Extend the 'set_memory_region_test' with an x86-only test case which
covers emulated MMIO during event vectoring error handling. The test case
1) Sets an IDT descriptor base to point to an MMIO address
2) Generates a #GP in the guest
3) Verifies userspace gets the correct exit reason, suberror code, and
GPA in internal.data[3]
Opportunistically add a definition for a non-canonical address to
processor.h so that the source of the #GP is somewhat self-documenting,
and so that future tests don't have to reinvent the wheel.
Signed-off-by: Ivan Orlov <iorlov@amazon.com>
Link: https://lore.kernel.org/r/20241217181458.68690-8-iorlov@amazon.com
[sean: massage changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Refresh selftests' CPUID cache in the vCPU structure when querying a CPUID
entry so that tests don't consume stale data when KVM modifies CPUID as a
side effect to a completely unrelated change. E.g. KVM adjusts OSXSAVE in
response to CR4.OSXSAVE changes.
Unnecessarily invoking KVM_GET_CPUID is suboptimal, but vcpu->cpuid exists
to simplify selftests development, not for performance reasons. And,
unfortunately, trying to handle the side effects in tests or other flows
is unpleasant, e.g. selftests could manually refresh if KVM_SET_SREGS is
successful, but that would still leave a gap with respect to guest CR4
changes.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Link: https://lore.kernel.org/r/20241128013424.4096668-9-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Use the kernel's canonical $(ARCH) paths instead of the raw target triple
for KVM selftests directories. KVM selftests are quite nearly the only
place in the entire kernel that using the target triple for directories,
tools/testing/selftests/drivers/s390x being the lone holdout.
Using the kernel's preferred nomenclature eliminates the minor, but
annoying, friction of having to translate to KVM's selftests directories,
e.g. for pattern matching, opening files, running selftests, etc.
Opportunsitically delete file comments that reference the full path of the
file, as they are obviously prone to becoming stale, and serve no known
purpose.
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Acked-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20241128005547.4077116-16-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Assert that the register being read/written by vcpu_{g,s}et_reg() is no
larger than a uint64_t, i.e. that a selftest isn't unintentionally
truncating the value being read/written.
Ideally, the assert would be done at compile-time, but that would limit
the checks to hardcoded accesses and/or require fancier compile-time
assertion infrastructure to filter out dynamic usage.
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20241128005547.4077116-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Return a uint64_t from vcpu_get_reg() instead of having the caller provide
a pointer to storage, as none of the vcpu_get_reg() usage in KVM selftests
accesses a register larger than 64 bits, and vcpu_set_reg() only accepts a
64-bit value. If a use case comes along that needs to get a register that
is larger than 64 bits, then a utility can be added to assert success and
take a void pointer, but until then, forcing an out param yields ugly code
and prevents feeding the output of vcpu_get_reg() into vcpu_set_reg().
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Link: https://lore.kernel.org/r/20241128005547.4077116-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
KVM/arm64 changes for 6.13, part #1
- Support for stage-1 permission indirection (FEAT_S1PIE) and
permission overlays (FEAT_S1POE), including nested virt + the
emulated page table walker
- Introduce PSCI SYSTEM_OFF2 support to KVM + client driver. This call
was introduced in PSCIv1.3 as a mechanism to request hibernation,
similar to the S4 state in ACPI
- Explicitly trap + hide FEAT_MPAM (QoS controls) from KVM guests. As
part of it, introduce trivial initialization of the host's MPAM
context so KVM can use the corresponding traps
- PMU support under nested virtualization, honoring the guest
hypervisor's trap configuration and event filtering when running a
nested guest
- Fixes to vgic ITS serialization where stale device/interrupt table
entries are not zeroed when the mapping is invalidated by the VM
- Avoid emulated MMIO completion if userspace has requested synchronous
external abort injection
- Various fixes and cleanups affecting pKVM, vCPU initialization, and
selftests
Add a test case manipulating s390 storage keys from within the ucontrol
VM.
Storage key instruction (ISKE, SSKE and RRBE) intercepts and
Keyless-subset facility are disabled on first use, where the skeys are
setup by KVM in non ucontrol VMs.
