KVM: selftests: Make sure vm->vpages_mapped is always up-to-date

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Call paths leading to __virt_pg_map() are currently:
(a) virt_pg_map() -> virt_arch_pg_map() -> __virt_pg_map()
(b) virt_map_level() -> __virt_pg_map()

For (a), calls to virt_pg_map() from kvm_util.c make sure they update
vm->vpages_mapped, but other callers do not. Move the sparsebit_set()
call into virt_pg_map() to make sure all callers are captured.

For (b), call sparsebit_set_num() from virt_map_level().

It's tempting to have a single the call inside __virt_pg_map(), however:
- The call path in (a) is not x86-specific, while (b) is. Moving the
  call into __virt_pg_map() would require doing something similar for
  other archs implementing virt_pg_map().

- Future changes will reusue __virt_pg_map() for nested PTEs, which should
  not update vm->vpages_mapped, i.e. a triple underscore version that does
  not update vm->vpages_mapped would need to be provided.

Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251021074736.1324328-12-yosry.ahmed@linux.dev
Signed-off-by: Sean Christopherson <seanjc@google.com>

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Yosry Ahmed 2025-10-21 07:47:24 +00:00 • committed by Sean Christopherson

parent 1de4dc15ba

commit d2e50389ab

3 changed files with 3 additions and 3 deletions

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1

tools/testing/selftests/kvm/include/kvm_util.h

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tools/testing/selftests/kvm/lib/kvm_util.c

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tools/testing/selftests/kvm/lib/x86/processor.c

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