[Qemu-devel] [PATCH 3/5] replace cpu_physical_memory_rw

[Glauber Costa <glommer@redhat.com>]

This patch introduces a kvm version of cpu_physical_memory_rw.
The main motivation is to bypass tcg version, which contains
tcg-specific code, as well as data structures not used by kvm,
such as l1_phys_map.

In this patch, I'm using a runtime selection of which function
to call, but the mid-term goal is to use function pointers in
a way very close to which QEMUAccel used to be.

Signed-off-by: Glauber Costa <glommer@redhat.com>
---
 exec.c    |   13 +++++++++++--
 kvm-all.c |   39 +++++++++++++++++++++++++++++++++++----
 kvm.h     |    2 ++
 3 files changed, 48 insertions(+), 6 deletions(-)

diff --git a/exec.c b/exec.c
index 04eadfe..d5c88b1 100644
--- a/exec.c
+++ b/exec.c
@@ -2938,8 +2938,8 @@ int cpu_physical_memory_do_io(target_phys_addr_t addr, uint8_t *buf, int l, int
     return l;
 }
 
-void cpu_physical_memory_rw(target_phys_addr_t addr, uint8_t *buf,
-                            int len, int is_write)
+static void tcg_physical_memory_rw(target_phys_addr_t addr, uint8_t *buf,
+                                   int len, int is_write)
 {
     int l;
     uint8_t *ptr;
@@ -2997,6 +2997,15 @@ void cpu_physical_memory_rw(target_phys_addr_t addr, uint8_t *buf,
     }
 }
 
+void cpu_physical_memory_rw(target_phys_addr_t addr, uint8_t *buf,
+                            int len, int is_write)
+{
+    if (kvm_enabled())
+        kvm_cpu_physical_memory_rw(addr, buf, len, is_write);
+    else
+        tcg_physical_memory_rw(addr, buf, len, is_write);
+}
+
 /* used for ROM loading : can write in RAM and ROM */
 void cpu_physical_memory_write_rom(target_phys_addr_t addr,
                                    const uint8_t *buf, int len)
diff --git a/kvm-all.c b/kvm-all.c
index 11034df..15eb326 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -540,7 +540,7 @@ void kvm_set_phys_mem(target_phys_addr_t start_addr,
 
     mem = kvm_lookup_slot(s, start_addr);
     if (mem) {
-        if ((flags == IO_MEM_UNASSIGNED) || (flags >= TLB_MMIO)) {
+        if ((flags == IO_MEM_UNASSIGNED))  {
             mem->memory_size = 0;
             mem->start_addr = start_addr;
             mem->phys_offset = 0;
@@ -559,6 +559,8 @@ void kvm_set_phys_mem(target_phys_addr_t start_addr,
                 mem->phys_offset)
                 return;
 
+            if ((phys_offset & ~TARGET_PAGE_MASK) != 0)
+                return;
             /* unregister whole slot */
             memcpy(&slot, mem, sizeof(slot));
             mem->memory_size = 0;
@@ -588,16 +590,21 @@ void kvm_set_phys_mem(target_phys_addr_t start_addr,
         }
     }
     /* KVM does not need to know about this memory */
-    if (flags >= IO_MEM_UNASSIGNED)
+    if (flags == IO_MEM_UNASSIGNED)
         return;
 
-    mem = kvm_alloc_slot(s);
+    if (!mem)
+        mem = kvm_alloc_slot(s);
     mem->memory_size = size;
     mem->start_addr = start_addr;
     mem->phys_offset = phys_offset;
     mem->flags = 0;
 
-    kvm_set_user_memory_region(s, mem);
+    if (flags < TLB_MMIO)
+        kvm_set_user_memory_region(s, mem);
+    else{
+        mem->phys_offset = flags;
+    }
     /* FIXME deal with errors */
 }
 
@@ -663,3 +670,27 @@ int kvm_has_sync_mmu(void)
 
     return 0;
 }
+
+void kvm_cpu_physical_memory_rw(target_phys_addr_t addr, uint8_t *buf,
+                                int len, int is_write)
+{
+    KVMSlot *mem;
+    KVMState *s = kvm_state;
+    int l;
+
+    mem = kvm_lookup_slot(s, addr);
+    if (!mem)
+        return;
+
+    if ((mem->phys_offset & ~TARGET_PAGE_MASK) >= TLB_MMIO) {
+        l = 0;
+        while (len > l)
+            l += cpu_physical_memory_do_io(addr + l, buf + l, len - l, is_write, mem->phys_offset);
+    } else {
+        uint8_t *uaddr = phys_ram_base + mem->phys_offset + (addr - mem->start_addr);
+        if (!is_write)
+            memcpy(buf, uaddr, len);
+        else
+            memcpy(uaddr, buf, len);
+    }
+}
diff --git a/kvm.h b/kvm.h
index efce145..e3e9ca0 100644
--- a/kvm.h
+++ b/kvm.h
@@ -49,6 +49,8 @@ int kvm_has_sync_mmu(void);
 int kvm_coalesce_mmio_region(target_phys_addr_t start, ram_addr_t size);
 int kvm_uncoalesce_mmio_region(target_phys_addr_t start, ram_addr_t size);
 
+void kvm_cpu_physical_memory_rw(target_phys_addr_t addr, uint8_t *buf,
+                                int len, int is_write);
 /* internal API */
 
 struct KVMState;
-- 
1.5.6.5