diff --git a/xen/arch/x86/msi.c b/xen/arch/x86/msi.c
index ff2e3d8687..677fd83218 100644
--- a/xen/arch/x86/msi.c
+++ b/xen/arch/x86/msi.c
@@ -278,23 +278,21 @@ void __msi_set_enable(u16 seg, u8 bus, u8 slot, u8 func, int pos, int enable)
 
 static void msi_set_enable(struct pci_dev *dev, int enable)
 {
-    int pos;
+    unsigned int pos = dev->msi_pos;
     u16 seg = dev->seg;
     u8 bus = dev->bus;
     u8 slot = PCI_SLOT(dev->devfn);
     u8 func = PCI_FUNC(dev->devfn);
 
-    pos = pci_find_cap_offset(dev->sbdf, PCI_CAP_ID_MSI);
     if ( pos )
         __msi_set_enable(seg, bus, slot, func, pos, enable);
 }
 
 static void msix_set_enable(struct pci_dev *dev, int enable)
 {
-    int pos;
+    unsigned int pos = dev->msix_pos;
     uint16_t control;
 
-    pos = pci_find_cap_offset(dev->sbdf, PCI_CAP_ID_MSIX);
     if ( pos )
     {
         control = pci_conf_read16(dev->sbdf, msix_control_reg(pos));
@@ -601,7 +599,7 @@ static int msi_capability_init(struct pci_dev *dev,
     uint16_t control;
 
     ASSERT_PDEV_LIST_IS_READ_LOCKED(dev->domain);
-    pos = pci_find_cap_offset(dev->sbdf, PCI_CAP_ID_MSI);
+    pos = dev->msi_pos;
     if ( !pos )
         return -ENODEV;
     control = pci_conf_read16(dev->sbdf, msi_control_reg(pos));
@@ -764,7 +762,7 @@ static int msix_capability_init(struct pci_dev *dev,
     u8 slot = PCI_SLOT(dev->devfn);
     u8 func = PCI_FUNC(dev->devfn);
     bool maskall = msix->host_maskall, zap_on_error = false;
-    unsigned int pos = pci_find_cap_offset(dev->sbdf, PCI_CAP_ID_MSIX);
+    unsigned int pos = dev->msix_pos;
 
     if ( !pos )
         return -ENODEV;
@@ -1133,11 +1131,13 @@ static void _pci_cleanup_msix(struct arch_msix *msix)
 static void __pci_disable_msix(struct msi_desc *entry)
 {
     struct pci_dev *dev = entry->dev;
-    unsigned int pos = pci_find_cap_offset(dev->sbdf, PCI_CAP_ID_MSIX);
+    unsigned int pos = dev->msix_pos;
     u16 control = pci_conf_read16(dev->sbdf,
                                   msix_control_reg(entry->msi_attrib.pos));
     bool maskall = dev->msix->host_maskall;
 
+    ASSERT(pos);
+
     if ( unlikely(!(control & PCI_MSIX_FLAGS_ENABLE)) )
     {
         dev->msix->host_maskall = 1;
@@ -1241,7 +1241,7 @@ void pci_cleanup_msi(struct pci_dev *pdev)
 
 int pci_reset_msix_state(struct pci_dev *pdev)
 {
-    unsigned int pos = pci_find_cap_offset(pdev->sbdf, PCI_CAP_ID_MSIX);
+    unsigned int pos = pdev->msix_pos;
 
     ASSERT(pos);
     /*
@@ -1269,8 +1269,7 @@ int pci_msi_conf_write_intercept(struct pci_dev *pdev, unsigned int reg,
     if ( pdev->msix )
     {
         entry = find_msi_entry(pdev, -1, PCI_CAP_ID_MSIX);
-        pos = entry ? entry->msi_attrib.pos
-                    : pci_find_cap_offset(pdev->sbdf, PCI_CAP_ID_MSIX);
+        pos = entry ? entry->msi_attrib.pos : pdev->msix_pos;
         ASSERT(pos);
 
         if ( reg >= pos && reg < msix_pba_offset_reg(pos) + 4 )
diff --git a/xen/drivers/passthrough/msi.c b/xen/drivers/passthrough/msi.c
index 13d904692e..ed2bc7ebe6 100644
--- a/xen/drivers/passthrough/msi.c
+++ b/xen/drivers/passthrough/msi.c
@@ -29,6 +29,7 @@ int pdev_msi_init(struct pci_dev *pdev)
     {
         uint16_t ctrl = pci_conf_read16(pdev->sbdf, msi_control_reg(pos));
 
+        pdev->msi_pos = pos;
         pdev->msi_maxvec = multi_msi_capable(ctrl);
     }
 
@@ -41,6 +42,8 @@ int pdev_msi_init(struct pci_dev *pdev)
         if ( !msix )
             return -ENOMEM;
 
+        pdev->msix_pos = pos;
+
         spin_lock_init(&msix->table_lock);
 
         ctrl = pci_conf_read16(pdev->sbdf, msix_control_reg(pos));
diff --git a/xen/drivers/vpci/msi.c b/xen/drivers/vpci/msi.c
index dd6620ec56..66e5a8a116 100644
--- a/xen/drivers/vpci/msi.c
+++ b/xen/drivers/vpci/msi.c
@@ -195,7 +195,7 @@ static void cf_check mask_write(
 
 static int cf_check init_msi(struct pci_dev *pdev)
 {
-    unsigned int pos = pci_find_cap_offset(pdev->sbdf, PCI_CAP_ID_MSI);
+    unsigned int pos = pdev->msi_pos;
     uint16_t control;
     int ret;
 
diff --git a/xen/drivers/vpci/msix.c b/xen/drivers/vpci/msix.c
index 5bb4444ce2..6bd8c55bb4 100644
--- a/xen/drivers/vpci/msix.c
+++ b/xen/drivers/vpci/msix.c
@@ -711,7 +711,7 @@ static int cf_check init_msix(struct pci_dev *pdev)
     struct vpci_msix *msix;
     int rc;
 
-    msix_offset = pci_find_cap_offset(pdev->sbdf, PCI_CAP_ID_MSIX);
+    msix_offset = pdev->msix_pos;
     if ( !msix_offset )
         return 0;
 
diff --git a/xen/include/xen/pci.h b/xen/include/xen/pci.h
index 63e49f0117..1e4fe68c60 100644
--- a/xen/include/xen/pci.h
+++ b/xen/include/xen/pci.h
@@ -113,6 +113,9 @@ struct pci_dev {
         pci_sbdf_t sbdf;
     };
 
+    uint8_t msi_pos;
+    uint8_t msix_pos;
+
     uint8_t msi_maxvec;
     uint8_t phantom_stride;