[PATCH] xen/vpci: automatically use iomem_permit_access for PCI device BARs

[Ariadne Conill <ariadne@ariadne.space>]

From: Steven Noonan <steven@xxxxxxxxx>

With vPCI, you shouldn't need to use xen-pciback for the device, so the
memory access permissions need to be defined somewhere. This allows vPCI
to automatically define the access permissions so that the domU can map
the BARs via IOMMU.

Signed-off-by: Steven Noonan <steven@xxxxxxxxx>
Signed-off-by: Ariadne Conill <ariadne@ariadne.space>
---
 xen/drivers/vpci/header.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/xen/drivers/vpci/header.c b/xen/drivers/vpci/header.c
index 1f930b2a1f..ad3c09667f 100644
--- a/xen/drivers/vpci/header.c
+++ b/xen/drivers/vpci/header.c
@@ -1017,6 +1017,18 @@ int vpci_init_header(struct pci_dev *pdev)
         bars[i].size = size;
         bars[i].prefetchable = val & PCI_BASE_ADDRESS_MEM_PREFETCH;
 
+        if ( !is_hwdom )
+        {
+            int rc = iomem_permit_access(pdev->domain,
+                                        PFN_DOWN(addr),
+                                        PFN_DOWN(addr + size - 1));
+            if ( rc )
+            {
+                printk(XENLOG_WARNING "Failed to grant MMIO access for BAR%d: 
%d\n", i, rc);
+                goto fail;
+            }
+        }
+
         rc = vpci_add_register(pdev->vpci,
                                is_hwdom ? vpci_hw_read32 : guest_mem_bar_read,
                                is_hwdom ? bar_write : guest_mem_bar_write,
@@ -1040,6 +1052,18 @@ int vpci_init_header(struct pci_dev *pdev)
         header->rom_enabled = pci_conf_read32(pdev->sbdf, rom_reg) &
                               PCI_ROM_ADDRESS_ENABLE;
 
+        if ( !is_hwdom )
+        {
+            int rc = iomem_permit_access(pdev->domain,
+                                        PFN_DOWN(addr),
+                                        PFN_DOWN(addr + size - 1));
+            if ( rc )
+            {
+                printk(XENLOG_WARNING "Failed to grant MMIO access for ROM 
BAR: %d\n", rc);
+                goto fail;
+            }
+        }
+
         rc = vpci_add_register(pdev->vpci, vpci_hw_read32, rom_write, rom_reg,
                                4, rom);
         if ( rc )
-- 
2.53.0