Signed-off-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
Link: https://lore.kernel.org/r/20241108091620.289406-1-schlameuss@linux.ibm.com
Acked-by: Janosch Frank <frankja@linux.ibm.com>
[frankja@linux.ibm.com: Fixed patch prefix]
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Message-ID: <20241108091620.289406-1-schlameuss@linux.ibm.com>
To play nice with compilers generating AVX instructions, set CR4.OSXSAVE
and configure XCR0 by default when creating selftests vCPUs. Some distros
have switched gcc to '-march=x86-64-v3' by default, and while it's hard to
find a CPU which doesn't support AVX today, many KVM selftests fail with
==== Test Assertion Failure ====
lib/x86_64/processor.c:570: Unhandled exception in guest
pid=72747 tid=72747 errno=4 - Interrupted system call
Unhandled exception '0x6' at guest RIP '0x4104f7'
due to selftests not enabling AVX by default for the guest. The failure
is easy to reproduce elsewhere with:
$ make clean && CFLAGS='-march=x86-64-v3' make -j && ./x86_64/kvm_pv_test
E.g. gcc-13 with -march=x86-64-v3 compiles this chunk from selftests'
kvm_fixup_exception():
regs->rip = regs->r11;
regs->r9 = regs->vector;
regs->r10 = regs->error_code;
into this monstronsity (which is clever, but oof):
405313: c4 e1 f9 6e c8 vmovq %rax,%xmm1
405318: 48 89 68 08 mov %rbp,0x8(%rax)
40531c: 48 89 e8 mov %rbp,%rax
40531f: c4 c3 f1 22 c4 01 vpinsrq $0x1,%r12,%xmm1,%xmm0
405325: 49 89 6d 38 mov %rbp,0x38(%r13)
405329: c5 fa 7f 45 00 vmovdqu %xmm0,0x0(%rbp)
Alternatively, KVM selftests could explicitly restrict the compiler to
-march=x86-64-v2, but odds are very good that punting on AVX enabling will
simply result in tests that "need" AVX doing their own thing, e.g. there
are already three or so additional cleanups that can be done on top.
Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Closes: https://lore.kernel.org/all/20240920154422.2890096-1-vkuznets@redhat.com
Reviewed-and-tested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20241003234337.273364-6-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Introduce new regression tests to verify the ASM inline block in the SORTL
and DFLTCC CPU subfunctions for the s390x architecture. These tests ensure
that future changes to the ASM code are properly validated.
The test procedure:
1. Create a VM and request the KVM_S390_VM_CPU_MACHINE_SUBFUNC attribute
from the KVM_S390_VM_CPU_MODEL group for this VM. This SUBFUNC attribute
contains the results of all CPU subfunction instructions.
2. For each tested subfunction (SORTL and DFLTCC), execute the
corresponding ASM instruction and capture the result array.
3. Perform a memory comparison between the results stored in the SUBFUNC
attribute (obtained in step 1) and the ASM instruction results (obtained
in step 2) for each tested subfunction.
This process ensures that the KVM implementation accurately reflects the
behavior of the actual CPU instructions for the tested subfunctions.
Suggested-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Hariharan Mari <hari55@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
Link: https://lore.kernel.org/r/20240823130947.38323-2-hari55@linux.ibm.com
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Message-ID: <20240823130947.38323-2-hari55@linux.ibm.com>
KVM selftests changes for 6.12:
- Fix a goof that caused some Hyper-V tests to be skipped when run on bare
metal, i.e. NOT in a VM.
- Add a regression test for KVM's handling of SHUTDOWN for an SEV-ES guest.
- Explicitly include one-off assets in .gitignore. Past Sean was completely
wrong about not being able to detect missing .gitignore entries.
- Verify userspace single-stepping works when KVM happens to handle a VM-Exit
in its fastpath.
- Misc cleanups
KVM x86 misc changes for 6.12
- Advertise AVX10.1 to userspace (effectively prep work for the "real" AVX10
functionality that is on the horizon).
- Rework common MSR handling code to suppress errors on userspace accesses to
unsupported-but-advertised MSRs. This will allow removing (almost?) all of
KVM's exemptions for userspace access to MSRs that shouldn't exist based on
the vCPU model (the actual cleanup is non-trivial future work).
