[kvm-unit-tests PATCH] x86: Prevent APIC base address from changing in test_enable_x2apic()

[nadav.amit@gmail.com]

From: Nadav Amit <nadav.amit@gmail.com>

test_enable_x2apic() unintentionally changes the APIC base address to
zero and resets the BSP indication. This actually causes the local APIC
to overlap the IDT area, which is wrong. Prevent it from happening by
keeping the APIC base address and BSP-bit as it was before.

Signed-off-by: Nadav Amit <nadav.amit@gmail.com>
---
 x86/apic.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/x86/apic.c b/x86/apic.c
index 51744cf..0849f87 100644
--- a/x86/apic.c
+++ b/x86/apic.c
@@ -90,11 +90,11 @@ static void test_enable_x2apic(void)
         report("disabled to x2apic enabled",
                test_write_apicbase_exception(APIC_EN | APIC_EXTD));
 
-        wrmsr(MSR_IA32_APICBASE, APIC_EN);
+        wrmsr(MSR_IA32_APICBASE, APIC_EN | APIC_DEFAULT_PHYS_BASE | APIC_BSP);
         report("apic enabled to invalid state",
                test_write_apicbase_exception(APIC_EXTD));
 
-        wrmsr(MSR_IA32_APICBASE, APIC_EN | APIC_EXTD);
+        wrmsr(MSR_IA32_APICBASE, APIC_EN | APIC_EXTD | APIC_DEFAULT_PHYS_BASE | APIC_BSP);
         apic_write(APIC_SPIV, 0x1ff);
     } else {
         printf("x2apic not detected\n");
-- 
2.17.1