Ignore the guest's CR3 when looking for a cached root for a direct MMU,
the guest's CR3 has no impact on the direct MMU's shadow pages (the
role check ensures compatibility with CR0.WP, etc...).

Zero out root_cr3 when allocating the direct roots to make it clear that
it's ignored.

Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The AVIC does not support guest use of the x2APIC interface. Currently,
KVM simply chooses to squash the x2APIC feature in the guest's CPUID
If the AVIC is enabled. Doing so prevents KVM from running a guest
with greater than 255 vCPUs, as such a guest necessitates the use
of the x2APIC interface.

Instead, inhibit AVIC enablement on a per-VM basis whenever the x2APIC
feature is set in the guest's CPUID.
Signed-off-by: NOliver Upton <oupton@google.com>
Reviewed-by: NJim Mattson <jmattson@google.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Remove includes of asm/kvm_host.h from files that already include
linux/kvm_host.h to make it more obvious that there is no ordering issue
between the two headers.  linux/kvm_host.h includes asm/kvm_host.h to
pick up architecture specific settings, and this will never change, i.e.
including asm/kvm_host.h after linux/kvm_host.h may seem problematic,
but in practice is simply redundant.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The TEST_ASSERT in x86_64/platform_info_test.c would have print 'ucall'
instead of 'uc.cmd'. Also fix all uc.cmd format types.
Signed-off-by: NAndrew Jones <drjones@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Move the VM allocation and free code to common x86 as the logic is
more or less identical across SVM and VMX.

Note, although hyperv.hv_pa_pg is part of the common kvm->arch, it's
(currently) only allocated by VMX VMs.  But, since kfree() plays nice
when passed a NULL pointer, the superfluous call for SVM is harmless
and avoids future churn if SVM gains support for HyperV's direct TLB
flush.
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: NVitaly Kuznetsov <vkuznets@redhat.com>
[Make vm_size a field instead of a function. - Paolo]
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Directly return the __vmalloc() result in {svm,vmx}_vm_alloc() to pave
the way for handling VM alloc/free in common x86 code, and to obviate
the need to check the result of __vmalloc() in vendor specific code.
Add a build-time assertion to ensure each structs' "kvm" field stays at
offset 0, which allows interpreting a "struct kvm_{svm,vmx}" as a
"struct kvm".
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Check the result of __vmalloc() to avoid dereferencing a NULL pointer in
the event that allocation failres.

Fixes: d1e5b0e9 ("kvm: Make VM ioctl do valloc for some archs")
Cc: stable@vger.kernel.org
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The sample_period of a counter tracks when that counter will
overflow and set global status/trigger a PMI. However this currently
only gets set when the initial counter is created or when a counter is
resumed; this updates the sample period after a wrmsr so running
counters will accurately reflect their new value.
Signed-off-by: NEric Hankland <ehankland@google.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Replace open coded instances of kvm_arch_flush_remote_tlbs_memslot()'s
functionality with calls to the aforementioned function.  Update the
comment in kvm_arch_flush_remote_tlbs_memslot() to elaborate on how it
is used and why it asserts that slots_lock is held.

No functional change intended.
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Use the with_address() variant when performing a TLB flush for a
specific memslot via kvm_arch_flush_remote_tlbs_memslot(), i.e. when
flushing after clearing dirty bits during KVM_{GET,CLEAR}_DIRTY_LOG.
This aligns all dirty log memslot-specific TLB flushes to use the
with_address() variant and paves the way for consolidating the relevant
code.

Note, moving to the with_address() variant only affects functionality
when running as a HyperV guest.

Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Move kvm_arch_flush_remote_tlbs_memslot() from x86.c to mmu.c in
preparation for calling kvm_flush_remote_tlbs_with_address() instead of
kvm_flush_remote_tlbs().  The with_address() variant is statically
defined in mmu.c, arguably kvm_arch_flush_remote_tlbs_memslot() belongs
in mmu.c anyways, and defining kvm_arch_flush_remote_tlbs_memslot() in
mmu.c will allow the compiler to inline said function when a future
patch consolidates open coded variants of the function.

No functional change intended.
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Add a KVM selftest to test moving the base gfn of a userspace memory
region.  Although the basic concept of moving memory regions is not x86
specific, the assumptions regarding large pages and MMIO shenanigans
used to verify the correctness make this x86_64 only for the time being.
Reviewed-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Now that the memslot logic doesn't assume memslots are always non-NULL,
dynamically size the array of memslots instead of unconditionally
allocating memory for the maximum number of memslots.

