From: Quentin Perret <qperret@google.com>
Date: Wed, 11 Aug 2021 17:36:25 +0000 (+0100)
Subject: KVM: arm64: Return -EPERM from __pkvm_host_share_hyp()
X-Git-Tag: v5.15-rc1~65^2~4^2~5^2~3
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=12593568d7319c34c72038ea799ab1bd0f0eb01c;p=thirdparty%2Fkernel%2Flinux.git

KVM: arm64: Return -EPERM from __pkvm_host_share_hyp()

Fix the error code returned by __pkvm_host_share_hyp() when the
host attempts to share with EL2 a page that has already been shared with
another entity.

Reported-by: Will Deacon <will@kernel.org>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210811173630.2536721-1-qperret@google.com
---

diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
index 8165390d3ec99..6ec6953114986 100644
--- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
+++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
@@ -404,7 +404,7 @@ int __pkvm_host_share_hyp(u64 pfn)
 	cur = kvm_pgtable_hyp_pte_prot(pte);
 	prot = pkvm_mkstate(PAGE_HYP, PKVM_PAGE_SHARED_BORROWED);
 	if (!check_prot(cur, prot, ~prot))
-		ret = EPERM;
+		ret = -EPERM;
 	goto unlock;
 
 map_shared: