<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-dev/tools/testing/selftests/kvm/lib/x86_64, branch linus/master</title>
<subtitle>Linux kernel development work - see feature branches</subtitle>
<id>https://git.zx2c4.com/linux-dev/atom/tools/testing/selftests/kvm/lib/x86_64?h=linus%2Fmaster</id>
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<updated>2022-06-09T14:52:27Z</updated>
<entry>
<title>KVM: selftests: Add option to run dirty_log_perf_test vCPUs in L2</title>
<updated>2022-06-09T14:52:27Z</updated>
<author>
<name>David Matlack</name>
<email>dmatlack@google.com</email>
</author>
<published>2022-05-20T23:32:48Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=71d489661904fcc3ec31b343acd5c0dac84b5410'/>
<id>urn:sha1:71d489661904fcc3ec31b343acd5c0dac84b5410</id>
<content type='text'>
Add an option to dirty_log_perf_test that configures the vCPUs to run in
L2 instead of L1. This makes it possible to benchmark the dirty logging
performance of nested virtualization, which is particularly interesting
because KVM must shadow L1's EPT/NPT tables.

For now this support only works on x86_64 CPUs with VMX. Otherwise
passing -n results in the test being skipped.

Signed-off-by: David Matlack &lt;dmatlack@google.com&gt;
Message-Id: &lt;20220520233249.3776001-11-dmatlack@google.com&gt;
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
</content>
</entry>
<entry>
<title>KVM: selftests: Add a helper to check EPT/VPID capabilities</title>
<updated>2022-06-09T14:52:24Z</updated>
<author>
<name>David Matlack</name>
<email>dmatlack@google.com</email>
</author>
<published>2022-05-20T23:32:44Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=c363d95986b1b930947305e2372665141721d15f'/>
<id>urn:sha1:c363d95986b1b930947305e2372665141721d15f</id>
<content type='text'>
Create a small helper function to check if a given EPT/VPID capability
is supported. This will be re-used in a follow-up commit to check for 1G
page support.

No functional change intended.

Reviewed-by: Peter Xu &lt;peterx@redhat.com&gt;
Signed-off-by: David Matlack &lt;dmatlack@google.com&gt;
Message-Id: &lt;20220520233249.3776001-7-dmatlack@google.com&gt;
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
</content>
</entry>
<entry>
<title>KVM: selftests: Refactor nested_map() to specify target level</title>
<updated>2022-06-09T14:52:23Z</updated>
<author>
<name>David Matlack</name>
<email>dmatlack@google.com</email>
</author>
<published>2022-05-20T23:32:42Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=ce690e9c17d27486af879defc506679cbbb14777'/>
<id>urn:sha1:ce690e9c17d27486af879defc506679cbbb14777</id>
<content type='text'>
Refactor nested_map() to specify that it explicityl wants 4K mappings
(the existing behavior) and push the implementation down into
__nested_map(), which can be used in subsequent commits to create huge
page mappings.

No function change intended.

Reviewed-by: Peter Xu &lt;peterx@redhat.com&gt;
Signed-off-by: David Matlack &lt;dmatlack@google.com&gt;
Message-Id: &lt;20220520233249.3776001-5-dmatlack@google.com&gt;
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
</content>
</entry>
<entry>
<title>KVM: selftests: Drop stale function parameter comment for nested_map()</title>
<updated>2022-06-09T14:52:23Z</updated>
<author>
<name>David Matlack</name>
<email>dmatlack@google.com</email>
</author>
<published>2022-05-20T23:32:41Z</published>
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<id>urn:sha1:b8ca01ea19068b54938ebb4ebc06814a89dee8ea</id>
<content type='text'>
nested_map() does not take a parameter named eptp_memslot. Drop the
comment referring to it.

Reviewed-by: Peter Xu &lt;peterx@redhat.com&gt;
Signed-off-by: David Matlack &lt;dmatlack@google.com&gt;
Message-Id: &lt;20220520233249.3776001-4-dmatlack@google.com&gt;
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
</content>
</entry>
<entry>
<title>KVM: selftests: Add option to create 2M and 1G EPT mappings</title>
<updated>2022-06-09T14:52:22Z</updated>
<author>
<name>David Matlack</name>
<email>dmatlack@google.com</email>
</author>
<published>2022-05-20T23:32:40Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=c5a0ccec4cb4edde8e5b7e369dbe4d169b111e42'/>
<id>urn:sha1:c5a0ccec4cb4edde8e5b7e369dbe4d169b111e42</id>
<content type='text'>
The current EPT mapping code in the selftests only supports mapping 4K
pages. This commit extends that support with an option to map at 2M or
1G. This will be used in a future commit to create large page mappings
to test eager page splitting.

