linux-stable.git/tools/testing/selftests/kvm/lib, branch linux-5.15.y

selftests: kvm: set rax before vmcall

2022-08-17T12:23:59+00:00

[ Upstream commit 281106f938d3daaea6f8b6723a8217a2a1ef6936 ]

kvm_hypercall has to place the hypercall number in rax.

Trace events show that kvm_pv_test doesn't work properly:
     kvm_pv_test-53132: kvm_hypercall: nr 0x0 a0 0x0 a1 0x0 a2 0x0 a3 0x0
     kvm_pv_test-53132: kvm_hypercall: nr 0x0 a0 0x0 a1 0x0 a2 0x0 a3 0x0
     kvm_pv_test-53132: kvm_hypercall: nr 0x0 a0 0x0 a1 0x0 a2 0x0 a3 0x0

With this change, it starts working as expected:
     kvm_pv_test-54285: kvm_hypercall: nr 0x5 a0 0x0 a1 0x0 a2 0x0 a3 0x0
     kvm_pv_test-54285: kvm_hypercall: nr 0xa a0 0x0 a1 0x0 a2 0x0 a3 0x0
     kvm_pv_test-54285: kvm_hypercall: nr 0xb a0 0x0 a1 0x0 a2 0x0 a3 0x0

Signed-off-by: Andrei Vagin 
Message-Id: <20220722230241.1944655-5-avagin@google.com>
Fixes: ac4a4d6de22e ("selftests: kvm: test enforcement of paravirtual cpuid features")
Signed-off-by: Paolo Bonzini 
Signed-off-by: Sasha Levin

selftests: KVM: Handle compiler optimizations in ucall

2022-08-11T11:07:51+00:00

[ Upstream commit 9e2f6498efbbc880d7caa7935839e682b64fe5a6 ]

The selftests, when built with newer versions of clang, is found
to have over optimized guests' ucall() function, and eliminating
the stores for uc.cmd (perhaps due to no immediate readers). This
resulted in the userspace side always reading a value of '0', and
causing multiple test failures.

As a result, prevent the compiler from optimizing the stores in
ucall() with WRITE_ONCE().

Suggested-by: Ricardo Koller 
Suggested-by: Reiji Watanabe 
Signed-off-by: Raghavendra Rao Ananta 
Message-Id: <20220615185706.1099208-1-rananta@google.com>
Reviewed-by: Andrew Jones 
Signed-off-by: Paolo Bonzini 
Signed-off-by: Sasha Levin

kvm: selftests: do not use bitfields larger than 32-bits for PTEs

2022-05-12T10:30:24+00:00

[ Upstream commit f18b4aebe107d092e384b1ae680b1e1de7a0196d ]

Red Hat's QE team reported test failure on access_tracking_perf_test:

Testing guest mode: PA-bits:ANY, VA-bits:48,  4K pages
guest physical test memory offset: 0x3fffbffff000

Populating memory             : 0.684014577s
Writing to populated memory   : 0.006230175s
Reading from populated memory : 0.004557805s
==== Test Assertion Failure ====
  lib/kvm_util.c:1411: false
  pid=125806 tid=125809 errno=4 - Interrupted system call
     1  0x0000000000402f7c: addr_gpa2hva at kvm_util.c:1411
     2   (inlined by) addr_gpa2hva at kvm_util.c:1405
     3  0x0000000000401f52: lookup_pfn at access_tracking_perf_test.c:98
     4   (inlined by) mark_vcpu_memory_idle at access_tracking_perf_test.c:152
     5   (inlined by) vcpu_thread_main at access_tracking_perf_test.c:232
     6  0x00007fefe9ff81ce: ?? ??:0
     7  0x00007fefe9c64d82: ?? ??:0
  No vm physical memory at 0xffbffff000

I can easily reproduce it with a Intel(R) Xeon(R) CPU E5-2630 with 46 bits
PA.

It turns out that the address translation for clearing idle page tracking
returned a wrong result; addr_gva2gpa()'s last step, which is based on
"pte[index[0]].pfn", did the calculation with 40 bits length and the
high 12 bits got truncated.  In above case the GPA address to be returned
should be 0x3fffbffff000 for GVA 0xc0000000, but it got truncated into
0xffbffff000 and the subsequent gpa2hva lookup failed.

