linux-stable.git/tools/testing/selftests/kvm/lib, branch v5.13.2

KVM: selftests: fix triple fault if ept=0 in dirty_log_test

2021-07-14T15:06:49+00:00

[ Upstream commit e5830fb13b8cad5e3bdf84f0f7a3dcb4f4d9bcbb ]

Commit 22f232d134e1 ("KVM: selftests: x86: Set supported CPUIDs on
default VM") moved vcpu_set_cpuid into vm_create_with_vcpus, but
dirty_log_test doesn't use it to create vm. So vcpu's CPUIDs is
not set, the guest's pa_bits in kvm would be smaller than the
value queried by userspace.

However, the dirty track memory slot is in the highest GPA, the
reserved bits in gpte would be set with wrong pa_bits.
For shadow paging, page fault would fail in permission_fault and
be injected into guest. Since guest doesn't have idt, it finally
leads to vm_exit for triple fault.

Move vcpu_set_cpuid into vm_vcpu_add_default to set supported
CPUIDs on default vcpu, since almost all tests need it.

Fixes: 22f232d134e1 ("KVM: selftests: x86: Set supported CPUIDs on default VM")
Signed-off-by: Hou Wenlong 
Message-Id: <411ea2173f89abce56fc1fca5af913ed9c5a89c9.1624351343.git.houwenlong93@linux.alibaba.com>
Signed-off-by: Paolo Bonzini 
Signed-off-by: Sasha Levin

KVM: selftests: Fix kvm_check_cap() assertion

2021-06-17T17:06:57+00:00

KVM_CHECK_EXTENSION ioctl can return any negative value on error,
and not necessarily -1. Change the assertion to reflect that.

Signed-off-by: Fuad Tabba 
Message-Id: <20210615150443.1183365-1-tabba@google.com>
Signed-off-by: Paolo Bonzini

KVM: selftests: Fix compiling errors when initializing the static structure

2021-06-10T11:46:10+00:00

Errors like below were produced from test_util.c when compiling the KVM
selftests on my local platform.

lib/test_util.c: In function 'vm_mem_backing_src_alias':
lib/test_util.c:177:12: error: initializer element is not constant
    .flag = anon_flags,
            ^~~~~~~~~~
lib/test_util.c:177:12: note: (near initialization for 'aliases[0].flag')

The reason is that we are using non-const expressions to initialize the
static structure, which will probably trigger a compiling error/warning
on stricter GCC versions. Fix it by converting the two const variables
"anon_flags" and "anon_huge_flags" into more stable macros.

Fixes: b3784bc28ccc0 ("KVM: selftests: refactor vm_mem_backing_src_type flags")
Reported-by: Zenghui Yu 
Signed-off-by: Yanan Wang 
Message-Id: <20210610085418.35544-1-wangyanan55@huawei.com>
Signed-off-by: Paolo Bonzini

selftests: kvm: Add support for customized slot0 memory size

2021-06-08T17:29:10+00:00

Until commit 39fe2fc96694 ("selftests: kvm: make allocation of extra
memory take effect", 2021-05-27), parameter extra_mem_pages was used
only to calculate the page table size for all the memory chunks,
because real memory allocation happened with calls of
vm_userspace_mem_region_add() after vm_create_default().

Commit 39fe2fc96694 however changed the meaning of extra_mem_pages to
the size of memory slot 0.  This makes the memory allocation more
flexible, but makes it harder to account for the number of
pages needed for the page tables.  For example, memslot_perf_test
has a small amount of memory in slot 0 but a lot in other slots,
and adding that memory twice (both in slot 0 and with later
calls to vm_userspace_mem_region_add()) causes an error that
was fixed in commit 000ac4295339 ("selftests: kvm: fix overlapping
addresses in memslot_perf_test", 2021-05-29)

Since both uses are sensible, add a new parameter slot0_mem_pages
to vm_create_with_vcpus() and some comments to clarify the meaning of
slot0_mem_pages and extra_mem_pages.  With this change,
memslot_perf_test can go back to passing the number of memory
pages as extra_mem_pages.

Signed-off-by: Zhenzhong Duan 
Message-Id: <20210608233816.423958-4-zhenzhong.duan@intel.com>
[Squashed in a single patch and rewrote the commit message. - Paolo]
Signed-off-by: Paolo Bonzini

KVM: selftests: introduce P47V64 for s390x

2021-06-08T17:19:19+00:00

s390x can have up to 47bits of physical guest and 64bits of virtual
address  bits. Add a new address mode to avoid errors of testcases
going beyond 47bits.

