diff --git a/docs/misc/xen-command-line.pandoc b/docs/misc/xen-command-line.pandoc
index a03c0b4bdf..ab853bda12 100644
--- a/docs/misc/xen-command-line.pandoc
+++ b/docs/misc/xen-command-line.pandoc
@@ -1172,7 +1172,7 @@ detection of systems known to misbehave upon accesses to that port.
 
 ### iommu
     = List of [ <bool>, verbose, debug, force, required,
-                sharept, intremap, intpost,
+                sharept, intremap, intpost, crash-disable,
                 snoop, qinval, igfx, workaround_bios_bug,
                 amd-iommu-perdev-intremap,
                 dom0-{passthrough,strict} ]
@@ -1235,6 +1235,12 @@ boolean (e.g. `iommu=no`) can override this and leave the IOMMUs disabled.
     This option depends on `intremap`, and is disabled by default due to some
     corner cases in the implementation which have yet to be resolved.
 
+*   The `crash-disable` boolean controls disabling IOMMU functionality (DMAR/IR/QI)
+    before switching to a crash kernel. This option is inactive by default and
+    is for compatibility with older kdump kernels only. Modern kernels copy
+    all the necessary tables from the previous one following kexec which makes
+    the transition transparent for them with IOMMU functions still on.
+
 The following options are specific to Intel VT-d hardware:
 
 *   The `snoop` boolean controls the Snoop Control sub-feature, and is active
diff --git a/xen/arch/x86/crash.c b/xen/arch/x86/crash.c
index 60c98b6175..01e48a1133 100644
--- a/xen/arch/x86/crash.c
+++ b/xen/arch/x86/crash.c
@@ -162,8 +162,11 @@ static void nmi_shootdown_cpus(void)
         printk("Failed to shoot down CPUs {%*pbl}\n",
                nr_cpu_ids, cpumask_bits(&waiting_to_crash));
 
-    /* Crash shutdown any IOMMU functionality as the crashdump kernel is not
-     * happy when booting if interrupt/dma remapping is still enabled */
+    /*
+     * Try to crash shutdown IOMMU functionality as some old crashdump
+     * kernels are not happy when booting if interrupt/dma remapping
+     * is still enabled.
+     */
     iommu_crash_shutdown();
 
     __stop_this_cpu();
diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c
index 5ecaa10bb4..611e857259 100644
--- a/xen/drivers/passthrough/iommu.c
+++ b/xen/drivers/passthrough/iommu.c
@@ -35,6 +35,7 @@ bool_t __read_mostly iommu_igfx = 1;
 bool_t __read_mostly iommu_snoop = 1;
 bool_t __read_mostly iommu_qinval = 1;
 bool_t __read_mostly iommu_intremap = 1;
+bool_t __read_mostly iommu_crash_disable;
 
 static bool __hwdom_initdata iommu_hwdom_none;
 bool __hwdom_initdata iommu_hwdom_strict;
@@ -88,6 +89,10 @@ static int __init parse_iommu_param(const char *s)
             iommu_intremap = val;
         else if ( (val = parse_boolean("intpost", s, ss)) >= 0 )
             iommu_intpost = val;
+#ifdef CONFIG_KEXEC
+        else if ( (val = parse_boolean("crash-disable", s, ss)) >= 0 )
+            iommu_crash_disable = val;
+#endif
         else if ( (val = parse_boolean("debug", s, ss)) >= 0 )
         {
             iommu_debug = val;
@@ -579,6 +584,9 @@ void iommu_share_p2m_table(struct domain* d)
 
 void iommu_crash_shutdown(void)
 {
+    if ( !iommu_crash_disable )
+        return;
+
     if ( iommu_enabled )
         iommu_get_ops()->crash_shutdown();
     iommu_enabled = iommu_intremap = iommu_intpost = 0;