The width of operations on bit fields greater than 32-bit is
implementation defined, and differs between GCC (which uses the bitfield
precision) and clang (which uses 64-bit arithmetic), so this is a
potential minefield.  Remove the bit fields and using manual masking
instead.

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2075036
Reported-by: Nana Liu 
Reviewed-by: Peter Xu 
Tested-by: Peter Xu 
Signed-off-by: Paolo Bonzini 
Signed-off-by: Sasha Levin

selftests: KVM: Fix non-x86 compiling

2021-12-29T11:28:37+00:00

commit 577e022b7b41854911dcfb03678d8d2b930e8a3f upstream.

Attempting to compile on a non-x86 architecture fails with

include/kvm_util.h: In function â€˜vm_compute_max_gfnâ€™:
include/kvm_util.h:79:21: error: dereferencing pointer to incomplete type â€˜struct kvm_vmâ€™
  return ((1ULL << vm->pa_bits) >> vm->page_shift) - 1;
                     ^~

This is because the declaration of struct kvm_vm is in
lib/kvm_util_internal.h as an effort to make it private to
the test lib code. We can still provide arch specific functions,
though, by making the generic function symbols weak. Do that to
fix the compile error.

Fixes: c8cc43c1eae2 ("selftests: KVM: avoid failures due to reserved HyperTransport region")
Cc: stable@vger.kernel.org
Signed-off-by: Andrew Jones 
Message-Id: <20211214151842.848314-1-drjones@redhat.com>
Signed-off-by: Paolo Bonzini 
Signed-off-by: Greg Kroah-Hartman

selftests: KVM: avoid failures due to reserved HyperTransport region

2021-12-14T09:57:14+00:00

commit c8cc43c1eae2910ac96daa4216e0fb3391ad0504 upstream.

AMD proceessors define an address range that is reserved by HyperTransport
and causes a failure if used for guest physical addresses.  Avoid
selftests failures by reserving those guest physical addresses; the
rules are:

- On parts with <40 bits, its fully hidden from software.

- Before Fam17h, it was always 12G just below 1T, even if there was more
RAM above this location.  In this case we just not use any RAM above 1T.

- On Fam17h and later, it is variable based on SME, and is either just
below 2^48 (no encryption) or 2^43 (encryption).

Fixes: ef4c9f4f6546 ("KVM: selftests: Fix 32-bit truncation of vm_get_max_gfn()")
Cc: stable@vger.kernel.org
Cc: David Matlack 
Reported-by: Maxim Levitsky 
Signed-off-by: Paolo Bonzini 
Message-Id: <20210805105423.412878-1-pbonzini@redhat.com>
Reviewed-by: Sean Christopherson 
Tested-by: Sean Christopherson 
Signed-off-by: Paolo Bonzini 
Signed-off-by: Greg Kroah-Hartman

KVM: selftests: Fix nested SVM tests when built with clang

2021-11-18T18:16:39+00:00

[ Upstream commit ed290e1c20da19fa100a3e0f421aa31b65984960 ]

Though gcc conveniently compiles a simple memset to "rep stos," clang
prefers to call the libc version of memset. If a test is dynamically
linked, the libc memset isn't available in L1 (nor is the PLT or the
GOT, for that matter). Even if the test is statically linked, the libc
memset may choose to use some CPU features, like AVX, which may not be
enabled in L1. Note that __builtin_memset doesn't solve the problem,
because (a) the compiler is free to call memset anyway, and (b)
__builtin_memset may also choose to use features like AVX, which may
not be available in L1.

To avoid a myriad of problems, use an explicit "rep stos" to clear the
VMCB in generic_svm_setup(), which is called both from L0 and L1.

