x86/msi: Fix msi message data shadow struct

commit 59b18a1 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: 6285aa5 ("x86/msi: Provide msi message shadow structs")
Co-developed-by: Adrian-Ken Rueegsegger <[email protected]>
Signed-off-by: Adrian-Ken Rueegsegger <[email protected]>
Signed-off-by: Reto Buerki <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: reet-

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