exec: introduce address_space_get_iotlb_entry()

This patch introduces a helper to query the iotlb entry for a
possible iova. This will be used by later device IOTLB API to enable
the capability for a dataplane (e.g vhost) to query the IOTLB.

Backports commit 052c8fa9983f553fdfa0d61034774070dd639c2b from qemu

qemu/aarch64.h

@@ -59,6 +59,7 @@
 #define address_space_init address_space_init_aarch64
 #define address_space_init_dispatch address_space_init_dispatch_aarch64
 #define address_space_init_shareable address_space_init_shareable_aarch64
+#define address_space_get_iotlb_entry address_space_get_iotlb_entry_aarch64
 #define address_space_ldl address_space_ldl_aarch64
 #define address_space_ldl_be address_space_ldl_be_aarch64
 #define address_space_ldl_be_cached address_space_ldl_be_cached_aarch64
@@ -2858,8 +2859,8 @@
 #define strpadcpy strpadcpy_aarch64
 #define strstart strstart_aarch64
 #define stw_be_p stw_be_p_aarch64
-#define stw_be_phys_cached stw_be_phys_cached_aarch64
 #define stw_be_phys stw_be_phys_aarch64
+#define stw_be_phys_cached stw_be_phys_cached_aarch64
 #define stw_he_p stw_he_p_aarch64
 #define stw_le_p stw_le_p_aarch64
 #define stw_le_phys stw_le_phys_aarch64

qemu/aarch64eb.h

@@ -59,6 +59,7 @@
 #define address_space_init address_space_init_aarch64eb
 #define address_space_init_dispatch address_space_init_dispatch_aarch64eb
 #define address_space_init_shareable address_space_init_shareable_aarch64eb
+#define address_space_get_iotlb_entry address_space_get_iotlb_entry_aarch64eb
 #define address_space_ldl address_space_ldl_aarch64eb
 #define address_space_ldl_be address_space_ldl_be_aarch64eb
 #define address_space_ldl_be_cached address_space_ldl_be_cached_aarch64eb
@@ -2858,8 +2859,8 @@
 #define strpadcpy strpadcpy_aarch64eb
 #define strstart strstart_aarch64eb
 #define stw_be_p stw_be_p_aarch64eb
-#define stw_be_phys_cached stw_be_phys_cached_aarch64eb
 #define stw_be_phys stw_be_phys_aarch64eb
+#define stw_be_phys_cached stw_be_phys_cached_aarch64eb
 #define stw_he_p stw_he_p_aarch64eb
 #define stw_le_p stw_le_p_aarch64eb
 #define stw_le_phys stw_le_phys_aarch64eb

qemu/arm.h

@@ -59,6 +59,7 @@
 #define address_space_init address_space_init_arm
 #define address_space_init_dispatch address_space_init_dispatch_arm
 #define address_space_init_shareable address_space_init_shareable_arm
+#define address_space_get_iotlb_entry address_space_get_iotlb_entry_arm
 #define address_space_ldl address_space_ldl_arm
 #define address_space_ldl_be address_space_ldl_be_arm
 #define address_space_ldl_be_cached address_space_ldl_be_cached_arm
@@ -2858,8 +2859,8 @@
 #define strpadcpy strpadcpy_arm
 #define strstart strstart_arm
 #define stw_be_p stw_be_p_arm
-#define stw_be_phys_cached stw_be_phys_cached_arm
 #define stw_be_phys stw_be_phys_arm
+#define stw_be_phys_cached stw_be_phys_cached_arm
 #define stw_he_p stw_he_p_arm
 #define stw_le_p stw_le_p_arm
 #define stw_le_phys stw_le_phys_arm

qemu/armeb.h

@@ -59,6 +59,7 @@
 #define address_space_init address_space_init_armeb
 #define address_space_init_dispatch address_space_init_dispatch_armeb
 #define address_space_init_shareable address_space_init_shareable_armeb
+#define address_space_get_iotlb_entry address_space_get_iotlb_entry_armeb
 #define address_space_ldl address_space_ldl_armeb
 #define address_space_ldl_be address_space_ldl_be_armeb
 #define address_space_ldl_be_cached address_space_ldl_be_cached_armeb
@@ -2858,8 +2859,8 @@
 #define strpadcpy strpadcpy_armeb
 #define strstart strstart_armeb
 #define stw_be_p stw_be_p_armeb
-#define stw_be_phys_cached stw_be_phys_cached_armeb
 #define stw_be_phys stw_be_phys_armeb
+#define stw_be_phys_cached stw_be_phys_cached_armeb
 #define stw_he_p stw_he_p_armeb
 #define stw_le_p stw_le_p_armeb
 #define stw_le_phys stw_le_phys_armeb

qemu/exec.c

@@ -393,6 +393,41 @@ address_space_translate_internal(AddressSpaceDispatch *d, hwaddr addr, hwaddr *x
     return section;
 }
 
