+     */
+    s->pci_io_non_contiguous.disable_reentrancy_guard = true;
+
     /* CPU address space */
     memory_region_add_subregion(address_space_mem, PCI_IO_BASE_ADDR,
                                 &s->pci_io);
-- 
2.37.3