- Rework KVM's handling of x2APIC ICR, again, because AMD (x2AVIC) splits the
64-bit value into the legacy ICR and ICR2 storage, whereas Intel (APICv)
stores the entire 64-bit value a the ICR offset.
- Fix a bug where KVM would fail to exit to userspace if one was triggered by
a fastpath exit handler.
- Add fastpath handling of HLT VM-Exit to expedite re-entering the guest when
there's already a pending wake event at the time of the exit.
- Finally fix the RSM vs. nested VM-Enter WARN by forcing the vCPU out of
guest mode prior to signalling SHUTDOWN (architecturally, the SHUTDOWN is
supposed to hit L1, not L2).
KVK generic changes for 6.12:
- Fix a bug that results in KVM prematurely exiting to userspace for coalesced
MMIO/PIO in many cases, clean up the related code, and add a testcase.
- Fix a bug in kvm_clear_guest() where it would trigger a buffer overflow _if_
the gpa+len crosses a page boundary, which thankfully is guaranteed to not
happen in the current code base. Add WARNs in more helpers that read/write
guest memory to detect similar bugs.
Add a new arch_timer_edge_cases selftests that validates:
* timers above the max TVAL value
* timers in the past
* moving counters ahead and behind pending timers
* reprograming timers
* timers fired multiple times
* masking/unmasking using the timer control mask
These are intentionally unusual scenarios to stress compliance with
the arm architecture.
Co-developed-by: Ricardo Koller <ricarkol@google.com>
Signed-off-by: Ricardo Koller <ricarkol@google.com>
Signed-off-by: Colton Lewis <coltonlewis@google.com>
Link: https://lore.kernel.org/r/20240823175836.2798235-3-coltonlewis@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
Add a test to verify that KVM correctly exits (or not) when a vCPU's
coalesced I/O ring is full (or isn't). Iterate over all legal starting
points in the ring (with an empty ring), and verify that KVM doesn't exit
until the ring is full.
Opportunistically verify that KVM exits immediately on non-coalesced I/O,
either because the MMIO/PIO region was never registered, or because a
previous region was unregistered.
This is a regression test for a KVM bug where KVM would prematurely exit
due to bad math resulting in a false positive if the first entry in the
ring was before the halfway mark. See commit 92f6d41304 ("KVM: Fix
coalesced_mmio_has_room() to avoid premature userspace exit").
Enable the test for x86, arm64, and risc-v, i.e. all architectures except
s390, which doesn't have MMIO.
On x86, which has both MMIO and PIO, interleave MMIO and PIO into the same
ring, as KVM shouldn't exit until a non-coalesced I/O is encountered,
regardless of whether the ring is filled with MMIO, PIO, or both.
Lastly, wrap the coalesced I/O ring in a structure to prepare for a
potential future where KVM supports multiple ring buffers beyond KVM's
"default" built-in buffer.
Link: https://lore.kernel.org/all/20240820133333.1724191-1-ilstam@amazon.com
Cc: Ilias Stamatis <ilstam@amazon.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20240828181446.652474-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
KVM_CAP_HYPERV_DIRECT_TLBFLUSH is only reported when KVM runs on top of
Hyper-V and hyperv_evmcs/hyperv_svm_test don't need that, these tests check
that the feature is properly emulated for Hyper-V on KVM guests. There's no
corresponding CAP for that, the feature is reported in
KVM_GET_SUPPORTED_HV_CPUID.
Hyper-V specific CPUIDs are not reported by KVM_GET_SUPPORTED_CPUID,
implement dedicated kvm_hv_cpu_has() helper to do the job.
Fixes: 6dac119518 ("KVM: selftests: Make Hyper-V tests explicitly require KVM Hyper-V support")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20240816130139.286246-3-vkuznets@redhat.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Add functions to simply print some basic state information in selftests.
The output can be enabled by setting:
#define TH_LOG_ENABLED 1
#define DEBUG 1
* print_psw: current SIE state description and VM run state
* print_hex_bytes: print memory with some counting markers
* print_hex: PRINT_HEX with 512 bytes
* print_run: use print_psw and print_hex to print contents of VM run
state and SIE state description
* print_regs: print content of general and control registers
All prints use pr_debug for the output and can be configured using
DEBUG.
