xen/arm: Add PHYSDEVOP_pci_device_(*add/remove) support for ARM

Hardware domain is in charge of doing the PCI enumeration and will
discover the PCI devices and then will communicate to XEN via hyper
call PHYSDEVOP_pci_device_add(..) to add the PCI devices in XEN.

Also implement PHYSDEVOP_pci_device_remove(..) to remove the PCI device.

As most of the code for PHYSDEVOP_pci_device_* is the same between x86
and ARM, move the code to a common file to avoid duplication.

There are other PHYSDEVOP_pci_device_* operations to add PCI devices.
Currently implemented PHYSDEVOP_pci_device_remove(..) and
PHYSDEVOP_pci_device_add(..) only as those are minimum required to
support PCI passthrough on ARM.

Signed-off-by: Rahul Singh <rahul.singh@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Acked-by: Jan Beulich <jbeulich@suse.com>

xen/arch/arm/physdev.c

@@ -8,13 +8,17 @@
 #include <xen/lib.h>
 #include <xen/errno.h>
 #include <xen/sched.h>
-#include <asm/hypercall.h>
+#include <xen/hypercall.h>
 
 
 int do_physdev_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
+#ifdef CONFIG_HAS_PCI
+    return pci_physdev_op(cmd, arg);
+#else
     gdprintk(XENLOG_DEBUG, "PHYSDEVOP cmd=%d: not implemented\n", cmd);
     return -ENOSYS;
+#endif
 }
 
 /*

xen/arch/x86/physdev.c

@@ -12,7 +12,7 @@
 #include <asm/io_apic.h>
 #include <asm/msi.h>
 #include <asm/hvm/irq.h>
-#include <asm/hypercall.h>
+#include <xen/hypercall.h>
 #include <public/xen.h>
 #include <public/physdev.h>
 #include <xsm/xsm.h>
@@ -480,54 +480,6 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
         break;
     }
 
-    case PHYSDEVOP_pci_device_add: {
-        struct physdev_pci_device_add add;
-        struct pci_dev_info pdev_info;
-        nodeid_t node;
-
-        ret = -EFAULT;
-        if ( copy_from_guest(&add, arg, 1) != 0 )
-            break;
-
-        pdev_info.is_extfn = !!(add.flags & XEN_PCI_DEV_EXTFN);
-        if ( add.flags & XEN_PCI_DEV_VIRTFN )
-        {
-            pdev_info.is_virtfn = 1;
-            pdev_info.physfn.bus = add.physfn.bus;
-            pdev_info.physfn.devfn = add.physfn.devfn;
-        }
-        else
-            pdev_info.is_virtfn = 0;
-
-        if ( add.flags & XEN_PCI_DEV_PXM )
-        {
-            uint32_t pxm;
-            size_t optarr_off = offsetof(struct physdev_pci_device_add, optarr) /
-                                sizeof(add.optarr[0]);
-
-            if ( copy_from_guest_offset(&pxm, arg, optarr_off, 1) )
-                break;
-
-            node = pxm_to_node(pxm);
-        }
-        else
-            node = NUMA_NO_NODE;
-
-        ret = pci_add_device(add.seg, add.bus, add.devfn, &pdev_info, node);
-        break;
-    }
-
-    case PHYSDEVOP_pci_device_remove: {
-        struct physdev_pci_device dev;
-
-        ret = -EFAULT;
-        if ( copy_from_guest(&dev, arg, 1) != 0 )
-            break;
-
-        ret = pci_remove_device(dev.seg, dev.bus, dev.devfn);
-        break;
-    }
-
     case PHYSDEVOP_prepare_msix:
     case PHYSDEVOP_release_msix: {
         struct physdev_pci_device dev;
@@ -663,7 +615,7 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
     }
 
     default:
-        ret = -ENOSYS;
+        ret = pci_physdev_op(cmd, arg);
         break;
     }
 

xen/arch/x86/x86_64/physdev.c

@@ -9,7 +9,7 @@ EMIT_FILE;
 #include <compat/xen.h>
 #include <compat/event_channel.h>
 #include <compat/physdev.h>
-#include <asm/hypercall.h>
+#include <xen/hypercall.h>
 
 #define do_physdev_op compat_physdev_op
 

xen/drivers/pci/Makefile

@@ -1 +1,2 @@
 obj-y += pci.o
+obj-y += physdev.o

xen/drivers/pci/physdev.c

@@ -0,0 +1,80 @@
+
+#include <xen/guest_access.h>
+#include <xen/hypercall.h>
+#include <xen/init.h>
+
+#ifndef COMPAT
+typedef long ret_t;
+#endif
+
+ret_t pci_physdev_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
+{
+    ret_t ret;
+
+    switch ( cmd )
+    {
+    case PHYSDEVOP_pci_device_add: {
+        struct physdev_pci_device_add add;
+        struct pci_dev_info pdev_info;
+        nodeid_t node = NUMA_NO_NODE;
+
+        ret = -EFAULT;
+        if ( copy_from_guest(&add, arg, 1) != 0 )
+            break;
+
+        pdev_info.is_extfn = (add.flags & XEN_PCI_DEV_EXTFN);
+        if ( add.flags & XEN_PCI_DEV_VIRTFN )
+        {
+            pdev_info.is_virtfn = true;
+            pdev_info.physfn.bus = add.physfn.bus;
+            pdev_info.physfn.devfn = add.physfn.devfn;
+        }
+        else
+            pdev_info.is_virtfn = false;
+
+#ifdef CONFIG_NUMA
+        if ( add.flags & XEN_PCI_DEV_PXM )
+        {
+            uint32_t pxm;
+            size_t optarr_off = offsetof(struct physdev_pci_device_add, optarr) /
+                                sizeof(add.optarr[0]);
+
+            if ( copy_from_guest_offset(&pxm, arg, optarr_off, 1) )
+                break;
+
+            node = pxm_to_node(pxm);
+        }
+#endif
+
+        ret = pci_add_device(add.seg, add.bus, add.devfn, &pdev_info, node);
+        break;
+    }
+
+    case PHYSDEVOP_pci_device_remove: {
+        struct physdev_pci_device dev;
+
+        ret = -EFAULT;
+        if ( copy_from_guest(&dev, arg, 1) != 0 )
+            break;
+
+        ret = pci_remove_device(dev.seg, dev.bus, dev.devfn);
+        break;
+    }
+
+    default:
+        ret = -ENOSYS;
+        break;
+    }
+
+    return ret;
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */

xen/include/public/arch-arm.h

@@ -107,7 +107,9 @@
  *   All generic sub-operations
  *
  *  HYPERVISOR_physdev_op
- *   No sub-operations are currenty supported
+ *   Exactly these sub-operations are supported:
+ *   PHYSDEVOP_pci_device_add
+ *   PHYSDEVOP_pci_device_remove
  *
  *  HYPERVISOR_sysctl
  *   All generic sub-operations, with the exception of:

xen/include/xen/hypercall.h

@@ -45,6 +45,10 @@ extern long
 do_platform_op(
     XEN_GUEST_HANDLE_PARAM(xen_platform_op_t) u_xenpf_op);
 
+extern long
+pci_physdev_op(
+    int cmd, XEN_GUEST_HANDLE_PARAM(void) arg);
+
 /*
  * To allow safe resume of do_memory_op() after preemption, we need to know
  * at what point in the page list to resume. For this purpose I steal the