[PATCH 17/20] KVM: arm64: Extend pKVM page ownership selftests to cover guest block split

[Vincent Donnefort]

Extend the pKVM page ownership selftests to test the split of a guest
stage-2 block and the per-page reclaim of that same block.

Signed-off-by: Vincent Donnefort <vdonnefort at google.com>

diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
index 71ebd1856cb0..e22a7991f8ec 100644
--- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
+++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
@@ -2070,6 +2070,38 @@ int __pkvm_ownership_selftest(u64 pfn, u64 nr_pages, u64 pgtable_pfn,
 	assert_transition_res(-EPERM,	__pkvm_host_donate_guest, pfn, gfn, nr_pages, vcpu);
 	assert_transition_res(-EPERM,	__pkvm_host_share_guest, pfn, gfn, nr_pages, vcpu, prot);
 
+	if (size == PMD_SIZE) {
+		/* [gfn, gfn + nr_pages) was poisoned. Skip it */
+		gfn += nr_pages;
+
+		selftest_state.host = PKVM_NOPAGE;
+		selftest_state.guest[1] = PKVM_PAGE_OWNED;
+		assert_transition_res(0,	__pkvm_host_donate_guest, pfn, gfn, nr_pages, vcpu);
+		assert_transition_res(0,	__pkvm_host_split_guest, gfn, nr_pages, vcpu);
+
+		assert_transition_res(-E2BIG, __pkvm_host_split_guest, gfn, nr_pages, vcpu);
+		assert_transition_res(-E2BIG, __pkvm_host_reclaim_page_guest, gfn, nr_pages, vm);
+
+		for (int i = 0; i < nr_pages; i++)
+			WARN_ON(__pkvm_host_reclaim_page_guest(gfn + i, 1, vm));
+
+		selftest_state.host = PKVM_PAGE_OWNED;
+		selftest_state.guest[1] = PKVM_NOPAGE;
+		assert_page_state();
+
+		selftest_state.host = PKVM_NOPAGE;
+		selftest_state.guest[1] = PKVM_PAGE_OWNED;
+		assert_transition_res(0,	__pkvm_host_donate_guest, pfn, gfn, nr_pages, vcpu);
+		assert_transition_res(0,	__pkvm_host_split_guest, gfn, nr_pages, vcpu);
+
+		for (int i = 0; i < nr_pages; i++)
+			WARN_ON(__pkvm_host_force_reclaim_page_guest(phys + i * PAGE_SIZE));
+
+		selftest_state.host = PKVM_PAGE_OWNED;
+		selftest_state.guest[1] = PKVM_POISON;
+		assert_page_state();
+	}
+
 	selftest_state.host = PKVM_NOPAGE;
 	selftest_state.hyp = PKVM_PAGE_OWNED;
 	assert_transition_res(0,	__pkvm_host_donate_hyp, pfn, nr_pages);
-- 
2.55.0.508.g3f0d502094-goog