[Qemu-devel] Re: [PATCH 1/6] Make fw_cfg interface 32-bit aware

[Juan Quintela <quintela@redhat.com>]

Alexander Graf <agraf@suse.de> wrote:
> On 13.11.2009, at 01:48, Glauber Costa wrote:
> Because that would mean I'd have to deal with it in the code later on
> and I don't see the point of writing code that's not in the load/save
> cycle because of limitations there.

Hi

could you take a look at this one?

This don't use the old_state function and should work as well.
I haven't tested it yet (test machine down), but will do a bit later.

Later, Juan.

PD. Yeap, I would have to add the HACK types to hw.h as several places
    have decided to change the size of several fields.

>From 25f7a6e401d72a0584fa4630a9dc97ce34520f7b Mon Sep 17 00:00:00 2001
From: Juan Quintela <quintela@redhat.com>
Date: Fri, 13 Nov 2009 11:56:38 +0100
Subject: [PATCH] fw_cfg: change cur_offset to 32 bits


Signed-off-by: Juan Quintela <quintela@redhat.com>
---
 hw/fw_cfg.c |   44 +++++++++++++++++++++++++++++++++++++++-----
 hw/fw_cfg.h |    2 +-
 2 files changed, 40 insertions(+), 6 deletions(-)

diff --git a/hw/fw_cfg.c b/hw/fw_cfg.c
index a6d811b..b79d58f 100644
--- a/hw/fw_cfg.c
+++ b/hw/fw_cfg.c
@@ -39,7 +39,7 @@
 #define FW_CFG_SIZE 2

 typedef struct _FWCfgEntry {
-    uint16_t len;
+    uint32_t len;
     uint8_t *data;
     void *callback_opaque;
     FWCfgCallback callback;
@@ -48,7 +48,7 @@ typedef struct _FWCfgEntry {
 typedef struct _FWCfgState {
     FWCfgEntry entries[2][FW_CFG_MAX_ENTRY];
     uint16_t cur_entry;
-    uint16_t cur_offset;
+    uint32_t cur_offset;
 } FWCfgState;

 static void fw_cfg_write(FWCfgState *s, uint8_t value)
@@ -164,19 +164,53 @@ static void fw_cfg_reset(void *opaque)
     fw_cfg_select(s, 0);
 }

+/* Save restore 32 bit int as uint16_t
+   This is a Big hack, but it is how the old state did it.
+   Or we broke compatibility in the state, or we can't use struct tm
+ */
+
+static int get_uint32_as_uint16(QEMUFile *f, void *pv, size_t size)
+{
+    uint32_t *v = pv;
+    *v = qemu_get_be16(f);
+    return 0;
+}
+
+static void put_unused(QEMUFile *f, void *pv, size_t size)
+{
+    fprintf(stderr, "uint32_as_uint16 is only used for backward compatibilty.\n");
+    fprintf(stderr, "This functions shouldn't be called.\n");
+}
+
+const VMStateInfo vmstate_hack_uint32_as_uint16 = {
+    .name = "int32_as_uint16",
+    .get  = get_uint32_as_uint16,
+    .put  = put_unused,
+};
+
+#define VMSTATE_UINT16_HACK(_f, _s, _t)                                    \
+    VMSTATE_SINGLE_TEST(_f, _s, _t, 0, vmstate_hack_uint32_as_uint16, uint32_t)
+
+
+static bool is_version_1(void *opaque, int version_id)
+{
+    return version_id == 1;
+}
+
 static const VMStateDescription vmstate_fw_cfg = {
     .name = "fw_cfg",
-    .version_id = 1,
+    .version_id = 2,
     .minimum_version_id = 1,
     .minimum_version_id_old = 1,
     .fields      = (VMStateField []) {
         VMSTATE_UINT16(cur_entry, FWCfgState),
-        VMSTATE_UINT16(cur_offset, FWCfgState),
+        VMSTATE_UINT16_HACK(cur_offset, FWCfgState, is_version_1),
+        VMSTATE_UINT32_V(cur_offset, FWCfgState, 2),
         VMSTATE_END_OF_LIST()
     }
 };

-int fw_cfg_add_bytes(void *opaque, uint16_t key, uint8_t *data, uint16_t len)
+int fw_cfg_add_bytes(void *opaque, uint16_t key, uint8_t *data, uint32_t len)
 {
     FWCfgState *s = opaque;
     int arch = !!(key & FW_CFG_ARCH_LOCAL);
diff --git a/hw/fw_cfg.h b/hw/fw_cfg.h
index 30dfec7..359d45a 100644
--- a/hw/fw_cfg.h
+++ b/hw/fw_cfg.h
@@ -28,7 +28,7 @@
 #ifndef NO_QEMU_PROTOS
 typedef void (*FWCfgCallback)(void *opaque, uint8_t *data);

-int fw_cfg_add_bytes(void *opaque, uint16_t key, uint8_t *data, uint16_t len);
+int fw_cfg_add_bytes(void *opaque, uint16_t key, uint8_t *data, uint32_t len);
 int fw_cfg_add_i16(void *opaque, uint16_t key, uint16_t value);
 int fw_cfg_add_i32(void *opaque, uint16_t key, uint32_t value);
 int fw_cfg_add_i64(void *opaque, uint16_t key, uint64_t value);
-- 
1.6.2.5