diff --git a/arch/x86/entry/entry_fred.c b/arch/x86/entry/entry_fred.c
index 89c1476fcdd9..f004a4dc74c2 100644
--- a/arch/x86/entry/entry_fred.c
+++ b/arch/x86/entry/entry_fred.c
@@ -117,6 +117,8 @@ static idtentry_t sysvec_table[NR_SYSTEM_VECTORS] __ro_after_init = {
 	SYSVEC(POSTED_INTR_VECTOR,		kvm_posted_intr_ipi),
 	SYSVEC(POSTED_INTR_WAKEUP_VECTOR,	kvm_posted_intr_wakeup_ipi),
 	SYSVEC(POSTED_INTR_NESTED_VECTOR,	kvm_posted_intr_nested_ipi),
+
+	SYSVEC(POSTED_MSI_NOTIFICATION_VECTOR,	posted_msi_notification),
 };
 
 static bool fred_setup_done __initdata;
diff --git a/arch/x86/include/asm/hardirq.h b/arch/x86/include/asm/hardirq.h
index e7ab594b3a7a..c67fa6ad098a 100644
--- a/arch/x86/include/asm/hardirq.h
+++ b/arch/x86/include/asm/hardirq.h
@@ -44,6 +44,9 @@ typedef struct {
 	unsigned int irq_hv_reenlightenment_count;
 	unsigned int hyperv_stimer0_count;
 #endif
+#ifdef CONFIG_X86_POSTED_MSI
+	unsigned int posted_msi_notification_count;
+#endif
 } ____cacheline_aligned irq_cpustat_t;
 
 DECLARE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index 749c7411d2f1..d4f24499b256 100644
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -751,6 +751,12 @@ DECLARE_IDTENTRY_SYSVEC(POSTED_INTR_NESTED_VECTOR,	sysvec_kvm_posted_intr_nested
 # define fred_sysvec_kvm_posted_intr_nested_ipi		NULL
 #endif
 
+# ifdef CONFIG_X86_POSTED_MSI
+DECLARE_IDTENTRY_SYSVEC(POSTED_MSI_NOTIFICATION_VECTOR,	sysvec_posted_msi_notification);
+#else
+# define fred_sysvec_posted_msi_notification		NULL
+# endif
+
 #if IS_ENABLED(CONFIG_HYPERV)
 DECLARE_IDTENTRY_SYSVEC(HYPERVISOR_CALLBACK_VECTOR,	sysvec_hyperv_callback);
 DECLARE_IDTENTRY_SYSVEC(HYPERV_REENLIGHTENMENT_VECTOR,	sysvec_hyperv_reenlightenment);
diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c
index fc37c8d83daf..f445bec516a0 100644
--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -163,6 +163,9 @@ static const __initconst struct idt_data apic_idts[] = {
 # endif
 	INTG(SPURIOUS_APIC_VECTOR,		asm_sysvec_spurious_apic_interrupt),
 	INTG(ERROR_APIC_VECTOR,			asm_sysvec_error_interrupt),
+# ifdef CONFIG_X86_POSTED_MSI
+	INTG(POSTED_MSI_NOTIFICATION_VECTOR,	asm_sysvec_posted_msi_notification),
+# endif
 #endif
 };
 
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index d652b0481899..578e4f6a5080 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -183,6 +183,13 @@ int arch_show_interrupts(struct seq_file *p, int prec)
 		seq_printf(p, "%10u ",
 			   irq_stats(j)->kvm_posted_intr_wakeup_ipis);
 	seq_puts(p, "  Posted-interrupt wakeup event\n");
+#endif
+#ifdef CONFIG_X86_POSTED_MSI
+	seq_printf(p, "%*s: ", prec, "PMN");
+	for_each_online_cpu(j)
+		seq_printf(p, "%10u ",
+			   irq_stats(j)->posted_msi_notification_count);
+	seq_puts(p, "  Posted MSI notification event\n");
 #endif
 	return 0;
 }
@@ -242,16 +249,16 @@ static __always_inline void handle_irq(struct irq_desc *desc,
 		__handle_irq(desc, regs);
 }
 
-static __always_inline void call_irq_handler(int vector, struct pt_regs *regs)
+static __always_inline int call_irq_handler(int vector, struct pt_regs *regs)
 {
 	struct irq_desc *desc;
+	int ret = 0;
 
 	desc = __this_cpu_read(vector_irq[vector]);
 	if (likely(!IS_ERR_OR_NULL(desc))) {
 		handle_irq(desc, regs);
 	} else {
-		apic_eoi();
-
+		ret = -EINVAL;
 		if (desc == VECTOR_UNUSED) {
 			pr_emerg_ratelimited("%s: %d.%u No irq handler for vector\n",
 					     __func__, smp_processor_id(),
@@ -260,6 +267,8 @@ static __always_inline void call_irq_handler(int vector, struct pt_regs *regs)
 			__this_cpu_write(vector_irq[vector], VECTOR_UNUSED);
 		}
 	}
+
+	return ret;
 }
 
