Change in ...coreboot[master]: cpu/intel/common: decouple IA32_FEATURE_CONTROL lock from set_vmx()

[Patrick Georgi (Code Review)]

Patrick Georgi has submitted this change and it was merged. ( https://review.coreboot.org/c/coreboot/+/30229 )

Change subject: cpu/intel/common: decouple IA32_FEATURE_CONTROL lock from set_vmx()
......................................................................

cpu/intel/common: decouple IA32_FEATURE_CONTROL lock from set_vmx()

Newer CPUs/SoCs need to configure other features via the
IA32_FEATURE_CONTROL msr, such as SGX, which cannot be done if the
msr is already locked. Create separate functions for setting the
vmx flag and lock bit, and rename existing function to indicate that
the lock bit will be set in addition to vmx flag (per Kconfig).

This will allow Skylake/Kabylake (and others?) to use the common
VMX code without breaking SGX, while ensuring no change in functionality
to existing platforms which current set both together.

Test: build/boot each affected platform, ensure no change in functionality

Change-Id: Iee772fe87306b4729ca012cef8640d3858e2cb06
Signed-off-by: Matt DeVillier 
Reviewed-on: https://review.coreboot.org/c/30229
Reviewed-by: Nico Huber 
Reviewed-by: David Guckian
Tested-by: build bot (Jenkins) 
---
M src/cpu/intel/common/Kconfig
M src/cpu/intel/common/common.h
M src/cpu/intel/common/common_init.c
M src/cpu/intel/fsp_model_406dx/model_406dx_init.c
M src/cpu/intel/haswell/haswell_init.c
M src/cpu/intel/model_1067x/model_1067x_init.c
M src/cpu/intel/model_106cx/model_106cx_init.c
M src/cpu/intel/model_2065x/model_2065x_init.c
M src/cpu/intel/model_206ax/model_206ax_init.c
M src/cpu/intel/model_6ex/model_6ex_init.c
M src/cpu/intel/model_6fx/model_6fx_init.c
M src/soc/intel/baytrail/cpu.c
M src/soc/intel/braswell/cpu.c
M src/soc/intel/broadwell/cpu.c
14 files changed, 46 insertions(+), 22 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Nico Huber: Looks good to me, approved
  David Guckian: Looks good to me, but someone else must approve

diff --git a/src/cpu/intel/common/Kconfig b/src/cpu/intel/common/Kconfig
index 739333e..56bed22 100644
--- a/src/cpu/intel/common/Kconfig
+++ b/src/cpu/intel/common/Kconfig
@@ -7,9 +7,8 @@
    bool "Enable VMX for virtualization"
    default y

-config SET_VMX_LOCK_BIT
-	bool "Set lock bit after configuring VMX"
-	depends on ENABLE_VMX
+config SET_IA32_FC_LOCK_BIT
+	bool "Set IA32_FEATURE_CONTROL lock bit"
    default y
    help
      Although the Intel manual says you must set the lock bit in addition
diff --git a/src/cpu/intel/common/common.h b/src/cpu/intel/common/common.h
index 81c9f16..b9ac056 100644
--- a/src/cpu/intel/common/common.h
+++ b/src/cpu/intel/common/common.h
@@ -15,7 +15,9 @@
 #ifndef _CPU_INTEL_COMMON_H
 #define _CPU_INTEL_COMMON_H

-void set_vmx(void);
+void set_vmx_and_lock(void);
+void set_feature_ctrl_vmx(void);
+void set_feature_ctrl_lock(void);

/*
  * Init CPPC block with MSRs for Intel Enhanced Speed Step Technology.
diff --git a/src/cpu/intel/common/common_init.c b/src/cpu/intel/common/common_init.c
index 7dbbfda..9c0fcbb 100644
--- a/src/cpu/intel/common/common_init.c
+++ b/src/cpu/intel/common/common_init.c
@@ -21,12 +21,17 @@
 #include <cpu/x86/msr.h>
 #include "common.h"

