Rename emulator_error_test to smaller_maxphyaddr_emulation_test and
update the comment at the top of the file to document that this is
explicitly a test to validate that KVM emulates instructions in response
to an EPT violation when emulating a smaller MAXPHYADDR.
Signed-off-by: David Matlack <dmatlack@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221102184654.282799-2-dmatlack@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Drop the reserved bit checks from the helper to retrieve a PTE, there's
very little value in sanity checking the constructed page tables as any
will quickly be noticed in the form of an unexpected #PF. The checks
also place unnecessary restrictions on the usage of the helpers, e.g. if
a test _wanted_ to set reserved bits for whatever reason.
Removing the NX check in particular allows for the removal of the @vcpu
param, which will in turn allow the helper to be reused nearly verbatim
for addr_gva2gpa().
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221006004512.666529-3-seanjc@google.com
Drop vm_{g,s}et_page_table_entry() and instead expose the "inner"
helper (was _vm_get_page_table_entry()) that returns a _pointer_ to the
PTE, i.e. let tests directly modify PTEs instead of bouncing through
helpers that just make life difficult.
Opportunsitically use BIT_ULL() in emulator_error_test, and use the
MAXPHYADDR define to set the "rogue" GPA bit instead of open coding the
same value.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221006004512.666529-2-seanjc@google.com
Many KVM selftests take command line arguments which are supposed to be
positive (>0) or non-negative (>=0). Some tests do these validation and
some missed adding the check.
Add atoi_positive() and atoi_non_negative() to validate inputs in
selftests before proceeding to use those values.
Signed-off-by: Vipin Sharma <vipinsh@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221103191719.1559407-7-vipinsh@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
When using the flags in KVM_X86_SET_MSR_FILTER and
KVM_CAP_X86_USER_SPACE_MSR it is expected that an attempt to write to
any of the unused bits will fail. Add testing to walk over every bit
in each of the flag fields in MSR filtering and MSR exiting to verify
that unused bits return and error and used bits, i.e. valid bits,
succeed.
Signed-off-by: Aaron Lewis <aaronlewis@google.com>
Message-Id: <20220921151525.904162-6-aaronlewis@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Some users of KVM implement the UEFI variable store through a paravirtual device
that does not require the "SMM lockbox" component of edk2; allow them to
compile out system management mode, which is not a full implementation
especially in how it interacts with nested virtualization.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20220929172016.319443-6-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Tag "guest_saw_irq" as "volatile" to ensure that the compiler will never
optimize away lookups. Relying on the compiler thinking that the flag
is global and thus might change also works, but it's subtle, less robust,
and looks like a bug at first glance, e.g. risks being "fixed" and
breaking the test.
Make the flag "static" as well since convincing the compiler it's global
is no longer necessary.
Alternatively, the flag could be accessed with {READ,WRITE}_ONCE(), but
literally every access would need the wrappers, and eking out performance
isn't exactly top priority for selftests.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221013211234.1318131-17-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Tests for races between shinfo_cache (de)activation and hypercall+ioctl()
processing. KVM has had bugs where activating the shared info cache
multiple times and/or with concurrent users results in lock corruption,
NULL pointer dereferences, and other fun.
For the timer injection testcase (#22), re-arm the timer until the IRQ
is successfully injected. If the timer expires while the shared info
is deactivated (invalid), KVM will drop the event.
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Co-developed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221013211234.1318131-16-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Map the test's huge page region with 2MiB virtual mappings when TDP is
disabled so that KVM can shadow the region with huge pages. This fixes
nx_huge_pages_test on hosts where TDP hardware support is disabled.
Purposely do not skip this test on TDP-disabled hosts. While we don't
care about NX Huge Pages on TDP-disabled hosts from a security
perspective, KVM does support it, and so we should test it.
For TDP-enabled hosts, continue mapping the region with 4KiB pages to
ensure that KVM can map it with huge pages irrespective of the guest
mappings.
Fixes: 8448ec5993 ("KVM: selftests: Add NX huge pages test")
Signed-off-by: David Matlack <dmatlack@google.com>
Message-Id: <20220929181207.2281449-4-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Combine fix_hypercall_test's two subtests into a common routine, the only
difference between the two is whether or not the quirk is disabled.
