.../ABI/testing/sysfs-platform-intel-ifs | 39 +++ MAINTAINERS | 8 + arch/x86/include/asm/cpu.h | 18 ++ arch/x86/include/asm/msr-index.h | 7 + arch/x86/kernel/cpu/intel.c | 32 +++ arch/x86/kernel/cpu/microcode/intel.c | 59 +--- drivers/platform/x86/intel/Kconfig | 1 + drivers/platform/x86/intel/Makefile | 1 + drivers/platform/x86/intel/ifs/Kconfig | 13 + drivers/platform/x86/intel/ifs/Makefile | 3 + drivers/platform/x86/intel/ifs/core.c | 74 +++++ drivers/platform/x86/intel/ifs/ifs.h | 124 ++++++++ drivers/platform/x86/intel/ifs/load.c | 266 ++++++++++++++++++ drivers/platform/x86/intel/ifs/runtest.c | 255 +++++++++++++++++ drivers/platform/x86/intel/ifs/sysfs.c | 149 ++++++++++ include/linux/stop_machine.h | 16 ++ include/trace/events/intel_ifs.h | 41 +++ kernel/stop_machine.c | 19 ++ 18 files changed, 1073 insertions(+), 52 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-platform-intel-ifs create mode 100644 drivers/platform/x86/intel/ifs/Kconfig create mode 100644 drivers/platform/x86/intel/ifs/Makefile create mode 100644 drivers/platform/x86/intel/ifs/core.c create mode 100644 drivers/platform/x86/intel/ifs/ifs.h create mode 100644 drivers/platform/x86/intel/ifs/load.c create mode 100644 drivers/platform/x86/intel/ifs/runtest.c create mode 100644 drivers/platform/x86/intel/ifs/sysfs.c create mode 100644 include/trace/events/intel_ifs.h
TL;DR this driver loads scan test files that can check whether silicon
in a CPU core is still running correctly. It is expected that these tests
would be run several times per day to catch problems as silicon ages.
Changes since v5:
Added various Reviewed tags. If anyone wants to take one or more
back in the light of changes listed below, please speak up.
Thomas Gleixner
---------------
03 "So checking for Intel Fam6 ANYMODEL and X86_FEATURE_CORE_CAPABILITIES is
sufficient, no?"
Longer explanation in earlier e-mail ... but the family/model/stepping
check is needed. No change.
04 "Why is ifs_load_firmware() not returning an error to the caller?"
In most cases the return isn't useful. But this did prompt a change
to make sure "echo 1 > reload" does give an error if the load fails.
05 "The above struct is nicely tabular. Can we have that here too please?"
Added <TAB>s to ifs_data structure to make it equally pretty.
06 "Setting the authenticated indicator _before_ actually doing the
authentication is just wrong. It does not matter in this case, but it's
still making my eyes bleed."
Moved indicator to after success has been checked.
06 "Why has this to be a smp function call? Just because it's conveniant?
This is nothing urgent and no hotpath, so this really can use
queue_work_on()."
Even simpler is schedule_work_on() [since other changes mean that
the driver no longer allocates a work queue.
07 "Waiting for a second with preemption disabled? Seriously?"
"Plus another half a second with preemption disabled. That's just insane."
"That local_irq_disable() solves what?"
"Why cpu_hotplug_disable()? Why is cpus_read_lock() not sufficient here?"
"Why does this need GFP_NOWAIT?"
"I put that into the wishful thinking realm"
"The real question is why you try to rendevouz CPUs via work queues."
"pseudo-code to use stomp_machine()"
PeterZ contributed a neatly tailored for this usage "stop_core_cpuslocked()"
function that works beautifully. See part 0003 of this new series. That
meant all of the code that triggered the above comments has gone.
Tony Luck
---------
Noticed unnecessary casts from u8 to u32 in the checksum calculation
in load.c. Fixed.
Changed the tracepoint to include the CPU number of the core being
tested (the tracepoint otherwise just tells you which CPU is executing
the driver code and executing "stop_core_cpuslocked()" to do the actual
work on the target CPUs.
Dropped the msec_to_tsc() function that was used to initialize
activate.delay. Just use a #define of 100000 cycles (two orders
of magnitude bigger than I saw for the slew between the two threads
executing the "stop_core_cpuslocked()" target function ... but not
too insane so if the threads do not sync, we give up quickly).
Jithu Joseph (7):
x86/microcode/intel: Expose collect_cpu_info_early() for IFS
platform/x86/intel/ifs: Read IFS firmware image
platform/x86/intel/ifs: Check IFS Image sanity
platform/x86/intel/ifs: Authenticate and copy to secured memory
platform/x86/intel/ifs: Add scan test support
platform/x86/intel/ifs: Add IFS sysfs interface
platform/x86/intel/ifs: add ABI documentation for IFS
Peter Zijlstra (1):
stop_machine: Add stop_core_cpuslocked() for per-core operations
Tony Luck (3):
x86/msr-index: Define INTEGRITY_CAPABILITIES MSR
platform/x86/intel/ifs: Add stub driver for In-Field Scan
trace: platform/x86/intel/ifs: Add trace point to track Intel IFS
operations
.../ABI/testing/sysfs-platform-intel-ifs | 39 +++
MAINTAINERS | 8 +
arch/x86/include/asm/cpu.h | 18 ++
arch/x86/include/asm/msr-index.h | 7 +
arch/x86/kernel/cpu/intel.c | 32 +++
arch/x86/kernel/cpu/microcode/intel.c | 59 +---
drivers/platform/x86/intel/Kconfig | 1 +
drivers/platform/x86/intel/Makefile | 1 +
drivers/platform/x86/intel/ifs/Kconfig | 13 +
drivers/platform/x86/intel/ifs/Makefile | 3 +
drivers/platform/x86/intel/ifs/core.c | 74 +++++
drivers/platform/x86/intel/ifs/ifs.h | 124 ++++++++
drivers/platform/x86/intel/ifs/load.c | 266 ++++++++++++++++++
drivers/platform/x86/intel/ifs/runtest.c | 255 +++++++++++++++++
drivers/platform/x86/intel/ifs/sysfs.c | 149 ++++++++++
include/linux/stop_machine.h | 16 ++
include/trace/events/intel_ifs.h | 41 +++
kernel/stop_machine.c | 19 ++
18 files changed, 1073 insertions(+), 52 deletions(-)
create mode 100644 Documentation/ABI/testing/sysfs-platform-intel-ifs
create mode 100644 drivers/platform/x86/intel/ifs/Kconfig
create mode 100644 drivers/platform/x86/intel/ifs/Makefile
create mode 100644 drivers/platform/x86/intel/ifs/core.c
create mode 100644 drivers/platform/x86/intel/ifs/ifs.h
create mode 100644 drivers/platform/x86/intel/ifs/load.c
create mode 100644 drivers/platform/x86/intel/ifs/runtest.c
create mode 100644 drivers/platform/x86/intel/ifs/sysfs.c
create mode 100644 include/trace/events/intel_ifs.h
base-commit: 672c0c5173427e6b3e2a9bbb7be51ceeec78093a
--
2.35.1
TL;DR this driver loads scan test files that can check whether silicon
in a CPU core is still running correctly. It is expected that these tests
would be run several times per day to catch problems as silicon ages.
Changes since v6
Thomas Gleixner
---------------
"struct workqueue_struct *ifs_wq; Seems to be unused."
True. Deleted.
"static bool oscan_enabled = true; What changes this?"
Code that cleared it deleted. Drop this too.
"Please add curly brackets as these are not one-line statements"
Added
cpumask_first(topology_sibling_cpumask(cpu)); Shouldn't that be cpu_smt_mask()?"
Changed (and several other places)
"take up to 200 milliseconds before it retires. 200ms per test chunk?"
Updated comment to note that 200ms is for all chunks.
"Documentation lost in the intertubes"
Dredged up the version from v3 series and changed:
1) Fixed pathnames now this is a virtual misc device instead of platform
device
2) Put all the text into a "/** DOC:" comment section in ifs.h with just
a "kernel-doc:: drivers/platform/x86/intel/ifs/ifs.h" in the ifs.rst
file under Documentation/x86.
3) Added a "big fat warning" (in all CAPS) pointing out that a core test
can take up to 200 milliseconds. So admins must take extra steps if they
are running latency sensitive workloads.
4) Added note that all HT threads of a core must be online to run a
test.