-void set_vmx(void)
+void set_vmx_and_lock(void)
+{
+	set_feature_ctrl_vmx();
+	set_feature_ctrl_lock();
+}
+
+void set_feature_ctrl_vmx(void)
 {
    msr_t msr;
    uint32_t feature_flag;
    int enable = IS_ENABLED(CONFIG_ENABLE_VMX);
-	int lock = IS_ENABLED(CONFIG_SET_VMX_LOCK_BIT);

feature_flag = cpu_get_feature_flags_ecx();
    /* Check that the VMX is supported before reading or writing the MSR. */
@@ -38,10 +43,10 @@
    msr = rdmsr(IA32_FEATURE_CONTROL);

if (msr.lo & (1 << 0)) {
-		printk(BIOS_ERR, "VMX is locked, so %s will do nothing\n",
+		printk(BIOS_ERR, "IA32_FEATURE_CONTROL is locked, so %s will do nothing\n",
    		__func__);
-		/* VMX locked. If we set it again we get an illegal
-		 * instruction
+		/* IA32_FEATURE_CONTROL locked. If we set it again we get an
+		 * illegal instruction
    	 */
    	return;
    }
@@ -59,14 +64,32 @@

wrmsr(IA32_FEATURE_CONTROL, msr);

+	printk(BIOS_DEBUG, "VMX status: %s\n",
+		enable ? "enabled" : "disabled");
+}
+void set_feature_ctrl_lock(void)
+{
+	msr_t msr;
+	int lock = IS_ENABLED(CONFIG_SET_IA32_FC_LOCK_BIT);
+
+	msr = rdmsr(IA32_FEATURE_CONTROL);
+
+	if (msr.lo & (1 << 0)) {
+		printk(BIOS_ERR, "IA32_FEATURE_CONTROL is locked, so %s will do nothing\n",
+			__func__);
+		/* IA32_FEATURE_CONTROL locked. If we set it again we get an
+		 * illegal instruction
+		 */
+		return;
+	}
+
    if (lock) {
    	/* Set lock bit */
    	msr.lo |= (1 << 0);
    	wrmsr(IA32_FEATURE_CONTROL, msr);
    }

-	printk(BIOS_DEBUG, "VMX status: %s, %s\n",
-		enable ? "enabled" : "disabled",
+	printk(BIOS_DEBUG, "IA32_FEATURE_CONTROL status: %s\n",
    	lock ? "locked" : "unlocked");
 }

diff --git a/src/cpu/intel/fsp_model_406dx/model_406dx_init.c b/src/cpu/intel/fsp_model_406dx/model_406dx_init.c
index 289305f..7994f0b 100644
--- a/src/cpu/intel/fsp_model_406dx/model_406dx_init.c
+++ b/src/cpu/intel/fsp_model_406dx/model_406dx_init.c
@@ -148,7 +148,7 @@
    setup_lapic();

/* Set virtualization based on Kconfig option */
-	set_vmx();
+	set_vmx_and_lock();

/* Configure Enhanced SpeedStep and Thermal Sensors */
    configure_misc();
diff --git a/src/cpu/intel/haswell/haswell_init.c b/src/cpu/intel/haswell/haswell_init.c
index 9d85960..aa77964 100644
--- a/src/cpu/intel/haswell/haswell_init.c
+++ b/src/cpu/intel/haswell/haswell_init.c
@@ -686,7 +686,7 @@
    setup_lapic();

/* Set virtualization based on Kconfig option */
-	set_vmx();
+	set_vmx_and_lock();

/* Configure C States */
    configure_c_states();
diff --git a/src/cpu/intel/model_1067x/model_1067x_init.c b/src/cpu/intel/model_1067x/model_1067x_init.c
index 7eb121e..dbb9631 100644
--- a/src/cpu/intel/model_1067x/model_1067x_init.c
+++ b/src/cpu/intel/model_1067x/model_1067x_init.c
@@ -296,7 +296,7 @@
    init_timer();

/* Set virtualization based on Kconfig option */
-	set_vmx();
+	set_vmx_and_lock();