Note, because a to-be-deleted memslot must first be invalidated, the
array size cannot be immediately reduced when deleting a memslot.
However, consecutive deletions will realize the memory savings, i.e.
a second deletion will trim the entry.
Tested-by: NChristoffer Dall <christoffer.dall@arm.com>
Tested-by: NMarc Zyngier <maz@kernel.org>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Refactor memslot handling to treat the number of used slots as the de
facto size of the memslot array, e.g. return NULL from id_to_memslot()
when an invalid index is provided instead of relying on npages==0 to
detect an invalid memslot.  Rework the sorting and walking of memslots
in advance of dynamically sizing memslots to aid bisection and debug,
e.g. with luck, a bug in the refactoring will bisect here and/or hit a
WARN instead of randomly corrupting memory.

Alternatively, a global null/invalid memslot could be returned, i.e. so
callers of id_to_memslot() don't have to explicitly check for a NULL
memslot, but that approach runs the risk of introducing difficult-to-
debug issues, e.g. if the global null slot is modified.  Constifying
the return from id_to_memslot() to combat such issues is possible, but
would require a massive refactoring of arch specific code and would
still be susceptible to casting shenanigans.

Add function comments to update_memslots() and search_memslots() to
explicitly (and loudly) state how memslots are sorted.

Opportunistically stuff @hva with a non-canonical value when deleting a
private memslot on x86 to detect bogus usage of the freed slot.

No functional change intended.
Tested-by: NChristoffer Dall <christoffer.dall@arm.com>
Tested-by: NMarc Zyngier <maz@kernel.org>
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Rework kvm_get_dirty_log() so that it "returns" the associated memslot
on success.  A future patch will rework memslot handling such that
id_to_memslot() can return NULL, returning the memslot makes it more
obvious that the validity of the memslot has been verified, i.e.
precludes the need to add validity checks in the arch code that are
technically unnecessary.

To maintain ordering in s390, move the call to kvm_arch_sync_dirty_log()
from s390's kvm_vm_ioctl_get_dirty_log() to the new kvm_get_dirty_log().
This is a nop for PPC, the only other arch that doesn't select
KVM_GENERIC_DIRTYLOG_READ_PROTECT, as its sync_dirty_log() is empty.

Ideally, moving the sync_dirty_log() call would be done in a separate
patch, but it can't be done in a follow-on patch because that would
temporarily break s390's ordering.  Making the move in a preparatory
patch would be functionally correct, but would create an odd scenario
where the moved sync_dirty_log() would operate on a "different" memslot
due to consuming the result of a different id_to_memslot().  The
memslot couldn't actually be different as slots_lock is held, but the
code is confusing enough as it is, i.e. moving sync_dirty_log() in this
patch is the lesser of all evils.
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Move the implementations of KVM_GET_DIRTY_LOG and KVM_CLEAR_DIRTY_LOG
for CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT into common KVM code.
The arch specific implemenations are extremely similar, differing
only in whether the dirty log needs to be sync'd from hardware (x86)
and how the TLBs are flushed.  Add new arch hooks to handle sync
and TLB flush; the sync will also be used for non-generic dirty log
support in a future patch (s390).

The ulterior motive for providing a common implementation is to
eliminate the dependency between arch and common code with respect to
the memslot referenced by the dirty log, i.e. to make it obvious in the
code that the validity of the memslot is guaranteed, as a future patch
will rework memslot handling such that id_to_memslot() can return NULL.
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Clean up __kvm_set_memory_region() to achieve several goals:

  - Remove local variables that serve no real purpose
  - Improve the readability of the code
  - Better show the relationship between the 'old' and 'new' memslot
  - Prepare for dynamically sizing memslots
  - Document subtle gotchas (via comments)

Note, using 'tmp' to hold the initial memslot is not strictly necessary
at this juncture, e.g. 'old' could be directly copied from
id_to_memslot(), but keep the pointer usage as id_to_memslot() will be
able to return a NULL pointer once memslots are dynamically sized.
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Now that all callers of kvm_free_memslot() pass NULL for @dont, remove
the param from the top-level routine and all arch's implementations.

No functional change intended.
Tested-by: NChristoffer Dall <christoffer.dall@arm.com>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Move memslot deletion into its own routine so that the success path for
other memslot updates does not need to use kvm_free_memslot(), i.e. can
explicitly destroy the dirty bitmap when necessary.  This paves the way
for dropping @dont from kvm_free_memslot(), i.e. all callers now pass
NULL for @dont.

Add a comment above the code to make a copy of the existing memslot
prior to deletion, it is not at all obvious that the pointer will become
stale during sorting and/or installation of new memslots.