Tony Luck
---------
Off-by-one on retries check (#define set to 5, but tried 6 times). Fixed
Fixed kerneldoc description of "integrity_cap_bit" (was missing a ":")
Jithu Joseph (7):
x86/microcode/intel: Expose collect_cpu_info_early() for IFS
platform/x86/intel/ifs: Read IFS firmware image
platform/x86/intel/ifs: Check IFS Image sanity
platform/x86/intel/ifs: Authenticate and copy to secured memory
platform/x86/intel/ifs: Add scan test support
platform/x86/intel/ifs: Add IFS sysfs interface
platform/x86/intel/ifs: add ABI documentation for IFS
Peter Zijlstra (1):
stop_machine: Add stop_core_cpuslocked() for per-core operations
Tony Luck (4):
x86/msr-index: Define INTEGRITY_CAPABILITIES MSR
platform/x86/intel/ifs: Add stub driver for In-Field Scan
trace: platform/x86/intel/ifs: Add trace point to track Intel IFS
operations
Documentation: In-Field Scan
.../ABI/testing/sysfs-platform-intel-ifs | 39 +++
Documentation/x86/ifs.rst | 2 +
Documentation/x86/index.rst | 1 +
MAINTAINERS | 8 +
arch/x86/include/asm/cpu.h | 18 ++
arch/x86/include/asm/msr-index.h | 7 +
arch/x86/kernel/cpu/intel.c | 32 +++
arch/x86/kernel/cpu/microcode/intel.c | 59 +---
drivers/platform/x86/intel/Kconfig | 1 +
drivers/platform/x86/intel/Makefile | 1 +
drivers/platform/x86/intel/ifs/Kconfig | 13 +
drivers/platform/x86/intel/ifs/Makefile | 3 +
drivers/platform/x86/intel/ifs/core.c | 73 +++++
drivers/platform/x86/intel/ifs/ifs.h | 234 +++++++++++++++
drivers/platform/x86/intel/ifs/load.c | 266 ++++++++++++++++++
drivers/platform/x86/intel/ifs/runtest.c | 252 +++++++++++++++++
drivers/platform/x86/intel/ifs/sysfs.c | 149 ++++++++++
include/linux/stop_machine.h | 16 ++
include/trace/events/intel_ifs.h | 41 +++
kernel/stop_machine.c | 19 ++
20 files changed, 1182 insertions(+), 52 deletions(-)
create mode 100644 Documentation/ABI/testing/sysfs-platform-intel-ifs
create mode 100644 Documentation/x86/ifs.rst
create mode 100644 drivers/platform/x86/intel/ifs/Kconfig
create mode 100644 drivers/platform/x86/intel/ifs/Makefile
create mode 100644 drivers/platform/x86/intel/ifs/core.c
create mode 100644 drivers/platform/x86/intel/ifs/ifs.h
create mode 100644 drivers/platform/x86/intel/ifs/load.c
create mode 100644 drivers/platform/x86/intel/ifs/runtest.c
create mode 100644 drivers/platform/x86/intel/ifs/sysfs.c
create mode 100644 include/trace/events/intel_ifs.h
base-commit: 672c0c5173427e6b3e2a9bbb7be51ceeec78093a
--
2.35.1
Hi, On 5/7/22 00:53, Tony Luck wrote: > TL;DR this driver loads scan test files that can check whether silicon > in a CPU core is still running correctly. It is expected that these tests > would be run several times per day to catch problems as silicon ages. Thank you for your patch-series, I've applied the series to my review-hans branch: https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/log/?h=review-hans Note it will show up in my review-hans branch once I've pushed my local branch there, which might take a while. Once I've run some tests on this branch the patches there will be added to the platform-drivers-x86/for-next branch and eventually will be included in the pdx86 pull-request to Linus for the next merge-window. Regards, Hans > > Changes since v6 > > Thomas Gleixner > --------------- > "struct workqueue_struct *ifs_wq; Seems to be unused." > > True. Deleted. > > "static bool oscan_enabled = true; What changes this?" > > Code that cleared it deleted. Drop this too. > > "Please add curly brackets as these are not one-line statements" > > Added > > cpumask_first(topology_sibling_cpumask(cpu)); Shouldn't that be cpu_smt_mask()?" > > Changed (and several other places) > > "take up to 200 milliseconds before it retires. 200ms per test chunk?" > > Updated comment to note that 200ms is for all chunks. > > "Documentation lost in the intertubes" > > Dredged up the version from v3 series and changed: > 1) Fixed pathnames now this is a virtual misc device instead of platform > device > 2) Put all the text into a "/** DOC:" comment section in ifs.h with just > a "kernel-doc:: drivers/platform/x86/intel/ifs/ifs.h" in the ifs.rst > file under Documentation/x86. > 3) Added a "big fat warning" (in all CAPS) pointing out that a core test > can take up to 200 milliseconds. So admins must take extra steps if they > are running latency sensitive workloads. > 4) Added note that all HT threads of a core must be online to run a > test. > > Tony Luck > --------- > Off-by-one on retries check (#define set to 5, but tried 6 times). Fixed > Fixed kerneldoc description of "integrity_cap_bit" (was missing a ":") > > Jithu Joseph (7): > x86/microcode/intel: Expose collect_cpu_info_early() for IFS > platform/x86/intel/ifs: Read IFS firmware image > platform/x86/intel/ifs: Check IFS Image sanity > platform/x86/intel/ifs: Authenticate and copy to secured memory > platform/x86/intel/ifs: Add scan test support > platform/x86/intel/ifs: Add IFS sysfs interface > platform/x86/intel/ifs: add ABI documentation for IFS > > Peter Zijlstra (1): > stop_machine: Add stop_core_cpuslocked() for per-core operations > > Tony Luck (4): > x86/msr-index: Define INTEGRITY_CAPABILITIES MSR > platform/x86/intel/ifs: Add stub driver for In-Field Scan > trace: platform/x86/intel/ifs: Add trace point to track Intel IFS > operations > Documentation: In-Field Scan > > .../ABI/testing/sysfs-platform-intel-ifs | 39 +++ > Documentation/x86/ifs.rst | 2 + > Documentation/x86/index.rst | 1 + > MAINTAINERS | 8 + > arch/x86/include/asm/cpu.h | 18 ++ > arch/x86/include/asm/msr-index.h | 7 + > arch/x86/kernel/cpu/intel.c | 32 +++ > arch/x86/kernel/cpu/microcode/intel.c | 59 +--- > drivers/platform/x86/intel/Kconfig | 1 + > drivers/platform/x86/intel/Makefile | 1 + > drivers/platform/x86/intel/ifs/Kconfig | 13 + > drivers/platform/x86/intel/ifs/Makefile | 3 + > drivers/platform/x86/intel/ifs/core.c | 73 +++++ > drivers/platform/x86/intel/ifs/ifs.h | 234 +++++++++++++++ > drivers/platform/x86/intel/ifs/load.c | 266 ++++++++++++++++++ > drivers/platform/x86/intel/ifs/runtest.c | 252 +++++++++++++++++ > drivers/platform/x86/intel/ifs/sysfs.c | 149 ++++++++++ > include/linux/stop_machine.h | 16 ++ > include/trace/events/intel_ifs.h | 41 +++ > kernel/stop_machine.c | 19 ++ > 20 files changed, 1182 insertions(+), 52 deletions(-) > create mode 100644 Documentation/ABI/testing/sysfs-platform-intel-ifs > create mode 100644 Documentation/x86/ifs.rst > create mode 100644 drivers/platform/x86/intel/ifs/Kconfig > create mode 100644 drivers/platform/x86/intel/ifs/Makefile > create mode 100644 drivers/platform/x86/intel/ifs/core.c > create mode 100644 drivers/platform/x86/intel/ifs/ifs.h > create mode 100644 drivers/platform/x86/intel/ifs/load.c > create mode 100644 drivers/platform/x86/intel/ifs/runtest.c > create mode 100644 drivers/platform/x86/intel/ifs/sysfs.c > create mode 100644 include/trace/events/intel_ifs.h > > > base-commit: 672c0c5173427e6b3e2a9bbb7be51ceeec78093a
From: Jithu Joseph <jithu.joseph@intel.com>
IFS is a CPU feature that allows a binary blob, similar to microcode,
to be loaded and consumed to perform low level validation of CPU
circuitry. In fact, it carries the same Processor Signature
(family/model/stepping) details that are contained in Intel microcode
blobs.
In support of an IFS driver to trigger loading, validation, and running
of these tests blobs, make the functionality of cpu_signatures_match()
and collect_cpu_info_early() available outside of the microcode driver.
Add an "intel_" prefix and drop the "_early" suffix from
collect_cpu_info_early() and EXPORT_SYMBOL_GPL() it. Add
declaration to x86 <asm/cpu.h>
Make cpu_signatures_match() an inline function in x86 <asm/cpu.h>,
and also give it an "intel_" prefix.
No functional change intended.
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Co-developed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Borislav Petkov <bp@suse.de>
Reviewed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/include/asm/cpu.h | 18 ++++++++
arch/x86/kernel/cpu/intel.c | 32 +++++++++++++++
arch/x86/kernel/cpu/microcode/intel.c | 59 ++++-----------------------
3 files changed, 57 insertions(+), 52 deletions(-)
diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h
index 86e5e4e26fcb..990167357c34 100644
--- a/arch/x86/include/asm/cpu.h
+++ b/arch/x86/include/asm/cpu.h
@@ -76,4 +76,22 @@ static inline void init_ia32_feat_ctl(struct cpuinfo_x86 *c) {}
extern __noendbr void cet_disable(void);
+struct ucode_cpu_info;
+
+int intel_cpu_collect_info(struct ucode_cpu_info *uci);
+
+static inline bool intel_cpu_signatures_match(unsigned int s1, unsigned int p1,
+ unsigned int s2, unsigned int p2)
+{
+ if (s1 != s2)
+ return false;
+
+ /* Processor flags are either both 0 ... */
+ if (!p1 && !p2)
+ return true;
+
+ /* ... or they intersect. */
+ return p1 & p2;
+}
+
#endif /* _ASM_X86_CPU_H */
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index f7a5370a9b3b..94779146275d 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -181,6 +181,38 @@ static bool bad_spectre_microcode(struct cpuinfo_x86 *c)
return false;
}
+int intel_cpu_collect_info(struct ucode_cpu_info *uci)
+{
+ unsigned int val[2];
+ unsigned int family, model;
+ struct cpu_signature csig = { 0 };
+ unsigned int eax, ebx, ecx, edx;
+
+ memset(uci, 0, sizeof(*uci));
+
+ eax = 0x00000001;
+ ecx = 0;
+ native_cpuid(&eax, &ebx, &ecx, &edx);
+ csig.sig = eax;
+
+ family = x86_family(eax);
+ model = x86_model(eax);
+
+ if (model >= 5 || family > 6) {
+ /* get processor flags from MSR 0x17 */
+ native_rdmsr(MSR_IA32_PLATFORM_ID, val[0], val[1]);
+ csig.pf = 1 << ((val[1] >> 18) & 7);
+ }
+
+ csig.rev = intel_get_microcode_revision();
+
+ uci->cpu_sig = csig;
+ uci->valid = 1;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(intel_cpu_collect_info);
+
static void early_init_intel(struct cpuinfo_x86 *c)
{
u64 misc_enable;
diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index d28a9f8f3fec..025c8f0cd948 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -45,20 +45,6 @@ static struct microcode_intel *intel_ucode_patch;
/* last level cache size per core */
static int llc_size_per_core;
-static inline bool cpu_signatures_match(unsigned int s1, unsigned int p1,
- unsigned int s2, unsigned int p2)
-{
- if (s1 != s2)
- return false;
-
- /* Processor flags are either both 0 ... */
- if (!p1 && !p2)
- return true;
-
- /* ... or they intersect. */
- return p1 & p2;
-}
-
/*
* Returns 1 if update has been found, 0 otherwise.
*/
@@ -69,7 +55,7 @@ static int find_matching_signature(void *mc, unsigned int csig, int cpf)
struct extended_signature *ext_sig;
int i;
- if (cpu_signatures_match(csig, cpf, mc_hdr->sig, mc_hdr->pf))
+ if (intel_cpu_signatures_match(csig, cpf, mc_hdr->sig, mc_hdr->pf))
return 1;
/* Look for ext. headers: */
@@ -80,7 +66,7 @@ static int find_matching_signature(void *mc, unsigned int csig, int cpf)
ext_sig = (void *)ext_hdr + EXT_HEADER_SIZE;
for (i = 0; i < ext_hdr->count; i++) {
- if (cpu_signatures_match(csig, cpf, ext_sig->sig, ext_sig->pf))
+ if (intel_cpu_signatures_match(csig, cpf, ext_sig->sig, ext_sig->pf))
return 1;
ext_sig++;
}
@@ -342,37 +328,6 @@ scan_microcode(void *data, size_t size, struct ucode_cpu_info *uci, bool save)
return patch;
}
-static int collect_cpu_info_early(struct ucode_cpu_info *uci)
-{
- unsigned int val[2];
- unsigned int family, model;
- struct cpu_signature csig = { 0 };
- unsigned int eax, ebx, ecx, edx;
-
- memset(uci, 0, sizeof(*uci));
-
- eax = 0x00000001;
- ecx = 0;
- native_cpuid(&eax, &ebx, &ecx, &edx);
- csig.sig = eax;
-
- family = x86_family(eax);
- model = x86_model(eax);
-
- if ((model >= 5) || (family > 6)) {
- /* get processor flags from MSR 0x17 */
- native_rdmsr(MSR_IA32_PLATFORM_ID, val[0], val[1]);
- csig.pf = 1 << ((val[1] >> 18) & 7);
- }
-
- csig.rev = intel_get_microcode_revision();
-
- uci->cpu_sig = csig;
- uci->valid = 1;
-
- return 0;
-}
-
static void show_saved_mc(void)
{
#ifdef DEBUG
@@ -386,7 +341,7 @@ static void show_saved_mc(void)
return;
}
- collect_cpu_info_early(&uci);
+ intel_cpu_collect_info(&uci);
sig = uci.cpu_sig.sig;
pf = uci.cpu_sig.pf;
@@ -502,7 +457,7 @@ void show_ucode_info_early(void)
struct ucode_cpu_info uci;
if (delay_ucode_info) {
- collect_cpu_info_early(&uci);
+ intel_cpu_collect_info(&uci);
print_ucode_info(&uci, current_mc_date);
delay_ucode_info = 0;
}
@@ -604,7 +559,7 @@ int __init save_microcode_in_initrd_intel(void)
if (!(cp.data && cp.size))
return 0;
- collect_cpu_info_early(&uci);
+ intel_cpu_collect_info(&uci);
scan_microcode(cp.data, cp.size, &uci, true);
@@ -637,7 +592,7 @@ static struct microcode_intel *__load_ucode_intel(struct ucode_cpu_info *uci)
if (!(cp.data && cp.size))
return NULL;
- collect_cpu_info_early(uci);
+ intel_cpu_collect_info(uci);
return scan_microcode(cp.data, cp.size, uci, false);
}
@@ -712,7 +667,7 @@ void reload_ucode_intel(void)
struct microcode_intel *p;
struct ucode_cpu_info uci;
- collect_cpu_info_early(&uci);
+ intel_cpu_collect_info(&uci);
p = find_patch(&uci);
if (!p)
--
2.35.1The INTEGRITY_CAPABILITIES MSR is enumerated by bit 2 of the
CORE_CAPABILITIES MSR.
