KVM: selftests: Remove redundant newlines

TEST_* functions append their own newline. Remove newlines from
TEST_* callsites to avoid extra newlines in output.

Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20231206170241.82801-8-ajones@ventanamicro.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

KVM: selftests: Introduce VM "shape" to allow tests to specify the VM type

Add a "vm_shape" structure to encapsulate the selftests-defined "mode",
along with the KVM-defined "type" for use when creating a new VM. "mode"
tracks physical and virtual address properties, as well as the preferred
backing memory type, while "type" corresponds to the VM type.

Taking the VM type will allow adding tests for KVM_CREATE_GUEST_MEMFD
without needing an entirely separate set of helpers. At this time,
guest_memfd is effectively usable only by confidential VM types in the
form of guest private memory, and it's expected that x86 will double down
and require unique VM types for TDX and SNP guests.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20231027182217.3615211-30-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

KVM: selftests: Move dirty logging functions to memstress.(c|h)

Move some helper functions from dirty_log_perf_test.c to the memstress
library so that they can be used in a future commit which tests page
splitting during dirty logging.

Reviewed-by: Vipin Sharma <vipinsh@google.com>
Signed-off-by: Ben Gardon <bgardon@google.com>
Link: https://lore.kernel.org/r/20230131181820.179033-2-bgardon@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

KVM: selftests: touch all pages of args on each memstress iteration

Access the same memory addresses on each iteration of the memstress
guest code. This ensures that the state of KVM's page tables
is the same after every iteration, including the pages that host the
guest page tables for args and vcpu_args.

This difference is visible when running the proposed
dirty_log_page_splitting_test[*] on AMD, or on Intel with pml=0 and
eptad=0. The tests fail due to different semantics of dirty bits for
page-table pages on AMD (and eptad=0) and Intel. Both AMD and Intel with
eptad=0 treat page-table accesses as writes, therefore more pages are
dropped before the repopulation phase when dirty logging is disabled.

The "missing" page had been included in the population phase because it
hosts the page tables for vcpu_args, but repopulation does not need it."

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Vipin Sharma <vipinsh@google.com>
Link: https://lore.kernel.org/r/20230412200913.1570873-1-pbonzini@redhat.com
[sean: add additional details in changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>

KVM: selftests: Drop now-unnecessary ucall_uninit()

Drop ucall_uninit() and ucall_arch_uninit() now that ARM doesn't modify
the host's copy of ucall_exit_mmio_addr, i.e. now that there's no need to
reset the pointer before potentially creating a new VM. The few calls to
ucall_uninit() are all immediately followed by kvm_vm_free(), and that is
likely always going to hold true, i.e. it's extremely unlikely a test
will want to effectively disable ucall in the middle of a test.

Reviewed-by: Andrew Jones <andrew.jones@linux.dev>
Tested-by: Peter Gonda <pgonda@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221006003409.649993-7-seanjc@google.com

KVM: selftests: Automatically do init_ucall() for non-barebones VMs

Do init_ucall() automatically during VM creation to kill two (three?)
birds with one stone.

First, initializing ucall immediately after VM creations allows forcing
aarch64's MMIO ucall address to immediately follow memslot0. This is
still somewhat fragile as tests could clobber the MMIO address with a
new memslot, but it's safe-ish since tests have to be conversative when
accounting for memslot0. And this can be hardened in the future by
creating a read-only memslot for the MMIO page (KVM ARM exits with MMIO
if the guest writes to a read-only memslot). Add a TODO to document that
selftests can and should use a memslot for the ucall MMIO (doing so
requires yet more rework because tests assumes thay can use all memslots
except memslot0).

Second, initializing ucall for all VMs prepares for making ucall
initialization meaningful on all architectures. aarch64 is currently the
only arch that needs to do any setup, but that will change in the future
by switching to a pool-based implementation (instead of the current
stack-based approach).

Lastly, defining the ucall MMIO address from common code will simplify
switching all architectures (except s390) to a common MMIO-based ucall
implementation (if there's ever sufficient motivation to do so).

Cc: Oliver Upton <oliver.upton@linux.dev>
Reviewed-by: Andrew Jones <andrew.jones@linux.dev>
Tested-by: Peter Gonda <pgonda@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221006003409.649993-4-seanjc@google.com

KVM: selftests: Rename perf_test_util symbols to memstress

Replace the perf_test_ prefix on symbol names with memstress_ to match
the new file name.

"memstress" better describes the functionality proveded by this library,
which is to provide functionality for creating and running a VM that
stresses VM memory by reading and writing to guest memory on all vCPUs
in parallel.

"memstress" also contains the same number of chracters as "perf_test",
making it a drop-in replacement in symbols, e.g. function names, without
impacting line lengths. Also the lack of underscore between "mem" and
"stress" makes it clear "memstress" is a noun.

Signed-off-by: David Matlack <dmatlack@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221012165729.3505266-4-dmatlack@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

KVM: selftests: Rename pta (short for perf_test_args) to args

Rename the local variables "pta" (which is short for perf_test_args) for
args. "pta" is not an obvious acronym and using "args" mirrors
"vcpu_args".

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221012165729.3505266-3-dmatlack@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

KVM: selftests: Rename perf_test_util.[ch] to memstress.[ch]

Rename the perf_test_util.[ch] files to memstress.[ch]. Symbols are
renamed in the following commit to reduce the amount of churn here in
hopes of playiing nice with git's file rename detection.

The name "memstress" was chosen to better describe the functionality
proveded by this library, which is to create and run a VM that
reads/writes to guest memory on all vCPUs in parallel.

"memstress" also contains the same number of chracters as "perf_test",
making it a drop-in replacement in symbols, e.g. function names, without
impacting line lengths. Also the lack of underscore between "mem" and
"stress" makes it clear "memstress" is a noun.

Signed-off-by: David Matlack <dmatlack@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221012165729.3505266-2-dmatlack@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>