x86/apic: Support 15 bits of APIC ID in MSI where available
Some hypervisors can allow the guest to use the Extended Destination ID
field in the MSI address to address up to 32768 CPUs.
This applies to all downstream devices which generate MSI cycles,
including HPET, I/O-APIC and PCI MSI.
HPET and PCI MSI use the same __irq_msi_compose_msg() function, while
I/O-APIC generates its own and had support for the extended bits added in
a previous commit.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201024213535.443185-33-dwmw2@infradead.org
diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h
index dde5b3f..5c69f7e 100644
--- a/arch/x86/include/asm/x86_init.h
+++ b/arch/x86/include/asm/x86_init.h
@@ -116,6 +116,7 @@ struct x86_init_pci {
* @init_platform: platform setup
* @guest_late_init: guest late init
* @x2apic_available: X2APIC detection
+ * @msi_ext_dest_id: MSI supports 15-bit APIC IDs
* @init_mem_mapping: setup early mappings during init_mem_mapping()
* @init_after_bootmem: guest init after boot allocator is finished
*/
@@ -123,6 +124,7 @@ struct x86_hyper_init {
void (*init_platform)(void);
void (*guest_late_init)(void);
bool (*x2apic_available)(void);
+ bool (*msi_ext_dest_id)(void);
void (*init_mem_mapping)(void);
void (*init_after_bootmem)(void);
};