Add defines for the CORE_CAPS enumeration as well as for the integrity
MSR.
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Reviewed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/include/asm/msr-index.h | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index ee15311b6be1..c3dc7ae32f1f 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -76,6 +76,8 @@
/* Abbreviated from Intel SDM name IA32_CORE_CAPABILITIES */
#define MSR_IA32_CORE_CAPS 0x000000cf
+#define MSR_IA32_CORE_CAPS_INTEGRITY_CAPS_BIT 2
+#define MSR_IA32_CORE_CAPS_INTEGRITY_CAPS BIT(MSR_IA32_CORE_CAPS_INTEGRITY_CAPS_BIT)
#define MSR_IA32_CORE_CAPS_SPLIT_LOCK_DETECT_BIT 5
#define MSR_IA32_CORE_CAPS_SPLIT_LOCK_DETECT BIT(MSR_IA32_CORE_CAPS_SPLIT_LOCK_DETECT_BIT)
@@ -154,6 +156,11 @@
#define MSR_IA32_POWER_CTL 0x000001fc
#define MSR_IA32_POWER_CTL_BIT_EE 19
+/* Abbreviated from Intel SDM name IA32_INTEGRITY_CAPABILITIES */
+#define MSR_INTEGRITY_CAPS 0x000002d9
+#define MSR_INTEGRITY_CAPS_PERIODIC_BIST_BIT 4
+#define MSR_INTEGRITY_CAPS_PERIODIC_BIST BIT(MSR_INTEGRITY_CAPS_PERIODIC_BIST_BIT)
+
#define MSR_LBR_NHM_FROM 0x00000680
#define MSR_LBR_NHM_TO 0x000006c0
#define MSR_LBR_CORE_FROM 0x00000040
--
2.35.1From: Peter Zijlstra <peterz@infradead.org>
Hardware core level testing features require near simultaneous execution
of WRMSR instructions on all threads of a core to initiate a test.
Provide a customized cut down version of stop_machine_cpuslocked() that
just operates on the threads of a single core.
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
---
include/linux/stop_machine.h | 16 ++++++++++++++++
kernel/stop_machine.c | 19 +++++++++++++++++++
2 files changed, 35 insertions(+)
diff --git a/include/linux/stop_machine.h b/include/linux/stop_machine.h
index 46fb3ebdd16e..ea7a74ea7389 100644
--- a/include/linux/stop_machine.h
+++ b/include/linux/stop_machine.h
@@ -124,6 +124,22 @@ int stop_machine(cpu_stop_fn_t fn, void *data, const struct cpumask *cpus);
*/
int stop_machine_cpuslocked(cpu_stop_fn_t fn, void *data, const struct cpumask *cpus);
+/**
+ * stop_core_cpuslocked: - stop all threads on just one core
+ * @cpu: any cpu in the targeted core
+ * @fn: the function to run
+ * @data: the data ptr for @fn()
+ *
+ * Same as above, but instead of every CPU, only the logical CPUs of a
+ * single core are affected.
+ *
+ * Context: Must be called from within a cpus_read_lock() protected region.
+ *
+ * Return: 0 if all executions of @fn returned 0, any non zero return
+ * value if any returned non zero.
+ */
+int stop_core_cpuslocked(unsigned int cpu, cpu_stop_fn_t fn, void *data);
+
int stop_machine_from_inactive_cpu(cpu_stop_fn_t fn, void *data,
const struct cpumask *cpus);
#else /* CONFIG_SMP || CONFIG_HOTPLUG_CPU */
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index cbc30271ea4d..579761729836 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -633,6 +633,25 @@ int stop_machine(cpu_stop_fn_t fn, void *data, const struct cpumask *cpus)
}
EXPORT_SYMBOL_GPL(stop_machine);
+int stop_core_cpuslocked(unsigned int cpu, cpu_stop_fn_t fn, void *data)
+{
+ const struct cpumask *smt_mask = cpu_smt_mask(cpu);
+
+ struct multi_stop_data msdata = {
+ .fn = fn,
+ .data = data,
+ .num_threads = cpumask_weight(smt_mask),
+ .active_cpus = smt_mask,
+ };
+
+ lockdep_assert_cpus_held();
+
+ /* Set the initial state and stop all online cpus. */
+ set_state(&msdata, MULTI_STOP_PREPARE);
+ return stop_cpus(smt_mask, multi_cpu_stop, &msdata);
+}
+EXPORT_SYMBOL_GPL(stop_core_cpuslocked);
+
/**
* stop_machine_from_inactive_cpu - stop_machine() from inactive CPU
* @fn: the function to run
--
2.35.1Cloud Service Providers that operate fleets of servers have reported
[1] occasions where they can detect that a CPU has gone bad due to
effects like electromigration, or isolated manufacturing defects.
However, that detection method is A/B testing seemingly random
application failures looking for a pattern. In-Field Scan (IFS) is
a driver for a platform capability to load a crafted 'scan image'
to run targeted low level diagnostics outside of the CPU's architectural
error detection capabilities.
Stub version of driver just does initial part of check for the IFS
feature. MSR_IA32_CORE_CAPS must enumerate the presence of the
MSR_INTEGRITY_CAPS MSR.
[1]: https://www.youtube.com/watch?v=QMF3rqhjYuM
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
---
MAINTAINERS | 7 ++++
drivers/platform/x86/intel/Kconfig | 1 +
drivers/platform/x86/intel/Makefile | 1 +
drivers/platform/x86/intel/ifs/Kconfig | 13 +++++++
drivers/platform/x86/intel/ifs/Makefile | 3 ++
drivers/platform/x86/intel/ifs/core.c | 48 +++++++++++++++++++++++++
6 files changed, 73 insertions(+)
create mode 100644 drivers/platform/x86/intel/ifs/Kconfig
create mode 100644 drivers/platform/x86/intel/ifs/Makefile
create mode 100644 drivers/platform/x86/intel/ifs/core.c
diff --git a/MAINTAINERS b/MAINTAINERS
index edc96cdb85e8..bb0c4ff25942 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9862,6 +9862,13 @@ B: https://bugzilla.kernel.org
T: git git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux.git
F: drivers/idle/intel_idle.c
+INTEL IN FIELD SCAN (IFS) DEVICE
+M: Jithu Joseph <jithu.joseph@intel.com>
+R: Ashok Raj <ashok.raj@intel.com>
+R: Tony Luck <tony.luck@intel.com>
+S: Maintained
+F: drivers/platform/x86/intel/ifs
+
INTEL INTEGRATED SENSOR HUB DRIVER
M: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
M: Jiri Kosina <jikos@kernel.org>
diff --git a/drivers/platform/x86/intel/Kconfig b/drivers/platform/x86/intel/Kconfig
index 1f01a8a23c57..794968bda115 100644
--- a/drivers/platform/x86/intel/Kconfig
+++ b/drivers/platform/x86/intel/Kconfig
@@ -4,6 +4,7 @@
#
source "drivers/platform/x86/intel/atomisp2/Kconfig"
+source "drivers/platform/x86/intel/ifs/Kconfig"
source "drivers/platform/x86/intel/int1092/Kconfig"
source "drivers/platform/x86/intel/int3472/Kconfig"
source "drivers/platform/x86/intel/pmc/Kconfig"
diff --git a/drivers/platform/x86/intel/Makefile b/drivers/platform/x86/intel/Makefile
index c61bc3e97121..717933dd0cfd 100644
--- a/drivers/platform/x86/intel/Makefile
+++ b/drivers/platform/x86/intel/Makefile
@@ -5,6 +5,7 @@
#
obj-$(CONFIG_INTEL_ATOMISP2_PDX86) += atomisp2/
+obj-$(CONFIG_INTEL_IFS) += ifs/
obj-$(CONFIG_INTEL_SAR_INT1092) += int1092/
obj-$(CONFIG_INTEL_SKL_INT3472) += int3472/
obj-$(CONFIG_INTEL_PMC_CORE) += pmc/
diff --git a/drivers/platform/x86/intel/ifs/Kconfig b/drivers/platform/x86/intel/ifs/Kconfig
new file mode 100644
index 000000000000..d84491cfb0db
--- /dev/null
+++ b/drivers/platform/x86/intel/ifs/Kconfig
@@ -0,0 +1,13 @@
+config INTEL_IFS
+ tristate "Intel In Field Scan"
+ depends on X86 && 64BIT && SMP
+ select INTEL_IFS_DEVICE
+ help
+ Enable support for the In Field Scan capability in select
+ CPUs. The capability allows for running low level tests via
+ a scan image distributed by Intel via Github to validate CPU
+ operation beyond baseline RAS capabilities. To compile this
+ support as a module, choose M here. The module will be called
+ intel_ifs.
+
+ If unsure, say N.
diff --git a/drivers/platform/x86/intel/ifs/Makefile b/drivers/platform/x86/intel/ifs/Makefile
new file mode 100644
index 000000000000..af904880e959
--- /dev/null
+++ b/drivers/platform/x86/intel/ifs/Makefile
@@ -0,0 +1,3 @@
+obj-$(CONFIG_INTEL_IFS) += intel_ifs.o
+
+intel_ifs-objs := core.o
diff --git a/drivers/platform/x86/intel/ifs/core.c b/drivers/platform/x86/intel/ifs/core.c
new file mode 100644
index 000000000000..e3623ac691b5
--- /dev/null
+++ b/drivers/platform/x86/intel/ifs/core.c
@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright(c) 2022 Intel Corporation. */
+
+#include <linux/module.h>
+#include <linux/kdev_t.h>
+
+#include <asm/cpu_device_id.h>
+
+#define X86_MATCH(model) \
+ X86_MATCH_VENDOR_FAM_MODEL_FEATURE(INTEL, 6, \
+ INTEL_FAM6_##model, X86_FEATURE_CORE_CAPABILITIES, NULL)
+
+static const struct x86_cpu_id ifs_cpu_ids[] __initconst = {
+ X86_MATCH(SAPPHIRERAPIDS_X),
+ {}
+};
+MODULE_DEVICE_TABLE(x86cpu, ifs_cpu_ids);
+
+static int __init ifs_init(void)
+{
+ const struct x86_cpu_id *m;
+ u64 msrval;
+
+ m = x86_match_cpu(ifs_cpu_ids);
+ if (!m)
+ return -ENODEV;
+
+ if (rdmsrl_safe(MSR_IA32_CORE_CAPS, &msrval))
+ return -ENODEV;
+
+ if (!(msrval & MSR_IA32_CORE_CAPS_INTEGRITY_CAPS))
+ return -ENODEV;
+
+ if (rdmsrl_safe(MSR_INTEGRITY_CAPS, &msrval))
+ return -ENODEV;
+
+ return 0;
+}
+
+static void __exit ifs_exit(void)
+{
+}
+
+module_init(ifs_init);
+module_exit(ifs_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Intel In Field Scan (IFS) device");
--
2.35.1From: Jithu Joseph <jithu.joseph@intel.com>
Driver probe routine allocates structure to communicate status
and parameters between functions in the driver. Also call
load_ifs_binary() to load the scan image file.
There is a separate scan image file for each processor family,
model, stepping combination. This is read from the static path:
/lib/firmware/intel/ifs/{ff-mm-ss}.scan
Step 1 in loading is to generate the correct path and use
request_firmware_direct() to load into memory.
Subsequent patches will use the IFS MSR interfaces to copy
the image to BIOS reserved memory and validate the SHA256
checksums.