Signed-off-by: Christian Borntraeger 
Message-Id: <20210608123954.10991-1-borntraeger@de.ibm.com>
Fixes: ef4c9f4f6546 ("KVM: selftests: Fix 32-bit truncation of vm_get_max_gfn()")
Cc: stable@vger.kernel.org
Reviewed-by: David Matlack 
Signed-off-by: Paolo Bonzini

KVM: selftests: add shared hugetlbfs backing source type

2021-05-27T11:45:57+00:00

This lets us run the demand paging test on top of a shared
hugetlbfs-backed area. The "shared" is key, as this allows us to
exercise userfaultfd minor faults on hugetlbfs.

Signed-off-by: Axel Rasmussen 
Message-Id: <20210519200339.829146-11-axelrasmussen@google.com>
Reviewed-by: Ben Gardon 
Signed-off-by: Paolo Bonzini

KVM: selftests: create alias mappings when using shared memory

2021-05-27T11:45:56+00:00

When a memory region is added with a src_type specifying that it should
use some kind of shared memory, also create an alias mapping to the same
underlying physical pages.

And, add an API so tests can get access to these alias addresses.
Basically, for a guest physical address, let us look up the analogous
host *alias* address.

In a future commit, we'll modify the demand paging test to take
advantage of this to exercise UFFD minor faults. The idea is, we
pre-fault the underlying pages *via the alias*. When the *guest*
faults, it gets a "minor" fault (PTEs don't exist yet, but a page is
already in the page cache). Then, the userfaultfd theads can handle the
fault: they could potentially modify the underlying memory *via the
alias* if they wanted to, and then they install the PTEs and let the
guest carry on via a UFFDIO_CONTINUE ioctl.

Reviewed-by: Ben Gardon 
Signed-off-by: Axel Rasmussen 
Message-Id: <20210519200339.829146-9-axelrasmussen@google.com>
Signed-off-by: Paolo Bonzini

KVM: selftests: add shmem backing source type

2021-05-27T11:45:56+00:00

This lets us run the demand paging test on top of a shmem-backed area.
In follow-up commits, we'll 1) leverage this new capability to create an
alias mapping, and then 2) use the alias mapping to exercise UFFD minor
faults.

Signed-off-by: Axel Rasmussen 
Message-Id: <20210519200339.829146-8-axelrasmussen@google.com>
Signed-off-by: Paolo Bonzini

KVM: selftests: refactor vm_mem_backing_src_type flags

2021-05-27T11:45:56+00:00

Each struct vm_mem_backing_src_alias has a flags field, which denotes
the flags used to mmap() an area of that type. Previously, this field
never included MAP_PRIVATE | MAP_ANONYMOUS, because
vm_userspace_mem_region_add assumed that *all* types would always use
those flags, and so it hardcoded them.

In a follow-up commit, we'll add a new type: shmem. Areas of this type
must not have MAP_PRIVATE | MAP_ANONYMOUS, and instead they must have
MAP_SHARED.

So, refactor things. Make it so that the flags field of
struct vm_mem_backing_src_alias really is a complete set of flags, and
don't add in any extras in vm_userspace_mem_region_add. This will let us
easily tack on shmem.

Signed-off-by: Axel Rasmussen 
Message-Id: <20210519200339.829146-7-axelrasmussen@google.com>
Signed-off-by: Paolo Bonzini

KVM: selftests: Print a message if /dev/kvm is missing

2021-05-27T11:45:55+00:00

If a KVM selftest is run on a machine without /dev/kvm, it will exit
silently. Make it easy to tell what's happening by printing an error
message.

Opportunistically consolidate all codepaths that open /dev/kvm into a
single function so they all print the same message.

This slightly changes the semantics of vm_is_unrestricted_guest() by
changing a TEST_ASSERT() to exit(KSFT_SKIP). However
vm_is_unrestricted_guest() is only called in one place
(x86_64/mmio_warning_test.c) and that is to determine if the test should
be skipped or not.

Signed-off-by: David Matlack 
Message-Id: <20210511202120.1371800-1-dmatlack@google.com>
Signed-off-by: Paolo Bonzini