Re: [PATCH v7 09/13] x86: Secure Launch SMP bringup support
Hi Ross,
kernel test robot noticed the following build warnings:
[auto build test WARNING on tip/x86/core]
[also build test WARNING on herbert-cryptodev-2.6/master
herbert-crypto-2.6/master linus/master v6.6 next-20231110]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url:
https://github.com/intel-lab-lkp/linux/commits/Ross-Philipson/x86-boot-Place-kernel_info-at-a-fixed-offset/2023-063453
base: tip/x86/core
patch link:
https://lore.kernel.org/r/20231110222751.219836-10-ross.philipson%40oracle.com
patch subject: [PATCH v7 09/13] x86: Secure Launch SMP bringup support
config: x86_64-rhel-8.3-rust
(https://download.01.org/0day-ci/archive/2023/20231806.sbmcwun1-...@intel.com/config)
compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git
ae42196bc493ffe877a7e3dff8be32035dea4d07)
reproduce (this is a W=1 build):
(https://download.01.org/0day-ci/archive/2023/20231806.sbmcwun1-...@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot
| Closes:
https://lore.kernel.org/oe-kbuild-all/20231806.sbmcwun1-...@intel.com/
All warnings (new ones prefixed by >>):
>> arch/x86/kernel/smpboot.c:1097:6: warning: variable 'ret' is used
>> uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
if (slaunch_is_txt_launch())
^~~
arch/x86/kernel/smpboot.c:1107:6: note: uninitialized use occurs here
if (ret)
^~~
arch/x86/kernel/smpboot.c:1097:2: note: remove the 'if' if its condition is
always false
if (slaunch_is_txt_launch())
^~~~
arch/x86/kernel/smpboot.c:1046:9: note: initialize the variable 'ret' to
silence this warning
int ret;
^
= 0
1 warning generated.
vim +1097 arch/x86/kernel/smpboot.c
1036
1037 /*
1038 * NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad
1039 * (ie clustered apic addressing mode), this is a LOGICAL apic ID.
1040 * Returns zero if startup was successfully sent, else error code from
1041 * ->wakeup_secondary_cpu.
1042 */
1043 static int do_boot_cpu(u32 apicid, int cpu, struct task_struct *idle)
1044 {
1045 unsigned long start_ip = real_mode_header->trampoline_start;
1046 int ret;
1047
1048 #ifdef CONFIG_X86_64
1049 /* If 64-bit wakeup method exists, use the 64-bit mode
trampoline IP */
1050 if (apic->wakeup_secondary_cpu_64)
1051 start_ip = real_mode_header->trampoline_start64;
1052 #endif
1053 idle->thread.sp = (unsigned long)task_pt_regs(idle);
1054 initial_code = (unsigned long)start_secondary;
1055
1056 if (IS_ENABLED(CONFIG_X86_32)) {
1057 early_gdt_descr.address = (unsigned
long)get_cpu_gdt_rw(cpu);
1058 initial_stack = idle->thread.sp;
1059 } else if (!(smpboot_control & STARTUP_PARALLEL_MASK)) {
1060 smpboot_control = cpu;
1061 }
1062
1063 /* Enable the espfix hack for this CPU */
1064 init_espfix_ap(cpu);
1065
1066 /* So we see what's up */
1067 announce_cpu(cpu, apicid);
1068
1069 /*
1070 * This grunge runs the startup process for
1071 * the targeted processor.
1072 */
1073 if (x86_platform.legacy.warm_reset) {
1074
1075 pr_debug("Setting warm reset code and vector.\n");
1076
1077 smpboot_setup_warm_reset_vector(start_ip);
1078 /*
1079 * Be paranoid about clearing APIC errors.
1080 */
1081 if (APIC_INTEGRATED(boot_cpu_apic_version)) {
1082 apic_write(APIC_ESR, 0);
1083 apic_read(APIC_ESR);
1084 }
1085 }
1086
1087 smp_mb();
1088
1089 /*
1090 * Wake up a CPU in difference cases:
1091 * - Intel TXT DRTM launch uses its own method to wake the APs
1092 * - Use a method from the APIC driver if one defined, with
wakeup
1093 * straight to 64-bit mode preferred over wakeup to RM.
1094 * Otherwise,
1095 * - Use an INIT boot APIC message
1096 */
> 1097 if (slaunch_is_txt_launch())
1098 slaunch_wakeup_cpu_from_txt(cpu, apicid);
1099 else if (apic->
[PATCH v7 09/13] x86: Secure Launch SMP bringup support
On Intel, the APs are left in a well documented state after TXT performs
the late launch. Specifically they cannot have #INIT asserted on them so
a standard startup via INIT/SIPI/SIPI cannot be performed. Instead the
early SL stub code uses MONITOR and MWAIT to park the APs. The realmode/init.c
code updates the jump address for the waiting APs with the location of the
Secure Launch entry point in the RM piggy after it is loaded and fixed up.