+/* Called from RCU critical section */
+IOMMUTLBEntry address_space_get_iotlb_entry(AddressSpace *as, hwaddr addr,
+                                            bool is_write)
+{
+    IOMMUTLBEntry iotlb = {0};
+    MemoryRegionSection *section;
+    MemoryRegion *mr;
+
+    for (;;) {
+        // Unicorn: atomic_read used instead of atomic_rcu_read
+        AddressSpaceDispatch *d = atomic_read(&as->dispatch);
+        section = address_space_lookup_region(d, addr, false);
+        addr = addr - section->offset_within_address_space
+               + section->offset_within_region;
+        mr = section->mr;
+
+        if (!mr->iommu_ops) {
+            break;
+        }
+
+        iotlb = mr->iommu_ops->translate(mr, addr, is_write);
+        if (!(iotlb.perm & (1 << is_write))) {
+            iotlb.target_as = NULL;
+            break;
+        }
+
+        addr = ((iotlb.translated_addr & ~iotlb.addr_mask)
+                | (addr & iotlb.addr_mask));
+        as = iotlb.target_as;
+    }
+
+    return iotlb;
+}
+
+/* Called from RCU critical section */
 MemoryRegion *address_space_translate(AddressSpace *as, hwaddr addr,
         hwaddr *xlat, hwaddr *plen,
         bool is_write)

qemu/header_gen.py

@@ -65,6 +65,7 @@ symbols = (
     'address_space_init',
     'address_space_init_dispatch',
     'address_space_init_shareable',
+    'address_space_get_iotlb_entry',
     'address_space_ldl',
     'address_space_ldl_be',
     'address_space_ldl_be_cached',

qemu/include/exec/memory.h

@@ -1213,6 +1213,11 @@ void stl_le_phys_cached(MemoryRegionCache *cache, hwaddr addr, uint32_t val);
 void stl_be_phys_cached(MemoryRegionCache *cache, hwaddr addr, uint32_t val);
 void stq_le_phys_cached(MemoryRegionCache *cache, hwaddr addr, uint64_t val);
 void stq_be_phys_cached(MemoryRegionCache *cache, hwaddr addr, uint64_t val);
+/* address_space_get_iotlb_entry: translate an address into an IOTLB
+ * entry. Should be called from an RCU critical section.
+ */
+IOMMUTLBEntry address_space_get_iotlb_entry(AddressSpace *as, hwaddr addr,
+                                            bool is_write);
 
 /* address_space_translate: translate an address range into an address space
  * into a MemoryRegion and an address range into that section

qemu/m68k.h

@@ -59,6 +59,7 @@
 #define address_space_init address_space_init_m68k
 #define address_space_init_dispatch address_space_init_dispatch_m68k
 #define address_space_init_shareable address_space_init_shareable_m68k
+#define address_space_get_iotlb_entry address_space_get_iotlb_entry_m68k
 #define address_space_ldl address_space_ldl_m68k
 #define address_space_ldl_be address_space_ldl_be_m68k
 #define address_space_ldl_be_cached address_space_ldl_be_cached_m68k
@@ -2858,8 +2859,8 @@
 #define strpadcpy strpadcpy_m68k
 #define strstart strstart_m68k
 #define stw_be_p stw_be_p_m68k
-#define stw_be_phys_cached stw_be_phys_cached_m68k
 #define stw_be_phys stw_be_phys_m68k
+#define stw_be_phys_cached stw_be_phys_cached_m68k
 #define stw_he_p stw_he_p_m68k
 #define stw_le_p stw_le_p_m68k
 #define stw_le_phys stw_le_phys_m68k

