[PATCH V4 11/24] xen/mm: Make x86's XENMEM_resource_ioreq_server handling common

[Oleksandr Tyshchenko <olekstysh@xxxxxxxxx>]

From: Julien Grall <julien.grall@xxxxxxx>

As x86 implementation of XENMEM_resource_ioreq_server can be
re-used on Arm later on, this patch makes it common and removes
arch_acquire_resource as unneeded.

Also re-order #include-s alphabetically.

This support is going to be used on Arm to be able run device
emulator outside of Xen hypervisor.

Signed-off-by: Julien Grall <julien.grall@xxxxxxx>
Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>
Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
[On Arm only]
Tested-by: Wei Chen <Wei.Chen@xxxxxxx>

---
Please note, this is a split/cleanup/hardening of Julien's PoC:
"Add support for Guest IO forwarding to a device emulator"

Changes RFC -> V1:
   - no changes

Changes V1 -> V2:
   - update the author of a patch

Changes V2 -> V3:
   - don't wrap #include <xen/ioreq.h>
   - limit the number of #ifdef-s
   - re-order #include-s alphabetically

Changes V3 -> V4:
   - rebase
   - Add Jan's R-b
---
 xen/arch/x86/mm.c        | 44 ---------------------------------
 xen/common/memory.c      | 63 +++++++++++++++++++++++++++++++++++++++---------
 xen/include/asm-arm/mm.h |  8 ------
 xen/include/asm-x86/mm.h |  4 ---
 4 files changed, 51 insertions(+), 68 deletions(-)

diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index f6e128e..54ac398 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -4587,50 +4587,6 @@ static int handle_iomem_range(unsigned long s, unsigned 
long e, void *p)
     return err || s > e ? err : _handle_iomem_range(s, e, p);
 }
 
-int arch_acquire_resource(struct domain *d, unsigned int type,
-                          unsigned int id, unsigned long frame,
-                          unsigned int nr_frames, xen_pfn_t mfn_list[])
-{
-    int rc;
-
-    switch ( type )
-    {
-#ifdef CONFIG_HVM
-    case XENMEM_resource_ioreq_server:
-    {
-        ioservid_t ioservid = id;
-        unsigned int i;
-
-        rc = -EINVAL;
-        if ( !is_hvm_domain(d) )
-            break;
-
-        if ( id != (unsigned int)ioservid )
-            break;
-
-        rc = 0;
-        for ( i = 0; i < nr_frames; i++ )
-        {
-            mfn_t mfn;
-
-            rc = hvm_get_ioreq_server_frame(d, id, frame + i, &mfn);
-            if ( rc )
-                break;
-
-            mfn_list[i] = mfn_x(mfn);
-        }
-        break;
-    }
-#endif
-
-    default:
-        rc = -EOPNOTSUPP;
-        break;
-    }
-
-    return rc;
-}
-
 long arch_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
     int rc;
diff --git a/xen/common/memory.c b/xen/common/memory.c
index b21b6c4..7e560b5 100644
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -8,22 +8,23 @@
  */
 
 #include <xen/domain_page.h>
-#include <xen/types.h>
+#include <xen/errno.h>
+#include <xen/event.h>
+#include <xen/grant_table.h>
+#include <xen/guest_access.h>
+#include <xen/hypercall.h>
+#include <xen/iocap.h>
+#include <xen/ioreq.h>
 #include <xen/lib.h>
+#include <xen/mem_access.h>
 #include <xen/mm.h>
+#include <xen/numa.h>
+#include <xen/paging.h>
 #include <xen/param.h>
 #include <xen/perfc.h>
 #include <xen/sched.h>
-#include <xen/event.h>
-#include <xen/paging.h>
-#include <xen/iocap.h>
-#include <xen/guest_access.h>
-#include <xen/hypercall.h>
-#include <xen/errno.h>
-#include <xen/numa.h>
-#include <xen/mem_access.h>
 #include <xen/trace.h>
-#include <xen/grant_table.h>
+#include <xen/types.h>
 #include <asm/current.h>
 #include <asm/hardirq.h>
 #include <asm/p2m.h>
@@ -1090,6 +1091,40 @@ static int acquire_grant_table(struct domain *d, 
unsigned int id,
     return 0;
 }
 
+static int acquire_ioreq_server(struct domain *d,
+                                unsigned int id,
+                                unsigned long frame,
+                                unsigned int nr_frames,
+                                xen_pfn_t mfn_list[])
+{
+#ifdef CONFIG_IOREQ_SERVER
+    ioservid_t ioservid = id;
+    unsigned int i;
+    int rc;
+
+    if ( !is_hvm_domain(d) )
+        return -EINVAL;
+
+    if ( id != (unsigned int)ioservid )
+        return -EINVAL;
+
+    for ( i = 0; i < nr_frames; i++ )
+    {
+        mfn_t mfn;
+
+        rc = hvm_get_ioreq_server_frame(d, id, frame + i, &mfn);
+        if ( rc )
+            return rc;
+
+        mfn_list[i] = mfn_x(mfn);
+    }
+
+    return 0;
+#else
+    return -EOPNOTSUPP;
+#endif
+}
+
 static int acquire_resource(
     XEN_GUEST_HANDLE_PARAM(xen_mem_acquire_resource_t) arg)
 {
@@ -1148,9 +1183,13 @@ static int acquire_resource(
                                  mfn_list);
         break;
 
+    case XENMEM_resource_ioreq_server:
+        rc = acquire_ioreq_server(d, xmar.id, xmar.frame, xmar.nr_frames,
+                                  mfn_list);
+        break;
+
     default:
-        rc = arch_acquire_resource(d, xmar.type, xmar.id, xmar.frame,
-                                   xmar.nr_frames, mfn_list);
+        rc = -EOPNOTSUPP;
         break;
     }
 
diff --git a/xen/include/asm-arm/mm.h b/xen/include/asm-arm/mm.h
index f8ba49b..0b7de31 100644
--- a/xen/include/asm-arm/mm.h
+++ b/xen/include/asm-arm/mm.h
@@ -358,14 +358,6 @@ static inline void put_page_and_type(struct page_info 
*page)
 
 void clear_and_clean_page(struct page_info *page);
 
-static inline
-int arch_acquire_resource(struct domain *d, unsigned int type, unsigned int id,
-                          unsigned long frame, unsigned int nr_frames,
-                          xen_pfn_t mfn_list[])
-{
-    return -EOPNOTSUPP;
-}
-
 unsigned int arch_get_dma_bitsize(void);
 
 #endif /*  __ARCH_ARM_MM__ */
diff --git a/xen/include/asm-x86/mm.h b/xen/include/asm-x86/mm.h
index deeba75..859214e 100644
--- a/xen/include/asm-x86/mm.h
+++ b/xen/include/asm-x86/mm.h
@@ -639,8 +639,4 @@ static inline bool arch_mfn_in_directmap(unsigned long mfn)
     return mfn <= (virt_to_mfn(eva - 1) + 1);
 }
 
-int arch_acquire_resource(struct domain *d, unsigned int type,
-                          unsigned int id, unsigned long frame,
-                          unsigned int nr_frames, xen_pfn_t mfn_list[]);
-
 #endif /* __ASM_X86_MM_H__ */
-- 
2.7.4