Note, kvm_arch_commit_memory_region() allows an architecture to free
resources when moving a memslot or changing its flags, e.g. x86 frees
its arch specific memslot metadata during commit_memory_region().
Acked-by: NChristoffer Dall <christoffer.dall@arm.com>
Tested-by: NChristoffer Dall <christoffer.dall@arm.com>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Explicitly free the metadata arrays (stored in slot->arch) in the old
memslot structure when moving the memslot's base gfn is committed.  This
eliminates x86's dependency on kvm_free_memslot() being called when a
memslot move is committed, and paves the way for removing the funky code
in kvm_free_memslot() that conditionally frees structures based on its
@dont param.
Reviewed-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Drop the "const" attribute from @old in kvm_arch_commit_memory_region()
to allow arch specific code to free arch specific resources in the old
memslot without having to cast away the attribute.  Freeing resources in
kvm_arch_commit_memory_region() paves the way for simplifying
kvm_free_memslot() by eliminating the last usage of its @dont param.
Reviewed-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Split out the core functionality of setting a memslot into a separate
helper in preparation for moving memslot deletion into its own routine.
Tested-by: NChristoffer Dall <christoffer.dall@arm.com>
Reviewed-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Replace a big pile o' gotos with returns to make it more obvious what
error code is being returned, and to prepare for refactoring the
functional, i.e. post-checks, portion of __kvm_set_memory_region().
Reviewed-by: NJanosch Frank <frankja@linux.ibm.com>
Reviewed-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Explicitly free an allocated-but-unused dirty bitmap instead of relying
on kvm_free_memslot() if an error occurs in __kvm_set_memory_region().
There is no longer a need to abuse kvm_free_memslot() to free arch
specific resources as arch specific code is now called only after the
common flow is guaranteed to succeed.  Arch code can still fail, but
it's responsible for its own cleanup in that case.

Eliminating the error path's abuse of kvm_free_memslot() paves the way
for simplifying kvm_free_memslot(), i.e. dropping its @dont param.
Reviewed-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Remove kvm_arch_create_memslot() now that all arch implementations are
effectively nops.  Removing kvm_arch_create_memslot() eliminates the
possibility for arch specific code to allocate memory prior to setting
a memslot, which sets the stage for simplifying kvm_free_memslot().

Cc: Janosch Frank <frankja@linux.ibm.com>
Acked-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Allocate the various metadata structures associated with a new memslot
during kvm_arch_prepare_memory_region(), which paves the way for
removing kvm_arch_create_memslot() altogether.  Moving x86's memory
allocation only changes the order of kernel memory allocations between
x86 and common KVM code.
Reviewed-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Allocate the rmap array during kvm_arch_prepare_memory_region() to pave
the way for removing kvm_arch_create_memslot() altogether.  Moving PPC's
memory allocation only changes the order of kernel memory allocations
between PPC and common KVM code.

No functional change intended.
Acked-by: NPaul Mackerras <paulus@ozlabs.org>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The two implementations of kvm_arch_create_memslot() in x86 and PPC are
both good citizens and free up all local resources if creation fails.
Return immediately (via a superfluous goto) instead of calling
kvm_free_memslot().

Note, the call to kvm_free_memslot() is effectively an expensive nop in
this case as there are no resources to be freed.

No functional change intended.
Acked-by: NChristoffer Dall <christoffer.dall@arm.com>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Reinstall the old memslots if preparing the new memory region fails
after invalidating a to-be-{re}moved memslot.

Remove the superfluous 'old_memslots' variable so that it's somewhat
clear that the error handling path needs to free the unused memslots,
not simply the 'old' memslots.

Fixes: bc6678a3 ("KVM: introduce kvm->srcu and convert kvm_set_memory_region to SRCU update")
Reviewed-by: NChristoffer Dall <christoffer.dall@arm.com>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Reallocate a rmap array and recalcuate large page compatibility when
moving an existing memslot to correctly handle the alignment properties
of the new memslot.  The number of rmap entries required at each level
is dependent on the alignment of the memslot's base gfn with respect to
that level, e.g. moving a large-page aligned memslot so that it becomes
unaligned will increase the number of rmap entries needed at the now
unaligned level.

Not updating the rmap array is the most obvious bug, as KVM accesses
garbage data beyond the end of the rmap.  KVM interprets the bad data as
pointers, leading to non-canonical #GPs, unexpected #PFs, etc...