Signed-off-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
Acked-by: Janosch Frank <frankja@linux.ibm.com>
Link: https://lore.kernel.org/r/20240807154512.316936-6-schlameuss@linux.ibm.com
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Message-ID: <20240807154512.316936-6-schlameuss@linux.ibm.com>
Subsequent tests do require direct manipulation of the SIE control
block. This commit introduces the SIE control block definition for use
within the selftests.
There are already definitions of this within the kernel.
This differs in two ways.
* This is the first definition of this in userspace.
* In the context of the selftests this does not require atomicity for
the flags.
With the userspace definition of the SIE block layout now being present
we can reuse the values in other tests where applicable.
Signed-off-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Link: https://lore.kernel.org/r/20240807154512.316936-3-schlameuss@linux.ibm.com
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Message-ID: <20240807154512.316936-3-schlameuss@linux.ibm.com>
KVM x86 misc changes for 6.11
- Add a global struct to consolidate tracking of host values, e.g. EFER, and
move "shadow_phys_bits" into the structure as "maxphyaddr".
- Add KVM_CAP_X86_APIC_BUS_CYCLES_NS to allow configuring the effective APIC
bus frequency, because TDX.
- Print the name of the APICv/AVIC inhibits in the relevant tracepoint.
- Clean up KVM's handling of vendor specific emulation to consistently act on
"compatible with Intel/AMD", versus checking for a specific vendor.
- Misc cleanups
Add udelay() for x86 tests to allow busy waiting in the guest for a
specific duration, and to match ARM and RISC-V's udelay() in the hopes
of eventually making udelay() available on all architectures.
Get the guest's TSC frequency using KVM_GET_TSC_KHZ and expose it to all
VMs via a new global, guest_tsc_khz. Assert that KVM_GET_TSC_KHZ returns
a valid frequency, instead of simply skipping tests, which would require
detecting which tests actually need/want udelay(). KVM hasn't returned an
error for KVM_GET_TSC_KHZ since commit cc578287e3 ("KVM: Infrastructure
for software and hardware based TSC rate scaling"), which predates KVM
selftests by 6+ years (KVM_GET_TSC_KHZ itself predates KVM selftest by 7+
years).
Note, if the GUEST_ASSERT() in udelay() somehow fires and the test doesn't
check for guest asserts, then the test will fail with a very cryptic
message. But fixing that, e.g. by automatically handling guest asserts,
is a much larger task, and practically speaking the odds of a test afoul
of this wart are infinitesimally small.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lore.kernel.org/r/5aa86285d1c1d7fe1960e3fe490f4b22273977e6.1718214999.git.reinette.chatre@intel.com
Co-developed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Use the max mappable GPA via GuestPhysBits advertised by KVM to calculate
max_gfn. Currently some selftests (e.g. access_tracking_perf_test,
dirty_log_test...) add RAM regions close to max_gfn, so guest may access
GPA beyond its mappable range and cause infinite loop.
Adjust max_gfn in vm_compute_max_gfn() since x86 selftests already
overrides vm_compute_max_gfn() specifically to deal with goofy edge cases.
Reported-by: Yi Lai <yi1.lai@intel.com>
Signed-off-by: Tao Su <tao1.su@linux.intel.com>
Tested-by: Yi Lai <yi1.lai@intel.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Link: https://lore.kernel.org/r/20240513014003.104593-1-tao1.su@linux.intel.com
[sean: tweak name, add comment and sanity check]
Signed-off-by: Sean Christopherson <seanjc@google.com>
This file was supposed to be removed in commit 2b7deea3ec ("Revert
"kvm: selftests: move base kvm_util.h declarations to kvm_util_base.h""),
but it survived. Remove it now.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM selftests treewide updates for 6.10:
- Define _GNU_SOURCE for all selftests to fix a warning that was introduced by
a change to kselftest_harness.h late in the 6.9 cycle, and because forcing
every test to #define _GNU_SOURCE is painful.
- Provide a global psuedo-RNG instance for all tests, so that library code can
generate random, but determinstic numbers.
