[kvm-unit-tests PATCH] x86: vmx: Consider CMCI enabled based on IA32_MCG_CAP[10]

[Nadav Amit <nadav.amit@gmail.com>]

CMCI is enabled if IA32_MCG_CAP[10] is set. VMX tests do not respect
this condition. Fix it.

Cc: Marc Orr <marcorr@google.com>
Signed-off-by: Nadav Amit <nadav.amit@gmail.com>
---
 x86/vmx_tests.c | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/x86/vmx_tests.c b/x86/vmx_tests.c
index 3731757..1776e46 100644
--- a/x86/vmx_tests.c
+++ b/x86/vmx_tests.c
@@ -5855,6 +5855,11 @@ static u64 virt_x2apic_mode_nibble1(u64 val)
 	return val & 0xf0;
 }
 
+static bool is_cmci_enabled(void)
+{
+	return rdmsr(MSR_IA32_MCG_CAP) & BIT_ULL(10);
+}
+
 static void virt_x2apic_mode_rd_expectation(
 	u32 reg, bool virt_x2apic_mode_on, bool disable_x2apic,
 	bool apic_register_virtualization, bool virtual_interrupt_delivery,
@@ -5862,8 +5867,10 @@ static void virt_x2apic_mode_rd_expectation(
 {
 	bool readable =
 		!x2apic_reg_reserved(reg) &&
-		reg != APIC_EOI &&
-		reg != APIC_CMCI;
+		reg != APIC_EOI;
+
+	if (reg == APIC_CMCI && !is_cmci_enabled())
+		readable = false;
 
 	expectation->rd_exit_reason = VMX_VMCALL;
 	expectation->virt_fn = virt_x2apic_mode_identity;
@@ -5893,9 +5900,6 @@ static void virt_x2apic_mode_rd_expectation(
  * For writable registers, get_x2apic_wr_val() deposits the write value into the
  * val pointer arg and returns true. For non-writable registers, val is not
  * modified and get_x2apic_wr_val() returns false.
- *
- * CMCI, including the LVT CMCI register, is disabled by default. Thus,
- * get_x2apic_wr_val() treats this register as non-writable.
  */
 static bool get_x2apic_wr_val(u32 reg, u64 *val)
 {
@@ -5930,6 +5934,11 @@ static bool get_x2apic_wr_val(u32 reg, u64 *val)
 		 */
 		*val = apic_read(reg);
 		break;
+	case APIC_CMCI:
+		if (!is_cmci_enabled())
+			return false;
+		*val = apic_read(reg);
+		break;
 	case APIC_ICR:
 		*val = 0x40000 | 0xf1;
 		break;
-- 
2.17.1