Passing a boolean is a little gross, but using an enum to make it super
obvious that the callers are enabling/disabling the quirk seems like
overkill.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Message-Id: <20220928233652.783504-7-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Explicitly verify that KVM doesn't patch in the native hypercall if the
FIX_HYPERCALL_INSN quirk is disabled. The test currently verifies that
a #UD occurred, but doesn't actually verify that no patching occurred.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220928233652.783504-6-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Hardcode the VMCALL/VMMCALL opcodes in dedicated arrays instead of
extracting the opcodes from inline asm, and patch in the "other" opcode
so as to preserve the original opcode, i.e. the opcode that the test
executes in the guest.
Preserving the original opcode (by not patching the source), will make
it easier to implement a check that KVM doesn't modify the opcode (the
test currently only verifies that a #UD occurred).
Use INT3 (0xcc) as the placeholder so that the guest will likely die a
horrible death if the test's patching goes awry.
As a bonus, patching from within the test dedups a decent chunk of code.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220928233652.783504-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Use input constraints to load RAX and RBX when testing that KVM correctly
does/doesn't patch the "wrong" hypercall. There's no need to manually
load RAX and RBX, and no reason to clobber them either (KVM is not
supposed to modify anything other than RAX).
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Message-Id: <20220928233652.783504-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Directly compare the expected versus observed hypercall instructions when
verifying that KVM patched in the native hypercall (FIX_HYPERCALL_INSN
quirk enabled). gcc rightly complains that doing a 4-byte memcpy() with
an "unsigned char" as the source generates an out-of-bounds accesses.
Alternatively, "exp" and "obs" could be declared as 3-byte arrays, but
there's no known reason to copy locally instead of comparing directly.
In function ‘assert_hypercall_insn’,
inlined from ‘guest_main’ at x86_64/fix_hypercall_test.c:91:2:
x86_64/fix_hypercall_test.c:63:9: error: array subscript ‘unsigned int[0]’
is partly outside array bounds of ‘unsigned char[1]’ [-Werror=array-bounds]
63 | memcpy(&exp, exp_insn, sizeof(exp));
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
x86_64/fix_hypercall_test.c: In function ‘guest_main’:
x86_64/fix_hypercall_test.c:42:22: note: object ‘vmx_hypercall_insn’ of size 1
42 | extern unsigned char vmx_hypercall_insn;
| ^~~~~~~~~~~~~~~~~~
x86_64/fix_hypercall_test.c:25:22: note: object ‘svm_hypercall_insn’ of size 1
25 | extern unsigned char svm_hypercall_insn;
| ^~~~~~~~~~~~~~~~~~
In function ‘assert_hypercall_insn’,
inlined from ‘guest_main’ at x86_64/fix_hypercall_test.c:91:2:
x86_64/fix_hypercall_test.c:64:9: error: array subscript ‘unsigned int[0]’
is partly outside array bounds of ‘unsigned char[1]’ [-Werror=array-bounds]
64 | memcpy(&obs, obs_insn, sizeof(obs));
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
x86_64/fix_hypercall_test.c: In function ‘guest_main’:
x86_64/fix_hypercall_test.c:25:22: note: object ‘svm_hypercall_insn’ of size 1
25 | extern unsigned char svm_hypercall_insn;
| ^~~~~~~~~~~~~~~~~~
x86_64/fix_hypercall_test.c:42:22: note: object ‘vmx_hypercall_insn’ of size 1
42 | extern unsigned char vmx_hypercall_insn;
| ^~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
make: *** [../lib.mk:135: tools/testing/selftests/kvm/x86_64/fix_hypercall_test] Error 1
Fixes: 6c2fa8b20d ("selftests: KVM: Test KVM_X86_QUIRK_FIX_HYPERCALL_INSN")
Cc: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Message-Id: <20220928233652.783504-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Bits 27 through 31 in Hyper-V hypercall 'control' are reserved (see
HV_HYPERCALL_RSVD0_MASK) but '0xdeadbeef' includes them. This causes
KVM to return HV_STATUS_INVALID_HYPERCALL_INPUT instead of the expected
HV_STATUS_INVALID_HYPERCALL_CODE.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/all/87fsgjol20.fsf@redhat.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Load RAX with -EFAULT prior to making a Hyper-V hypercall so that tests
can't get false negatives due to the compiler coincidentally loading the
"right" value into RAX, i.e. to ensure that _KVM_ and not the compiler
is correctly clearing RAX on a successful hypercall.
Note, initializing *hv_status (in C code) to -EFAULT is not sufficient
to avoid false negatives, as the compiler can still "clobber" RAX and
thus load garbage into *hv_status if the hypercall faults (or if KVM
doesn't set RAX).
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vipin Sharma <vipinsh@google.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20220922062451.2927010-1-vipinsh@google.com
[sean: move to separate patch, massage changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Commit cc5851c6be ("KVM: selftests: Use exception fixup for #UD/#GP
Hyper-V MSR/hcall tests") introduced a wrong guest assert in guest_hcall().
It is not checking the successful hypercall results and only checks the
result when a fault happens.
GUEST_ASSERT_2(!hcall->ud_expected || res == hcall->expect,
hcall->expect, res);
Correct the assertion by only checking results of the successful
hypercalls.
This issue was observed when this test started failing after building it
in Clang. Above guest assert statement fails because "res" is not equal
to "hcall->expect" when "hcall->ud_expected" is true. "res" gets some
garbage value in Clang from the RAX register. In GCC, RAX is 0 because
it using RAX for @output_address in the asm statement and resetting it
to 0 before using it as output operand in the same asm statement. Clang
is not using RAX for @output_address.
Fixes: cc5851c6be ("KVM: selftests: Use exception fixup for #UD/#GP Hyper-V MSR/hcall tests")
Signed-off-by: Vipin Sharma <vipinsh@google.com>
Suggested-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20220922062451.2927010-1-vipinsh@google.com
[sean: wrap changelog at ~75 chars, move -EFAULT change to separate patch]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Require KVM_CAP_VM_DISABLE_NX_HUGE_PAGES for the entire NX hugepage test
instead of skipping the "disable" subtest if the capability isn't
supported by the host kernel. While the "enable" subtest does provide
value when the capability isn't supported, silently providing only half
the promised coveraged is undesirable, i.e. it's better to skip the test
so that the user knows something.
Alternatively, the test could print something to alert the user instead
of silently skipping the subtest, but that would encourage other tests
to follow suit, and it's not clear that it's desirable to take selftests
in that direction. And if selftests do head down the path of skipping
subtests, such behavior needs first-class support in the framework.
Opportunistically convert other test preconditions to TEST_REQUIRE().
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Reviewed-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20220812175301.3915004-1-oliver.upton@linux.dev
[sean: rewrote changelog to capture discussion about skipping the test]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Test all possible input values to verify that KVM rejects all values
except the exact host value. Due to the LBR format affecting the core
functionality of LBRs, KVM can't emulate "other" formats, so even though
there are a variety of legal values, KVM should reject anything but an
exact host match.
Suggested-by: Like Xu <like.xu.linux@gmail.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Provide informative error messages for the various checks related to
requesting access to XSAVE features that are buried behind XSAVE Feature
Disabling (XFD).
Opportunistically rename the helper to have "require" in the name so that
it's somewhat obvious that the helper may skip the test.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220614200707.3315957-41-seanjc@google.com
Use kvm_get_supported_cpuid_entry() instead of
kvm_get_supported_cpuid_index() when passing in '0' for the index, which
just so happens to be the case in all remaining users of
kvm_get_supported_cpuid_index() except kvm_get_supported_cpuid_entry().
Keep the helper as there may be users in the future, and it's not doing
any harm.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220614200707.3315957-36-seanjc@google.com
Set the function/index for CPUID in the helper instead of relying on the
caller to do so. In addition to reducing the risk of consuming an
uninitialized ECX, having the function/index embedded in the call makes
it easier to understand what is being checked.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220614200707.3315957-32-seanjc@google.com
Tag the returned CPUID pointers from kvm_get_supported_cpuid(),
kvm_get_supported_hv_cpuid(), and vcpu_get_supported_hv_cpuid() "const"
to prevent reintroducing the broken pattern of modifying the static
"cpuid" variable used by kvm_get_supported_cpuid() to cache the results
of KVM_GET_SUPPORTED_CPUID.
