[PATCH] KVM: arm64: Use correct accessor to parse stage-1 PTEs

From: Quentin Perret
Date: Tue Oct 25 2022 - 10:52:30 EST


hyp_get_page_state() is used with pKVM to retrieve metadata about a page
by parsing a hypervisor stage-1 PTE. However, it incorrectly uses a
helper which parses *stage-2* mappings. Ouch.

Luckily, pkvm_getstate() only looks at the software bits, which happen
to be in the same place for stage-1 and stage-2 PTEs, and this all ends
up working correctly by accident. But clearly, we should do better.

Fix hyp_get_page_state() to use the correct helper.

Fixes: e82edcc75c4e ("KVM: arm64: Implement do_share() helper for sharing memory")
Signed-off-by: Quentin Perret <qperret@xxxxxxxxxx>
---
arch/arm64/kvm/hyp/nvhe/mem_protect.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
index 1e78acf9662e..07f9dc9848ef 100644
--- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
+++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
@@ -516,7 +516,7 @@ static enum pkvm_page_state hyp_get_page_state(kvm_pte_t pte)
if (!kvm_pte_valid(pte))
return PKVM_NOPAGE;

- return pkvm_getstate(kvm_pgtable_stage2_pte_prot(pte));
+ return pkvm_getstate(kvm_pgtable_hyp_pte_prot(pte));
}

static int __hyp_check_page_state_range(u64 addr, u64 size,
--
2.38.0.135.g90850a2211-goog