[RFC PATCH V1 03/12] xen/mm: Make x86's XENMEM_resource_ioreq_server handling common

[Oleksandr Tyshchenko <olekstysh@gmail.com>]

From: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>

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.

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

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

Signed-off-by: Julien Grall <julien.grall@arm.com>
Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
---
 xen/arch/x86/mm.c        | 45 ---------------------------------------------
 xen/common/memory.c      | 45 +++++++++++++++++++++++++++++++++++++++++++--
 xen/include/asm-arm/mm.h |  8 --------
 xen/include/asm-x86/mm.h |  4 ----
 4 files changed, 43 insertions(+), 59 deletions(-)

diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 2b06e15..33238d0 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -99,7 +99,6 @@
  * doing the final put_page(), and remove it from the iommu if so.
  */
 
-#include <xen/hvm/ioreq.h>
 #include <xen/init.h>
 #include <xen/kernel.h>
 #include <xen/lib.h>
@@ -4600,50 +4599,6 @@ int xenmem_add_to_physmap_one(
     return rc;
 }
 
-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 714077c..9283e5e 100644
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -30,6 +30,10 @@
 #include <public/memory.h>
 #include <xsm/xsm.h>
 
+#ifdef CONFIG_IOREQ_SERVER
+#include <xen/hvm/ioreq.h>
+#endif
+
 #ifdef CONFIG_X86
 #include <asm/guest.h>
 #endif
@@ -1045,6 +1049,38 @@ static int acquire_grant_table(struct domain *d, unsigned int id,
     return 0;
 }
 
+#ifdef CONFIG_IOREQ_SERVER
+static int acquire_ioreq_server(struct domain *d,
+                                unsigned int id,
+                                unsigned long frame,
+                                unsigned int nr_frames,
+                                xen_pfn_t mfn_list[])
+{
+    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;
+}
+#endif
+
 static int acquire_resource(
     XEN_GUEST_HANDLE_PARAM(xen_mem_acquire_resource_t) arg)
 {
@@ -1095,9 +1131,14 @@ static int acquire_resource(
                                  mfn_list);
         break;
 
+#ifdef CONFIG_IOREQ_SERVER
+    case XENMEM_resource_ioreq_server:
+        rc = acquire_ioreq_server(d, xmar.id, xmar.frame, xmar.nr_frames,
+                                  mfn_list);
+        break;
+#endif
     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 7e74996..2e111ad 100644
--- a/xen/include/asm-x86/mm.h
+++ b/xen/include/asm-x86/mm.h
@@ -649,8 +649,4 @@ 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