On 04/15/2019 06:10 AM, Paolo Bonzini wrote:
We will allow this behavior for KVM in some specific cases
(CR8 load/store exits enabled, virtualize APIC accesses
disabled).
I am wondering whether it will be useful to mention here the reason for
allowing such an exception.
Ensure these specific values of the controls
are there in the VMCS, and remove the XFAIL.
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
x86/vmx_tests.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/x86/vmx_tests.c b/x86/vmx_tests.c
index ab7e8cc..0ca5363 100644
--- a/x86/vmx_tests.c
+++ b/x86/vmx_tests.c
@@ -3669,9 +3669,17 @@ static void test_msr_bitmap(void)
*/
static void test_apic_virt_addr(void)
{
+ /*
+ * Ensure the processor will never use the virtual-APIC page, since
+ * we will point it to invalid RAM. Otherwise KVM is puzzled about
+ * what we're trying to achieve and fails vmentry.
+ */
+ u32 cpu_ctrls0 = vmcs_read(CPU_EXEC_CTRL0);
+ vmcs_write(CPU_EXEC_CTRL0, cpu_ctrls0 | CPU_CR8_LOAD | CPU_CR8_STORE);
Even though "virtualize APIC accesses" is not set by default, it might
be cleaner to unset it explicitly here in the test, in case someone sets
it prior to the execution of this piece of VMX controls test and forgets
to unset it.
test_vmcs_addr_reference(CPU_TPR_SHADOW, APIC_VIRT_ADDR,
"virtual-APIC address", "Use TPR shadow",
- PAGE_SIZE, true, true);
+ PAGE_SIZE, false, true);
+ vmcs_write(CPU_EXEC_CTRL0, cpu_ctrls0);
}
/*
