[Xen-devel] [PATCH v6 09/12] microcode: remove struct microcode_info

[Chao Gao <chao.gao@xxxxxxxxx>]

Struct microcode_info is useless now. microcode pointer and size inside
it were passed to other CPUs to parse microcode locally. Now, parsing
microcode blob is done on one of CPUs. Other CPUs needn't parse the
microcode blob; the pointer and size can be removed.

The 'cpu' field is also redundent because it always can be inferred from
current cpu id.

Signed-off-by: Chao Gao <chao.gao@xxxxxxxxx>
---
v6:
 - remove the whole microcode_info instead of two fields of it.
---
 xen/arch/x86/microcode.c | 62 +++++++++++++++++++-----------------------------
 1 file changed, 25 insertions(+), 37 deletions(-)

diff --git a/xen/arch/x86/microcode.c b/xen/arch/x86/microcode.c
index e4e2e74..c510808 100644
--- a/xen/arch/x86/microcode.c
+++ b/xen/arch/x86/microcode.c
@@ -188,13 +188,6 @@ static DEFINE_SPINLOCK(microcode_mutex);
 
 DEFINE_PER_CPU(struct cpu_signature, cpu_sig);
 
-struct microcode_info {
-    unsigned int cpu;
-    uint32_t buffer_size;
-    int error;
-    char buffer[1];
-};
-
 /*
  * Save an ucode patch to the global cache list.
  *
@@ -291,30 +284,25 @@ static int microcode_update_cpu(void)
     return ret;
 }
 
-static long do_microcode_update(void *_info)
+static long do_microcode_update(void *unused)
 {
-    struct microcode_info *info = _info;
-    int error;
-
-    BUG_ON(info->cpu != smp_processor_id());
+    int error, cpu;
 
     error = microcode_update_cpu();
     if ( error )
-        info->error = error;
+        return error;
 
-    info->cpu = cpumask_next(info->cpu, &cpu_online_map);
-    if ( info->cpu < nr_cpu_ids )
-        return continue_hypercall_on_cpu(info->cpu, do_microcode_update, info);
+    cpu = cpumask_next(smp_processor_id(), &cpu_online_map);
+    if ( cpu < nr_cpu_ids )
+        return continue_hypercall_on_cpu(cpu, do_microcode_update, NULL);
 
-    error = info->error;
-    xfree(info);
     return error;
 }
 
 int microcode_update(XEN_GUEST_HANDLE_PARAM(const_void) buf, unsigned long len)
 {
     int ret;
-    struct microcode_info *info;
+    void *buffer;
 
     if ( len != (uint32_t)len )
         return -E2BIG;
@@ -322,40 +310,40 @@ int microcode_update(XEN_GUEST_HANDLE_PARAM(const_void) 
buf, unsigned long len)
     if ( microcode_ops == NULL )
         return -EINVAL;
 
-    info = xmalloc_bytes(sizeof(*info) + len);
-    if ( info == NULL )
-        return -ENOMEM;
+    buffer = xmalloc_bytes(len);
+    if ( !buffer )
+    {
+        ret = -ENOMEM;
+        goto free;
+    }
 
-    ret = copy_from_guest(info->buffer, buf, len);
-    if ( ret != 0 )
+    if ( copy_from_guest(buffer, buf, len) )
     {
-        xfree(info);
-        return ret;
+        ret = -EFAULT;
+        goto free;
     }
 
     if ( microcode_ops->start_update )
     {
         ret = microcode_ops->start_update();
         if ( ret != 0 )
-        {
-            xfree(info);
-            return ret;
-        }
+            goto free;
     }
 
-    ret = microcode_parse_blob(info->buffer, len);
+    ret = microcode_parse_blob(buffer, len);
     if ( ret <= 0 )
     {
         printk(XENLOG_ERR "No valid or newer ucode found. Update abort!\n");
-        xfree(info);
-        return -EINVAL;
+        ret = -EINVAL;
+        goto free;
     }
 
-    info->buffer_size = len;
-    info->error = 0;
-    info->cpu = cpumask_first(&cpu_online_map);
+    return continue_hypercall_on_cpu(cpumask_first(&cpu_online_map),
+                                     do_microcode_update, NULL);
 
-    return continue_hypercall_on_cpu(info->cpu, do_microcode_update, info);
+ free:
+    xfree(buffer);
+    return ret;
 }
 
 static int __init microcode_init(void)
-- 
1.8.3.1


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel