Provide an immutable point in kvm-x86/selftests so that the guest printf()
support can be merged into other architectures' trees.

Add a test to ensure that setting both generic and fixed performance
event filters does not affect the consistency of the fixed event filter
behavior in KVM.
Signed-off-by: Jinrong Liang <cloudliang@tencent.com>
Link: https://lore.kernel.org/r/20230810090945.16053-7-cloudliang@tencent.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Add tests to cover that pmu event_filter works as expected when it's
applied to fixed performance counters, even if there is none fixed
counter exists (e.g. Intel guest pmu version=1 or AMD guest).
Signed-off-by: Jinrong Liang <cloudliang@tencent.com>
Reviewed-by: Isaku Yamahata <isaku.yamahata@intel.com>
Link: https://lore.kernel.org/r/20230810090945.16053-6-cloudliang@tencent.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Add test cases to verify the handling of unsupported input values for the
PMU event filter. The tests cover unsupported "action" values, unsupported
"flags" values, and unsupported "nevents" values. All these cases should
return an error, as they are currently not supported by the filter.
Furthermore, the tests also cover the case where setting non-existent
fixed counters in the fixed bitmap does not fail.
Signed-off-by: Jinrong Liang <cloudliang@tencent.com>
Reviewed-by: Isaku Yamahata <isaku.yamahata@intel.com>
Link: https://lore.kernel.org/r/20230810090945.16053-5-cloudliang@tencent.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Add custom "__kvm_pmu_event_filter" structure to improve pmu event
filter settings. Simplifies event filter setup by organizing event
filter parameters in a cleaner, more organized way.

Alternatively, selftests could use a struct overlay ala vcpu_set_msr()
to avoid dynamically allocating the array:

        struct {
                struct kvm_msrs header;
                struct kvm_msr_entry entry;
        } buffer = {};

        memset(&buffer, 0, sizeof(buffer));
        buffer.header.nmsrs = 1;
        buffer.entry.index = msr_index;
        buffer.entry.data = msr_value;

but the extra layer added by the nested structs is counterproductive
to writing efficient, clean code.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Jinrong Liang <cloudliang@tencent.com>
Link: https://lore.kernel.org/r/20230810090945.16053-4-cloudliang@tencent.com
[sean: massage changelog to explain alternative]
Signed-off-by: Sean Christopherson <seanjc@google.com>

None of the callers consume remove_event(), and it incorrectly implies
that the incoming filter isn't modified. Drop the return.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Jinrong Liang <cloudliang@tencent.com>
Link: https://lore.kernel.org/r/20230810090945.16053-3-cloudliang@tencent.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Add x86 properties for Intel PMU so that tests don't have to manually
retrieve the correct CPUID leaf+register, and so that the resulting code
is self-documenting.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Jinrong Liang <cloudliang@tencent.com>
Link: https://lore.kernel.org/r/20230810090945.16053-2-cloudliang@tencent.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Use GUEST_FAIL() in ARM's arch timer helpers now that printf-based
guest asserts are the default (and only) style of guest asserts, and
say goodbye to the GUEST_ASSERT_1() alias.

Link: https://lore.kernel.org/r/20230729003643.1053367-35-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Use the newfanged printf-based guest assert framework to spit out the
guest RIP when an unhandled exception is detected, which makes debugging
such failures *much* easier.

Link: https://lore.kernel.org/r/20230729003643.1053367-34-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Drop the param-based guest assert macros and enable the printf versions
for all selftests.  Note!  This change can affect tests even if they
don't use directly use guest asserts!  E.g. via library code, or due to
the compiler making different optimization decisions.

Link: https://lore.kernel.org/r/20230729003643.1053367-33-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Convert x86's XCR0 vs. CPUID test to use printf-based guest asserts.

Link: https://lore.kernel.org/r/20230729003643.1053367-32-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Convert x86's VMX PMU capabilities test to use printf-based guest asserts.
Opportunstically add a helper to do the WRMSR+assert so as to reduce the
amount of copy+paste needed to spit out debug information.

Link: https://lore.kernel.org/r/20230729003643.1053367-31-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Convert x86's userspace I/O test to use printf-based guest asserts.

Link: https://lore.kernel.org/r/20230729003643.1053367-30-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Convert x86's TSC MSRs test, and it's liberal use of GUEST_ASSERT_EQ(), to
use printf-based guest assert reporting.

Link: https://lore.kernel.org/r/20230729003643.1053367-29-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Convert x86's nested SVM software interrupt injection test to use printf-
based guest asserts.  Opportunistically use GUEST_ASSERT() and
GUEST_FAIL() in a few locations to spit out more debug information.

Link: https://lore.kernel.org/r/20230729003643.1053367-28-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Convert the set_boot_cpu_id test to use printf-based guest asserts,
specifically the EQ and NE variants.

Link: https://lore.kernel.org/r/20230729003643.1053367-27-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Convert x86's nested exceptions test to printf-based guest asserts, and
use REPORT_GUEST_ASSERT() instead of TEST_FAIL() so that output is
formatted correctly.

Link: https://lore.kernel.org/r/20230729003643.1053367-26-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Convert x86's MONITOR/MWAIT test to use printf-based guest asserts.  Add a
macro to handle reporting failures to reduce the amount of copy+paste
needed for MONITOR vs. MWAIT.

Link: https://lore.kernel.org/r/20230729003643.1053367-25-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Convert x86's KVM paravirtualization test to use the printf-based
GUEST_ASSERT_EQ().

Link: https://lore.kernel.org/r/20230729003643.1053367-24-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Convert x86's Hyper-V feature test to use print-based guest asserts.
Opportunistically use the EQ and NE variants in a few places to capture
additional information.

Link: https://lore.kernel.org/r/20230729003643.1053367-23-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Convert x86's Hyper-V extended hypercalls test to use printf-based
GUEST_ASSERT_EQ().

Link: https://lore.kernel.org/r/20230729003643.1053367-22-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Convert x86's CPUID test to use printf-based GUEST_ASSERT_EQ() so that
the test prints out debug information.  Note, the test previously used
REPORT_GUEST_ASSERT_2(), but that was pointless because none of the
guest-side code passed any parameters to the assert.

Link: https://lore.kernel.org/r/20230729003643.1053367-21-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Convert the steal_time test to use printf-based GUEST_ASERT.
Opportunistically use GUEST_ASSERT_EQ() and GUEST_ASSERT_NE() so that the
test spits out debug information on failure.

Link: https://lore.kernel.org/r/20230729003643.1053367-20-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Convert set_memory_region_test to print-based GUEST_ASSERT, using a combo
of newfangled macros to report (hopefully) useful information.

Link: https://lore.kernel.org/r/20230729003643.1053367-19-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Convert s390's tprot test to printf-based GUEST_ASSERT.

Link: https://lore.kernel.org/r/20230729003643.1053367-18-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Convert s390's memop test to printf-based GUEST_ASSERT, and
opportunistically use GUEST_FAIL() to report invalid sizes.

Link: https://lore.kernel.org/r/20230729003643.1053367-17-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Use the printf-based GUEST_ASSERT_EQ() in the memslot perf test instead of
an half-baked open code version.

Link: https://lore.kernel.org/r/20230729003643.1053367-16-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Use printf-based guest assert reporting in ARM's vGIC IRQ test.  Note,
this is not as innocuous as it looks!  The printf-based version of
GUEST_ASSERT_EQ() ensures the expressions are evaluated only once, whereas
the old version did not!

Link: https://lore.kernel.org/r/20230729003643.1053367-15-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Use GUEST_FAIL() in ARM's page fault test to report unexpected faults.

Link: https://lore.kernel.org/r/20230729003643.1053367-14-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Convert ARM's hypercalls test to use printf-based GUEST_ASSERT().
Opportunistically use GUEST_FAIL() to complain about an unexpected stage.

Link: https://lore.kernel.org/r/20230729003643.1053367-13-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Convert ARM's debug exceptions  test to use printf-based GUEST_ASSERT().
Opportunistically Use GUEST_ASSERT_EQ() in guest_code_ss() so that the
expected vs. actual values get printed out.

Link: https://lore.kernel.org/r/20230729003643.1053367-12-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Convert ARM's aarch_timer test to use printf-based GUEST_ASSERT().
To maintain existing functionality, manually print the host information,
e.g. stage and iteration, to stderr prior to reporting the guest assert.

Link: https://lore.kernel.org/r/20230729003643.1053367-11-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Add a test to exercise the various features in KVM selftest's local
snprintf() and compare them to LIBC's snprintf() to ensure they behave
the same.

This is not an exhaustive test.  KVM's local snprintf() does not
implement all the features LIBC does, e.g. KVM's local snprintf() does
not support floats or doubles, so testing for those features were
excluded.

Testing was added for the features that are expected to work to
support a minimal version of printf() in the guest.
Signed-off-by: Aaron Lewis <aaronlewis@google.com>
[sean: use UCALL_EXIT_REASON, enable for all architectures]
Link: https://lore.kernel.org/r/20230731203026.1192091-4-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Define the expected architecture specific exit reason for a successful
ucall so that common tests can assert that a ucall occurred without the
test needing to implement arch specific code.
Suggested-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20230731203026.1192091-3-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Add an architecture specific ucall.h and inline the simple arch hooks,
e.g. the init hook for everything except ARM, and the actual "do ucall"
hook for everything except x86 (which should be simple, but temporarily
isn't due to carrying a workaround).

