x86: drop unneeded __packed attributes

There where a couple of unneeded packed attributes in several x86-specific
structures, that are obviously aligned. The only non-trivial one is
vmcb_struct, which has been checked to have the same layout with and without
the packed attribute using pahole. In that case add a build-time size check to
be on the safe side.

No functional change is expected as a result of this commit.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
master commit: 4036e7c592905c2292cdeba8269e969959427237
master date: 2017-03-07 17:11:06 +0100

diff --git a/xen/arch/x86/hvm/svm/vmcb.c b/xen/arch/x86/hvm/svm/vmcb.c
index 9ea014fa5e463c607772a67234854e9603b22025..f982fc9faeaf740192af2db3bb86fe1aeaa43f28 100644 (file)
--- a/xen/arch/x86/hvm/svm/vmcb.c
+++ b/xen/arch/x86/hvm/svm/vmcb.c
@@ -72,6 +72,9 @@ static int construct_vmcb(struct vcpu *v)
     struct arch_svm_struct *arch_svm = &v->arch.hvm_svm;
     struct vmcb_struct *vmcb = arch_svm->vmcb;
 
+    /* Build-time check of the size of VMCB AMD structure. */
+    BUILD_BUG_ON(sizeof(*vmcb) != PAGE_SIZE);
+
     vmcb->_general1_intercepts = 
         GENERAL1_INTERCEPT_INTR        | GENERAL1_INTERCEPT_NMI         |
         GENERAL1_INTERCEPT_SMI         | GENERAL1_INTERCEPT_INIT        |

diff --git a/xen/arch/x86/x86_emulate/x86_emulate.h b/xen/arch/x86/x86_emulate/x86_emulate.h
index 993c576083be8db6170c0f831033bd51634a8878..708ce78dda1047696ba67d467871a354db103de7 100644 (file)
--- a/xen/arch/x86/x86_emulate/x86_emulate.h
+++ b/xen/arch/x86/x86_emulate/x86_emulate.h
@@ -71,7 +71,7 @@ enum x86_swint_emulation {
  * Attribute for segment selector. This is a copy of bit 40:47 & 52:55 of the
  * segment descriptor. It happens to match the format of an AMD SVM VMCB.
  */
-typedef union __attribute__((__packed__)) segment_attributes {
+typedef union segment_attributes {
     uint16_t bytes;
     struct
     {
@@ -91,7 +91,7 @@ typedef union __attribute__((__packed__)) segment_attributes {
  * Full state of a segment register (visible and hidden portions).
  * Again, this happens to match the format of an AMD SVM VMCB.
  */
-struct __attribute__((__packed__)) segment_register {
+struct segment_register {
     uint16_t   sel;
     segment_attributes_t attr;
     uint32_t   limit;

diff --git a/xen/include/asm-x86/hvm/svm/vmcb.h b/xen/include/asm-x86/hvm/svm/vmcb.h
index bad23826dcf743eab650699f3d323c472c55ab39..a3cd1b1879672cbdc6dc6168c6b5bace51d11a21 100644 (file)
--- a/xen/include/asm-x86/hvm/svm/vmcb.h
+++ b/xen/include/asm-x86/hvm/svm/vmcb.h
@@ -308,7 +308,7 @@ enum VMEXIT_EXITCODE
 /* Definition of segment state is borrowed by the generic HVM code. */
 typedef struct segment_register svm_segment_register_t;
 
-typedef union __packed
+typedef union
 {
     u64 bytes;
     struct 
@@ -322,7 +322,7 @@ typedef union __packed
     } fields;
 } eventinj_t;
 
-typedef union __packed
+typedef union
 {
     u64 bytes;
     struct 
@@ -340,7 +340,7 @@ typedef union __packed
     } fields;
 } vintr_t;
 
-typedef union __packed
+typedef union
 {
     u64 bytes;
     struct 
@@ -357,7 +357,7 @@ typedef union __packed
     } fields;
 } ioio_info_t;
 
-typedef union __packed
+typedef union
 {
     u64 bytes;
     struct
@@ -366,7 +366,7 @@ typedef union __packed
     } fields;
 } lbrctrl_t;
 
-typedef union __packed
+typedef union
 {
     uint32_t bytes;
     struct
@@ -401,7 +401,7 @@ typedef union __packed
 #define IOPM_SIZE   (12 * 1024)
 #define MSRPM_SIZE  (8  * 1024)
 
-struct __packed vmcb_struct {
+struct vmcb_struct {
     u32 _cr_intercepts;         /* offset 0x00 - cleanbit 0 */
     u32 _dr_intercepts;         /* offset 0x04 - cleanbit 0 */
     u32 _exception_intercepts;  /* offset 0x08 - cleanbit 0 */