Reported-by: Ricardo Koller 
Signed-off-by: Jim Mattson 
Fixes: 20ba262f8631a ("selftests: KVM: AMD Nested test infrastructure")
Message-Id: <20210930003649.4026553-1-jmattson@google.com>
Signed-off-by: Paolo Bonzini 
Signed-off-by: Sasha Levin

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2021-09-27T20:58:23+00:00

Pull kvm fixes from Paolo Bonzini:
 "A bit late... I got sidetracked by back-from-vacation routines and
  conferences. But most of these patches are already a few weeks old and
  things look more calm on the mailing list than what this pull request
  would suggest.

  x86:

   - missing TLB flush

   - nested virtualization fixes for SMM (secure boot on nested
     hypervisor) and other nested SVM fixes

   - syscall fuzzing fixes

   - live migration fix for AMD SEV

   - mirror VMs now work for SEV-ES too

   - fixes for reset

   - possible out-of-bounds access in IOAPIC emulation

   - fix enlightened VMCS on Windows 2022

  ARM:

   - Add missing FORCE target when building the EL2 object

   - Fix a PMU probe regression on some platforms

  Generic:

   - KCSAN fixes

  selftests:

   - random fixes, mostly for clang compilation"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (43 commits)
  selftests: KVM: Explicitly use movq to read xmm registers
  selftests: KVM: Call ucall_init when setting up in rseq_test
  KVM: Remove tlbs_dirty
  KVM: X86: Synchronize the shadow pagetable before link it
  KVM: X86: Fix missed remote tlb flush in rmap_write_protect()
  KVM: x86: nSVM: don't copy virt_ext from vmcb12
  KVM: x86: nSVM: test eax for 4K alignment for GP errata workaround
  KVM: x86: selftests: test simultaneous uses of V_IRQ from L1 and L0
  KVM: x86: nSVM: restore int_vector in svm_clear_vintr
  kvm: x86: Add AMD PMU MSRs to msrs_to_save_all[]
  KVM: x86: nVMX: re-evaluate emulation_required on nested VM exit
  KVM: x86: nVMX: don't fail nested VM entry on invalid guest state if !from_vmentry
  KVM: x86: VMX: synthesize invalid VM exit when emulating invalid guest state
  KVM: x86: nSVM: refactor svm_leave_smm and smm_enter_smm
  KVM: x86: SVM: call KVM_REQ_GET_NESTED_STATE_PAGES on exit from SMM mode
  KVM: x86: reset pdptrs_from_userspace when exiting smm
  KVM: x86: nSVM: restore the L1 host state prior to resuming nested guest on SMM exit
  KVM: nVMX: Filter out all unsupported controls when eVMCS was activated
  KVM: KVM: Use cpumask_available() to check for NULL cpumask when kicking vCPUs
  KVM: Clean up benign vcpu->cpu data races when kicking vCPUs
  ...

KVM: selftests: Refactor help message for -s backing_src

2021-09-22T14:33:14+00:00

All selftests that support the backing_src option were printing their
own description of the flag and then calling backing_src_help() to dump
the list of available backing sources. Consolidate the flag printing in
backing_src_help() to align indentation, reduce duplicated strings, and
improve consistency across tests.

Note: Passing "-s" to backing_src_help is unnecessary since every test
uses the same flag. However I decided to keep it for code readability
at the call sites.

While here this opportunistically fixes the incorrectly interleaved
printing -x help message and list of backing source types in
dirty_log_perf_test.

Fixes: 609e6202ea5f ("KVM: selftests: Support multiple slots in dirty_log_perf_test")
Reviewed-by: Ben Gardon 
Reviewed-by: Andrew Jones 
Signed-off-by: David Matlack 
Message-Id: <20210917173657.44011-3-dmatlack@google.com>
Signed-off-by: Paolo Bonzini

selftests: kvm: fix get_run_delay() ignoring fscanf() return warn

2021-09-16T18:57:32+00:00

Fix get_run_delay() to check fscanf() return value to get rid of the
following warning. When fscanf() fails return MIN_RUN_DELAY_NS from
get_run_delay(). Move MIN_RUN_DELAY_NS from steal_time.c to test_util.h
so get_run_delay() and steal_time.c can use it.

lib/test_util.c: In function ‘get_run_delay’:
lib/test_util.c:316:2: warning: ignoring return value of ‘fscanf’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
  316 |  fscanf(fp, "%ld %ld ", &val[0], &val[1]);
      |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Shuah Khan 
Acked-by: Paolo Bonzini 
Signed-off-by: Shuah Khan

selftests: kvm: move get_run_delay() into lib/test_util

2021-09-16T18:57:26+00:00

get_run_delay() is defined static in xen_shinfo_test and steal_time test.
Move it to lib and remove code duplication.

Signed-off-by: Shuah Khan 
Acked-by: Paolo Bonzini 
Signed-off-by: Shuah Khan