 /*
@@ -273,7 +282,9 @@ DEFINE_IDTENTRY_IRQ(common_interrupt)
 	/* entry code tells RCU that we're not quiescent.  Check it. */
 	RCU_LOCKDEP_WARN(!rcu_is_watching(), "IRQ failed to wake up RCU");
 
-	call_irq_handler(vector, regs);
+	if (unlikely(call_irq_handler(vector, regs)))
+		apic_eoi();
+
 	set_irq_regs(old_regs);
 }
 
@@ -361,6 +372,112 @@ void intel_posted_msi_init(void)
 	destination = x2apic_enabled() ? apic_id : apic_id << 8;
 	this_cpu_write(posted_msi_pi_desc.ndst, destination);
 }
+
+/*
+ * De-multiplexing posted interrupts is on the performance path, the code
+ * below is written to optimize the cache performance based on the following
+ * considerations:
+ * 1.Posted interrupt descriptor (PID) fits in a cache line that is frequently
+ *   accessed by both CPU and IOMMU.
+ * 2.During posted MSI processing, the CPU needs to do 64-bit read and xchg
+ *   for checking and clearing posted interrupt request (PIR), a 256 bit field
+ *   within the PID.
+ * 3.On the other side, the IOMMU does atomic swaps of the entire PID cache
+ *   line when posting interrupts and setting control bits.
+ * 4.The CPU can access the cache line a magnitude faster than the IOMMU.
+ * 5.Each time the IOMMU does interrupt posting to the PIR will evict the PID
+ *   cache line. The cache line states after each operation are as follows:
+ *   CPU		IOMMU			PID Cache line state
+ *   ---------------------------------------------------------------
+ *...read64					exclusive
+ *...lock xchg64				modified
+ *...			post/atomic swap	invalid
+ *...-------------------------------------------------------------
+ *
+ * To reduce L1 data cache miss, it is important to avoid contention with
+ * IOMMU's interrupt posting/atomic swap. Therefore, a copy of PIR is used
+ * to dispatch interrupt handlers.
+ *
+ * In addition, the code is trying to keep the cache line state consistent
+ * as much as possible. e.g. when making a copy and clearing the PIR
+ * (assuming non-zero PIR bits are present in the entire PIR), it does:
+ *		read, read, read, read, xchg, xchg, xchg, xchg
+ * instead of:
+ *		read, xchg, read, xchg, read, xchg, read, xchg
+ */
+static __always_inline bool handle_pending_pir(u64 *pir, struct pt_regs *regs)
+{
+	int i, vec = FIRST_EXTERNAL_VECTOR;
+	unsigned long pir_copy[4];
+	bool handled = false;
+
+	for (i = 0; i < 4; i++)
+		pir_copy[i] = pir[i];
+
+	for (i = 0; i < 4; i++) {
+		if (!pir_copy[i])
+			continue;
+
+		pir_copy[i] = arch_xchg(&pir[i], 0);
+		handled = true;
+	}
+
+	if (handled) {
+		for_each_set_bit_from(vec, pir_copy, FIRST_SYSTEM_VECTOR)
+			call_irq_handler(vec, regs);
+	}
+
+	return handled;
+}
+
+/*
+ * Performance data shows that 3 is good enough to harvest 90+% of the benefit
+ * on high IRQ rate workload.
+ */
+#define MAX_POSTED_MSI_COALESCING_LOOP 3
+
+/*
+ * For MSIs that are delivered as posted interrupts, the CPU notifications
+ * can be coalesced if the MSIs arrive in high frequency bursts.
+ */
+DEFINE_IDTENTRY_SYSVEC(sysvec_posted_msi_notification)
+{
+	struct pt_regs *old_regs = set_irq_regs(regs);
+	struct pi_desc *pid;
+	int i = 0;
+
+	pid = this_cpu_ptr(&posted_msi_pi_desc);
+
+	inc_irq_stat(posted_msi_notification_count);
+	irq_enter();
+
+	/*
+	 * Max coalescing count includes the extra round of handle_pending_pir
+	 * after clearing the outstanding notification bit. Hence, at most
+	 * MAX_POSTED_MSI_COALESCING_LOOP - 1 loops are executed here.
+	 */
+	while (++i < MAX_POSTED_MSI_COALESCING_LOOP) {
+		if (!handle_pending_pir(pid->pir64, regs))
+			break;
+	}
+
+	/*
+	 * Clear outstanding notification bit to allow new IRQ notifications,
+	 * do this last to maximize the window of interrupt coalescing.
+	 */
+	pi_clear_on(pid);
+
+	/*
+	 * There could be a race of PI notification and the clearing of ON bit,
+	 * process PIR bits one last time such that handling the new interrupts
+	 * are not delayed until the next IRQ.
+	 */
+	handle_pending_pir(pid->pir64, regs);
+
+	apic_eoi();
+	irq_exit();
+	set_irq_regs(old_regs);
+}
 #endif /* X86_POSTED_MSI */
 
 #ifdef CONFIG_HOTPLUG_CPU