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Co-developed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/platform/x86/intel/ifs/Makefile | 2 +-
drivers/platform/x86/intel/ifs/core.c | 22 ++++++++++++++++++-
drivers/platform/x86/intel/ifs/ifs.h | 25 ++++++++++++++++++++++
drivers/platform/x86/intel/ifs/load.c | 28 +++++++++++++++++++++++++
4 files changed, 75 insertions(+), 2 deletions(-)
create mode 100644 drivers/platform/x86/intel/ifs/ifs.h
create mode 100644 drivers/platform/x86/intel/ifs/load.c
diff --git a/drivers/platform/x86/intel/ifs/Makefile b/drivers/platform/x86/intel/ifs/Makefile
index af904880e959..98b6fde15689 100644
--- a/drivers/platform/x86/intel/ifs/Makefile
+++ b/drivers/platform/x86/intel/ifs/Makefile
@@ -1,3 +1,3 @@
obj-$(CONFIG_INTEL_IFS) += intel_ifs.o
-intel_ifs-objs := core.o
+intel_ifs-objs := core.o load.o
diff --git a/drivers/platform/x86/intel/ifs/core.c b/drivers/platform/x86/intel/ifs/core.c
index e3623ac691b5..f62578dae8e9 100644
--- a/drivers/platform/x86/intel/ifs/core.c
+++ b/drivers/platform/x86/intel/ifs/core.c
@@ -6,6 +6,8 @@
#include <asm/cpu_device_id.h>
+#include "ifs.h"
+
#define X86_MATCH(model) \
X86_MATCH_VENDOR_FAM_MODEL_FEATURE(INTEL, 6, \
INTEL_FAM6_##model, X86_FEATURE_CORE_CAPABILITIES, NULL)
@@ -16,6 +18,17 @@ static const struct x86_cpu_id ifs_cpu_ids[] __initconst = {
};
MODULE_DEVICE_TABLE(x86cpu, ifs_cpu_ids);
+static struct ifs_device ifs_device = {
+ .data = {
+ .integrity_cap_bit = MSR_INTEGRITY_CAPS_PERIODIC_BIST_BIT,
+ },
+ .misc = {
+ .name = "intel_ifs_0",
+ .nodename = "intel_ifs/0",
+ .minor = MISC_DYNAMIC_MINOR,
+ },
+};
+
static int __init ifs_init(void)
{
const struct x86_cpu_id *m;
@@ -34,11 +47,18 @@ static int __init ifs_init(void)
if (rdmsrl_safe(MSR_INTEGRITY_CAPS, &msrval))
return -ENODEV;
- return 0;
+ if ((msrval & BIT(ifs_device.data.integrity_cap_bit)) &&
+ !misc_register(&ifs_device.misc)) {
+ ifs_load_firmware(ifs_device.misc.this_device);
+ return 0;
+ }
+
+ return -ENODEV;
}
static void __exit ifs_exit(void)
{
+ misc_deregister(&ifs_device.misc);
}
module_init(ifs_init);
diff --git a/drivers/platform/x86/intel/ifs/ifs.h b/drivers/platform/x86/intel/ifs/ifs.h
new file mode 100644
index 000000000000..9d151324ae83
--- /dev/null
+++ b/drivers/platform/x86/intel/ifs/ifs.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright(c) 2022 Intel Corporation. */
+
+#ifndef _IFS_H_
+#define _IFS_H_
+
+#include <linux/device.h>
+#include <linux/miscdevice.h>
+
+/**
+ * struct ifs_data - attributes related to intel IFS driver
+ * @integrity_cap_bit: MSR_INTEGRITY_CAPS bit enumerating this test
+ */
+struct ifs_data {
+ int integrity_cap_bit;
+};
+
+struct ifs_device {
+ struct ifs_data data;
+ struct miscdevice misc;
+};
+
+void ifs_load_firmware(struct device *dev);
+
+#endif
diff --git a/drivers/platform/x86/intel/ifs/load.c b/drivers/platform/x86/intel/ifs/load.c
new file mode 100644
index 000000000000..9fb71d38c819
--- /dev/null
+++ b/drivers/platform/x86/intel/ifs/load.c
@@ -0,0 +1,28 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright(c) 2022 Intel Corporation. */
+
+#include <linux/firmware.h>
+
+#include "ifs.h"
+
+/*
+ * Load ifs image. Before loading ifs module, the ifs image must be located
+ * in /lib/firmware/intel/ifs and named as {family/model/stepping}.{testname}.
+ */
+void ifs_load_firmware(struct device *dev)
+{
+ const struct firmware *fw;
+ char scan_path[32];
+ int ret;
+
+ snprintf(scan_path, sizeof(scan_path), "intel/ifs/%02x-%02x-%02x.scan",
+ boot_cpu_data.x86, boot_cpu_data.x86_model, boot_cpu_data.x86_stepping);
+
+ ret = request_firmware_direct(&fw, scan_path, dev);
+ if (ret) {
+ dev_err(dev, "ifs file %s load failed\n", scan_path);
+ return;
+ }
+
+ release_firmware(fw);
+}
--
2.35.1On Fri, May 06 2022 at 15:54, Tony Luck wrote: > Reviewed-by: Dan Williams <dan.j.williams@intel.com> > Signed-off-by: Jithu Joseph <jithu.joseph@intel.com> > Co-developed-by: Tony Luck <tony.luck@intel.com> > Signed-off-by: Tony Luck <tony.luck@intel.com> > Acked-by: Hans de Goede <hdegoede@redhat.com> > Reviewed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
From: Jithu Joseph <jithu.joseph@intel.com>
IFS image is designed specifically for a given family, model and
stepping of the processor. Like Intel microcode header, the IFS image
has the Processor Signature, Checksum and Processor Flags that must be
matched with the information returned by the CPUID.
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Co-developed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/platform/x86/intel/ifs/load.c | 66 +++++++++++++++++++++++++++
1 file changed, 66 insertions(+)
diff --git a/drivers/platform/x86/intel/ifs/load.c b/drivers/platform/x86/intel/ifs/load.c
index 9fb71d38c819..cfbf62494c89 100644
--- a/drivers/platform/x86/intel/ifs/load.c
+++ b/drivers/platform/x86/intel/ifs/load.c
@@ -2,9 +2,72 @@
/* Copyright(c) 2022 Intel Corporation. */
#include <linux/firmware.h>
+#include <asm/cpu.h>
+#include <asm/microcode_intel.h>
#include "ifs.h"
+static int ifs_sanity_check(struct device *dev,
+ const struct microcode_header_intel *mc_header)
+{
+ unsigned long total_size, data_size;
+ u32 sum, *mc;
+
+ total_size = get_totalsize(mc_header);
+ data_size = get_datasize(mc_header);
+
+ if ((data_size + MC_HEADER_SIZE > total_size) || (total_size % sizeof(u32))) {
+ dev_err(dev, "bad ifs data file size.\n");
+ return -EINVAL;
+ }
+
+ if (mc_header->ldrver != 1 || mc_header->hdrver != 1) {
+ dev_err(dev, "invalid/unknown ifs update format.\n");
+ return -EINVAL;
+ }
+
+ mc = (u32 *)mc_header;
+ sum = 0;
+ for (int i = 0; i < total_size / sizeof(u32); i++)
+ sum += mc[i];
+
+ if (sum) {
+ dev_err(dev, "bad ifs data checksum, aborting.\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static bool find_ifs_matching_signature(struct device *dev, struct ucode_cpu_info *uci,
+ const struct microcode_header_intel *shdr)
+{
+ unsigned int mc_size;
+
+ mc_size = get_totalsize(shdr);
+
+ if (!mc_size || ifs_sanity_check(dev, shdr) < 0) {
+ dev_err(dev, "ifs sanity check failure\n");
+ return false;
+ }
+
+ if (!intel_cpu_signatures_match(uci->cpu_sig.sig, uci->cpu_sig.pf, shdr->sig, shdr->pf)) {
+ dev_err(dev, "ifs signature, pf not matching\n");
+ return false;
+ }
+
+ return true;
+}
+
+static bool ifs_image_sanity_check(struct device *dev, const struct microcode_header_intel *data)
+{
+ struct ucode_cpu_info uci;
+
+ intel_cpu_collect_info(&uci);
+
+ return find_ifs_matching_signature(dev, &uci, data);
+}
+
/*
* Load ifs image. Before loading ifs module, the ifs image must be located
* in /lib/firmware/intel/ifs and named as {family/model/stepping}.{testname}.
@@ -24,5 +87,8 @@ void ifs_load_firmware(struct device *dev)
return;
}
+ if (!ifs_image_sanity_check(dev, (struct microcode_header_intel *)fw->data))
+ dev_err(dev, "ifs header sanity check failed\n");
+
release_firmware(fw);
}
--
2.35.1On Fri, May 06, 2022 at 03:54:04PM -0700, Tony Luck wrote:
> From: Jithu Joseph <jithu.joseph@intel.com>
>
> IFS image is designed specifically for a given family, model and
> stepping of the processor. Like Intel microcode header, the IFS image
> has the Processor Signature, Checksum and Processor Flags that must be
> matched with the information returned by the CPUID.
Is the checksum the only protection against people loading arbitrary IFS
images or are those things signed or encrypted, just like the microcode?
I'd hope they pass the same checks as microcode, when they get loaded,
considering the similarity of how they're handled...
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
> Is the checksum the only protection against people loading arbitrary IFS > images or are those things signed or encrypted, just like the microcode? > > I'd hope they pass the same checks as microcode, when they get loaded, > considering the similarity of how they're handled... The checksum is just a "did this file get corrupted check". The file contains SHA256 checksums for each of the chunks. These checksums are digitally signed. Checking of these is done by microcode when the file is loaded into BIOS reserved memory (where it is inaccessible to OS and I/O). -Tony
On Mon, May 09, 2022 at 04:51:56PM +0000, Luck, Tony wrote:
> The checksum is just a "did this file get corrupted check". The file contains
> SHA256 checksums for each of the chunks. These checksums are digitally
> signed. Checking of these is done by microcode when the file is loaded into
> BIOS reserved memory (where it is inaccessible to OS and I/O).
That sounds like something I was hoping to hear, good. :-)
Thx.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
On Fri, May 06 2022 at 15:54, Tony Luck wrote: > Reviewed-by: Dan Williams <dan.j.williams@intel.com> > Signed-off-by: Jithu Joseph <jithu.joseph@intel.com> > Co-developed-by: Tony Luck <tony.luck@intel.com> > Signed-off-by: Tony Luck <tony.luck@intel.com> > Acked-by: Hans de Goede <hdegoede@redhat.com> > Reviewed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
From: Jithu Joseph <jithu.joseph@intel.com>
The IFS image contains hashes that will be used to authenticate the ifs
test chunks. First, use WRMSR to copy the hashes and enumerate the number
of test chunks, chunk size and the maximum number of cores that can run
scan test simultaneously.
Next, use WRMSR to authenticate each and every scan test chunk which is
stored in the IFS image. The CPU will check if the test chunks match
the hashes, otherwise failure is indicated to system software. If the test
chunk is authenticated, it is automatically copied to secured memory.
Use schedule_work_on() to perform the hash copy and authentication. Note
this needs only be done on the first logical cpu of each socket.
