KVM: arm64: Don't WARN from __pkvm_host_share_guest()

We currently WARN() if the host attempts to share a page that is not in
an acceptable state with a guest. This isn't strictly necessary and
makes testing much harder, so drop the WARN and make sure to propage the
error code instead.

Signed-off-by: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20250416160900.3078417-3-qperret@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>

diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
index 2a5284f749b427927791f0706f66542e90611df9..cf6207aa1434ffb07de38d32c190c38283b26637 100644 (file)
--- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
+++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
@@ -919,7 +919,6 @@ int __pkvm_host_share_guest(u64 pfn, u64 gfn, struct pkvm_hyp_vcpu *vcpu,
                if (page->host_share_guest_count)
                        break;
                /* Only host to np-guest multi-sharing is tolerated */
-               WARN_ON(1);
                fallthrough;
        default:
                ret = -EPERM;