linux-stable.git/tools/testing/selftests/kvm, branch v5.1.2

KVM: selftests: make hyperv_cpuid test pass on AMD

2019-04-30T19:22:16+00:00

Enlightened VMCS is only supported on Intel CPUs but the test shouldn't
fail completely.

Signed-off-by: Vitaly Kuznetsov 
Signed-off-by: Paolo Bonzini

KVM: fix KVM_CLEAR_DIRTY_LOG for memory slots of unaligned size

2019-04-30T19:22:15+00:00

If a memory slot's size is not a multiple of 64 pages (256K), then
the KVM_CLEAR_DIRTY_LOG API is unusable: clearing the final 64 pages
either requires the requested page range to go beyond memslot->npages,
or requires log->num_pages to be unaligned, and kvm_clear_dirty_log_protect
requires log->num_pages to be both in range and aligned.

To allow this case, allow log->num_pages not to be a multiple of 64 if
it ends exactly on the last page of the slot.

Reported-by: Peter Xu 
Fixes: 98938aa8edd6 ("KVM: validate userspace input in kvm_clear_dirty_log_protect()", 2019-01-02)
Signed-off-by: Paolo Bonzini

selftests: kvm: add a selftest for SMM

2019-04-16T13:38:06+00:00

Add a simple test for SMM, based on VMX.  The test implements its own
sync between the guest and the host as using our ucall library seems to
be too cumbersome: SMI handler is happening in real-address mode.

This patch also fixes KVM_SET_NESTED_STATE to happen after
KVM_SET_VCPU_EVENTS, in fact it places it last.  This is because
KVM needs to know whether the processor is in SMM or not.

Signed-off-by: Vitaly Kuznetsov 
Signed-off-by: Paolo Bonzini

selftests: kvm: fix for compilers that do not support -no-pie

2019-04-16T13:38:05+00:00

-no-pie was added to GCC at the same time as their configuration option
--enable-default-pie.  Compilers that were built before do not have
-no-pie, but they also do not need it.  Detect the option at build
time.

Signed-off-by: Paolo Bonzini

selftests: kvm/evmcs_test: complete I/O before migrating guest state

2019-04-16T13:37:39+00:00

Starting state migration after an IO exit without first completing IO
may result in test failures.  We already have two tests that need this
(this patch in fact fixes evmcs_test, similar to what was fixed for
state_test in commit 0f73bbc851ed, "KVM: selftests: complete IO before
migrating guest state", 2019-03-13) and a third is coming.  So, move the
code to vcpu_save_state, and while at it do not access register state
until after I/O is complete.

Signed-off-by: Paolo Bonzini

KVM: selftests: complete IO before migrating guest state

2019-03-28T16:29:09+00:00

Documentation/virtual/kvm/api.txt states:

  NOTE: For KVM_EXIT_IO, KVM_EXIT_MMIO, KVM_EXIT_OSI, KVM_EXIT_PAPR and
        KVM_EXIT_EPR the corresponding operations are complete (and guest
        state is consistent) only after userspace has re-entered the
        kernel with KVM_RUN.  The kernel side will first finish incomplete
        operations and then check for pending signals.  Userspace can
        re-enter the guest with an unmasked signal pending to complete
        pending operations.

Because guest state may be inconsistent, starting state migration after
an IO exit without first completing IO may result in test failures, e.g.
a proposed change to KVM's handling of %rip in its fast PIO handling[1]
will cause the new VM, i.e. the post-migration VM, to have its %rip set
to the IN instruction that triggered KVM_EXIT_IO, leading to a test
assertion due to a stage mismatch.

For simplicitly, require KVM_CAP_IMMEDIATE_EXIT to complete IO and skip
the test if it's not available.  The addition of KVM_CAP_IMMEDIATE_EXIT
predates the state selftest by more than a year.

[1] https://patchwork.kernel.org/patch/10848545/

Fixes: fa3899add1056 ("kvm: selftests: add basic test for state save and restore")
Reported-by: Jim Mattson 
Signed-off-by: Sean Christopherson 
Signed-off-by: Paolo Bonzini

KVM: selftests: disable stack protector for all KVM tests

2019-03-28T16:29:08+00:00

Since 4.8.3, gcc has enabled -fstack-protector by default.  This is
problematic for the KVM selftests as they do not configure fs or gs
segments (the stack canary is pulled from fs:0x28).  With the default
behavior, gcc will insert a stack canary on any function that creates
buffers of 8 bytes or more.  As a result, ucall() will hit a triple
fault shutdown due to reading a bad fs segment when inserting its
stack canary, i.e. every test fails with an unexpected SHUTDOWN.

Fixes: 14c47b7530e2d ("kvm: selftests: introduce ucall")
Signed-off-by: Sean Christopherson 
Signed-off-by: Paolo Bonzini

KVM: selftests: explicitly disable PIE for tests

2019-03-28T16:29:07+00:00

KVM selftests embed the guest "image" as a function in the test itself
and extract the guest code at runtime by manually parsing the elf
headers.  The parsing is very simple and doesn't supporting fancy things
like position independent executables.  Recent versions of gcc enable
pie by default, which results in triple fault shutdowns in the guest due
to the virtual address in the headers not matching up with the virtual
address retrieved from the function pointer.

Signed-off-by: Sean Christopherson 
Signed-off-by: Paolo Bonzini

KVM: selftests: assert on exit reason in CR4/cpuid sync test

2019-03-28T16:29:05+00:00

...so that the test doesn't end up in an infinite loop if it fails for
whatever reason, e.g. SHUTDOWN due to gcc inserting stack canary code
into ucall() and attempting to derefence a null segment.

Fixes: ca359066889f7 ("kvm: selftests: add cr4_cpuid_sync_test")
Cc: Wei Huang 
Signed-off-by: Sean Christopherson 
Signed-off-by: Paolo Bonzini

selftests: kvm: add selftest for releasing VM file descriptor while in L2

2019-02-12T12:12:12+00:00

This adds a test for the previous bug.

Signed-off-by: Paolo Bonzini