diff mbox series

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

Message ID 20221025145156.855308-1-qperret@google.com
State New
Headers
Series KVM: arm64: Use correct accessor to parse stage-1 PTEs |

Commit Message

Quentin Perret Oct. 25, 2022, 2:51 p.m. UTC 
  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@google.com>
---
 arch/arm64/kvm/hyp/nvhe/mem_protect.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Marc Zyngier Oct. 25, 2022, 3:30 p.m. UTC | #1 
On Tue, 25 Oct 2022 14:51:56 +0000, Quentin Perret wrote:
> 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.
> 
> [...]

Applied to fixes, thanks!

[1/1] KVM: arm64: Use correct accessor to parse stage-1 PTEs
      commit: 6853a71726b6f5930b4450889faf02e8f1cfe35c

Cheers,

	M.
diff mbox series

Patch

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,