[PATCH v9 12/19] reboot: Secure Launch SEXIT support on reboot paths

Ross Philipson
2024-05-31T01:32:55Z

If the MLE kernel is being powered off, rebooted or halted,
then SEXIT must be called. Note that the SEXIT GETSEC leaf
can only be called after a machine_shutdown() has been done on
these paths. The machine_shutdown() is not called on a few paths
like when poweroff action does not have a poweroff callback (into
ACPI code) or when an emergency reset is done. In these cases,
just the TXT registers are finalized but SEXIT is skipped.

Signed-off-by: Ross Philipson <ross.philipson@oracle.com>
---
arch/x86/kernel/reboot.c | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index f3130f762784..66060fdb0822 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -12,6 +12,7 @@
#include <linux/delay.h>
#include <linux/objtool.h>
#include <linux/pgtable.h>
+#include <linux/slaunch.h>
#include <acpi/reboot.h>
#include <asm/io.h>
#include <asm/apic.h>
@@ -766,6 +767,7 @@ static void native_machine_restart(char *__unused)

if (!reboot_force)
machine_shutdown();
+ slaunch_finalize(!reboot_force);
__machine_emergency_restart(0);
}

@@ -776,6 +778,9 @@ static void native_machine_halt(void)

tboot_shutdown(TB_SHUTDOWN_HALT);

+ /* SEXIT done after machine_shutdown() to meet TXT requirements */
+ slaunch_finalize(1);
+
stop_this_cpu(NULL);
}

@@ -784,8 +789,12 @@ static void native_machine_power_off(void)
if (kernel_can_power_off()) {
if (!reboot_force)
machine_shutdown();
+ slaunch_finalize(!reboot_force);
do_kernel_power_off();
+ } else {
+ slaunch_finalize(0);
}
+
/* A fallback in case there is no PM info available */
tboot_shutdown(TB_SHUTDOWN_HALT);
}
@@ -813,6 +822,7 @@ void machine_shutdown(void)

void machine_emergency_restart(void)
{
+ slaunch_finalize(0);
__machine_emergency_restart(1);
}

--
2.39.3