[PATCH 66/89] KVM: arm64: Donate memory to protected guests

[Will Deacon]

From: Marc Zyngier <maz at kernel.org>

Instead of sharing memory with protected guests, which still leaves the
host with r/w access, donate the underlying pages so that they are
unmapped from the host stage-2.

Signed-off-by: Marc Zyngier <maz at kernel.org>
---
 arch/arm64/kvm/hyp/nvhe/hyp-main.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index c1939dd2294f..e987f34641dd 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -465,7 +465,10 @@ static void handle___pkvm_host_map_guest(struct kvm_cpu_context *host_ctxt)
 	if (ret)
 		goto out;
 
-	ret = __pkvm_host_share_guest(pfn, gfn, shadow_vcpu);
+	if (shadow_state_is_protected(shadow_state))
+		ret = __pkvm_host_donate_guest(pfn, gfn, shadow_vcpu);
+	else
+		ret = __pkvm_host_share_guest(pfn, gfn, shadow_vcpu);
 out:
 	cpu_reg(host_ctxt, 1) =  ret;
 }
-- 
2.36.1.124.g0e6072fb45-goog