[kvm-unit-tests]: nVMX, gcc labels as values, FEATURE_CONTROL lock bit

[Marius Vlad <mv@xxxxxxxxxxxxxxxxx>]

Hello, 

        $ qemu --version
        QEMU emulator version 1.7.0 (Debian 1.7.0+dfsg-3), Copyright (c) 2003-2008 Fabrice Bellard

        $ gcc --version
        gcc (Debian 4.8.2-15) 4.8.2

        $ git rev-list HEAD | head -n1
        c0a4e715eb30944f984a92fbd4bb2cff6ee298a5

        $ git branch 
        master

        $ qemu-system-x86_64 -enable-kvm -device pc-testdev -device isa-debug-exit,iobase=0xf4,iosize=0x4 \
                -display none -serial stdio -device pci-testdev -kernel x86/vmx.flat -cpu host,+vmx,+x2apic -smp 1
        enabling apic
        paging enabled
        cr0 = 80010011
        cr3 = 7fff000
        cr4 = 20
        PASS: test vmxon with FEATURE_CONTROL cleared
        PASS: test vmxon without FEATURE_CONTROL lock
        PASS: test enable VMX in FEATURE_CONTROL
        unhandled excecption 6
        + ret=15
        + echo Return value from qemu: 15
        Return value from qemu: 15
        + exit 15

        I need to add a nop statement for GCC to generate the 
        proper jump address.

        w/o:

        0000000000400493 <do_write_feature_control>:
          400493:       48 c7 05 02 f4 00 00 b0 04 40 00        movq   $0x4004b0,0xf402(%rip)        # 40f8a0 <exception_return>
          40049e:       b9 3a 00 00 00          mov    $0x3a,%ecx
          4004a3:       ba 00 00 00 00          mov    $0x0,%edx
          4004a8:       b8 00 00 00 00          mov    $0x0,%eax
          4004ad:       0f 30                   wrmsr  
          4004af:       c3                      retq   

        00000000004004b0 <init_vmcs>:
          4004b0:       53                      push   %rbx             # <- jumps here, in case of GP

        with:

        0000000000400493 <do_write_feature_control>:
          400493:       48 c7 05 02 f4 00 00 af 04 40 00        movq   $0x4004af,0xf402(%rip)        # 40f8a0 <exception_return>
          40049e:       b9 3a 00 00 00          mov    $0x3a,%ecx
          4004a3:       ba 00 00 00 00          mov    $0x0,%edx
          4004a8:       b8 00 00 00 00          mov    $0x0,%eax
          4004ad:       0f 30                   wrmsr  
          4004af:       90                      nop                     # <- lands here
          4004b0:       c3                      retq   

          $ qemu-system-x86_64 -enable-kvm -device pc-testdev -device isa-debug-exit,iobase=0xf4,iosize=0x4 \
                -display none -serial stdio -device pci-testdev -kernel x86/vmx.flat -cpu host,+vmx,+x2apic -smp 1
          enabling apic
          paging enabled
          cr0 = 80010011
          cr3 = 7fff000
          cr4 = 20
          PASS: test vmxon with FEATURE_CONTROL cleared
          PASS: test vmxon without FEATURE_CONTROL lock
          PASS: test enable VMX in FEATURE_CONTROL
          PASS: test FEATURE_CONTROL lock bit
          PASS: test vmxon
          PASS: test vmptrld
          PASS: test vmclear
          PASS: test vmptrst
          PASS: test vmxoff
          ....
          SUMMARY: 57 tests, 0 failures
          + ret=1
          + echo Return value from qemu: 1
          Return value from qemu: 1
          + exit 1

Attachment: signature.asc
Description: Digital signature