[coreboot] New patch to review for coreboot: 34a9aab Revert "Remove code that enables/disables VMX in coreboot on chromebooks."

[Stefan Reinauer (stefan.reinauer@coreboot.org)]

Stefan Reinauer (stefan.reinauer at coreboot.org) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/1793

-gerrit

commit 34a9aabb440ee63d30c37774fdb3e2a5b7af12be
Author: Marc Jones <marc.jones at se-eng.com>
Date:   Thu Oct 25 09:37:19 2012 -0600

    Revert "Remove code that enables/disables VMX in coreboot on chromebooks."
    
    The MSR for VMX can start with a random value and needs to be
    cleared by coreboot. I am reverting this change, as
    it handles almost everything and doing a follow-on change to fix
    the improper clearing of the MSR.
    
    Change-Id: Ibad7a27b03f199241c52c1ebdd2b6d4e81a18a4e
    Signed-off-by: Marc Jones <marc.jones at se-eng.com>
---
 src/cpu/intel/model_206ax/Kconfig            |  4 +++
 src/cpu/intel/model_206ax/finalize.c         |  1 +
 src/cpu/intel/model_206ax/model_206ax_init.c | 38 ++++++++++++++++++++++++++++
 3 files changed, 43 insertions(+)

diff --git a/src/cpu/intel/model_206ax/Kconfig b/src/cpu/intel/model_206ax/Kconfig
index 5c543b8..5b3f893 100644
--- a/src/cpu/intel/model_206ax/Kconfig
+++ b/src/cpu/intel/model_206ax/Kconfig
@@ -28,6 +28,10 @@ config SMM_TSEG_SIZE
 	hex
 	default 0x800000
 
+config ENABLE_VMX
+	bool "Enable VMX for virtualization"
+	default n
+
 config MICROCODE_INCLUDE_PATH
 	string
 	default "src/cpu/intel/model_206ax"
diff --git a/src/cpu/intel/model_206ax/finalize.c b/src/cpu/intel/model_206ax/finalize.c
index 4ed5d1e..ca7048d 100644
--- a/src/cpu/intel/model_206ax/finalize.c
+++ b/src/cpu/intel/model_206ax/finalize.c
@@ -43,6 +43,7 @@ static void msr_set_bit(unsigned reg, unsigned bit)
 
 void intel_model_206ax_finalize_smm(void)
 {
+	msr_set_bit(IA32_FEATURE_CONTROL, 0);
 	msr_set_bit(MSR_PMG_CST_CONFIG_CONTROL, 15);
 
 	/* Lock AES-NI only if supported */
diff --git a/src/cpu/intel/model_206ax/model_206ax_init.c b/src/cpu/intel/model_206ax/model_206ax_init.c
index 6dfc12f..58593c8 100644
--- a/src/cpu/intel/model_206ax/model_206ax_init.c
+++ b/src/cpu/intel/model_206ax/model_206ax_init.c
@@ -116,6 +116,41 @@ static acpi_cstate_t cstate_map[] = {
 	{ 0 }
 };
 
+static void enable_vmx(void)
+{
+	struct cpuid_result regs;
+	msr_t msr;
+	int enable = CONFIG_ENABLE_VMX;
+
+	msr = rdmsr(IA32_FEATURE_CONTROL);
+
+	if (msr.lo & (1 << 0)) {
+		printk(BIOS_ERR, "VMX is locked, so enable_vmx will do nothing\n");
+		/* VMX locked. If we set it again we get an illegal
+		 * instruction
+		 */
+		return;
+	}
+
+	regs = cpuid(1);
+	printk(BIOS_DEBUG, "%s VMX\n", enable ? "Enabling" : "Disabling");
+	if (regs.ecx & CPUID_VMX) {
+		if (enable)
+			msr.lo |= (1 << 2);
+		else
+			msr.lo &= ~(1 << 2);
+
+		if (regs.ecx & CPUID_SMX) {
+			if (enable)
+				msr.lo |= (1 << 1);
+			else
+				msr.lo &= ~(1 << 1);
+		}
+	}
+
+	wrmsr(IA32_FEATURE_CONTROL, msr);
+}
+
 /* Convert time in seconds to POWER_LIMIT_1_TIME MSR value */
 static const u8 power_limit_time_sec_to_msr[] = {
 	[0]   = 0x00,
@@ -526,6 +561,9 @@ static void model_206ax_init(device_t cpu)
 	enable_lapic_tpr();
 	setup_lapic();
 
+	/* Enable virtualization if enabled in CMOS */
+	enable_vmx();
+
 	/* Configure C States */
 	configure_c_states();