[PATCH v3 11/13] x86/smpboot: Add a helper get the address of the wakeup mailbox

Ricardo Neri
2025-05-03T19:10:18Z

A Hyper-V VTL level 2 guest on a TDX environment needs to map the
physical page of the ACPI Multiprocessor Wakeup Structure as private
(encrypted). It needs to know the physical address of this structure.
Add a helper function.

Suggested-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
---
Changes since v2:
- Introduced this patch

Changes since v1:
- N/A
---
arch/x86/include/asm/smp.h | 1 +
arch/x86/kernel/smpboot.c | 5 +++++
2 files changed, 6 insertions(+)

diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h
index 97bfbd0d24d4..18003453569a 100644
--- a/arch/x86/include/asm/smp.h
+++ b/arch/x86/include/asm/smp.h
@@ -149,6 +149,7 @@ static inline struct cpumask *cpu_l2c_shared_mask(int cpu)
#ifdef CONFIG_X86_64
void setup_mp_wakeup_mailbox(u64 addr);
struct acpi_madt_multiproc_wakeup_mailbox *get_mp_wakeup_mailbox(void);
+u64 get_mp_wakeup_mailbox_paddr(void);
#endif

#else /* !CONFIG_SMP */
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 6f39ebe4d192..1e211c78c1d3 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1431,4 +1431,9 @@ struct acpi_madt_multiproc_wakeup_mailbox *get_mp_wakeup_mailbox(void)
{
return acpi_mp_wake_mailbox;
}
+
+u64 get_mp_wakeup_mailbox_paddr(void)
+{
+ return acpi_mp_wake_mailbox_paddr;
+}
#endif
--
2.43.0