Update downstream consumers as needed.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220614200707.3315957-31-seanjc@google.com
Use the vCPU's persistent CPUID array directly when manipulating the set
of exposed Hyper-V CPUID features. Drop set_cpuid() to route all future
modification through the vCPU helpers; the Hyper-V features test was the
last user.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220614200707.3315957-27-seanjc@google.com
Add a new helper, vcpu_clear_cpuid_entry(), to do a RMW operation on the
vCPU's CPUID model to clear a given CPUID entry, and use it to clear
KVM's paravirt feature instead of operating on kvm_get_supported_cpuid()'s
static "cpuid" variable. This also eliminates a user of
the soon-be-defunct set_cpuid() helper.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220614200707.3315957-26-seanjc@google.com
Use vcpu_clear_cpuid_feature() to the MONITOR/MWAIT CPUID feature bit in
the MONITOR/MWAIT quirk test.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Add a helper to set a vCPU's guest.MAXPHYADDR, and use it in the test
that verifies the emulator returns an error on an unknown instruction
when KVM emulates in response to an EPT violation with a GPA that is
legal in hardware but illegal with respect to the guest's MAXPHYADDR.
Add a helper even though there's only a single user at this time. Before
its removal, mmu_role_test also stuffed guest.MAXPHYADDR, and the helper
provides a small amount of clarity.
More importantly, this eliminates a set_cpuid() user and an instance of
modifying kvm_get_supported_cpuid()'s static "cpuid".
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220614200707.3315957-25-seanjc@google.com
Rename get_cpuid() to get_cpuid_entry() to better reflect its behavior.
Leave set_cpuid() as is to avoid unnecessary churn, that helper will soon
be removed entirely.
Oppurtunistically tweak the implementation to avoid using a temporary
variable in anticipation of taggin the input @cpuid with "const".
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220614200707.3315957-21-seanjc@google.com
Cache a vCPU's CPUID information in "struct kvm_vcpu" to allow fixing the
mess where tests, often unknowingly, modify the global/static "cpuid"
allocated by kvm_get_supported_cpuid().
Add vcpu_init_cpuid() to handle stuffing an entirely different CPUID
model, e.g. during vCPU creation or when switching to the Hyper-V enabled
CPUID model. Automatically refresh the cache on vcpu_set_cpuid() so that
any adjustments made by KVM are always reflected in the cache. Drop
vcpu_get_cpuid() entirely to force tests to use the cache, and to allow
adding e.g. vcpu_get_cpuid_entry() in the future without creating a
conflicting set of APIs where vcpu_get_cpuid() does KVM_GET_CPUID2, but
vcpu_get_cpuid_entry() does not.
Opportunistically convert the VMX nested state test and KVM PV test to
manipulating the vCPU's CPUID (because it's easy), but use
vcpu_init_cpuid() for the Hyper-V features test and "emulator error" test
to effectively retain their current behavior as they're less trivial to
convert.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220614200707.3315957-19-seanjc@google.com
In the CPUID test, verify that KVM doesn't modify the kvm_cpuid2.entries
layout, i.e. that the order of entries and their flags is identical
between what the test provides via KVM_SET_CPUID2 and what KVM returns
via KVM_GET_CPUID2.
Asserting that the layouts match simplifies the test as there's no need
to iterate over both arrays.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220614200707.3315957-17-seanjc@google.com
Remove the MMU role test, which was made obsolete by KVM commit
feb627e8d6 ("KVM: x86: Forbid KVM_SET_CPUID{,2} after KVM_RUN"). The
ongoing costs of keeping the test updated far outweigh any benefits,
e.g. the test _might_ be useful as an example or for documentation
purposes, but otherwise the test is dead weight.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220614200707.3315957-14-seanjc@google.com
Check for _both_ XTILE data and cfg support in the AMX test instead of
checking for _either_ feature. Practically speaking, no sane CPU or vCPU
will support one but not the other, but the effective "or" behavior is
subtle and technically incorrect.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220614200707.3315957-11-seanjc@google.com