qemu/mips.h

@@ -59,6 +59,7 @@
 #define address_space_init address_space_init_mips
 #define address_space_init_dispatch address_space_init_dispatch_mips
 #define address_space_init_shareable address_space_init_shareable_mips
+#define address_space_get_iotlb_entry address_space_get_iotlb_entry_mips
 #define address_space_ldl address_space_ldl_mips
 #define address_space_ldl_be address_space_ldl_be_mips
 #define address_space_ldl_be_cached address_space_ldl_be_cached_mips
@@ -2858,8 +2859,8 @@
 #define strpadcpy strpadcpy_mips
 #define strstart strstart_mips
 #define stw_be_p stw_be_p_mips
-#define stw_be_phys_cached stw_be_phys_cached_mips
 #define stw_be_phys stw_be_phys_mips
+#define stw_be_phys_cached stw_be_phys_cached_mips
 #define stw_he_p stw_he_p_mips
 #define stw_le_p stw_le_p_mips
 #define stw_le_phys stw_le_phys_mips

qemu/mips64.h

@@ -59,6 +59,7 @@
 #define address_space_init address_space_init_mips64
 #define address_space_init_dispatch address_space_init_dispatch_mips64
 #define address_space_init_shareable address_space_init_shareable_mips64
+#define address_space_get_iotlb_entry address_space_get_iotlb_entry_mips64
 #define address_space_ldl address_space_ldl_mips64
 #define address_space_ldl_be address_space_ldl_be_mips64
 #define address_space_ldl_be_cached address_space_ldl_be_cached_mips64
@@ -2858,8 +2859,8 @@
 #define strpadcpy strpadcpy_mips64
 #define strstart strstart_mips64
 #define stw_be_p stw_be_p_mips64
-#define stw_be_phys_cached stw_be_phys_cached_mips64
 #define stw_be_phys stw_be_phys_mips64
+#define stw_be_phys_cached stw_be_phys_cached_mips64
 #define stw_he_p stw_he_p_mips64
 #define stw_le_p stw_le_p_mips64
 #define stw_le_phys stw_le_phys_mips64

qemu/mips64el.h

@@ -59,6 +59,7 @@
 #define address_space_init address_space_init_mips64el
 #define address_space_init_dispatch address_space_init_dispatch_mips64el
 #define address_space_init_shareable address_space_init_shareable_mips64el
+#define address_space_get_iotlb_entry address_space_get_iotlb_entry_mips64el
 #define address_space_ldl address_space_ldl_mips64el
 #define address_space_ldl_be address_space_ldl_be_mips64el
 #define address_space_ldl_be_cached address_space_ldl_be_cached_mips64el
@@ -2858,8 +2859,8 @@
 #define strpadcpy strpadcpy_mips64el
 #define strstart strstart_mips64el
 #define stw_be_p stw_be_p_mips64el
-#define stw_be_phys_cached stw_be_phys_cached_mips64el
 #define stw_be_phys stw_be_phys_mips64el
+#define stw_be_phys_cached stw_be_phys_cached_mips64el
 #define stw_he_p stw_he_p_mips64el
 #define stw_le_p stw_le_p_mips64el
 #define stw_le_phys stw_le_phys_mips64el

qemu/mipsel.h

@@ -59,6 +59,7 @@
 #define address_space_init address_space_init_mipsel
 #define address_space_init_dispatch address_space_init_dispatch_mipsel
 #define address_space_init_shareable address_space_init_shareable_mipsel
+#define address_space_get_iotlb_entry address_space_get_iotlb_entry_mipsel
 #define address_space_ldl address_space_ldl_mipsel
 #define address_space_ldl_be address_space_ldl_be_mipsel
 #define address_space_ldl_be_cached address_space_ldl_be_cached_mipsel
@@ -2858,8 +2859,8 @@
 #define strpadcpy strpadcpy_mipsel
 #define strstart strstart_mipsel
 #define stw_be_p stw_be_p_mipsel
-#define stw_be_phys_cached stw_be_phys_cached_mipsel
 #define stw_be_phys stw_be_phys_mipsel
+#define stw_be_phys_cached stw_be_phys_cached_mipsel
 #define stw_he_p stw_he_p_mipsel
 #define stw_le_p stw_le_p_mipsel
 #define stw_le_phys stw_le_phys_mipsel

