lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20241021180252.3531-11-mario.limonciello@amd.com>
Date: Mon, 21 Oct 2024 13:02:49 -0500
From: Mario Limonciello <mario.limonciello@....com>
To: Borislav Petkov <bp@...en8.de>, Hans de Goede <hdegoede@...hat.com>,
	Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>
CC: <x86@...nel.org>, "Gautham R . Shenoy" <gautham.shenoy@....com>, "Mario
 Limonciello" <mario.limonciello@....com>, Perry Yuan <perry.yuan@....com>,
	<linux-kernel@...r.kernel.org>, <linux-doc@...r.kernel.org>,
	<linux-pm@...r.kernel.org>, <platform-driver-x86@...r.kernel.org>, "Shyam
 Sundar S K" <Shyam-sundar.S-k@....com>
Subject: [PATCH v4 10/13] x86/process: Clear hardware feedback history for AMD processors

From: Perry Yuan <perry.yuan@....com>

Incorporate a mechanism within the context switching code to reset
the hardware history for AMD processors. Specifically, when a task
is switched in, the class ID was read and reset the hardware workload
classification history of CPU firmware and then it start to trigger
workload classification for the next running thread.

Signed-off-by: Perry Yuan <perry.yuan@....com>
Co-developed-by: Mario Limonciello <mario.limonciello@....com>
Signed-off-by: Mario Limonciello <mario.limonciello@....com>
---
 arch/x86/include/asm/hreset.h |  6 ++++++
 arch/x86/kernel/cpu/common.c  | 15 +++++++++++++++
 arch/x86/kernel/process_32.c  |  3 +++
 arch/x86/kernel/process_64.c  |  3 +++
 4 files changed, 27 insertions(+)
 create mode 100644 arch/x86/include/asm/hreset.h

diff --git a/arch/x86/include/asm/hreset.h b/arch/x86/include/asm/hreset.h
new file mode 100644
index 0000000000000..ae1f72602bbd0
--- /dev/null
+++ b/arch/x86/include/asm/hreset.h
@@ -0,0 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_HRESET_H
+
+void reset_hardware_history_hetero(void);
+
+#endif /* _ASM_X86_HRESET_H */
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 07a34d7235057..658c8fb4e25df 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -57,6 +57,7 @@
 #include <asm/mce.h>
 #include <asm/msr.h>
 #include <asm/cacheinfo.h>
+#include <asm/hreset.h>
 #include <asm/memtype.h>
 #include <asm/microcode.h>
 #include <asm/intel-family.h>
@@ -403,6 +404,7 @@ static const unsigned long cr4_pinned_mask = X86_CR4_SMEP | X86_CR4_SMAP | X86_C
 					     X86_CR4_FSGSBASE | X86_CR4_CET | X86_CR4_FRED;
 static DEFINE_STATIC_KEY_FALSE_RO(cr_pinning);
 static unsigned long cr4_pinned_bits __ro_after_init;
+static DEFINE_STATIC_KEY_FALSE_RO(hardware_history_features);
 
 void native_write_cr0(unsigned long val)
 {
@@ -481,6 +483,12 @@ void cr4_init(void)
 	this_cpu_write(cpu_tlbstate.cr4, cr4);
 }
 
+static void __init setup_hreset(struct cpuinfo_x86 *c)
+{
+	if (cpu_feature_enabled(X86_FEATURE_AMD_WORKLOAD_CLASS))
+		static_key_enable_cpuslocked(&hardware_history_features.key);
+}
+
 /*
  * Once CPU feature detection is finished (and boot params have been
  * parsed), record any of the sensitive CR bits that are set, and
@@ -1844,6 +1852,7 @@ static void identify_cpu(struct cpuinfo_x86 *c)
 	setup_smep(c);
 	setup_smap(c);
 	setup_umip(c);
+	setup_hreset(c);
 
 	/* Enable FSGSBASE instructions if available. */
 	if (cpu_has(c, X86_FEATURE_FSGSBASE)) {
@@ -2410,3 +2419,9 @@ void __init arch_cpu_finalize_init(void)
 	 */
 	mem_encrypt_init();
 }
+
+__always_inline void reset_hardware_history_hetero(void)
+{
+	if (static_branch_unlikely(&hardware_history_features))
+		wrmsrl(AMD_WORKLOAD_HRST, 0x1);
+}
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 0917c7f25720b..6a3a1339f7a77 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -52,6 +52,7 @@
 #include <asm/switch_to.h>
 #include <asm/vm86.h>
 #include <asm/resctrl.h>
+#include <asm/hreset.h>
 #include <asm/proto.h>
 
 #include "process.h"
@@ -213,6 +214,8 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
 	/* Load the Intel cache allocation PQR MSR. */
 	resctrl_sched_in(next_p);
 
+	reset_hardware_history_hetero();
+
 	return prev_p;
 }
 
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 226472332a70d..ea7f765c6262a 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -54,6 +54,7 @@
 #include <asm/xen/hypervisor.h>
 #include <asm/vdso.h>
 #include <asm/resctrl.h>
+#include <asm/hreset.h>
 #include <asm/unistd.h>
 #include <asm/fsgsbase.h>
 #include <asm/fred.h>
@@ -709,6 +710,8 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
 	/* Load the Intel cache allocation PQR MSR. */
 	resctrl_sched_in(next_p);
 
+	reset_hardware_history_hetero();
+
 	return prev_p;
 }
 
-- 
2.43.0


Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