From bea4eea60a88511e53e6126ed5a4ee4beabe300b Mon Sep 17 00:00:00 2001
From: Will Deacon <willdeacon@google.com>
Date: Thu, 7 Jul 2022 15:51:53 +0100
Subject: [PATCH] Revert "FROMGIT: KVM: arm64: Expose unshare hypercall to the
 host"

This reverts commit b45ecf7774a0cff3021d8a7ce412029e352ef716.

Bug: 233587962
Signed-off-by: Will Deacon <willdeacon@google.com>
Change-Id: I88682e661a42d8aabc0f5f46461b750e9206c6ea
---
 arch/arm64/include/asm/kvm_asm.h              |  1 -
 arch/arm64/kvm/hyp/include/nvhe/mem_protect.h |  1 -
 arch/arm64/kvm/hyp/nvhe/hyp-main.c            |  8 -----
 arch/arm64/kvm/hyp/nvhe/mem_protect.c         | 33 -------------------
 4 files changed, 43 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index 59c55aedb0ae..0167f3702c61 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -63,7 +63,6 @@ enum __kvm_host_smccc_func {
 
 	/* Hypercalls available after pKVM finalisation */
 	__KVM_HOST_SMCCC_FUNC___pkvm_host_share_hyp,
-	__KVM_HOST_SMCCC_FUNC___pkvm_host_unshare_hyp,
 	__KVM_HOST_SMCCC_FUNC___kvm_adjust_pc,
 	__KVM_HOST_SMCCC_FUNC___kvm_vcpu_run,
 	__KVM_HOST_SMCCC_FUNC___kvm_flush_vm_context,
diff --git a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
index 80e99836eac7..56445586c755 100644
--- a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
@@ -55,7 +55,6 @@ extern const u8 pkvm_hyp_id;
 
 int __pkvm_prot_finalize(void);
 int __pkvm_host_share_hyp(u64 pfn);
-int __pkvm_host_unshare_hyp(u64 pfn);
 
 bool addr_is_memory(phys_addr_t phys);
 int host_stage2_idmap_locked(phys_addr_t addr, u64 size, enum kvm_pgtable_prot prot);
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index 5e2197db0d32..b096bf009144 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -147,13 +147,6 @@ static void handle___pkvm_host_share_hyp(struct kvm_cpu_context *host_ctxt)
 	cpu_reg(host_ctxt, 1) = __pkvm_host_share_hyp(pfn);
 }
 
-static void handle___pkvm_host_unshare_hyp(struct kvm_cpu_context *host_ctxt)
-{
-	DECLARE_REG(u64, pfn, host_ctxt, 1);
-
-	cpu_reg(host_ctxt, 1) = __pkvm_host_unshare_hyp(pfn);
-}
-
 static void handle___pkvm_create_private_mapping(struct kvm_cpu_context *host_ctxt)
 {
 	DECLARE_REG(phys_addr_t, phys, host_ctxt, 1);
@@ -191,7 +184,6 @@ static const hcall_t host_hcall[] = {
 	HANDLE_FUNC(__pkvm_prot_finalize),
 
 	HANDLE_FUNC(__pkvm_host_share_hyp),
-	HANDLE_FUNC(__pkvm_host_unshare_hyp),
 	HANDLE_FUNC(__kvm_adjust_pc),
 	HANDLE_FUNC(__kvm_vcpu_run),
 	HANDLE_FUNC(__kvm_flush_vm_context),
diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
index 16776d1d6151..2b23b2db8d4a 100644
--- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
+++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
@@ -769,36 +769,3 @@ int __pkvm_host_share_hyp(u64 pfn)
 
 	return ret;
 }
-
-int __pkvm_host_unshare_hyp(u64 pfn)
-{
-	int ret;
-	u64 host_addr = hyp_pfn_to_phys(pfn);
-	u64 hyp_addr = (u64)__hyp_va(host_addr);
-	struct pkvm_mem_share share = {
-		.tx	= {
-			.nr_pages	= 1,
-			.initiator	= {
-				.id	= PKVM_ID_HOST,
-				.addr	= host_addr,
-				.host	= {
-					.completer_addr = hyp_addr,
-				},
-			},
-			.completer	= {
-				.id	= PKVM_ID_HYP,
-			},
-		},
-		.completer_prot	= PAGE_HYP,
-	};
-
-	host_lock_component();
-	hyp_lock_component();
-
-	ret = do_unshare(&share);
-
-	hyp_unlock_component();
-	host_unlock_component();
-
-	return ret;
-}