  general protection fault: 0000 [#1] SMP
  CPU: 0 PID: 1909 Comm: move_memory_reg Not tainted 5.4.0-rc7+ #139
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
  RIP: 0010:rmap_get_first+0x37/0x50 [kvm]
  Code: <48> 8b 3b 48 85 ff 74 ec e8 6c f4 ff ff 85 c0 74 e3 48 89 d8 5b c3
  RSP: 0018:ffffc9000021bbc8 EFLAGS: 00010246
  RAX: ffff00617461642e RBX: ffff00617461642e RCX: 0000000000000012
  RDX: ffff88827400f568 RSI: ffffc9000021bbe0 RDI: ffff88827400f570
  RBP: 0010000000000000 R08: ffffc9000021bd00 R09: ffffc9000021bda8
  R10: ffffc9000021bc48 R11: 0000000000000000 R12: 0030000000000000
  R13: 0000000000000000 R14: ffff88827427d700 R15: ffffc9000021bce8
  FS:  00007f7eda014700(0000) GS:ffff888277a00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007f7ed9216ff8 CR3: 0000000274391003 CR4: 0000000000162eb0
  Call Trace:
   kvm_mmu_slot_set_dirty+0xa1/0x150 [kvm]
   __kvm_set_memory_region.part.64+0x559/0x960 [kvm]
   kvm_set_memory_region+0x45/0x60 [kvm]
   kvm_vm_ioctl+0x30f/0x920 [kvm]
   do_vfs_ioctl+0xa1/0x620
   ksys_ioctl+0x66/0x70
   __x64_sys_ioctl+0x16/0x20
   do_syscall_64+0x4c/0x170
   entry_SYSCALL_64_after_hwframe+0x44/0xa9
  RIP: 0033:0x7f7ed9911f47
  Code: <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 21 6f 2c 00 f7 d8 64 89 01 48
  RSP: 002b:00007ffc00937498 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
  RAX: ffffffffffffffda RBX: 0000000001ab0010 RCX: 00007f7ed9911f47
  RDX: 0000000001ab1350 RSI: 000000004020ae46 RDI: 0000000000000004
  RBP: 000000000000000a R08: 0000000000000000 R09: 00007f7ed9214700
  R10: 00007f7ed92149d0 R11: 0000000000000246 R12: 00000000bffff000
  R13: 0000000000000003 R14: 00007f7ed9215000 R15: 0000000000000000
  Modules linked in: kvm_intel kvm irqbypass
  ---[ end trace 0c5f570b3358ca89 ]---

The disallow_lpage tracking is more subtle.  Failure to update results
in KVM creating large pages when it shouldn't, either due to stale data
or again due to indexing beyond the end of the metadata arrays, which
can lead to memory corruption and/or leaking data to guest/userspace.

Note, the arrays for the old memslot are freed by the unconditional call
to kvm_free_memslot() in __kvm_set_memory_region().

Fixes: 05da4558 ("KVM: MMU: large page support")
Cc: stable@vger.kernel.org
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Move the GPA tracking into the emulator context now that the context is
guaranteed to be initialized via __init_emulate_ctxt() prior to
dereferencing gpa_{available,val}, i.e. now that seeing a stale
gpa_available will also trigger a WARN due to an invalid context.
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Add a new emulation type flag to explicitly mark emulation related to a
page fault.  Move the propation of the GPA into the emulator from the
page fault handler into x86_emulate_instruction, using EMULTYPE_PF as an
indicator that cr2 is valid.  Similarly, don't propagate cr2 into the
exception.address when it's *not* valid.
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The function apic_lvt_vector() is unused now, remove it.
Signed-off-by: NMiaohe Lin <linmiaohe@huawei.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Each if branch in handle_external_interrupt_irqoff() is mutually
exclusive. Add 'else' to make it clear and also avoid some unnecessary
check.
Signed-off-by: NMiaohe Lin <linmiaohe@huawei.com>
Reviewed-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

These code are unreachable, remove them.
Signed-off-by: NMiaohe Lin <linmiaohe@huawei.com>
Reviewed-by: NKrish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Use %u to print u32 var and correct some coding style.
Signed-off-by: NMiaohe Lin <linmiaohe@huawei.com>
Reviewed-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Better reflect the structure of the code and metion why we could not
always honor the guest.
Signed-off-by: NChia-I Wu <olvaffe@gmail.com>
Cc: Gurchetan Singh <gurchetansingh@chromium.org>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

We leave some printf's because they inform the user the test is being
skipped. QUIET should not disable those. We also leave the printf's
used for help text.
Signed-off-by: NAndrew Jones <drjones@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

There were a few problems with the way we output "debug" messages.
The first is that we used DEBUG() which is defined when NDEBUG is
not defined, but NDEBUG will never be defined for kselftests
because it relies too much on assert(). The next is that most
of the DEBUG() messages were actually "info" messages, which
users may want to turn off if they just want a silent test that
either completes or asserts. Finally, a debug message output from
a library function, and thus for all tests, was annoying when its
information wasn't interesting for a test.

Rework these messages so debug messages only output when DEBUG
is defined and info messages output unless QUIET is defined.
Also name the functions pr_debug and pr_info and make sure that
when they're disabled we eat all the inputs. The later avoids
unused variable warnings when the variables were only defined
for the purpose of printing.
Signed-off-by: NAndrew Jones <drjones@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

In order to quantify demand paging performance, time guest execution
during demand paging.
Signed-off-by: NBen Gardon <bgardon@google.com>
[Move timespec-diff to test_util.h]
Signed-off-by: NAndrew Jones <drjones@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>