/* Configure C States */
    configure_c_states(quad);
diff --git a/src/cpu/intel/model_106cx/model_106cx_init.c b/src/cpu/intel/model_106cx/model_106cx_init.c
index 56598fa..a609aed 100644
--- a/src/cpu/intel/model_106cx/model_106cx_init.c
+++ b/src/cpu/intel/model_106cx/model_106cx_init.c
@@ -99,7 +99,7 @@
    setup_lapic();

/* Set virtualization based on Kconfig option */
-	set_vmx();
+	set_vmx_and_lock();

/* Configure C States */
    configure_c_states();
diff --git a/src/cpu/intel/model_2065x/model_2065x_init.c b/src/cpu/intel/model_2065x/model_2065x_init.c
index 7ce516b..240bf50 100644
--- a/src/cpu/intel/model_2065x/model_2065x_init.c
+++ b/src/cpu/intel/model_2065x/model_2065x_init.c
@@ -333,7 +333,7 @@
    setup_lapic();

/* Set virtualization based on Kconfig option */
-	set_vmx();
+	set_vmx_and_lock();

/* Configure Enhanced SpeedStep and Thermal Sensors */
    configure_misc();
diff --git a/src/cpu/intel/model_206ax/model_206ax_init.c b/src/cpu/intel/model_206ax/model_206ax_init.c
index 27f56be..58aabdb 100644
--- a/src/cpu/intel/model_206ax/model_206ax_init.c
+++ b/src/cpu/intel/model_206ax/model_206ax_init.c
@@ -556,7 +556,7 @@
    setup_lapic();

/* Set virtualization based on Kconfig option */
-	set_vmx();
+	set_vmx_and_lock();

/* Configure C States */
    configure_c_states();
diff --git a/src/cpu/intel/model_6ex/model_6ex_init.c b/src/cpu/intel/model_6ex/model_6ex_init.c
index 5041dcd..78ece74 100644
--- a/src/cpu/intel/model_6ex/model_6ex_init.c
+++ b/src/cpu/intel/model_6ex/model_6ex_init.c
@@ -136,7 +136,7 @@
    setup_lapic();

/* Set virtualization based on Kconfig option */
-	set_vmx();
+	set_vmx_and_lock();

/* Configure C States */
    configure_c_states();
diff --git a/src/cpu/intel/model_6fx/model_6fx_init.c b/src/cpu/intel/model_6fx/model_6fx_init.c
index c5659f3..9d11478 100644
--- a/src/cpu/intel/model_6fx/model_6fx_init.c
+++ b/src/cpu/intel/model_6fx/model_6fx_init.c
@@ -150,7 +150,7 @@
    setup_lapic();

/* Set virtualization based on Kconfig option */
-	set_vmx();
+	set_vmx_and_lock();

/* Configure C States */
    configure_c_states();
diff --git a/src/soc/intel/baytrail/cpu.c b/src/soc/intel/baytrail/cpu.c
index 6c37aa86..9526932 100644
--- a/src/soc/intel/baytrail/cpu.c
+++ b/src/soc/intel/baytrail/cpu.c
@@ -57,7 +57,7 @@
    	enable_turbo();

/* Set virtualization based on Kconfig option */
-	set_vmx();
+	set_vmx_and_lock();

/* Set core MSRs */
    reg_script_run(core_msr_script);
diff --git a/src/soc/intel/braswell/cpu.c b/src/soc/intel/braswell/cpu.c
index 9063c2a..12f34fb 100644
--- a/src/soc/intel/braswell/cpu.c
+++ b/src/soc/intel/braswell/cpu.c
@@ -62,7 +62,7 @@
    	enable_turbo();

/* Set virtualization based on Kconfig option */
-	set_vmx();
+	set_vmx_and_lock();

/* Set core MSRs */
    reg_script_run(core_msr_script);
diff --git a/src/soc/intel/broadwell/cpu.c b/src/soc/intel/broadwell/cpu.c
index 66ec345..eab6b00 100644
--- a/src/soc/intel/broadwell/cpu.c
+++ b/src/soc/intel/broadwell/cpu.c
@@ -581,7 +581,7 @@
    setup_lapic();

/* Set virtualization based on Kconfig option */
-	set_vmx();
+	set_vmx_and_lock();

/* Configure C States */
    configure_c_states();