linux-toradex.git/tools, branch v6.2-rc2

Merge branch 'kvm-late-6.1-fixes' into HEAD

2022-12-28T12:19:14+00:00

x86:

* several fixes to nested VMX execution controls

* fixes and clarification to the documentation for Xen emulation

* do not unnecessarily release a pmu event with zero period

* MMU fixes

* fix Coverity warning in kvm_hv_flush_tlb()

selftests:

* fixes for the ucall mechanism in selftests

* other fixes mostly related to compilation with clang

KVM: selftests: restore special vmmcall code layout needed by the harness

2022-12-28T12:18:01+00:00

Commit 8fda37cf3d41 ("KVM: selftests: Stuff RAX/RCX with 'safe' values
in vmmcall()/vmcall()", 2022-11-21) broke the svm_nested_soft_inject_test
because it placed a "pop rbp" instruction after vmmcall.  While this is
correct and mimics what is done in the VMX case, this particular test
expects a ud2 instruction right after the vmmcall, so that it can skip
over it in the L1 part of the test.

Inline a suitably-modified version of vmmcall() to restore the
functionality of the test.

Fixes: 8fda37cf3d41 ("KVM: selftests: Stuff RAX/RCX with 'safe' values in vmmcall()/vmcall()"
Cc: Vitaly Kuznetsov 
Signed-off-by: Paolo Bonzini 
Reviewed-by: Sean Christopherson 
Reviewed-by: Vitaly Kuznetsov 
Reviewed-by: Maxim Levitsky 
Message-Id: <20221130181147.9911-1-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini

KVM: x86: fix deadlock for KVM_XEN_EVTCHN_RESET

2022-12-28T10:53:57+00:00

While KVM_XEN_EVTCHN_RESET is usually called with no vCPUs running,
if that happened it could cause a deadlock.  This is due to
kvm_xen_eventfd_reset() doing a synchronize_srcu() inside
a kvm->lock critical section.

To avoid this, first collect all the evtchnfd objects in an
array and free all of them once the kvm->lock critical section
is over and th SRCU grace period has expired.

Reported-by: Michal Luczaj 
Cc: David Woodhouse 
Signed-off-by: Paolo Bonzini

KVM: selftests: Mark correct page as mapped in virt_map()

2022-12-27T11:00:50+00:00

The loop marks vaddr as mapped after incrementing it by page size,
thereby marking the *next* page as mapped. Set the bit in vpages_mapped
first instead.

Fixes: 56fc7732031d ("KVM: selftests: Fill in vm->vpages_mapped bitmap in virt_map() too")
Signed-off-by: Oliver Upton 
Message-Id: <20221209015307.1781352-4-oliver.upton@linux.dev>
Signed-off-by: Paolo Bonzini

KVM: arm64: selftests: Don't identity map the ucall MMIO hole

2022-12-27T11:00:50+00:00

Currently the ucall MMIO hole is placed immediately after slot0, which
is a relatively safe address in the PA space. However, it is possible
that the same address has already been used for something else (like the
guest program image) in the VA space. At least in my own testing,
building the vgic_irq test with clang leads to the MMIO hole appearing
underneath gicv3_ops.

Stop identity mapping the MMIO hole and instead find an unused VA to map
to it. Yet another subtle detail of the KVM selftests library is that
virt_pg_map() does not update vm->vpages_mapped. Switch over to
virt_map() instead to guarantee that the chosen VA isn't to something
else.

Signed-off-by: Oliver Upton 
Message-Id: <20221209015307.1781352-6-oliver.upton@linux.dev>
Signed-off-by: Paolo Bonzini

KVM: selftests: document the default implementation of vm_vaddr_populate_bitmap

2022-12-27T11:00:49+00:00

Explain the meaning of the bit manipulations of vm_vaddr_populate_bitmap.
These correspond to the "canonical addresses" of x86 and other
architectures, but that is not obvious.

Signed-off-by: Paolo Bonzini

KVM: selftests: Use magic value to signal ucall_alloc() failure

2022-12-27T11:00:49+00:00

Use a magic value to signal a ucall_alloc() failure instead of simply
doing GUEST_ASSERT().  GUEST_ASSERT() relies on ucall_alloc() and so a
failure puts the guest into an infinite loop.

