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

selftests: kvm: Fix a compile error in selftests/kvm/rseq_test.c

2023-01-18T10:48:47+00:00

commit 561cafebb2cf97b0927b4fb0eba22de6200f682e upstream.

The following warning appears when executing:
	make -C tools/testing/selftests/kvm

rseq_test.c: In function ‘main’:
rseq_test.c:237:33: warning: implicit declaration of function ‘gettid’; did you mean ‘getgid’? [-Wimplicit-function-declaration]
          (void *)(unsigned long)gettid());
                                 ^~~~~~
                                 getgid
/usr/bin/ld: /tmp/ccr5mMko.o: in function `main':
../kvm/tools/testing/selftests/kvm/rseq_test.c:237: undefined reference to `gettid'
collect2: error: ld returned 1 exit status
make: *** [../lib.mk:173: ../kvm/tools/testing/selftests/kvm/rseq_test] Error 1

Use the more compatible syscall(SYS_gettid) instead of gettid() to fix it.
More subsequent reuse may cause it to be wrapped in a lib file.

Signed-off-by: Jinrong Liang 
Message-Id: <20220802071240.84626-1-cloudliang@tencent.com>
Signed-off-by: Paolo Bonzini 
Cc: Harshit Mogalapalli 
Signed-off-by: Greg Kroah-Hartman

KVM: selftests: Fix build regression by using accessor function

2022-12-31T12:14:44+00:00

Fix the stable backport of commit 05c2224d4b04 ("KVM: selftests: Fix
number of pages for memory slot in memslot_modification_stress_test"),
which caused memslot_modification_stress_test.c build failures due to
trying to access private members of struct kvm_vm.

v6.0 commit b530eba14c70 ("KVM: selftests: Get rid of
kvm_util_internal.h") and some other commits got rid of the accessors
and made all of the KVM data structures public. Keep using the accessors
in older kernels.

There is no corresponding upstream commit for this change.

Signed-off-by: Tyler Hicks (Microsoft) 
Signed-off-by: Sasha Levin

KVM: selftests: Fix number of pages for memory slot in memslot_modification_stress_test

2022-11-03T14:59:15+00:00

[ Upstream commit 05c2224d4b049406b0545a10be05280ff4b8ba0a ]

It's required by vm_userspace_mem_region_add() that memory size
should be aligned to host page size. However, one guest page is
provided by memslot_modification_stress_test. It triggers failure
in the scenario of 64KB-page-size-host and 4KB-page-size-guest,
as the following messages indicate.

 # ./memslot_modification_stress_test
 Testing guest mode: PA-bits:40,  VA-bits:48,  4K pages
 guest physical test memory: [0xffbfff0000, 0xffffff0000)
 Finished creating vCPUs
 Started all vCPUs
 ==== Test Assertion Failure ====
   lib/kvm_util.c:824: vm_adjust_num_guest_pages(vm->mode, npages) == npages
   pid=5712 tid=5712 errno=0 - Success
      1	0x0000000000404eeb: vm_userspace_mem_region_add at kvm_util.c:822
      2	0x0000000000401a5b: add_remove_memslot at memslot_modification_stress_test.c:82
      3	 (inlined by) run_test at memslot_modification_stress_test.c:110
      4	0x0000000000402417: for_each_guest_mode at guest_modes.c:100
      5	0x00000000004016a7: main at memslot_modification_stress_test.c:187
      6	0x0000ffffb8cd4383: ?? ??:0
      7	0x0000000000401827: _start at :?
   Number of guest pages is not compatible with the host. Try npages=16

Fix the issue by providing 16 guest pages to the memory slot for this
particular combination of 64KB-page-size-host and 4KB-page-size-guest
on aarch64.

Fixes: ef4c9f4f65462 ("KVM: selftests: Fix 32-bit truncation of vm_get_max_gfn()")
Signed-off-by: Gavin Shan 
Signed-off-by: Marc Zyngier 
Link: https://lore.kernel.org/r/20221013063020.201856-1-gshan@redhat.com
Signed-off-by: Sasha Levin

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: Make hyperv_clock selftest more stable

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

[ Upstream commit eae260be3a0111a28fe95923e117a55dddec0384 ]

hyperv_clock doesn't always give a stable test result, especially with
AMD CPUs. The test compares Hyper-V MSR clocksource (acquired either
with rdmsr() from within the guest or KVM_GET_MSRS from the host)
against rdtsc(). To increase the accuracy, increase the measured delay
(done with nop loop) by two orders of magnitude and take the mean rdtsc()
value before and after rdmsr()/KVM_GET_MSRS.

