linux-stable.git/tools/testing/selftests/kvm/lib, branch v6.0

KVM: selftests: Implement memcmp(), memcpy(), and memset() for guest use

2022-09-30T10:38:02+00:00

Implement memcmp(), memcpy(), and memset() to override the compiler's
built-in versions in order to guarantee that the compiler won't generate
out-of-line calls to external functions via the PLT.  This allows the
helpers to be safely used in guest code, as KVM selftests don't support
dynamic loading of guest code.

Steal the implementations from the kernel's generic versions, sans the
optimizations in memcmp() for unaligned accesses.

Put the utilities in a separate compilation unit and build with
-ffreestanding to fudge around a gcc "feature" where it will optimize
memset(), memcpy(), etc... by generating a recursive call.  I.e. the
compiler optimizes itself into infinite recursion.  Alternatively, the
individual functions could be tagged with
optimize("no-tree-loop-distribute-patterns"), but using "optimize" for
anything but debug is discouraged, and Linus NAK'd the use of the flag
in the kernel proper[*].

https://lore.kernel.org/lkml/CAHk-=wik-oXnUpfZ6Hw37uLykc-_P0Apyn2XuX-odh-3Nzop8w@mail.gmail.com

Cc: Andrew Jones 
Cc: Anup Patel 
Cc: Atish Patra 
Cc: Christian Borntraeger 
Cc: Janosch Frank 
Cc: Claudio Imbrenda 
Signed-off-by: Sean Christopherson 
Message-Id: <20220928233652.783504-2-seanjc@google.com>
Reviewed-by: Andrew Jones 
Signed-off-by: Paolo Bonzini

KVM: selftests: Gracefully handle empty stack traces

2022-09-30T10:38:00+00:00

Bail out of test_dump_stack() if the stack trace is empty rather than
invoking addr2line with zero addresses. The problem with the latter is
that addr2line will block waiting for addresses to be passed in via
stdin, e.g. if running a selftest from an interactive terminal.

Opportunistically fix up the comment that mentions skipping 3 frames
since only 2 are skipped in the code.

Cc: Vipin Sharma 
Cc: Sean Christopherson 
Signed-off-by: David Matlack 
Message-Id: <20220922231724.3560211-1-dmatlack@google.com>
[Small tweak to keep backtrace() call close to if(). - Paolo]
Signed-off-by: Paolo Bonzini

KVM: selftests: Skip tests that require EPT when it is not available

2022-09-27T11:58:03+00:00

Skip selftests that require EPT support in the VM when it is not
available. For example, if running on a machine where kvm_intel.ept=N
since KVM does not offer EPT support to guests if EPT is not supported
on the host.

This commit causes vmx_dirty_log_test to be skipped instead of failing
on hosts where kvm_intel.ept=N.

Signed-off-by: David Matlack 
Message-Id: <20220926171457.532542-1-dmatlack@google.com>
Signed-off-by: Paolo Bonzini

selftests: kvm: set rax before vmcall

2022-08-01T12:43:05+00:00

kvm_hypercall has to place the hypercall number in rax.

Trace events show that kvm_pv_test doesn't work properly:
     kvm_pv_test-53132: kvm_hypercall: nr 0x0 a0 0x0 a1 0x0 a2 0x0 a3 0x0
     kvm_pv_test-53132: kvm_hypercall: nr 0x0 a0 0x0 a1 0x0 a2 0x0 a3 0x0
     kvm_pv_test-53132: kvm_hypercall: nr 0x0 a0 0x0 a1 0x0 a2 0x0 a3 0x0

With this change, it starts working as expected:
     kvm_pv_test-54285: kvm_hypercall: nr 0x5 a0 0x0 a1 0x0 a2 0x0 a3 0x0
     kvm_pv_test-54285: kvm_hypercall: nr 0xa a0 0x0 a1 0x0 a2 0x0 a3 0x0
     kvm_pv_test-54285: kvm_hypercall: nr 0xb a0 0x0 a1 0x0 a2 0x0 a3 0x0

Signed-off-by: Andrei Vagin 
Message-Id: <20220722230241.1944655-5-avagin@google.com>
Fixes: ac4a4d6de22e ("selftests: kvm: test enforcement of paravirtual cpuid features")
Signed-off-by: Paolo Bonzini