No functional change intended.

Signed-off-by: David Matlack &lt;dmatlack@google.com&gt;
Message-Id: &lt;20220520233249.3776001-3-dmatlack@google.com&gt;
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
</content>
</entry>
<entry>
<title>KVM: selftests: Replace x86_page_size with PG_LEVEL_XX</title>
<updated>2022-06-09T14:52:22Z</updated>
<author>
<name>David Matlack</name>
<email>dmatlack@google.com</email>
</author>
<published>2022-05-20T23:32:39Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=4ee602e78d706e740a48be9b6ddb239df4a113b5'/>
<id>urn:sha1:4ee602e78d706e740a48be9b6ddb239df4a113b5</id>
<content type='text'>
x86_page_size is an enum used to communicate the desired page size with
which to map a range of memory. Under the hood they just encode the
desired level at which to map the page. This ends up being clunky in a
few ways:

 - The name suggests it encodes the size of the page rather than the
   level.
 - In other places in x86_64/processor.c we just use a raw int to encode
   the level.

Simplify this by adopting the kernel style of PG_LEVEL_XX enums and pass
around raw ints when referring to the level. This makes the code easier
to understand since these macros are very common in KVM MMU code.

Signed-off-by: David Matlack &lt;dmatlack@google.com&gt;
Message-Id: &lt;20220520233249.3776001-2-dmatlack@google.com&gt;
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
</content>
</entry>
<entry>
<title>kvm: selftests: introduce and use more page size-related constants</title>
<updated>2022-04-21T19:41:01Z</updated>
<author>
<name>Paolo Bonzini</name>
<email>pbonzini@redhat.com</email>
</author>
<published>2022-04-20T10:27:27Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=e852be8b148e117e25be1c98cf72ee489b05919e'/>
<id>urn:sha1:e852be8b148e117e25be1c98cf72ee489b05919e</id>
<content type='text'>
Clean up code that was hardcoding masks for various fields,
now that the masks are included in processor.h.

For more cleanup, define PAGE_SIZE and PAGE_MASK just like in Linux.
PAGE_SIZE in particular was defined by several tests.

Suggested-by: Sean Christopherson &lt;seanjc@google.com&gt;
Reviewed-by: Peter Xu &lt;peterx@redhat.com&gt;
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
</content>
</entry>
<entry>
<title>kvm: selftests: do not use bitfields larger than 32-bits for PTEs</title>
<updated>2022-04-21T19:41:01Z</updated>
<author>
<name>Paolo Bonzini</name>
<email>pbonzini@redhat.com</email>
</author>
<published>2022-04-20T10:27:27Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=f18b4aebe107d092e384b1ae680b1e1de7a0196d'/>
<id>urn:sha1:f18b4aebe107d092e384b1ae680b1e1de7a0196d</id>
<content type='text'>
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 &lt;nanliu@redhat.com&gt;
Reviewed-by: Peter Xu &lt;peterx@redhat.com&gt;
Tested-by: Peter Xu &lt;peterx@redhat.com&gt;
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
</content>
</entry>
<entry>
<title>KVM: selftests: nSVM: Set up MSR-Bitmap for SVM guests</title>
<updated>2022-02-10T18:50:47Z</updated>
<author>
<name>Vitaly Kuznetsov</name>
<email>vkuznets@redhat.com</email>
</author>
<published>2022-02-03T10:46:18Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=0b815117da63ba71e06faffc7b9b43e49b08bfea'/>
<id>urn:sha1:0b815117da63ba71e06faffc7b9b43e49b08bfea</id>
<content type='text'>
Similar to VMX, allocate memory for MSR-Bitmap and fill in 'msrpm_base_pa'
in VMCB. To use it, tests will need to set INTERCEPT_MSR_PROT interception
along with the required bits in the MSR-Bitmap.

Signed-off-by: Vitaly Kuznetsov &lt;vkuznets@redhat.com&gt;
Message-Id: &lt;20220203104620.277031-5-vkuznets@redhat.com&gt;
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
</content>
</entry>
<entry>
<title>selftests: kvm: check dynamic bits against KVM_X86_XCOMP_GUEST_SUPP</title>
<updated>2022-01-28T12:38:25Z</updated>
<author>
<name>Paolo Bonzini</name>
<email>pbonzini@redhat.com</email>
</author>
<published>2022-01-26T12:51:00Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=b19c99b9f4486f23e3b7248dd4ce3d83e19b9032'/>
<id>urn:sha1:b19c99b9f4486f23e3b7248dd4ce3d83e19b9032</id>
<content type='text'>
Provide coverage for the new API.

Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
</content>
</entry>
</feed>