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Co-developed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/platform/x86/intel/ifs/ifs.h | 52 ++++++++
drivers/platform/x86/intel/ifs/load.c | 176 +++++++++++++++++++++++++-
2 files changed, 226 insertions(+), 2 deletions(-)
diff --git a/drivers/platform/x86/intel/ifs/ifs.h b/drivers/platform/x86/intel/ifs/ifs.h
index 9d151324ae83..bed70dc1e5b7 100644
--- a/drivers/platform/x86/intel/ifs/ifs.h
+++ b/drivers/platform/x86/intel/ifs/ifs.h
@@ -7,12 +7,56 @@
#include <linux/device.h>
#include <linux/miscdevice.h>
+#define MSR_COPY_SCAN_HASHES 0x000002c2
+#define MSR_SCAN_HASHES_STATUS 0x000002c3
+#define MSR_AUTHENTICATE_AND_COPY_CHUNK 0x000002c4
+#define MSR_CHUNKS_AUTHENTICATION_STATUS 0x000002c5
+
+/* MSR_SCAN_HASHES_STATUS bit fields */
+union ifs_scan_hashes_status {
+ u64 data;
+ struct {
+ u32 chunk_size :16;
+ u32 num_chunks :8;
+ u32 rsvd1 :8;
+ u32 error_code :8;
+ u32 rsvd2 :11;
+ u32 max_core_limit :12;
+ u32 valid :1;
+ };
+};
+
+/* MSR_CHUNKS_AUTH_STATUS bit fields */
+union ifs_chunks_auth_status {
+ u64 data;
+ struct {
+ u32 valid_chunks :8;
+ u32 total_chunks :8;
+ u32 rsvd1 :16;
+ u32 error_code :8;
+ u32 rsvd2 :24;
+ };
+};
+
/**
* struct ifs_data - attributes related to intel IFS driver
* @integrity_cap_bit: MSR_INTEGRITY_CAPS bit enumerating this test
+ * @loaded_version: stores the currently loaded ifs image version.
+ * @loaded: If a valid test binary has been loaded into the memory
+ * @loading_error: Error occurred on another CPU while loading image
+ * @valid_chunks: number of chunks which could be validated.
*/
struct ifs_data {
int integrity_cap_bit;
+ int loaded_version;
+ bool loaded;
+ bool loading_error;
+ int valid_chunks;
+};
+
+struct ifs_work {
+ struct work_struct w;
+ struct device *dev;
};
struct ifs_device {
@@ -20,6 +64,14 @@ struct ifs_device {
struct miscdevice misc;
};
+static inline struct ifs_data *ifs_get_data(struct device *dev)
+{
+ struct miscdevice *m = dev_get_drvdata(dev);
+ struct ifs_device *d = container_of(m, struct ifs_device, misc);
+
+ return &d->data;
+}
+
void ifs_load_firmware(struct device *dev);
#endif
diff --git a/drivers/platform/x86/intel/ifs/load.c b/drivers/platform/x86/intel/ifs/load.c
index cfbf62494c89..d056617ddc85 100644
--- a/drivers/platform/x86/intel/ifs/load.c
+++ b/drivers/platform/x86/intel/ifs/load.c
@@ -3,10 +3,172 @@
#include <linux/firmware.h>
#include <asm/cpu.h>
+#include <linux/slab.h>
#include <asm/microcode_intel.h>
#include "ifs.h"
+struct ifs_header {
+ u32 header_ver;
+ u32 blob_revision;
+ u32 date;
+ u32 processor_sig;
+ u32 check_sum;
+ u32 loader_rev;
+ u32 processor_flags;
+ u32 metadata_size;
+ u32 total_size;
+ u32 fusa_info;
+ u64 reserved;
+};
+
+#define IFS_HEADER_SIZE (sizeof(struct ifs_header))
+static struct ifs_header *ifs_header_ptr; /* pointer to the ifs image header */
+static u64 ifs_hash_ptr; /* Address of ifs metadata (hash) */
+static u64 ifs_test_image_ptr; /* 256B aligned address of test pattern */
+static DECLARE_COMPLETION(ifs_done);
+
+static const char * const scan_hash_status[] = {
+ [0] = "No error reported",
+ [1] = "Attempt to copy scan hashes when copy already in progress",
+ [2] = "Secure Memory not set up correctly",
+ [3] = "FuSaInfo.ProgramID does not match or ff-mm-ss does not match",
+ [4] = "Reserved",
+ [5] = "Integrity check failed",
+ [6] = "Scan reload or test is in progress"
+};
+
+static const char * const scan_authentication_status[] = {
+ [0] = "No error reported",
+ [1] = "Attempt to authenticate a chunk which is already marked as authentic",
+ [2] = "Chunk authentication error. The hash of chunk did not match expected value"
+};
+
+/*
+ * To copy scan hashes and authenticate test chunks, the initiating cpu must point
+ * to the EDX:EAX to the test image in linear address.
+ * Run wrmsr(MSR_COPY_SCAN_HASHES) for scan hash copy and run wrmsr(MSR_AUTHENTICATE_AND_COPY_CHUNK)
+ * for scan hash copy and test chunk authentication.
+ */
+static void copy_hashes_authenticate_chunks(struct work_struct *work)
+{
+ struct ifs_work *local_work = container_of(work, struct ifs_work, w);
+ union ifs_scan_hashes_status hashes_status;
+ union ifs_chunks_auth_status chunk_status;
+ struct device *dev = local_work->dev;
+ int i, num_chunks, chunk_size;
+ struct ifs_data *ifsd;
+ u64 linear_addr, base;
+ u32 err_code;
+
+ ifsd = ifs_get_data(dev);
+ /* run scan hash copy */
+ wrmsrl(MSR_COPY_SCAN_HASHES, ifs_hash_ptr);
+ rdmsrl(MSR_SCAN_HASHES_STATUS, hashes_status.data);
+
+ /* enumerate the scan image information */
+ num_chunks = hashes_status.num_chunks;
+ chunk_size = hashes_status.chunk_size * 1024;
+ err_code = hashes_status.error_code;
+
+ if (!hashes_status.valid) {
+ ifsd->loading_error = true;
+ if (err_code >= ARRAY_SIZE(scan_hash_status)) {
+ dev_err(dev, "invalid error code 0x%x for hash copy\n", err_code);
+ goto done;
+ }
+ dev_err(dev, "Hash copy error : %s", scan_hash_status[err_code]);
+ goto done;
+ }
+
+ /* base linear address to the scan data */
+ base = ifs_test_image_ptr;
+
+ /* scan data authentication and copy chunks to secured memory */
+ for (i = 0; i < num_chunks; i++) {
+ linear_addr = base + i * chunk_size;
+ linear_addr |= i;
+
+ wrmsrl(MSR_AUTHENTICATE_AND_COPY_CHUNK, linear_addr);
+ rdmsrl(MSR_CHUNKS_AUTHENTICATION_STATUS, chunk_status.data);
+
+ ifsd->valid_chunks = chunk_status.valid_chunks;
+ err_code = chunk_status.error_code;
+
+ if (err_code) {
+ ifsd->loading_error = true;
+ if (err_code >= ARRAY_SIZE(scan_authentication_status)) {
+ dev_err(dev,
+ "invalid error code 0x%x for authentication\n", err_code);
+ goto done;
+ }
+ dev_err(dev, "Chunk authentication error %s\n",
+ scan_authentication_status[err_code]);
+ goto done;
+ }
+ }
+done:
+ complete(&ifs_done);
+}
+
+/*
+ * IFS requires scan chunks authenticated per each socket in the platform.
+ * Once the test chunk is authenticated, it is automatically copied to secured memory
+ * and proceed the authentication for the next chunk.
+ */
+static int scan_chunks_sanity_check(struct device *dev)
+{
+ int metadata_size, curr_pkg, cpu, ret = -ENOMEM;
+ struct ifs_data *ifsd = ifs_get_data(dev);
+ bool *package_authenticated;
+ struct ifs_work local_work;
+ char *test_ptr;
+
+ package_authenticated = kcalloc(topology_max_packages(), sizeof(bool), GFP_KERNEL);
+ if (!package_authenticated)
+ return ret;
+
+ metadata_size = ifs_header_ptr->metadata_size;
+
+ /* Spec says that if the Meta Data Size = 0 then it should be treated as 2000 */
+ if (metadata_size == 0)
+ metadata_size = 2000;
+
+ /* Scan chunk start must be 256 byte aligned */
+ if ((metadata_size + IFS_HEADER_SIZE) % 256) {
+ dev_err(dev, "Scan pattern offset within the binary is not 256 byte aligned\n");
+ return -EINVAL;
+ }
+
+ test_ptr = (char *)ifs_header_ptr + IFS_HEADER_SIZE + metadata_size;
+ ifsd->loading_error = false;
+
+ ifs_test_image_ptr = (u64)test_ptr;
+ ifsd->loaded_version = ifs_header_ptr->blob_revision;
+
+ /* copy the scan hash and authenticate per package */
+ cpus_read_lock();
+ for_each_online_cpu(cpu) {
+ curr_pkg = topology_physical_package_id(cpu);
+ if (package_authenticated[curr_pkg])
+ continue;
+ reinit_completion(&ifs_done);
+ local_work.dev = dev;
+ INIT_WORK(&local_work.w, copy_hashes_authenticate_chunks);
+ schedule_work_on(cpu, &local_work.w);
+ wait_for_completion(&ifs_done);
+ if (ifsd->loading_error)
+ goto out;
+ package_authenticated[curr_pkg] = 1;
+ }
+ ret = 0;
+out:
+ cpus_read_unlock();
+ kfree(package_authenticated);
+
+ return ret;
+}
+
static int ifs_sanity_check(struct device *dev,
const struct microcode_header_intel *mc_header)
{
@@ -74,6 +236,7 @@ static bool ifs_image_sanity_check(struct device *dev, const struct microcode_he
*/
void ifs_load_firmware(struct device *dev)
{
+ struct ifs_data *ifsd = ifs_get_data(dev);
const struct firmware *fw;
char scan_path[32];
int ret;
@@ -84,11 +247,20 @@ void ifs_load_firmware(struct device *dev)
ret = request_firmware_direct(&fw, scan_path, dev);
if (ret) {
dev_err(dev, "ifs file %s load failed\n", scan_path);
- return;
+ goto done;
}
- if (!ifs_image_sanity_check(dev, (struct microcode_header_intel *)fw->data))
+ if (!ifs_image_sanity_check(dev, (struct microcode_header_intel *)fw->data)) {
dev_err(dev, "ifs header sanity check failed\n");
+ goto release;
+ }
+
+ ifs_header_ptr = (struct ifs_header *)fw->data;
+ ifs_hash_ptr = (u64)(ifs_header_ptr + 1);
+ ret = scan_chunks_sanity_check(dev);
+release:
release_firmware(fw);
+done:
+ ifsd->loaded = (ret == 0);
}
--
2.35.1On Fri, May 06 2022 at 15:54, Tony Luck wrote: > Use schedule_work_on() to perform the hash copy and authentication. Note > this needs only be done on the first logical cpu of each socket. > > Reviewed-by: Dan Williams <dan.j.williams@intel.com> > Signed-off-by: Jithu Joseph <jithu.joseph@intel.com> > Co-developed-by: Tony Luck <tony.luck@intel.com> > Signed-off-by: Tony Luck <tony.luck@intel.com> > Acked-by: Hans de Goede <hdegoede@redhat.com> > Reviewed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
From: Jithu Joseph <jithu.joseph@intel.com>
In a core, the scan engine is shared between sibling cpus.
When a Scan test (for a particular core) is triggered by the user,
the scan chunks are executed on all the threads on the core using
stop_core_cpuslocked.
Scan may be aborted by some reasons. Scan test will be aborted in certain
circumstances such as when interrupt occurred or cpu does not have enough
power budget for scan. In this case, the kernel restart scan from the chunk
where it stopped. Scan will also be aborted when the test is failed. In
this case, the test is immediately stopped without retry.
