From 9010b0c7a9a097590e183f63716091f6c42a223f Mon Sep 17 00:00:00 2001
From: Thomas Huth <thuth@redhat.com>
Date: Wed, 21 Jul 2021 16:15:59 +0200
Subject: [PATCH] hw/net/vmxnet3: Do not abort QEMU if guest specified bad
 queue numbers

QEMU should never terminate unexpectedly just because the guest is
doing something wrong like specifying wrong queue numbers. Let's
simply refuse to set the device active in this case.

Buglink: https://bugs.launchpad.net/qemu/+bug/1890160
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 hw/net/vmxnet3.c | 34 ++++++++++++++++++++++------------
 1 file changed, 22 insertions(+), 12 deletions(-)

diff --git a/hw/net/vmxnet3.c b/hw/net/vmxnet3.c
index f6bd8c53b1..41f796a247 100644
--- a/hw/net/vmxnet3.c
+++ b/hw/net/vmxnet3.c
@@ -1381,7 +1381,7 @@ static void vmxnet3_validate_interrupts(VMXNET3State *s)
     }
 }
 
-static void vmxnet3_validate_queues(VMXNET3State *s)
+static bool vmxnet3_validate_queues(VMXNET3State *s)
 {
     /*
     * txq_num and rxq_num are total number of queues
@@ -1390,12 +1390,18 @@ static void vmxnet3_validate_queues(VMXNET3State *s)
     */
 
     if (s->txq_num > VMXNET3_DEVICE_MAX_TX_QUEUES) {
-        hw_error("Bad TX queues number: %d\n", s->txq_num);
+        qemu_log_mask(LOG_GUEST_ERROR, "vmxnet3: Bad TX queues number: %d\n",
+                      s->txq_num);
+        return false;
     }
 
     if (s->rxq_num > VMXNET3_DEVICE_MAX_RX_QUEUES) {
-        hw_error("Bad RX queues number: %d\n", s->rxq_num);
+        qemu_log_mask(LOG_GUEST_ERROR, "vmxnet3: Bad RX queues number: %d\n",
+                      s->rxq_num);
+        return false;
     }
+
+    return true;
 }
 
 static void vmxnet3_activate_device(VMXNET3State *s)
@@ -1419,6 +1425,16 @@ static void vmxnet3_activate_device(VMXNET3State *s)
         return;
     }
 
+    s->txq_num =
+        VMXNET3_READ_DRV_SHARED8(d, s->drv_shmem, devRead.misc.numTxQueues);
+    s->rxq_num =
+        VMXNET3_READ_DRV_SHARED8(d, s->drv_shmem, devRead.misc.numRxQueues);
+
+    VMW_CFPRN("Number of TX/RX queues %u/%u", s->txq_num, s->rxq_num);
+    if (!vmxnet3_validate_queues(s)) {
+        return;
+    }
+
     vmxnet3_adjust_by_guest_type(s);
     vmxnet3_update_features(s);
     vmxnet3_update_pm_state(s);
@@ -1445,14 +1461,6 @@ static void vmxnet3_activate_device(VMXNET3State *s)
         VMXNET3_READ_DRV_SHARED8(d, s->drv_shmem, devRead.intrConf.autoMask);
     VMW_CFPRN("Automatic interrupt masking is %d", (int)s->auto_int_masking);
 
-    s->txq_num =
-        VMXNET3_READ_DRV_SHARED8(d, s->drv_shmem, devRead.misc.numTxQueues);
-    s->rxq_num =
-        VMXNET3_READ_DRV_SHARED8(d, s->drv_shmem, devRead.misc.numRxQueues);
-
-    VMW_CFPRN("Number of TX/RX queues %u/%u", s->txq_num, s->rxq_num);
-    vmxnet3_validate_queues(s);
-
     qdescr_table_pa =
         VMXNET3_READ_DRV_SHARED64(d, s->drv_shmem, devRead.misc.queueDescPA);
     VMW_CFPRN("TX queues descriptors table is at 0x%" PRIx64, qdescr_table_pa);
@@ -2404,7 +2412,9 @@ static int vmxnet3_post_load(void *opaque, int version_id)
         }
     }
 
-    vmxnet3_validate_queues(s);
+    if (!vmxnet3_validate_queues(s)) {
+        return -1;
+    }
     vmxnet3_validate_interrupts(s);
 
     return 0;