On Mon, Oct 3, 2022 at 4:31 PM Sean Christopherson <seanjc@xxxxxxxxxx> wrote: > > On Thu, Sep 29, 2022, David Matlack wrote: > > Miscellaneous fixes and cleanups to emulator_error_test. The reason I > > started looking at this test is because it fails when TDP is disabled, > > which pollutes my test results when I am testing a new series for > > upstream. > > This series defeats the (not well documented) purpose of emulator_error_test. The > test exists specifically to verify that KVM emulates in response to EPT violations > when "allow_smaller_maxphyaddr && guest.MAXPHYADDR < host.MAXPHADDR". I thought that might have been the case before I sent this series, but I could not (and still can't) find any evidence to support it. The commit message and comment at the top of the test all indicate this is a test for KVM_CAP_EXIT_ON_EMULATION_FAILURE. What did I miss? Either way, I think we want both types of tests. In v2 how about I split out: (1) exit_on_emulation_failure_test.c: Test that emulation failures exit to userspace when the cap is enabled, i.e. what emulator_error_test does by the end of this series. (2) smaller_maxphyaddr_emulation_test.c: Test the interaction of allow_smaller_maxphyaddr and instruction emulation. i.e. what emulator_error_does at the start of this series plus your suggestions. The main benefit of splitting out (1) is to test KVM_CAP_EXIT_ON_EMULATION_FAILURE independent of allow_smaller_maxphyaddr, since allow_smaller_maxphyaddr is not enabled by default. > > That said, the test could use some upgrades: > > 1. Verify that a well-emulated instruction takes #PF(RSVD) > 2. Verify that FLDS takes #PF(RSVD) when EPT is disabled