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Co-developed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/platform/x86/intel/ifs/Makefile | 2 +-
drivers/platform/x86/intel/ifs/ifs.h | 44 ++++
drivers/platform/x86/intel/ifs/runtest.c | 247 +++++++++++++++++++++++
3 files changed, 292 insertions(+), 1 deletion(-)
create mode 100644 drivers/platform/x86/intel/ifs/runtest.c
diff --git a/drivers/platform/x86/intel/ifs/Makefile b/drivers/platform/x86/intel/ifs/Makefile
index 98b6fde15689..cedcb103f860 100644
--- a/drivers/platform/x86/intel/ifs/Makefile
+++ b/drivers/platform/x86/intel/ifs/Makefile
@@ -1,3 +1,3 @@
obj-$(CONFIG_INTEL_IFS) += intel_ifs.o
-intel_ifs-objs := core.o load.o
+intel_ifs-objs := core.o load.o runtest.o
diff --git a/drivers/platform/x86/intel/ifs/ifs.h b/drivers/platform/x86/intel/ifs/ifs.h
index bed70dc1e5b7..b648cccda3ec 100644
--- a/drivers/platform/x86/intel/ifs/ifs.h
+++ b/drivers/platform/x86/intel/ifs/ifs.h
@@ -11,6 +11,11 @@
#define MSR_SCAN_HASHES_STATUS 0x000002c3
#define MSR_AUTHENTICATE_AND_COPY_CHUNK 0x000002c4
#define MSR_CHUNKS_AUTHENTICATION_STATUS 0x000002c5
+#define MSR_ACTIVATE_SCAN 0x000002c6
+#define MSR_SCAN_STATUS 0x000002c7
+#define SCAN_NOT_TESTED 0
+#define SCAN_TEST_PASS 1
+#define SCAN_TEST_FAIL 2
/* MSR_SCAN_HASHES_STATUS bit fields */
union ifs_scan_hashes_status {
@@ -38,6 +43,40 @@ union ifs_chunks_auth_status {
};
};
+/* MSR_ACTIVATE_SCAN bit fields */
+union ifs_scan {
+ u64 data;
+ struct {
+ u32 start :8;
+ u32 stop :8;
+ u32 rsvd :16;
+ u32 delay :31;
+ u32 sigmce :1;
+ };
+};
+
+/* MSR_SCAN_STATUS bit fields */
+union ifs_status {
+ u64 data;
+ struct {
+ u32 chunk_num :8;
+ u32 chunk_stop_index :8;
+ u32 rsvd1 :16;
+ u32 error_code :8;
+ u32 rsvd2 :22;
+ u32 control_error :1;
+ u32 signature_error :1;
+ };
+};
+
+/*
+ * Driver populated error-codes
+ * 0xFD: Test timed out before completing all the chunks.
+ * 0xFE: not all scan chunks were executed. Maximum forward progress retries exceeded.
+ */
+#define IFS_SW_TIMEOUT 0xFD
+#define IFS_SW_PARTIAL_COMPLETION 0xFE
+
/**
* struct ifs_data - attributes related to intel IFS driver
* @integrity_cap_bit: MSR_INTEGRITY_CAPS bit enumerating this test
@@ -45,6 +84,8 @@ union ifs_chunks_auth_status {
* @loaded: If a valid test binary has been loaded into the memory
* @loading_error: Error occurred on another CPU while loading image
* @valid_chunks: number of chunks which could be validated.
+ * @status: it holds simple status pass/fail/untested
+ * @scan_details: opaque scan status code from h/w
*/
struct ifs_data {
int integrity_cap_bit;
@@ -52,6 +93,8 @@ struct ifs_data {
bool loaded;
bool loading_error;
int valid_chunks;
+ int status;
+ u64 scan_details;
};
struct ifs_work {
@@ -73,5 +116,6 @@ static inline struct ifs_data *ifs_get_data(struct device *dev)
}
void ifs_load_firmware(struct device *dev);
+int do_core_test(int cpu, struct device *dev);
#endif
diff --git a/drivers/platform/x86/intel/ifs/runtest.c b/drivers/platform/x86/intel/ifs/runtest.c
new file mode 100644
index 000000000000..7efcce35e0e9
--- /dev/null
+++ b/drivers/platform/x86/intel/ifs/runtest.c
@@ -0,0 +1,247 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright(c) 2022 Intel Corporation. */
+
+#include <linux/cpu.h>
+#include <linux/delay.h>
+#include <linux/fs.h>
+#include <linux/nmi.h>
+#include <linux/slab.h>
+#include <linux/stop_machine.h>
+
+#include "ifs.h"
+
+/*
+ * Note all code and data in this file is protected by
+ * ifs_sem. On HT systems all threads on a core will
+ * execute together, but only the first thread on the
+ * core will update results of the test.
+ */
+
+/* Max retries on the same chunk */
+#define MAX_IFS_RETRIES 5
+
+/*
+ * Number of TSC cycles that a logical CPU will wait for the other
+ * logical CPU on the core in the WRMSR(ACTIVATE_SCAN).
+ */
+#define IFS_THREAD_WAIT 100000
+
+enum ifs_status_err_code {
+ IFS_NO_ERROR = 0,
+ IFS_OTHER_THREAD_COULD_NOT_JOIN = 1,
+ IFS_INTERRUPTED_BEFORE_RENDEZVOUS = 2,
+ IFS_POWER_MGMT_INADEQUATE_FOR_SCAN = 3,
+ IFS_INVALID_CHUNK_RANGE = 4,
+ IFS_MISMATCH_ARGUMENTS_BETWEEN_THREADS = 5,
+ IFS_CORE_NOT_CAPABLE_CURRENTLY = 6,
+ IFS_UNASSIGNED_ERROR_CODE = 7,
+ IFS_EXCEED_NUMBER_OF_THREADS_CONCURRENT = 8,
+ IFS_INTERRUPTED_DURING_EXECUTION = 9,
+};
+
+static const char * const scan_test_status[] = {
+ [IFS_NO_ERROR] = "SCAN no error",
+ [IFS_OTHER_THREAD_COULD_NOT_JOIN] = "Other thread could not join.",
+ [IFS_INTERRUPTED_BEFORE_RENDEZVOUS] = "Interrupt occurred prior to SCAN coordination.",
+ [IFS_POWER_MGMT_INADEQUATE_FOR_SCAN] =
+ "Core Abort SCAN Response due to power management condition.",
+ [IFS_INVALID_CHUNK_RANGE] = "Non valid chunks in the range",
+ [IFS_MISMATCH_ARGUMENTS_BETWEEN_THREADS] = "Mismatch in arguments between threads T0/T1.",
+ [IFS_CORE_NOT_CAPABLE_CURRENTLY] = "Core not capable of performing SCAN currently",
+ [IFS_UNASSIGNED_ERROR_CODE] = "Unassigned error code 0x7",
+ [IFS_EXCEED_NUMBER_OF_THREADS_CONCURRENT] =
+ "Exceeded number of Logical Processors (LP) allowed to run Scan-At-Field concurrently",
+ [IFS_INTERRUPTED_DURING_EXECUTION] = "Interrupt occurred prior to SCAN start",
+};
+
+static void message_not_tested(struct device *dev, int cpu, union ifs_status status)
+{
+ if (status.error_code < ARRAY_SIZE(scan_test_status)) {
+ dev_info(dev, "CPU(s) %*pbl: SCAN operation did not start. %s\n",
+ cpumask_pr_args(cpu_smt_mask(cpu)),
+ scan_test_status[status.error_code]);
+ } else if (status.error_code == IFS_SW_TIMEOUT) {
+ dev_info(dev, "CPU(s) %*pbl: software timeout during scan\n",
+ cpumask_pr_args(cpu_smt_mask(cpu)));
+ } else if (status.error_code == IFS_SW_PARTIAL_COMPLETION) {
+ dev_info(dev, "CPU(s) %*pbl: %s\n",
+ cpumask_pr_args(cpu_smt_mask(cpu)),
+ "Not all scan chunks were executed. Maximum forward progress retries exceeded");
+ } else {
+ dev_info(dev, "CPU(s) %*pbl: SCAN unknown status %llx\n",
+ cpumask_pr_args(cpu_smt_mask(cpu)), status.data);
+ }
+}
+
+static void message_fail(struct device *dev, int cpu, union ifs_status status)
+{
+ /*
+ * control_error is set when the microcode runs into a problem
+ * loading the image from the reserved BIOS memory, or it has
+ * been corrupted. Reloading the image may fix this issue.
+ */
+ if (status.control_error) {
+ dev_err(dev, "CPU(s) %*pbl: could not execute from loaded scan image\n",
+ cpumask_pr_args(cpu_smt_mask(cpu)));
+ }
+
+ /*
+ * signature_error is set when the output from the scan chains does not
+ * match the expected signature. This might be a transient problem (e.g.
+ * due to a bit flip from an alpha particle or neutron). If the problem
+ * repeats on a subsequent test, then it indicates an actual problem in
+ * the core being tested.
+ */
+ if (status.signature_error) {
+ dev_err(dev, "CPU(s) %*pbl: test signature incorrect.\n",
+ cpumask_pr_args(cpu_smt_mask(cpu)));
+ }
+}
+
+static bool can_restart(union ifs_status status)
+{
+ enum ifs_status_err_code err_code = status.error_code;
+
+ /* Signature for chunk is bad, or scan test failed */
+ if (status.signature_error || status.control_error)
+ return false;
+
+ switch (err_code) {
+ case IFS_NO_ERROR:
+ case IFS_OTHER_THREAD_COULD_NOT_JOIN:
+ case IFS_INTERRUPTED_BEFORE_RENDEZVOUS:
+ case IFS_POWER_MGMT_INADEQUATE_FOR_SCAN:
+ case IFS_EXCEED_NUMBER_OF_THREADS_CONCURRENT:
+ case IFS_INTERRUPTED_DURING_EXECUTION:
+ return true;
+ case IFS_INVALID_CHUNK_RANGE:
+ case IFS_MISMATCH_ARGUMENTS_BETWEEN_THREADS:
+ case IFS_CORE_NOT_CAPABLE_CURRENTLY:
+ case IFS_UNASSIGNED_ERROR_CODE:
+ break;
+ }
+ return false;
+}
+
+/*
+ * Execute the scan. Called "simultaneously" on all threads of a core
+ * at high priority using the stop_cpus mechanism.
+ */
+static int doscan(void *data)
+{
+ int cpu = smp_processor_id();
+ u64 *msrs = data;
+ int first;
+
+ /* Only the first logical CPU on a core reports result */
+ first = cpumask_first(cpu_smt_mask(cpu));
+
+ /*
+ * This WRMSR will wait for other HT threads to also write
+ * to this MSR (at most for activate.delay cycles). Then it
+ * starts scan of each requested chunk. The core scan happens
+ * during the "execution" of the WRMSR. This instruction can
+ * take up to 200 milliseconds (in the case where all chunks
+ * are processed in a single pass) before it retires.
+ */
+ wrmsrl(MSR_ACTIVATE_SCAN, msrs[0]);
+
+ if (cpu == first) {
+ /* Pass back the result of the scan */
+ rdmsrl(MSR_SCAN_STATUS, msrs[1]);
+ }
+
+ return 0;
+}
+
+/*
+ * Use stop_core_cpuslocked() to synchronize writing to MSR_ACTIVATE_SCAN
+ * on all threads of the core to be tested. Loop if necessary to complete
+ * run of all chunks. Include some defensive tests to make sure forward
+ * progress is made, and that the whole test completes in a reasonable time.
