diff options
| author | Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> | 2022-04-06 02:29:30 +0300 |
|---|---|---|
| committer | Dave Hansen <dave.hansen@linux.intel.com> | 2022-04-07 18:27:53 +0300 |
| commit | f39642d0dbacded8b4a816a9197a73efb74e5702 (patch) | |
| tree | fc1cab0d10c7a22f63348e705b176facc7b7bb92 /arch/x86/include/asm/apic.h | |
| parent | ff2e64684f153a61f6ae553e860af4b6ef2f4ca5 (diff) | |
| download | linux-f39642d0dbacded8b4a816a9197a73efb74e5702.tar.xz | |
x86/acpi/x86/boot: Add multiprocessor wake-up support
Secondary CPU startup is currently performed with something called
the "INIT/SIPI protocol". This protocol requires assistance from
VMMs to boot guests. As should be a familiar story by now, that
support can not be provded to TDX guests because TDX VMMs are
not trusted by guests.
To remedy this situation a new[1] "Multiprocessor Wakeup Structure"
has been added to to an existing ACPI table (MADT). This structure
provides the physical address of a "mailbox". A write to the mailbox
then steers the secondary CPU to the boot code.
Add ACPI MADT wake structure parsing support and wake support. Use
this support to wake CPUs whenever it is present instead of INIT/SIPI.
While this structure can theoretically be used on 32-bit kernels,
there are no 32-bit TDX guest kernels. It has not been tested and
can not practically *be* tested on 32-bit. Make it 64-bit only.
1. Details about the new structure can be found in ACPI v6.4, in the
"Multiprocessor Wakeup Structure" section.
Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lkml.kernel.org/r/20220405232939.73860-22-kirill.shutemov@linux.intel.com
Diffstat (limited to 'arch/x86/include/asm/apic.h')
| -rw-r--r-- | arch/x86/include/asm/apic.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h index 35006e151774..bd8ae0a7010a 100644 --- a/arch/x86/include/asm/apic.h +++ b/arch/x86/include/asm/apic.h @@ -490,6 +490,11 @@ static inline unsigned int read_apic_id(void) return apic->get_apic_id(reg); } +#ifdef CONFIG_X86_64 +typedef int (*wakeup_cpu_handler)(int apicid, unsigned long start_eip); +extern void acpi_wake_cpu_handler_update(wakeup_cpu_handler handler); +#endif + extern int default_apic_id_valid(u32 apicid); extern int default_acpi_madt_oem_check(char *, char *); extern void default_setup_apic_routing(void); |