Replace all occurrences of vm_vaddr_t with gva_t to align with KVM code
and with the conversion helpers (e.g. addr_gva2hva()).

This commit was generated with the following command:

  git ls-files tools/testing/selftests/kvm | xargs sed -i 's/vm_vaddr_/gva_/g'

Then by manually adjusting whitespace to make checkpatch.pl happy, and
dropping renames of functions that allocate memory within a given VM.

No functional change intended.

Signed-off-by: David Matlack <dmatlack@google.com>
[sean: drop renames of allocator APIs]
Link: https://patch.msgid.link/20260420212004.3938325-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

Update the nested dirty log test to validate KVM's handling of READ faults
when dirty logging is enabled.  Specifically, set the Dirty bit in the
guest PTEs used to map L2 GPAs, so that KVM will create writable SPTEs
when handling L2 read faults.  When handling read faults in the shadow MMU,
KVM opportunistically creates a writable SPTE if the mapping can be
writable *and* the gPTE is dirty (or doesn't support the Dirty bit), i.e.
if KVM doesn't need to intercept writes in order to emulate Dirty-bit
updates.

To actually test the L2 READ=>WRITE sequence, e.g. without masking a false
pass by other test activity, route the READ=>WRITE and WRITE=>WRITE
sequences to separate L1 pages, and differentiate between "marked dirty
due to a WRITE access/fault" and "marked dirty due to creating a writable
SPTE for a READ access/fault".  The updated sequence exposes the bug fixed
by KVM commit 1f4e5fc83a42 ("KVM: x86: fix nested guest live migration
with PML") when the guest performs a READ=>WRITE sequence with dirty guest
PTEs.

Opportunistically tweak and rename the address macros, and add comments,
to make it more obvious what the test is doing.  E.g. NESTED_TEST_MEM1
vs. GUEST_TEST_MEM doesn't make it all that obvious that the test is
creating aliases in both the L2 GPA and GVA address spaces, but only when
L1 is using TDP to run L2.

Cc: Yosry Ahmed <yosry.ahmed@linux.dev>
Reviewed-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20260115172154.709024-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

Generalize the code in vmx_dirty_log_test.c by adding SVM-specific L1
code, doing some renaming (e.g. EPT -> TDP), and having setup code for
both SVM and VMX in test_dirty_log().

Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251230230150.4150236-19-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>