On Mon, Jul 13, 2020 at 5:23 PM Sean Christopherson
<sean.j.christopherson@xxxxxxxxx> wrote:
>
> Perform one last VMX transition to actually load the host's RIP and CR4
> at the end of test_host_addr_size(). Simply writing the VMCS doesn't
> restore the values in hardware, e.g. as is, CR4.PCIDE can be left set,
> which causes spectacularly confusing explosions when other misguided
> tests assume setting bit 63 in CR3 will cause a non-canonical #GP.
>
> Fixes: 0786c0316ac05 ("kvm-unit-test: nVMX: Check Host Address Space Size on vmentry of nested guests")
> Cc: Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>
> Cc: Karl Heubaum <karl.heubaum@xxxxxxxxxx>
> Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Reviewed-by: Oliver Upton <oupton@xxxxxxxxxx>
> ---
> x86/vmx_tests.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/x86/vmx_tests.c b/x86/vmx_tests.c
> index 29f3d0e..cb42a2d 100644
> --- a/x86/vmx_tests.c
> +++ b/x86/vmx_tests.c
> @@ -7673,6 +7673,11 @@ static void test_host_addr_size(void)
> vmcs_write(ENT_CONTROLS, entry_ctrl_saved | ENT_GUEST_64);
> vmcs_write(HOST_RIP, rip_saved);
> vmcs_write(HOST_CR4, cr4_saved);
> +
> + /* Restore host's active RIP and CR4 values. */
> + report_prefix_pushf("restore host state");
> + test_vmx_vmlaunch(0);
> + report_prefix_pop();
> }
> }
>
> --
> 2.26.0
>