Merge remote-tracking branch 'kvm/next' into kvm-next-5.20

2022-08-01T07:21:00+00:00

KVM/s390, KVM/x86 and common infrastructure changes for 5.20

x86:

* Permit guests to ignore single-bit ECC errors

* Fix races in gfn->pfn cache refresh; do not pin pages tracked by the cache

* Intel IPI virtualization

* Allow getting/setting pending triple fault with KVM_GET/SET_VCPU_EVENTS

* PEBS virtualization

* Simplify PMU emulation by just using PERF_TYPE_RAW events

* More accurate event reinjection on SVM (avoid retrying instructions)

* Allow getting/setting the state of the speaker port data bit

* Refuse starting the kvm-intel module if VM-Entry/VM-Exit controls are inconsistent

* "Notify" VM exit (detect microarchitectural hangs) for Intel

* Cleanups for MCE MSR emulation

s390:

* add an interface to provide a hypervisor dump for secure guests

* improve selftests to use TAP interface

* enable interpretive execution of zPCI instructions (for PCI passthrough)

* First part of deferred teardown

* CPU Topology

* PV attestation

* Minor fixes

Generic:

* new selftests API using struct kvm_vcpu instead of a (vm, id) tuple

x86:

* Use try_cmpxchg64 instead of cmpxchg64

* Bugfixes

* Ignore benign host accesses to PMU MSRs when PMU is disabled

* Allow disabling KVM's "MONITOR/MWAIT are NOPs!" behavior

* x86/MMU: Allow NX huge pages to be disabled on a per-vm basis

* Port eager page splitting to shadow MMU as well

* Enable CMCI capability by default and handle injected UCNA errors

* Expose pid of vcpu threads in debugfs

* x2AVIC support for AMD

* cleanup PIO emulation

* Fixes for LLDT/LTR emulation

* Don't require refcounted "struct page" to create huge SPTEs

x86 cleanups:

* Use separate namespaces for guest PTEs and shadow PTEs bitmasks

* PIO emulation

* Reorganize rmap API, mostly around rmap destruction

* Do not workaround very old KVM bugs for L0 that runs with nesting enabled

* new selftests API for CPUID

KVM: selftests: Use the common cpuid() helper in cpu_vendor_string_is()

2022-07-14T01:14:25+00:00

Use cpuid() to get CPUID.0x0 in cpu_vendor_string_is(), thus eliminating
the last open coded usage of CPUID (ignoring debug_regs.c, which emits
CPUID from the guest to trigger a VM-Exit and doesn't actually care about
the results of CPUID).

Signed-off-by: Sean Christopherson 
Link: https://lore.kernel.org/r/20220614200707.3315957-42-seanjc@google.com

KVM: selftests: Clean up requirements for XFD-aware XSAVE features

2022-07-14T01:14:24+00:00

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 
Link: https://lore.kernel.org/r/20220614200707.3315957-41-seanjc@google.com

KVM: selftests: Skip AMX test if ARCH_REQ_XCOMP_GUEST_PERM isn't supported

2022-07-14T01:14:24+00:00

Skip the AMX test instead of silently returning if the host kernel
doesn't support ARCH_REQ_XCOMP_GUEST_PERM.  KVM didn't support XFD until
v5.17, so it's extremely unlikely allowing the test to run on a pre-v5.15
kernel is the right thing to do.

Signed-off-by: Sean Christopherson 
Link: https://lore.kernel.org/r/20220614200707.3315957-40-seanjc@google.com

KVM: selftests: Check KVM's supported CPUID, not host CPUID, for XFD

2022-07-14T01:14:24+00:00

Use kvm_cpu_has() to check for XFD supported in vm_xsave_req_perm(),
simply checking host CPUID doesn't guarantee KVM supports AMX/XFD.

Opportunistically hoist the check above the bit check; if XFD isn't
supported, it's far better to get a "not supported at all" message, as
opposed to a "feature X isn't supported" message".

Signed-off-by: Sean Christopherson 
Link: https://lore.kernel.org/r/20220614200707.3315957-39-seanjc@google.com

KVM: selftests: Inline "get max CPUID leaf" helpers

2022-07-14T01:14:23+00:00

Make the "get max CPUID leaf" helpers static inline, there's no reason to
bury the one liners in processor.c.

Signed-off-by: Sean Christopherson 
Link: https://lore.kernel.org/r/20220614200707.3315957-38-seanjc@google.com