Having a per-arch ucall header will allow adding a #define for the
expected KVM exit reason for a ucall that is colocated (for everything
except x86) with the ucall itself.
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20230731203026.1192091-2-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Add printf-based GUEST_ASSERT macros and accompanying host-side support to
provide an assert-specific versions of GUEST_PRINTF().  To make it easier
to parse assert messages, for humans and bots alike, preserve/use the same
layout as host asserts, e.g. in the example below, the reported expression,
file, line number, and message are from the guest assertion, not the host
reporting of the assertion.

The call stack still captures the host reporting, but capturing the guest
stack is a less pressing concern, i.e. can be done in the future, and an
optimal solution would capture *both* the host and guest stacks, i.e.
capturing the host stack isn't an outright bug.

  Running soft int test
  ==== Test Assertion Failure ====
    x86_64/svm_nested_soft_inject_test.c:39: regs->rip != (unsigned long)l2_guest_code_int
    pid=214104 tid=214104 errno=4 - Interrupted system call
       1	0x0000000000401b35: run_test at svm_nested_soft_inject_test.c:191
       2	0x00000000004017d2: main at svm_nested_soft_inject_test.c:212
       3	0x0000000000415b03: __libc_start_call_main at libc-start.o:?
       4	0x000000000041714f: __libc_start_main_impl at ??:?
       5	0x0000000000401660: _start at ??:?
    Expected IRQ at RIP 0x401e50, received IRQ at 0x401e50

Don't bother sharing code between ucall_assert() and ucall_fmt(), as
forwarding the variable arguments would either require using macros or
building a va_list, i.e. would make the code less readable and/or require
just as much copy+paste code anyways.

Gate the new macros with a flag so that tests can more or less be switched
over one-by-one.  The slow conversion won't be perfect, e.g. library code
won't pick up the flag, but the only asserts in library code are of the
vanilla GUEST_ASSERT() variety, i.e. don't print out variables.

Add a temporary alias to GUEST_ASSERT_1() to fudge around ARM's
arch_timer.h header using GUEST_ASSERT_1(), thus thwarting any attempt to
convert tests one-by-one.

Link: https://lore.kernel.org/r/20230729003643.1053367-9-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Add more flexibility to guest debugging and testing by adding
GUEST_PRINTF() and GUEST_ASSERT_FMT() to the ucall framework.

Add a sized buffer to the ucall structure to hold the formatted string,
i.e. to allow the guest to easily resolve the string, and thus avoid the
ugly pattern of the host side having to make assumptions about the desired
format, as well as having to pass around a large number of parameters.

The buffer size was chosen to accommodate most use cases, and based on
similar usage.  E.g. printf() uses the same size buffer in
arch/x86/boot/printf.c.  And 1KiB ought to be enough for anybody.
Signed-off-by: Aaron Lewis <aaronlewis@google.com>
[sean: massage changelog, wrap macro param in ()]
Link: https://lore.kernel.org/r/20230729003643.1053367-8-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Add additional pages to the guest to account for the number of pages
the ucall headers need.  The only reason things worked before is the
ucall headers are fairly small.  If they were ever to increase in
size the guest could run out of memory.

This is done in preparation for adding string formatting options to
the guest through the ucall framework which increases the size of
the ucall headers.

Fixes: 426729b2 ("KVM: selftests: Add ucall pool based implementation")
Signed-off-by: Aaron Lewis <aaronlewis@google.com>
Link: https://lore.kernel.org/r/20230729003643.1053367-7-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Add a local version of guest_snprintf() for use in the guest.

Having a local copy allows the guest access to string formatting
options without dependencies on LIBC.  LIBC is problematic because
it heavily relies on both AVX-512 instructions and a TLS, neither of
which are guaranteed to be set up in the guest.

The file guest_sprintf.c was lifted from arch/x86/boot/printf.c and
adapted to work in the guest, including the addition of buffer length.
I.e. s/sprintf/snprintf/

The functions where prefixed with "guest_" to allow guests to
explicitly call them.

A string formatted by this function is expected to succeed or die.  If
something goes wrong during the formatting process a GUEST_ASSERT()
will be thrown.
Signed-off-by: Aaron Lewis <aaronlewis@google.com>
Link: https://lore.kernel.org/all/mtdi6smhur5rqffvpu7qux7mptonw223y2653x2nwzvgm72nlo@zyc4w3kwl3rg
[sean: add a link to the discussion of other options]
Link: https://lore.kernel.org/r/20230729003643.1053367-6-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>

Add strnlen() to the string overrides to allow it to be called in the
guest.

The implementation for strnlen() was taken from the kernel's generic
version, lib/string.c.

This will be needed when printf() is introduced.
Signed-off-by: Aaron Lewis <aaronlewis@google.com>
Link: https://lore.kernel.org/r/20230729003643.1053367-5-seanjc@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>