qemu/powerpc.h

@@ -59,6 +59,7 @@
 #define address_space_init address_space_init_powerpc
 #define address_space_init_dispatch address_space_init_dispatch_powerpc
 #define address_space_init_shareable address_space_init_shareable_powerpc
+#define address_space_get_iotlb_entry address_space_get_iotlb_entry_powerpc
 #define address_space_ldl address_space_ldl_powerpc
 #define address_space_ldl_be address_space_ldl_be_powerpc
 #define address_space_ldl_be_cached address_space_ldl_be_cached_powerpc
@@ -2858,8 +2859,8 @@
 #define strpadcpy strpadcpy_powerpc
 #define strstart strstart_powerpc
 #define stw_be_p stw_be_p_powerpc
-#define stw_be_phys_cached stw_be_phys_cached_powerpc
 #define stw_be_phys stw_be_phys_powerpc
+#define stw_be_phys_cached stw_be_phys_cached_powerpc
 #define stw_he_p stw_he_p_powerpc
 #define stw_le_p stw_le_p_powerpc
 #define stw_le_phys stw_le_phys_powerpc

qemu/sparc.h

@@ -59,6 +59,7 @@
 #define address_space_init address_space_init_sparc
 #define address_space_init_dispatch address_space_init_dispatch_sparc
 #define address_space_init_shareable address_space_init_shareable_sparc
+#define address_space_get_iotlb_entry address_space_get_iotlb_entry_sparc
 #define address_space_ldl address_space_ldl_sparc
 #define address_space_ldl_be address_space_ldl_be_sparc
 #define address_space_ldl_be_cached address_space_ldl_be_cached_sparc
@@ -2858,8 +2859,8 @@
 #define strpadcpy strpadcpy_sparc
 #define strstart strstart_sparc
 #define stw_be_p stw_be_p_sparc
-#define stw_be_phys_cached stw_be_phys_cached_sparc
 #define stw_be_phys stw_be_phys_sparc
+#define stw_be_phys_cached stw_be_phys_cached_sparc
 #define stw_he_p stw_he_p_sparc
 #define stw_le_p stw_le_p_sparc
 #define stw_le_phys stw_le_phys_sparc

qemu/sparc64.h

@@ -59,6 +59,7 @@
 #define address_space_init address_space_init_sparc64
 #define address_space_init_dispatch address_space_init_dispatch_sparc64
 #define address_space_init_shareable address_space_init_shareable_sparc64
+#define address_space_get_iotlb_entry address_space_get_iotlb_entry_sparc64
 #define address_space_ldl address_space_ldl_sparc64
 #define address_space_ldl_be address_space_ldl_be_sparc64
 #define address_space_ldl_be_cached address_space_ldl_be_cached_sparc64
@@ -2858,8 +2859,8 @@
 #define strpadcpy strpadcpy_sparc64
 #define strstart strstart_sparc64
 #define stw_be_p stw_be_p_sparc64
-#define stw_be_phys_cached stw_be_phys_cached_sparc64
 #define stw_be_phys stw_be_phys_sparc64
+#define stw_be_phys_cached stw_be_phys_cached_sparc64
 #define stw_he_p stw_he_p_sparc64
 #define stw_le_p stw_le_p_sparc64
 #define stw_le_phys stw_le_phys_sparc64

qemu/x86_64.h

@@ -59,6 +59,7 @@
 #define address_space_init address_space_init_x86_64
 #define address_space_init_dispatch address_space_init_dispatch_x86_64
 #define address_space_init_shareable address_space_init_shareable_x86_64
+#define address_space_get_iotlb_entry address_space_get_iotlb_entry_x86_64
 #define address_space_ldl address_space_ldl_x86_64
 #define address_space_ldl_be address_space_ldl_be_x86_64
 #define address_space_ldl_be_cached address_space_ldl_be_cached_x86_64
@@ -2858,8 +2859,8 @@
 #define strpadcpy strpadcpy_x86_64
 #define strstart strstart_x86_64
 #define stw_be_p stw_be_p_x86_64
-#define stw_be_phys_cached stw_be_phys_cached_x86_64
 #define stw_be_phys stw_be_phys_x86_64
+#define stw_be_phys_cached stw_be_phys_cached_x86_64
 #define stw_he_p stw_he_p_x86_64
 #define stw_le_p stw_le_p_x86_64
 #define stw_le_phys stw_le_phys_x86_64