Reported-by: Maxim Levitsky 
Signed-off-by: Vitaly Kuznetsov 
Reviewed-by: Maxim Levitsky 
Tested-by: Maxim Levitsky 
Message-Id: <20220601144322.1968742-1-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini 
Signed-off-by: Sasha Levin

KVM: selftests: Fix target thread to be migrated in rseq_test

2022-07-29T15:25:23+00:00

commit e923b0537d28e15c9d31ce8b38f810b325816903 upstream.

In rseq_test, there are two threads, which are vCPU thread and migration
worker separately. Unfortunately, the test has the wrong PID passed to
sched_setaffinity() in the migration worker. It forces migration on the
migration worker because zeroed PID represents the calling thread, which
is the migration worker itself. It means the vCPU thread is never enforced
to migration and it can migrate at any time, which eventually leads to
failure as the following logs show.

  host# uname -r
  5.19.0-rc6-gavin+
  host# # cat /proc/cpuinfo | grep processor | tail -n 1
  processor    : 223
  host# pwd
  /home/gavin/sandbox/linux.main/tools/testing/selftests/kvm
  host# for i in `seq 1 100`; do \
        echo "--------> $i"; ./rseq_test; done
  --------> 1
  --------> 2
  --------> 3
  --------> 4
  --------> 5
  --------> 6
  ==== Test Assertion Failure ====
    rseq_test.c:265: rseq_cpu == cpu
    pid=3925 tid=3925 errno=4 - Interrupted system call
       1  0x0000000000401963: main at rseq_test.c:265 (discriminator 2)
       2  0x0000ffffb044affb: ?? ??:0
       3  0x0000ffffb044b0c7: ?? ??:0
       4  0x0000000000401a6f: _start at ??:?
    rseq CPU = 4, sched CPU = 27

Fix the issue by passing correct parameter, TID of the vCPU thread, to
sched_setaffinity() in the migration worker.

Fixes: 61e52f1630f5 ("KVM: selftests: Add a test for KVM_RUN+rseq to detect task migration bugs")
Suggested-by: Sean Christopherson 
Signed-off-by: Gavin Shan 
Reviewed-by: Oliver Upton 
Message-Id: <20220719020830.3479482-1-gshan@redhat.com>
Reviewed-by: Andrew Jones 
Signed-off-by: Paolo Bonzini 
Signed-off-by: Greg Kroah-Hartman

KVM: selftests: Silence compiler warning in the kvm_page_table_test

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

[ Upstream commit 266a19a0bc4fbfab4d981a47640ca98972a01865 ]

When compiling kvm_page_table_test.c, I get this compiler warning
with gcc 11.2:

kvm_page_table_test.c: In function 'pre_init_before_test':
../../../../tools/include/linux/kernel.h:44:24: warning: comparison of
 distinct pointer types lacks a cast
   44 |         (void) (&_max1 == &_max2);              \
      |                        ^~
kvm_page_table_test.c:281:21: note: in expansion of macro 'max'
  281 |         alignment = max(0x100000, alignment);
      |                     ^~~

Fix it by adjusting the type of the absolute value.

Signed-off-by: Thomas Huth 
Reviewed-by: Claudio Imbrenda 
Message-Id: <20220414103031.565037-1-thuth@redhat.com>
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

KVM: selftests: Don't skip L2's VMCALL in SMM test for SVM guest

2022-02-01T16:27:14+00:00

[ Upstream commit 4cf3d3ebe8794c449af3e0e8c1d790c97e461d20 ]

Don't skip the vmcall() in l2_guest_code() prior to re-entering L2, doing
so will result in L2 running to completion, popping '0' off the stack for
RET, jumping to address '0', and ultimately dying with a triple fault
shutdown.

It's not at all obvious why the test re-enters L2 and re-executes VMCALL,
but presumably it serves a purpose.  The VMX path doesn't skip vmcall(),
and the test can't possibly have passed on SVM, so just do what VMX does.

Fixes: d951b2210c1a ("KVM: selftests: smm_test: Test SMM enter from L2")
Cc: Maxim Levitsky 
Signed-off-by: Sean Christopherson 
Message-Id: <20220125221725.2101126-1-seanjc@google.com>
Reviewed-by: Vitaly Kuznetsov 
Tested-by: Vitaly Kuznetsov 
Signed-off-by: Paolo Bonzini 
Signed-off-by: Sasha Levin