x86/msi: Fix msi message data shadow struct

commit 59b18a1e65b7a2134814106d0860010e10babe18 upstream.

The x86 MSI message data is 32 bits in total and is either in
compatibility or remappable format, see Intel Virtualization Technology
for Directed I/O, section 5.1.2.

Fixes: 6285aa50736 ("x86/msi: Provide msi message shadow structs")
Co-developed-by: Adrian-Ken Rueegsegger <ken@codelabs.ch>
Signed-off-by: Adrian-Ken Rueegsegger <ken@codelabs.ch>
Signed-off-by: Reto Buerki <reet@codelabs.ch>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220407110647.67372-1-reet@codelabs.ch
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/include/asm/msi.h b/arch/x86/include/asm/msi.h
index b85147d..d71c7e8 100644 (file)
--- a/arch/x86/include/asm/msi.h
+++ b/arch/x86/include/asm/msi.h
@@ -12,14 +12,17 @@ int pci_msi_prepare(struct irq_domain *domain, struct device *dev, int nvec,
 /* Structs and defines for the X86 specific MSI message format */
 
 typedef struct x86_msi_data {
-       u32     vector                  :  8,
-               delivery_mode           :  3,
-               dest_mode_logical       :  1,
-               reserved                :  2,
-               active_low              :  1,
-               is_level                :  1;
-
-       u32     dmar_subhandle;
+       union {
+               struct {
+                       u32     vector                  :  8,
+                               delivery_mode           :  3,
+                               dest_mode_logical       :  1,
+                               reserved                :  2,
+                               active_low              :  1,
+                               is_level                :  1;
+               };
+               u32     dmar_subhandle;
+       };
 } __attribute__ ((packed)) arch_msi_msg_data_t;
 #define arch_msi_msg_data      x86_msi_data