+ */
+static void ifs_test_core(int cpu, struct device *dev)
+{
+ union ifs_scan activate;
+ union ifs_status status;
+ unsigned long timeout;
+ struct ifs_data *ifsd;
+ u64 msrvals[2];
+ int retries;
+
+ ifsd = ifs_get_data(dev);
+
+ activate.rsvd = 0;
+ activate.delay = IFS_THREAD_WAIT;
+ activate.sigmce = 0;
+ activate.start = 0;
+ activate.stop = ifsd->valid_chunks - 1;
+
+ timeout = jiffies + HZ / 2;
+ retries = MAX_IFS_RETRIES;
+
+ while (activate.start <= activate.stop) {
+ if (time_after(jiffies, timeout)) {
+ status.error_code = IFS_SW_TIMEOUT;
+ break;
+ }
+
+ msrvals[0] = activate.data;
+ stop_core_cpuslocked(cpu, doscan, msrvals);
+
+ status.data = msrvals[1];
+
+ /* Some cases can be retried, give up for others */
+ if (!can_restart(status))
+ break;
+
+ if (status.chunk_num == activate.start) {
+ /* Check for forward progress */
+ if (--retries == 0) {
+ if (status.error_code == IFS_NO_ERROR)
+ status.error_code = IFS_SW_PARTIAL_COMPLETION;
+ break;
+ }
+ } else {
+ retries = MAX_IFS_RETRIES;
+ activate.start = status.chunk_num;
+ }
+ }
+
+ /* Update status for this core */
+ ifsd->scan_details = status.data;
+
+ if (status.control_error || status.signature_error) {
+ ifsd->status = SCAN_TEST_FAIL;
+ message_fail(dev, cpu, status);
+ } else if (status.error_code) {
+ ifsd->status = SCAN_NOT_TESTED;
+ message_not_tested(dev, cpu, status);
+ } else {
+ ifsd->status = SCAN_TEST_PASS;
+ }
+}
+
+/*
+ * Initiate per core test. It wakes up work queue threads on the target cpu and
+ * its sibling cpu. Once all sibling threads wake up, the scan test gets executed and
+ * wait for all sibling threads to finish the scan test.
+ */
+int do_core_test(int cpu, struct device *dev)
+{
+ int ret = 0;
+
+ /* Prevent CPUs from being taken offline during the scan test */
+ cpus_read_lock();
+
+ if (!cpu_online(cpu)) {
+ dev_info(dev, "cannot test on the offline cpu %d\n", cpu);
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ifs_test_core(cpu, dev);
+out:
+ cpus_read_unlock();
+ return ret;
+}
--
2.35.1On Fri, May 06 2022 at 15:54, Tony Luck wrote: > From: Jithu Joseph <jithu.joseph@intel.com> > > In a core, the scan engine is shared between sibling cpus. > > When a Scan test (for a particular core) is triggered by the user, > the scan chunks are executed on all the threads on the core using > stop_core_cpuslocked. > > Scan may be aborted by some reasons. Scan test will be aborted in certain > circumstances such as when interrupt occurred or cpu does not have enough > power budget for scan. In this case, the kernel restart scan from the chunk > where it stopped. Scan will also be aborted when the test is failed. In > this case, the test is immediately stopped without retry. > > Reviewed-by: Dan Williams <dan.j.williams@intel.com> > Signed-off-by: Jithu Joseph <jithu.joseph@intel.com> > Co-developed-by: Tony Luck <tony.luck@intel.com> > Signed-off-by: Tony Luck <tony.luck@intel.com> > Acked-by: Hans de Goede <hdegoede@redhat.com> > Reviewed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
From: Jithu Joseph <jithu.joseph@intel.com>
Implement sysfs interface to trigger ifs test for a specific cpu.
Additional interfaces related to checking the status of the
scan test and seeing the version of the loaded IFS binary
are also added.
The basic usage is as below.
- To start test, for example on cpu5:
echo 5 > /sys/devices/platform/intel_ifs/run_test
- To see the status of the last test
cat /sys/devices/platform/intel_ifs/status
- To see the version of the loaded scan binary
cat /sys/devices/platform/intel_ifs/image_version
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Co-developed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/platform/x86/intel/ifs/Makefile | 2 +-
drivers/platform/x86/intel/ifs/core.c | 5 +
drivers/platform/x86/intel/ifs/ifs.h | 3 +
drivers/platform/x86/intel/ifs/sysfs.c | 149 ++++++++++++++++++++++++
4 files changed, 158 insertions(+), 1 deletion(-)
create mode 100644 drivers/platform/x86/intel/ifs/sysfs.c
diff --git a/drivers/platform/x86/intel/ifs/Makefile b/drivers/platform/x86/intel/ifs/Makefile
index cedcb103f860..30f035ef5581 100644
--- a/drivers/platform/x86/intel/ifs/Makefile
+++ b/drivers/platform/x86/intel/ifs/Makefile
@@ -1,3 +1,3 @@
obj-$(CONFIG_INTEL_IFS) += intel_ifs.o
-intel_ifs-objs := core.o load.o runtest.o
+intel_ifs-objs := core.o load.o runtest.o sysfs.o
diff --git a/drivers/platform/x86/intel/ifs/core.c b/drivers/platform/x86/intel/ifs/core.c
index f62578dae8e9..27204e3d674d 100644
--- a/drivers/platform/x86/intel/ifs/core.c
+++ b/drivers/platform/x86/intel/ifs/core.c
@@ -3,6 +3,7 @@
#include <linux/module.h>
#include <linux/kdev_t.h>
+#include <linux/semaphore.h>
#include <asm/cpu_device_id.h>
@@ -47,9 +48,13 @@ static int __init ifs_init(void)
if (rdmsrl_safe(MSR_INTEGRITY_CAPS, &msrval))
return -ENODEV;
+ ifs_device.misc.groups = ifs_get_groups();
+
if ((msrval & BIT(ifs_device.data.integrity_cap_bit)) &&
!misc_register(&ifs_device.misc)) {
+ down(&ifs_sem);
ifs_load_firmware(ifs_device.misc.this_device);
+ up(&ifs_sem);
return 0;
}
diff --git a/drivers/platform/x86/intel/ifs/ifs.h b/drivers/platform/x86/intel/ifs/ifs.h
index b648cccda3ec..720bd18a5e91 100644
--- a/drivers/platform/x86/intel/ifs/ifs.h
+++ b/drivers/platform/x86/intel/ifs/ifs.h
@@ -117,5 +117,8 @@ static inline struct ifs_data *ifs_get_data(struct device *dev)
void ifs_load_firmware(struct device *dev);
int do_core_test(int cpu, struct device *dev);
+const struct attribute_group **ifs_get_groups(void);
+
+extern struct semaphore ifs_sem;
#endif
diff --git a/drivers/platform/x86/intel/ifs/sysfs.c b/drivers/platform/x86/intel/ifs/sysfs.c
new file mode 100644
index 000000000000..37d8380d6fa8
--- /dev/null
+++ b/drivers/platform/x86/intel/ifs/sysfs.c
@@ -0,0 +1,149 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright(c) 2022 Intel Corporation. */
+
+#include <linux/cpu.h>
+#include <linux/delay.h>
+#include <linux/fs.h>
+#include <linux/semaphore.h>
+#include <linux/slab.h>
+
+#include "ifs.h"
+
+/*
+ * Protects against simultaneous tests on multiple cores, or
+ * reloading can file while a test is in progress
+ */
+DEFINE_SEMAPHORE(ifs_sem);
+
+/*
+ * The sysfs interface to check additional details of last test
+ * cat /sys/devices/system/platform/ifs/details
+ */
+static ssize_t details_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct ifs_data *ifsd = ifs_get_data(dev);
+
+ return sysfs_emit(buf, "%#llx\n", ifsd->scan_details);
+}
+
+static DEVICE_ATTR_RO(details);
+
+static const char * const status_msg[] = {
+ [SCAN_NOT_TESTED] = "untested",
+ [SCAN_TEST_PASS] = "pass",
+ [SCAN_TEST_FAIL] = "fail"
+};
+
+/*
+ * The sysfs interface to check the test status:
+ * To check the status of last test
+ * cat /sys/devices/platform/ifs/status
+ */
+static ssize_t status_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct ifs_data *ifsd = ifs_get_data(dev);
+
+ return sysfs_emit(buf, "%s\n", status_msg[ifsd->status]);
+}
+
+static DEVICE_ATTR_RO(status);
+
+/*
+ * The sysfs interface for single core testing
+ * To start test, for example, cpu5
+ * echo 5 > /sys/devices/platform/ifs/run_test
+ * To check the result:
+ * cat /sys/devices/platform/ifs/result
+ * The sibling core gets tested at the same time.
+ */
+static ssize_t run_test_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct ifs_data *ifsd = ifs_get_data(dev);
+ unsigned int cpu;
+ int rc;
+
+ rc = kstrtouint(buf, 0, &cpu);
+ if (rc < 0 || cpu >= nr_cpu_ids)
+ return -EINVAL;
+
+ if (down_interruptible(&ifs_sem))
+ return -EINTR;
+
+ if (!ifsd->loaded)
+ rc = -EPERM;
+ else
+ rc = do_core_test(cpu, dev);
+
+ up(&ifs_sem);
+
+ return rc ? rc : count;
+}
+
+static DEVICE_ATTR_WO(run_test);
+
+/*
+ * Reload the IFS image. When user wants to install new IFS image
+ */
+static ssize_t reload_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct ifs_data *ifsd = ifs_get_data(dev);
+ bool res;
+
+
+ if (kstrtobool(buf, &res))
+ return -EINVAL;
+ if (!res)
+ return count;
+
+ if (down_interruptible(&ifs_sem))
+ return -EINTR;
+
+ ifs_load_firmware(dev);
+
+ up(&ifs_sem);
+
+ return ifsd->loaded ? count : -ENODEV;
+}
+
+static DEVICE_ATTR_WO(reload);
+
+/*
+ * Display currently loaded IFS image version.
+ */
+static ssize_t image_version_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct ifs_data *ifsd = ifs_get_data(dev);
+
+ if (!ifsd->loaded)
+ return sysfs_emit(buf, "%s\n", "none");
+ else
+ return sysfs_emit(buf, "%#x\n", ifsd->loaded_version);
+}
+
+static DEVICE_ATTR_RO(image_version);
+
+/* global scan sysfs attributes */
+static struct attribute *plat_ifs_attrs[] = {
+ &dev_attr_details.attr,
+ &dev_attr_status.attr,
+ &dev_attr_run_test.attr,
+ &dev_attr_reload.attr,
+ &dev_attr_image_version.attr,
+ NULL
+};
+
+ATTRIBUTE_GROUPS(plat_ifs);
+
+const struct attribute_group **ifs_get_groups(void)
+{
+ return plat_ifs_groups;
+}
--
2.35.1On Fri, May 06 2022 at 15:54, Tony Luck wrote: > Implement sysfs interface to trigger ifs test for a specific cpu. > Additional interfaces related to checking the status of the > scan test and seeing the version of the loaded IFS binary > are also added. > > The basic usage is as below. > - To start test, for example on cpu5: > echo 5 > /sys/devices/platform/intel_ifs/run_test > - To see the status of the last test > cat /sys/devices/platform/intel_ifs/status > - To see the version of the loaded scan binary > cat /sys/devices/platform/intel_ifs/image_version > > Reviewed-by: Dan Williams <dan.j.williams@intel.com> > Signed-off-by: Jithu Joseph <jithu.joseph@intel.com> > Co-developed-by: Tony Luck <tony.luck@intel.com> > Signed-off-by: Tony Luck <tony.luck@intel.com> > Acked-by: Hans de Goede <hdegoede@redhat.com> > Reviewed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Add tracing support which may be useful for debugging systems that fail to complete
In Field Scan tests.