As the APs are woken up by writing the monitor, the APs jump to the Secure
Launch entry point in the RM piggy which mimics what the real mode code would
do then jumps to the standard RM piggy protected mode entry point.
Signed-off-by: Ross Philipson
---
arch/x86/include/asm/realmode.h | 3 ++
arch/x86/kernel/smpboot.c| 56 +++-
arch/x86/realmode/init.c | 3 ++
arch/x86/realmode/rm/header.S| 3 ++
arch/x86/realmode/rm/trampoline_64.S | 32
5 files changed, 96 insertions(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/realmode.h b/arch/x86/include/asm/realmode.h
index 87e5482acd0d..339b48e2543d 100644
--- a/arch/x86/include/asm/realmode.h
+++ b/arch/x86/include/asm/realmode.h
@@ -38,6 +38,9 @@ struct real_mode_header {
#ifdef CONFIG_X86_64
u32 machine_real_restart_seg;
#endif
+#ifdef CONFIG_SECURE_LAUNCH
+ u32 sl_trampoline_start32;
+#endif
};
/* This must match data at realmode/rm/trampoline_{32,64}.S */
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 2cc2aa120b4b..6f2a5ee458ce 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -60,6 +60,7 @@
#include
#include
#include
+#include
#include
#include
@@ -986,6 +987,56 @@ int common_cpu_up(unsigned int cpu, struct task_struct
*idle)
return 0;
}
+#ifdef CONFIG_SECURE_LAUNCH
+
+static bool slaunch_is_txt_launch(void)
+{
+ if ((slaunch_get_flags() & (SL_FLAG_ACTIVE|SL_FLAG_ARCH_TXT)) ==
+ (SL_FLAG_ACTIVE | SL_FLAG_ARCH_TXT))
+ return true;
+
+ return false;
+}
+
+/*
+ * TXT AP startup is quite different than normal. The APs cannot have #INIT
+ * asserted on them or receive SIPIs. The early Secure Launch code has parked
+ * the APs using monitor/mwait. This will wake the APs by writing the monitor
+ * and have them jump to the protected mode code in the rmpiggy where the rest
+ * of the SMP boot of the AP will proceed normally.
+ */
+static void slaunch_wakeup_cpu_from_txt(int cpu, int apicid)
+{
+ struct sl_ap_wake_info *ap_wake_info;
+ struct sl_ap_stack_and_monitor *stack_monitor = NULL;
+
+ ap_wake_info = slaunch_get_ap_wake_info();
+
+ stack_monitor = (struct sl_ap_stack_and_monitor
*)__va(ap_wake_info->ap_wake_block +
+
ap_wake_info->ap_stacks_offset);
+
+ for (unsigned int i = TXT_MAX_CPUS - 1; i >= 0; i--) {
+ if (stack_monitor[i].apicid == apicid) {
+ /* Write the monitor */
+ stack_monitor[i].monitor = 1;
+ break;
+ }
+ }
+}
+
+#else
+
+static inline bool slaunch_is_txt_launch(void)
+{
+ return false;
+}
+
+static inline void slaunch_wakeup_cpu_from_txt(int cpu, int apicid)
+{
+}
+
+#endif /* !CONFIG_SECURE_LAUNCH */
+
/*
* NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad
* (ie clustered apic addressing mode), this is a LOGICAL apic ID.
@@ -1040,12 +1091,15 @@ static int do_boot_cpu(u32 apicid, int cpu, struct
task_struct *idle)
/*
* Wake up a CPU in difference cases:
+* - Intel TXT DRTM launch uses its own method to wake the APs
* - Use a method from the APIC driver if one defined, with wakeup
* straight to 64-bit mode preferred over wakeup to RM.
* Otherwise,
* - Use an INIT boot APIC message
*/
- if (apic->wakeup_secondary_cpu_64)
+ if (slaunch_is_txt_launch())
+ slaunch_wakeup_cpu_from_txt(cpu, apicid);
+ else if (apic->wakeup_secondary_cpu_64)
ret = apic->wakeup_secondary_cpu_64(apicid, start_ip);
else if (apic->wakeup_secondary_cpu)
ret = apic->wakeup_secondary_cpu(apicid, start_ip);
diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c
index 788e5559549f..b548b3376765 100644
--- a/arch/x86/realmode/init.c
+++ b/arch/x86/realmode/init.c
@@ -4,6 +4,7 @@
#include
#include
#include
+#include
#include
#include
@@ -210,6 +211,8 @@ void __init init_real_mode(void)
setup_real_mode();
set_real_mode_permissions();
+
+ slaunch_fixup_jump_vector();
}
static int __init do_init_real_mode(void)
diff --git a/arch/x86/realmode/rm/header.S b/arch/x86/realmode/rm/header.S
index 2eb62be6d256..3b5cbcbbfc90 100644
--- a/arch/x86/realmode/rm/header.S
+++ b/arch/x86/realmode/rm/header.S
@@ -37,6 +37