- Use the global pRNG to randomly force emulation of select writes from guest
code on x86, e.g. to help validate KVM's emulation of locked accesses.
- Rename kvm_util_base.h back to kvm_util.h, as the weird layer of indirection
was added purely to avoid manually #including ucall_common.h in a handful of
locations.
- Allocate and initialize x86's GDT, IDT, TSS, segments, and default exception
handlers at VM creation, instead of forcing tests to manually trigger the
related setup.
KVM selftests cleanups and fixes for 6.10:
- Enhance the demand paging test to allow for better reporting and stressing
of UFFD performance.
- Convert the steal time test to generate TAP-friendly output.
- Fix a flaky false positive in the xen_shinfo_test due to comparing elapsed
time across two different clock domains.
- Skip the MONITOR/MWAIT test if the host doesn't actually support MWAIT.
- Avoid unnecessary use of "sudo" in the NX hugepage test to play nice with
running in a minimal userspace environment.
- Allow skipping the RSEQ test's sanity check that the vCPU was able to
complete a reasonable number of KVM_RUNs, as the assert can fail on a
completely valid setup. If the test is run on a large-ish system that is
otherwise idle, and the test isn't affined to a low-ish number of CPUs, the
vCPU task can be repeatedly migrated to CPUs that are in deep sleep states,
which results in the vCPU having very little net runtime before the next
migration due to high wakeup latencies.
KVM/arm64 updates for Linux 6.10
- Move a lot of state that was previously stored on a per vcpu
basis into a per-CPU area, because it is only pertinent to the
host while the vcpu is loaded. This results in better state
tracking, and a smaller vcpu structure.
- Add full handling of the ERET/ERETAA/ERETAB instructions in
nested virtualisation. The last two instructions also require
emulating part of the pointer authentication extension.
As a result, the trap handling of pointer authentication has
been greattly simplified.
- Turn the global (and not very scalable) LPI translation cache
into a per-ITS, scalable cache, making non directly injected
LPIs much cheaper to make visible to the vcpu.
- A batch of pKVM patches, mostly fixes and cleanups, as the
upstreaming process seems to be resuming. Fingers crossed!
- Allocate PPIs and SGIs outside of the vcpu structure, allowing
for smaller EL2 mapping and some flexibility in implementing
more or less than 32 private IRQs.
- Purge stale mpidr_data if a vcpu is created after the MPIDR
map has been created.
- Preserve vcpu-specific ID registers across a vcpu reset.
- Various minor cleanups and improvements.
KVM/riscv changes for 6.10
- Support guest breakpoints using ebreak
- Introduce per-VCPU mp_state_lock and reset_cntx_lock
- Virtualize SBI PMU snapshot and counter overflow interrupts
- New selftests for SBI PMU and Guest ebreak
Initialize the IDT and exception handlers for all non-barebones VMs and
vCPUs on x86. Forcing tests to manually configure the IDT just to save
8KiB of memory is a terrible tradeoff, and also leads to weird tests
(multiple tests have deliberately relied on shutdown to indicate success),
and hard-to-debug failures, e.g. instead of a precise unexpected exception
failure, tests see only shutdown.
Reviewed-by: Ackerley Tng <ackerleytng@google.com>
Link: https://lore.kernel.org/r/20240314232637.2538648-11-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Move the base types unique to KVM selftests out of kvm_util.h and into a
new header, kvm_util_types.h. This will allow kvm_util_arch.h, i.e. core
arch headers, to reference common types, e.g. vm_vaddr_t and vm_paddr_t.
No functional change intended.
Reviewed-by: Ackerley Tng <ackerleytng@google.com>
Link: https://lore.kernel.org/r/20240314232637.2538648-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Effectively revert the movement of code from kvm_util.h => kvm_util_base.h,
as the TL;DR of the justification for the move was to avoid #idefs and/or
circular dependencies between what ended up being ucall_common.h and what
was (and now again, is), kvm_util.h.
But avoiding #ifdef and circular includes is trivial: don't do that. The
cost of removing kvm_util_base.h is a few extra includes of ucall_common.h,
but that cost is practically nothing. On the other hand, having a "base"
version of a header that is really just the header itself is confusing,
and makes it weird/hard to choose names for headers that actually are
"base" headers, e.g. to hold core KVM selftests typedefs.