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
MAINTAINERS | 1 +
drivers/platform/x86/intel/ifs/runtest.c | 5 +++
include/trace/events/intel_ifs.h | 41 ++++++++++++++++++++++++
3 files changed, 47 insertions(+)
create mode 100644 include/trace/events/intel_ifs.h
diff --git a/MAINTAINERS b/MAINTAINERS
index bb0c4ff25942..6864fa039974 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9868,6 +9868,7 @@ R: Ashok Raj <ashok.raj@intel.com>
R: Tony Luck <tony.luck@intel.com>
S: Maintained
F: drivers/platform/x86/intel/ifs
+F: include/trace/events/intel_ifs.h
INTEL INTEGRATED SENSOR HUB DRIVER
M: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
diff --git a/drivers/platform/x86/intel/ifs/runtest.c b/drivers/platform/x86/intel/ifs/runtest.c
index 7efcce35e0e9..b2ca2bb4501f 100644
--- a/drivers/platform/x86/intel/ifs/runtest.c
+++ b/drivers/platform/x86/intel/ifs/runtest.c
@@ -17,6 +17,9 @@
* core will update results of the test.
*/
+#define CREATE_TRACE_POINTS
+#include <trace/events/intel_ifs.h>
+
/* Max retries on the same chunk */
#define MAX_IFS_RETRIES 5
@@ -191,6 +194,8 @@ static void ifs_test_core(int cpu, struct device *dev)
status.data = msrvals[1];
+ trace_ifs_status(cpu, activate, status);
+
/* Some cases can be retried, give up for others */
if (!can_restart(status))
break;
diff --git a/include/trace/events/intel_ifs.h b/include/trace/events/intel_ifs.h
new file mode 100644
index 000000000000..d7353024016c
--- /dev/null
+++ b/include/trace/events/intel_ifs.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM intel_ifs
+
+#if !defined(_TRACE_IFS_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_IFS_H
+
+#include <linux/ktime.h>
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(ifs_status,
+
+ TP_PROTO(int cpu, union ifs_scan activate, union ifs_status status),
+
+ TP_ARGS(cpu, activate, status),
+
+ TP_STRUCT__entry(
+ __field( u64, status )
+ __field( int, cpu )
+ __field( u8, start )
+ __field( u8, stop )
+ ),
+
+ TP_fast_assign(
+ __entry->cpu = cpu;
+ __entry->start = activate.start;
+ __entry->stop = activate.stop;
+ __entry->status = status.data;
+ ),
+
+ TP_printk("cpu: %d, start: %.2x, stop: %.2x, status: %llx",
+ __entry->cpu,
+ __entry->start,
+ __entry->stop,
+ __entry->status)
+);
+
+#endif /* _TRACE_IFS_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
--
2.35.1From: Jithu Joseph <jithu.joseph@intel.com>
Add the sysfs attributes in ABI/testing for In-Field Scan.
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Co-developed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
.../ABI/testing/sysfs-platform-intel-ifs | 39 +++++++++++++++++++
1 file changed, 39 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-platform-intel-ifs
diff --git a/Documentation/ABI/testing/sysfs-platform-intel-ifs b/Documentation/ABI/testing/sysfs-platform-intel-ifs
new file mode 100644
index 000000000000..486d6d2ff8a0
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-platform-intel-ifs
@@ -0,0 +1,39 @@
+What: /sys/devices/virtual/misc/intel_ifs_<N>/run_test
+Date: April 21 2022
+KernelVersion: 5.19
+Contact: "Jithu Joseph" <jithu.joseph@intel.com>
+Description: Write <cpu#> to trigger IFS test for one online core.
+ Note that the test is per core. The cpu# can be
+ for any thread on the core. Running on one thread
+ completes the test for the core containing that thread.
+ Example: to test the core containing cpu5: echo 5 >
+ /sys/devices/platform/intel_ifs.<N>/run_test
+
+What: /sys/devices/virtual/misc/intel_ifs_<N>/status
+Date: April 21 2022
+KernelVersion: 5.19
+Contact: "Jithu Joseph" <jithu.joseph@intel.com>
+Description: The status of the last test. It can be one of "pass", "fail"
+ or "untested".
+
+What: /sys/devices/virtual/misc/intel_ifs_<N>/details
+Date: April 21 2022
+KernelVersion: 5.19
+Contact: "Jithu Joseph" <jithu.joseph@intel.com>
+Description: Additional information regarding the last test. The details file reports
+ the hex value of the SCAN_STATUS MSR. Note that the error_code field
+ may contain driver defined software code not defined in the Intel SDM.
+
+What: /sys/devices/virtual/misc/intel_ifs_<N>/image_version
+Date: April 21 2022
+KernelVersion: 5.19
+Contact: "Jithu Joseph" <jithu.joseph@intel.com>
+Description: Version (hexadecimal) of loaded IFS binary image. If no scan image
+ is loaded reports "none".
+
+What: /sys/devices/virtual/misc/intel_ifs_<N>/reload
+Date: April 21 2022
+KernelVersion: 5.19
+Contact: "Jithu Joseph" <jithu.joseph@intel.com>
+Description: Write "1" (or "y" or "Y") to reload the IFS image from
+ /lib/firmware/intel/ifs/ff-mm-ss.scan.
--
2.35.1Add documentation for In-Field Scan (IFS). This documentation
describes the basics of IFS, the loading IFS image, chunk
authentication, running scan and how to check result via sysfs.
The CORE_CAPABILITIES MSR enumerates whether IFS is supported.
The full github location for distributing the IFS images is
still being decided. So just a placeholder included for now
in the documentation.
Future CPUs will support more than one type of test. Plan for
that now by using a "_0" suffix on the ABI directory names.
Additional test types will use "_1", etc.
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
---
Documentation/x86/ifs.rst | 2 +
Documentation/x86/index.rst | 1 +
drivers/platform/x86/intel/ifs/ifs.h | 110 +++++++++++++++++++++++++++
3 files changed, 113 insertions(+)
create mode 100644 Documentation/x86/ifs.rst
diff --git a/Documentation/x86/ifs.rst b/Documentation/x86/ifs.rst
new file mode 100644
index 000000000000..97abb696a680
--- /dev/null
+++ b/Documentation/x86/ifs.rst
@@ -0,0 +1,2 @@
+.. SPDX-License-Identifier: GPL-2.0
+.. kernel-doc:: drivers/platform/x86/intel/ifs/ifs.h
diff --git a/Documentation/x86/index.rst b/Documentation/x86/index.rst
index 91b2fa456618..9d8e8a73d57b 100644
--- a/Documentation/x86/index.rst
+++ b/Documentation/x86/index.rst
@@ -35,6 +35,7 @@ x86-specific Documentation
usb-legacy-support
i386/index
x86_64/index
+ ifs
sva
sgx
features
diff --git a/drivers/platform/x86/intel/ifs/ifs.h b/drivers/platform/x86/intel/ifs/ifs.h
index 720bd18a5e91..73c8e91cf144 100644
--- a/drivers/platform/x86/intel/ifs/ifs.h
+++ b/drivers/platform/x86/intel/ifs/ifs.h
@@ -4,6 +4,116 @@
#ifndef _IFS_H_
#define _IFS_H_
+/**
+ * DOC: In-Field Scan
+ *
+ * =============
+ * In-Field Scan
+ * =============
+ *
+ * Introduction
+ * ------------
+ *
+ * In Field Scan (IFS) is a hardware feature to run circuit level tests on
+ * a CPU core to detect problems that are not caught by parity or ECC checks.
+ * Future CPUs will support more than one type of test which will show up
+ * with a new platform-device instance-id, for now only .0 is exposed.
+ *
+ *
+ * IFS Image
+ * ---------
+ *
+ * Intel provides a firmware file containing the scan tests via
+ * github [#f1]_. Similar to microcode there is a separate file for each
+ * family-model-stepping.
+ *
+ * IFS Image Loading
+ * -----------------
+ *
+ * The driver loads the tests into memory reserved BIOS local to each CPU
+ * socket in a two step process using writes to MSRs to first load the
+ * SHA hashes for the test. Then the tests themselves. Status MSRs provide
+ * feedback on the success/failure of these steps. When a new test file
+ * is installed it can be loaded by writing to the driver reload file::
+ *
+ * # echo 1 > /sys/devices/virtual/misc/intel_ifs_0/reload
+ *
+ * Similar to microcode, the current version of the scan tests is stored
+ * in a fixed location: /lib/firmware/intel/ifs.0/family-model-stepping.scan
+ *
+ * Running tests
+ * -------------
+ *
+ * Tests are run by the driver synchronizing execution of all threads on a
+ * core and then writing to the ACTIVATE_SCAN MSR on all threads. Instruction
+ * execution continues when:
+ *
+ * 1) All tests have completed.
+ * 2) Execution was interrupted.
+ * 3) A test detected a problem.
+ *
+ * Note that ALL THREADS ON THE CORE ARE EFFECTIVELY OFFLINE FOR THE
+ * DURATION OF THE TEST. This can be up to 200 milliseconds. If the system
+ * is running latency sensitive applications that cannot tolerate an
+ * interruption of this magnitude, the system administrator must arrange
+ * to migrate those applications to other cores before running a core test.
+ * It may also be necessary to redirect interrupts to other CPUs.
+ *
+ * In all cases reading the SCAN_STATUS MSR provides details on what
+ * happened. The driver makes the value of this MSR visible to applications
+ * via the "details" file (see below). Interrupted tests may be restarted.
+ *
+ * The IFS driver provides sysfs interfaces via /sys/devices/virtual/misc/intel_ifs_0/
+ * to control execution:
+ *
+ * Test a specific core::
+ *
+ * # echo <cpu#> > /sys/devices/virtual/misc/intel_ifs_0/run_test
+ *
+ * when HT is enabled any of the sibling cpu# can be specified to test
+ * its corresponding physical core. Since the tests are per physical core,
+ * the result of testing any thread is same. All siblings must be online
+ * to run a core test. It is only necessary to test one thread.
+ *
+ * For e.g. to test core corresponding to cpu5
+ *
+ * # echo 5 > /sys/devices/virtual/misc/intel_ifs_0/run_test
+ *
+ * Results of the last test is provided in /sys::
+ *
+ * $ cat /sys/devices/virtual/misc/intel_ifs_0/status
+ * pass
+ *
+ * Status can be one of pass, fail, untested
+ *
+ * Additional details of the last test is provided by the details file::
+ *
+ * $ cat /sys/devices/virtual/misc/intel_ifs_0/details
+ * 0x8081
+ *
+ * The details file reports the hex value of the SCAN_STATUS MSR.
+ * Hardware defined error codes are documented in volume 4 of the Intel
+ * Software Developer's Manual but the error_code field may contain one of
+ * the following driver defined software codes:
+ *
+ * +------+--------------------+
+ * | 0xFD | Software timeout |
+ * +------+--------------------+
+ * | 0xFE | Partial completion |
+ * +------+--------------------+
+ *
+ * Driver design choices
+ * ---------------------
+ *
+ * 1) The ACTIVATE_SCAN MSR allows for running any consecutive subrange of
+ * available tests. But the driver always tries to run all tests and only
+ * uses the subrange feature to restart an interrupted test.
+ *
+ * 2) Hardware allows for some number of cores to be tested in parallel.
+ * The driver does not make use of this, it only tests one core at a time.
+ *
+ * .. [#f1] https://github.com/intel/TBD
+ */
#include <linux/device.h>
#include <linux/miscdevice.h>
--
2.35.1On Fri, May 06 2022 at 15:54, Tony Luck wrote: > Add documentation for In-Field Scan (IFS). This documentation > describes the basics of IFS, the loading IFS image, chunk > authentication, running scan and how to check result via sysfs. > > The CORE_CAPABILITIES MSR enumerates whether IFS is supported. > > The full github location for distributing the IFS images is > still being decided. So just a placeholder included for now > in the documentation. > > Future CPUs will support more than one type of test. Plan for > that now by using a "_0" suffix on the ABI directory names. > Additional test types will use "_1", etc. > > Reviewed-by: Dan Williams <dan.j.williams@intel.com> > Signed-off-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
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