On Wed, 24 Jan 2024 08:39:33 -0500 Audra Mitchell audra@redhat.com wrote:
A more complete description of these "test failures" would be helpful please.
Hey, sorry for the incomplete description. The test does a series of mmap calls including three using the MAP_FIXED flag and specifying an address that is 1<<47 or 1<<48. These addresses are only available if you are using level 5 page tables, which requires both the CPU to have the capabiltiy (la57 flag) and the kernel to be configured. Currently the test only checks for the kernel configuration option, so this test can still report a false positive. Here are the three failing lines:
$ ./va_high_addr_switch | grep FAILED mmap(ADDR_SWITCH_HINT, 2 * PAGE_SIZE, MAP_FIXED): 0xffffffffffffffff - FAILED mmap(HIGH_ADDR, MAP_FIXED): 0xffffffffffffffff - FAILED mmap(ADDR_SWITCH_HINT, 2 * PAGE_SIZE, MAP_FIXED): 0xffffffffffffffff - FAILED
I thought (for about a second) refactoring the test so that these three mmap calls will only be run on systems with the level 5 page tables available, but the whole point of the test is to check the level 5 feature...
If you would like me to also update the description on the patch let me know and I'll update it and resubmit. Thanks!
I pasted the above into the changelog, thanks.