[PATCH] x86/MSI: drop "packed" attribute from message data/address structures

Jan Beulich posted 1 patch 1 year, 2 months ago
Failed in applying to current master (apply log)
[PATCH] x86/MSI: drop "packed" attribute from message data/address structures
Posted by Jan Beulich 1 year, 2 months ago
The attribute has no purpose here and, in the worst case, could lead to
the compiler generating worse code. In practice, however: No change to
generated code (surprisingly not even to generated debug info), at least
with gcc12 and the .config-s I've tried.

Requested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/arch/x86/include/asm/msi.h
+++ b/xen/arch/x86/include/asm/msi.h
@@ -178,7 +178,7 @@ int msi_free_irq(struct msi_desc *entry)
  * MSI Defined Data Structures
  */
 
-struct __packed msg_data {
+struct msg_data {
     uint32_t vector        :  8;
     uint32_t delivery_mode :  3;    /* 000b: FIXED | 001b: lowest prior */
     uint32_t               :  3;
@@ -187,7 +187,7 @@ struct __packed msg_data {
     uint32_t               : 16;
 };
 
-struct __packed msg_address {
+struct msg_address {
     union {
         struct {
             uint32_t              :  2;
Re: [PATCH] x86/MSI: drop "packed" attribute from message data/address structures
Posted by Andrew Cooper 1 year, 2 months ago
On 22/02/2023 10:35 am, Jan Beulich wrote:
> The attribute has no purpose here and, in the worst case, could lead to
> the compiler generating worse code. In practice, however: No change to
> generated code (surprisingly not even to generated debug info), at least
> with gcc12 and the .config-s I've tried.
>
> Requested-by: Andrew Cooper <andrew.cooper3@citrix.com>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>