diff --git a/xen/drivers/passthrough/amd/iommu.h b/xen/drivers/passthrough/amd/iommu.h
index e2d174f3b4..2cd87a5230 100644
--- a/xen/drivers/passthrough/amd/iommu.h
+++ b/xen/drivers/passthrough/amd/iommu.h
@@ -277,8 +277,6 @@ unsigned int amd_iommu_read_ioapic_from_ire(
     unsigned int apic, unsigned int reg);
 int amd_iommu_msi_msg_update_ire(
     struct msi_desc *msi_desc, struct msi_msg *msg);
-void amd_iommu_read_msi_from_ire(
-    struct msi_desc *msi_desc, struct msi_msg *msg);
 int amd_setup_hpet_msi(struct msi_desc *msi_desc);
 void amd_iommu_dump_intremap_tables(unsigned char key);
 
diff --git a/xen/drivers/passthrough/amd/iommu_intr.c b/xen/drivers/passthrough/amd/iommu_intr.c
index 0adee53fb8..d78bb209bc 100644
--- a/xen/drivers/passthrough/amd/iommu_intr.c
+++ b/xen/drivers/passthrough/amd/iommu_intr.c
@@ -659,47 +659,6 @@ int amd_iommu_msi_msg_update_ire(
     return rc;
 }
 
-void amd_iommu_read_msi_from_ire(
-    struct msi_desc *msi_desc, struct msi_msg *msg)
-{
-    unsigned int offset = msg->data & (INTREMAP_MAX_ENTRIES - 1);
-    const struct pci_dev *pdev = msi_desc->dev;
-    u16 bdf = pdev ? PCI_BDF2(pdev->bus, pdev->devfn) : hpet_sbdf.bdf;
-    u16 seg = pdev ? pdev->seg : hpet_sbdf.seg;
-    const struct amd_iommu *iommu = _find_iommu_for_device(seg, bdf);
-    union irte_ptr entry;
-
-    if ( IS_ERR_OR_NULL(iommu) )
-        return;
-
-    entry = get_intremap_entry(iommu, get_dma_requestor_id(seg, bdf), offset);
-
-    if ( msi_desc->msi_attrib.type == PCI_CAP_ID_MSI )
-    {
-        int nr = msi_desc->msi_attrib.entry_nr;
-
-        ASSERT(!(offset & (msi_desc[-nr].msi.nvec - 1)));
-        offset |= nr;
-    }
-
-    msg->data &= ~(INTREMAP_MAX_ENTRIES - 1);
-    /* The IntType fields match for both formats. */
-    msg->data |= MASK_INSR(entry.ptr32->flds.int_type,
-                           MSI_DATA_DELIVERY_MODE_MASK);
-    if ( iommu->ctrl.ga_en )
-    {
-        msg->data |= MASK_INSR(entry.ptr128->full.vector,
-                               MSI_DATA_VECTOR_MASK);
-        msg->dest32 = get_full_dest(entry.ptr128);
-    }
-    else
-    {
-        msg->data |= MASK_INSR(entry.ptr32->flds.vector,
-                               MSI_DATA_VECTOR_MASK);
-        msg->dest32 = entry.ptr32->flds.dest;
-    }
-}
-
 int amd_iommu_free_intremap_table(
     const struct amd_iommu *iommu, struct ivrs_mappings *ivrs_mapping,
     uint16_t bdf)
diff --git a/xen/drivers/passthrough/amd/pci_amd_iommu.c b/xen/drivers/passthrough/amd/pci_amd_iommu.c
index 3390c22cf3..304363f5d2 100644
--- a/xen/drivers/passthrough/amd/pci_amd_iommu.c
+++ b/xen/drivers/passthrough/amd/pci_amd_iommu.c
@@ -572,7 +572,6 @@ static const struct iommu_ops __initconstrel _iommu_ops = {
     .update_ire_from_apic = amd_iommu_ioapic_update_ire,
     .update_ire_from_msi = amd_iommu_msi_msg_update_ire,
     .read_apic_from_ire = amd_iommu_read_ioapic_from_ire,
-    .read_msi_from_ire = amd_iommu_read_msi_from_ire,
     .setup_hpet_msi = amd_setup_hpet_msi,
     .adjust_irq_affinities = iov_adjust_irq_affinities,
     .suspend = amd_iommu_suspend,
diff --git a/xen/drivers/passthrough/pci.c b/xen/drivers/passthrough/pci.c
index e54974bcb0..b035067975 100644
--- a/xen/drivers/passthrough/pci.c
+++ b/xen/drivers/passthrough/pci.c
@@ -1382,13 +1382,6 @@ int iommu_update_ire_from_msi(
            ? iommu_call(&iommu_ops, update_ire_from_msi, msi_desc, msg) : 0;
 }
 
-void iommu_read_msi_from_ire(
-    struct msi_desc *msi_desc, struct msi_msg *msg)
-{
-    if ( iommu_intremap )
-        iommu_vcall(&iommu_ops, read_msi_from_ire, msi_desc, msg);
-}
-
 static int iommu_add_device(struct pci_dev *pdev)
 {
     const struct domain_iommu *hd;
diff --git a/xen/drivers/passthrough/vtd/extern.h b/xen/drivers/passthrough/vtd/extern.h
index ada3c3098c..ad6c5f907b 100644
--- a/xen/drivers/passthrough/vtd/extern.h
+++ b/xen/drivers/passthrough/vtd/extern.h
@@ -85,7 +85,6 @@ void io_apic_write_remap_rte(unsigned int apic,
 
 struct msi_desc;
 struct msi_msg;
-void msi_msg_read_remap_rte(struct msi_desc *, struct msi_msg *);
 int msi_msg_write_remap_rte(struct msi_desc *, struct msi_msg *);
 
 int intel_setup_hpet_msi(struct msi_desc *);
diff --git a/xen/drivers/passthrough/vtd/intremap.c b/xen/drivers/passthrough/vtd/intremap.c
index 0d2a9d78de..d0f70d90eb 100644
--- a/xen/drivers/passthrough/vtd/intremap.c
+++ b/xen/drivers/passthrough/vtd/intremap.c
@@ -532,68 +532,6 @@ static void set_msi_source_id(struct pci_dev *pdev, struct iremap_entry *ire)
    }
 }
 
-static int remap_entry_to_msi_msg(
-    struct vtd_iommu *iommu, struct msi_msg *msg, unsigned int index)
-{
-    struct iremap_entry *iremap_entry = NULL, *iremap_entries;
-    struct msi_msg_remap_entry *remap_rte;
-    unsigned long flags;
-
-    remap_rte = (struct msi_msg_remap_entry *) msg;
-    index += (remap_rte->address_lo.index_15 << 15) |
-             remap_rte->address_lo.index_0_14;
-
-    if ( index >= IREMAP_ENTRY_NR )
-    {
-        dprintk(XENLOG_ERR VTDPREFIX,
-                "MSI index (%d) for remap table is invalid\n",
-                index);
-        return -EFAULT;
-    }
-
-    spin_lock_irqsave(&iommu->intremap.lock, flags);
-
-    GET_IREMAP_ENTRY(iommu->intremap.maddr, index,
-                     iremap_entries, iremap_entry);
-
-    if ( iremap_entry->val == 0 )
-    {
-        dprintk(XENLOG_ERR VTDPREFIX,
-                "MSI index (%d) has an empty entry\n",
-                index);
-        unmap_vtd_domain_page(iremap_entries);
-        spin_unlock_irqrestore(&iommu->intremap.lock, flags);
-        return -EFAULT;
-    }
-
-    msg->address_hi = MSI_ADDR_BASE_HI;
-    msg->address_lo =
-        MSI_ADDR_BASE_LO |
-        ((iremap_entry->remap.dm == 0) ?
-            MSI_ADDR_DESTMODE_PHYS:
-            MSI_ADDR_DESTMODE_LOGIC) |
-        ((iremap_entry->remap.dlm != dest_LowestPrio) ?
-            MSI_ADDR_REDIRECTION_CPU:
-            MSI_ADDR_REDIRECTION_LOWPRI);
-    if ( x2apic_enabled )
-        msg->dest32 = iremap_entry->remap.dst;
-    else
-        msg->dest32 = (iremap_entry->remap.dst >> 8) & 0xff;
-    msg->address_lo |= MSI_ADDR_DEST_ID(msg->dest32);
-
-    msg->data =
-        MSI_DATA_TRIGGER_EDGE |
-        MSI_DATA_LEVEL_ASSERT |
-        ((iremap_entry->remap.dlm != dest_LowestPrio) ?
-            MSI_DATA_DELIVERY_FIXED:
-            MSI_DATA_DELIVERY_LOWPRI) |
-        iremap_entry->remap.vector;
-
-    unmap_vtd_domain_page(iremap_entries);
-    spin_unlock_irqrestore(&iommu->intremap.lock, flags);
-    return 0;
-}
-
 static int msi_msg_to_remap_entry(
     struct vtd_iommu *iommu, struct pci_dev *pdev,
     struct msi_desc *msi_desc, struct msi_msg *msg)
@@ -701,20 +639,6 @@ static int msi_msg_to_remap_entry(
     return 0;
 }
 
-void msi_msg_read_remap_rte(
-    struct msi_desc *msi_desc, struct msi_msg *msg)
-{
-    struct pci_dev *pdev = msi_desc->dev;
-    struct acpi_drhd_unit *drhd = NULL;
-
-    drhd = pdev ? acpi_find_matched_drhd_unit(pdev)
-                : hpet_to_drhd(msi_desc->hpet_id);
-    if ( drhd )
-        remap_entry_to_msi_msg(drhd->iommu, msg,
-                               msi_desc->msi_attrib.type == PCI_CAP_ID_MSI
-                               ? msi_desc->msi_attrib.entry_nr : 0);
-}
-
 int msi_msg_write_remap_rte(
     struct msi_desc *msi_desc, struct msi_msg *msg)
 {
diff --git a/xen/drivers/passthrough/vtd/iommu.c b/xen/drivers/passthrough/vtd/iommu.c
index 94e0455a4d..1ee4baff36 100644
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -2745,7 +2745,6 @@ static struct iommu_ops __initdata vtd_ops = {
     .update_ire_from_apic = io_apic_write_remap_rte,
     .update_ire_from_msi = msi_msg_write_remap_rte,
     .read_apic_from_ire = io_apic_read_remap_rte,
-    .read_msi_from_ire = msi_msg_read_remap_rte,
     .setup_hpet_msi = intel_setup_hpet_msi,
     .adjust_irq_affinities = adjust_vtd_irq_affinities,
     .suspend = vtd_suspend,
diff --git a/xen/include/xen/iommu.h b/xen/include/xen/iommu.h
index 3272874958..fde5fdc415 100644
--- a/xen/include/xen/iommu.h
+++ b/xen/include/xen/iommu.h
@@ -194,7 +194,6 @@ struct msi_desc;
 struct msi_msg;
 
 int iommu_update_ire_from_msi(struct msi_desc *msi_desc, struct msi_msg *msg);
-void iommu_read_msi_from_ire(struct msi_desc *msi_desc, struct msi_msg *msg);
 
 #define PT_IRQ_TIME_OUT MILLISECS(8)
 #endif /* HAS_PCI */