For all intents and purposes, this reverts commit
7d9a662ed9.
Reviewed-by: Ackerley Tng <ackerleytng@google.com>
Link: https://lore.kernel.org/r/20240314232637.2538648-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Override vcpu_arch_put_guest() to randomly force emulation on supported
accesses. Force emulation of LOCK CMPXCHG as well as a regular MOV to
stress KVM's emulation of atomic accesses, which has a unique path in
KVM's emulator.
Arbitrarily give all the decisions 50/50 odds; absent much, much more
sophisticated infrastructure for generating random numbers, it's highly
unlikely that doing more than a coin flip with affect selftests' ability
to find KVM bugs.
This is effectively a regression test for commit 910c57dfa4 ("KVM: x86:
Mark target gfn of emulated atomic instruction as dirty").
Link: https://lore.kernel.org/r/20240314185459.2439072-6-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Introduce a macro, vcpu_arch_put_guest(), for "putting" values to memory
from guest code in "interesting" situations, e.g. when writing memory that
is being dirty logged. Structure the macro so that arch code can provide
a custom implementation, e.g. x86 will use the macro to force emulation of
the access.
Use the helper in dirty_log_test, which is of particular interest (see
above), and in xen_shinfo_test, which isn't all that interesting, but
provides a second usage of the macro with a different size operand
(uint8_t versus uint64_t), i.e. to help verify that the macro works for
more than just 64-bit values.
Use "put" as the verb to align with the kernel's {get,put}_user()
terminology.
Link: https://lore.kernel.org/r/20240314185459.2439072-5-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Add a global snapshot of kvm_is_forced_emulation_enabled() and sync it to
all VMs by default so that core library code can force emulation, e.g. to
allow for easier testing of the intersections between emulation and other
features in KVM.
Link: https://lore.kernel.org/r/20240314185459.2439072-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Move memstress' random bool logic into common code to avoid reinventing
the wheel for basic yes/no decisions. Provide an outer wrapper to handle
the basic/common case of just wanting a 50/50 chance of something
happening.
Link: https://lore.kernel.org/r/20240314185459.2439072-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Add a global guest_random_state instance, i.e. a pseudo-RNG, so that an
RNG is available for *all* tests. This will allow randomizing behavior
in core library code, e.g. x86 will utilize the pRNG to conditionally
force emulation of writes from within common guest code.
To allow for deterministic runs, and to be compatible with existing tests,
allow tests to override the seed used to initialize the pRNG.
Note, the seed *must* be overwritten before a VM is created in order for
the seed to take effect, though it's perfectly fine for a test to
initialize multiple VMs with different seeds.
And as evidenced by memstress_guest_code(), it's also a-ok to instantiate
more RNGs using the global seed (or a modified version of it). The goal
of the global RNG is purely to ensure that _a_ source of random numbers is
available, it doesn't have to be the _only_ RNG.
Link: https://lore.kernel.org/r/20240314185459.2439072-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Define _GNU_SOURCE is the base CFLAGS instead of relying on selftests to
manually #define _GNU_SOURCE, which is repetitive and error prone. E.g.
kselftest_harness.h requires _GNU_SOURCE for asprintf(), but if a selftest
includes kvm_test_harness.h after stdio.h, the include guards result in
the effective version of stdio.h consumed by kvm_test_harness.h not
defining asprintf():
In file included from x86_64/fix_hypercall_test.c:12:
In file included from include/kvm_test_harness.h:11:
../kselftest_harness.h:1169:2: error: call to undeclared function
'asprintf'; ISO C99 and later do not support implicit function declarations
[-Wimplicit-function-declaration]
1169 | asprintf(&test_name, "%s%s%s.%s", f->name,
| ^
When including the rseq selftest's "library" code, #undef _GNU_SOURCE so
that rseq.c controls whether or not it wants to build with _GNU_SOURCE.
Reported-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Acked-by: Oliver Upton <oliver.upton@linux.dev>
Acked-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Link: https://lore.kernel.org/r/20240423190308.2883084-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
