diff --git a/docs/misc/xen-command-line.markdown b/docs/misc/xen-command-line.markdown
index b8f5f67810..d99a20a44b 100644
--- a/docs/misc/xen-command-line.markdown
+++ b/docs/misc/xen-command-line.markdown
@@ -1491,6 +1491,21 @@ Note that if **watchdog** option is also specified vpmu will be turned off.
 As the virtualisation is not 100% safe, don't use the vpmu flag on
 production systems (see http://xenbits.xen.org/xsa/advisory-163.html)!
 
+### vwfi
+> `= trap | native
+
+> Default: `trap`
+
+WFI is the ARM instruction to "wait for interrupt". WFE is similar and
+means "wait for event". This option, which is ARM specific, changes the
+way guest WFI and WFE are implemented in Xen. By default, Xen traps both
+instructions. In the case of WFI, Xen blocks the guest vcpu; in the case
+of WFE, Xen yield the guest vcpu. When setting vwfi to `native`, Xen
+doesn't trap either instruction, running them in guest context. Setting
+vwfi to `native` reduces irq latency significantly. It can also lead to
+suboptimal scheduling decisions, but only when the system is
+oversubscribed (i.e., in total there are more vCPUs than pCPUs).
+
 ### watchdog
 > `= force | <boolean>`
 
diff --git a/xen/arch/arm/traps.c b/xen/arch/arm/traps.c
index 1c13b05d00..5dbc8be003 100644
--- a/xen/arch/arm/traps.c
+++ b/xen/arch/arm/traps.c
@@ -98,6 +98,19 @@ static int debug_stack_lines = 40;
 
 integer_param("debug_stack_lines", debug_stack_lines);
 
+static enum {
+	TRAP,
+	NATIVE,
+} vwfi;
+
+static void __init parse_vwfi(const char *s)
+{
+	if ( !strcmp(s, "native") )
+		vwfi = NATIVE;
+	else
+		vwfi = TRAP;
+}
+custom_param("vwfi", parse_vwfi);
 
 void __cpuinit init_traps(void)
 {
@@ -124,8 +137,8 @@ void __cpuinit init_traps(void)
 
     /* Setup hypervisor traps */
     WRITE_SYSREG(HCR_PTW|HCR_BSU_INNER|HCR_AMO|HCR_IMO|HCR_FMO|HCR_VM|
-                 HCR_TWE|HCR_TWI|HCR_TSC|HCR_TAC|HCR_SWIO|HCR_TIDCP|HCR_FB,
-                 HCR_EL2);
+                 (vwfi != NATIVE ? (HCR_TWI|HCR_TWE) : 0) |
+                 HCR_TSC|HCR_TAC|HCR_SWIO|HCR_TIDCP|HCR_FB,HCR_EL2);
     isb();
 }