[LTP] [PATCH 5/5] Add test for CVE 2021-3653

[Petr Vorel]

Hi Martin,

because Nicolai is busy, patches looks good and Cyril also acked them [1], I
merge first four patches.

The test itself introduces warnings. Could you please have look if they could be
easily fixed?

kvm_svm01.c: In function ‘guest_main’:
kvm_svm01.c:42:13: warning: array subscript 0 is outside array bounds of ‘uint32_t[0]’ {aka ‘unsigned int[]’} [-Warray-bounds]
   42 |         if (*avic_ptr != 0xaaaaaaaa)
      |             ^~~~~~~~~
kvm_svm01.c:45:9: warning: array subscript 0 is outside array bounds of ‘uint32_t[0]’ {aka ‘unsigned int[]’} [-Warray-bounds]
   45 |         *avic_ptr = AVIC_TEST_VAL;
      |         ^~~~~~~~~
kvm_svm01.c: In function ‘main’:
kvm_svm01.c:93:13: warning: array subscript 0 is outside array bounds of ‘uint32_t[0]’ {aka ‘unsigned int[]’} [-Warray-bounds]
   93 |         if (*avic_ptr != AVIC_TEST_VAL) {

Kind regards,
Petr

[1] https://lore.kernel.org/ltp/ZFIp4Sulcy20GWkc@rei/