Use -1 as the magic value, as a real ucall struct should never wrap.

Reported-by: Oliver Upton 
Signed-off-by: Sean Christopherson 
Signed-off-by: Paolo Bonzini

KVM: selftests: Disable "gnu-variable-sized-type-not-at-end" warning

2022-12-27T11:00:48+00:00

Disable gnu-variable-sized-type-not-at-end so that tests and libraries
can create overlays of variable sized arrays at the end of structs when
using a fixed number of entries, e.g. to get/set a single MSR.

It's possible to fudge around the warning, e.g. by defining a custom
struct that hardcodes the number of entries, but that is a burden for
both developers and readers of the code.

lib/x86_64/processor.c:664:19: warning: field 'header' with variable sized type 'struct kvm_msrs'
not at the end of a struct or class is a GNU extension [-Wgnu-variable-sized-type-not-at-end]
                struct kvm_msrs header;
                                ^
lib/x86_64/processor.c:772:19: warning: field 'header' with variable sized type 'struct kvm_msrs'
not at the end of a struct or class is a GNU extension [-Wgnu-variable-sized-type-not-at-end]
                struct kvm_msrs header;
                                ^
lib/x86_64/processor.c:787:19: warning: field 'header' with variable sized type 'struct kvm_msrs'
not at the end of a struct or class is a GNU extension [-Wgnu-variable-sized-type-not-at-end]
                struct kvm_msrs header;
                                ^
3 warnings generated.

x86_64/hyperv_tlb_flush.c:54:18: warning: field 'hv_vp_set' with variable sized type 'struct hv_vpset'
not at the end of a struct or class is a GNU extension [-Wgnu-variable-sized-type-not-at-end]
        struct hv_vpset hv_vp_set;
                        ^
1 warning generated.

x86_64/xen_shinfo_test.c:137:25: warning: field 'info' with variable sized type 'struct kvm_irq_routing'
not at the end of a struct or class is a GNU extension [-Wgnu-variable-sized-type-not-at-end]
        struct kvm_irq_routing info;
                               ^
1 warning generated.

Signed-off-by: Sean Christopherson 
Message-Id: <20221213001653.3852042-12-seanjc@google.com>
Signed-off-by: Paolo Bonzini

KVM: selftests: Include lib.mk before consuming $(CC)

2022-12-27T11:00:48+00:00

Include lib.mk before consuming $(CC) and document that lib.mk overwrites
$(CC) unless make was invoked with -e or $(CC) was specified after make
(which makes the environment override the Makefile).  Including lib.mk
after using it for probing, e.g. for -no-pie, can lead to weirdness.

Signed-off-by: Sean Christopherson 
Message-Id: <20221213001653.3852042-11-seanjc@google.com>
Signed-off-by: Paolo Bonzini

KVM: selftests: Explicitly disable builtins for mem*() overrides

2022-12-27T11:00:48+00:00

Explicitly disable the compiler's builtin memcmp(), memcpy(), and
memset().  Because only lib/string_override.c is built with -ffreestanding,
the compiler reserves the right to do what it wants and can try to link the
non-freestanding code to its own crud.

  /usr/bin/x86_64-linux-gnu-ld: /lib/x86_64-linux-gnu/libc.a(memcmp.o): in function `memcmp_ifunc':
  (.text+0x0): multiple definition of `memcmp'; tools/testing/selftests/kvm/lib/string_override.o:
  tools/testing/selftests/kvm/lib/string_override.c:15: first defined here
  clang: error: linker command failed with exit code 1 (use -v to see invocation)

Fixes: 6b6f71484bf4 ("KVM: selftests: Implement memcmp(), memcpy(), and memset() for guest use")
Reported-by: Aaron Lewis 
Reported-by: Raghavendra Rao Ananta 
Signed-off-by: Sean Christopherson 
Message-Id: <20221213001653.3852042-10-seanjc@google.com>
Signed-off-by: Paolo Bonzini