[PATCH 07/20] KVM: arm64: Add a range to __pkvm_host_donate_guest()

In preparation for supporting stage-2 huge mappings for protected VMs, add a
nr_pages argument to the __pkvm_host_donate_guest() hypercall. This
range supports only two values: 1 or PMD_SIZE / PAGE_SIZE (that is 512
on a 4K-pages system).

Signed-off-by: Vincent Donnefort <[email protected]>

diff --git a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
index 1f70162fa625..c13f258fffb7 100644
--- a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
@@ -39,7 +39,7 @@ int __pkvm_host_donate_hyp(u64 pfn, u64 nr_pages);
 int __pkvm_hyp_donate_host(u64 pfn, u64 nr_pages);
 int __pkvm_host_share_ffa(u64 pfn, u64 nr_pages);
 int __pkvm_host_unshare_ffa(u64 pfn, u64 nr_pages);
-int __pkvm_host_donate_guest(u64 pfn, u64 gfn, struct pkvm_hyp_vcpu *vcpu);
+int __pkvm_host_donate_guest(u64 pfn, u64 gfn, u64 nr_pages, struct pkvm_hyp_vcpu *vcpu);
 int __pkvm_vcpu_in_poison_fault(struct pkvm_hyp_vcpu *hyp_vcpu);
 int __pkvm_host_force_reclaim_page_guest(phys_addr_t phys);
 int __pkvm_host_reclaim_page_guest(u64 gfn, struct pkvm_hyp_vm *vm);
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index c922288a77e6..c7a8c2eea157 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -268,6 +268,7 @@ static void handle___pkvm_host_donate_guest(struct kvm_cpu_context *host_ctxt)
 {
 	DECLARE_REG(u64, pfn, host_ctxt, 1);
 	DECLARE_REG(u64, gfn, host_ctxt, 2);
+	DECLARE_REG(u64, nr_pages, host_ctxt, 3);
 	struct pkvm_hyp_vcpu *hyp_vcpu;
 	int ret = -EINVAL;
 
@@ -279,7 +280,7 @@ static void handle___pkvm_host_donate_guest(struct kvm_cpu_context *host_ctxt)
 	if (ret)
 		goto out;
 
-	ret = __pkvm_host_donate_guest(pfn, gfn, hyp_vcpu);
+	ret = __pkvm_host_donate_guest(pfn, gfn, nr_pages, hyp_vcpu);
 out:
 	cpu_reg(host_ctxt, 1) =  ret;
 }
diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
index 3118941a11a7..9ea448895c15 100644
--- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
+++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
@@ -1422,22 +1422,30 @@ static int __guest_check_pgtable_memcache(struct pkvm_hyp_vcpu *vcpu)
 	return 0;
 }
 
-int __pkvm_host_donate_guest(u64 pfn, u64 gfn, struct pkvm_hyp_vcpu *vcpu)
+int __pkvm_host_donate_guest(u64 pfn, u64 gfn, u64 nr_pages, struct pkvm_hyp_vcpu *vcpu)
 {
 	struct pkvm_hyp_vm *vm = pkvm_hyp_vcpu_to_hyp_vm(vcpu);
 	u64 phys = hyp_pfn_to_phys(pfn);
 	u64 ipa = hyp_pfn_to_phys(gfn);
+	u64 size;
 	u64 meta;
 	int ret;
 
+	if (!pfn_range_is_valid(pfn, nr_pages))
+		return -EINVAL;
+
+	ret = __guest_check_transition_size(phys, ipa, nr_pages, &size);
+	if (ret)
+		return ret;
+
 	host_lock_component();
 	guest_lock_component(vm);
 
-	ret = __host_check_page_state_range(phys, PAGE_SIZE, PKVM_PAGE_OWNED);
+	ret = __host_check_page_state_range(phys, size, PKVM_PAGE_OWNED);
 	if (ret)
 		goto unlock;
 
-	ret = __guest_check_page_state_range(vm, ipa, PAGE_SIZE, PKVM_NOPAGE);
+	ret = __guest_check_page_state_range(vm, ipa, size, PKVM_NOPAGE);
 	if (ret)
 		goto unlock;
 
@@ -1446,9 +1454,9 @@ int __pkvm_host_donate_guest(u64 pfn, u64 gfn, struct pkvm_hyp_vcpu *vcpu)
 		goto unlock;
 
 	meta = host_stage2_encode_gfn_meta(vm, gfn);
-	WARN_ON(host_stage2_set_owner_metadata_locked(phys, PAGE_SIZE,
+	WARN_ON(host_stage2_set_owner_metadata_locked(phys, size,
 						      PKVM_ID_GUEST, meta));
-	WARN_ON(kvm_pgtable_stage2_map(&vm->pgt, ipa, PAGE_SIZE, phys,
+	WARN_ON(kvm_pgtable_stage2_map(&vm->pgt, ipa, size, phys,
 				       pkvm_mkstate(KVM_PGTABLE_PROT_RWX, PKVM_PAGE_OWNED),
 				       &vcpu->vcpu.arch.pkvm_memcache, 0));
 
@@ -1790,7 +1798,7 @@ int __pkvm_ownership_selftest(u64 pfn, u64 pgtable_pfn, unsigned long pgtable_nr
 	assert_transition_res(-EPERM,	hyp_pin_shared_mem, virt, virt + size);
 	assert_transition_res(-EPERM,	__pkvm_host_share_guest, pfn, gfn, 1, vcpu, prot);
 	assert_transition_res(-ENOENT,	__pkvm_host_unshare_guest, gfn, 1, vm);
-	assert_transition_res(-EPERM,   __pkvm_host_donate_guest, pfn, gfn, vcpu);
+	assert_transition_res(-EPERM,   __pkvm_host_donate_guest, pfn, gfn, 1, vcpu);
 
 	selftest_state.host = PKVM_PAGE_OWNED;
 	selftest_state.hyp = PKVM_NOPAGE;
@@ -1810,7 +1818,7 @@ int __pkvm_ownership_selftest(u64 pfn, u64 pgtable_pfn, unsigned long pgtable_nr
 	assert_transition_res(-EPERM,	__pkvm_hyp_donate_host, pfn, 1);
 	assert_transition_res(-EPERM,	__pkvm_host_share_guest, pfn, gfn, 1, vcpu, prot);
 	assert_transition_res(-ENOENT,	__pkvm_host_unshare_guest, gfn, 1, vm);
-	assert_transition_res(-EPERM,   __pkvm_host_donate_guest, pfn, gfn, vcpu);
+	assert_transition_res(-EPERM,   __pkvm_host_donate_guest, pfn, gfn, 1, vcpu);
 
 	assert_transition_res(0,	hyp_pin_shared_mem, virt, virt + size);
 	assert_transition_res(0,	hyp_pin_shared_mem, virt, virt + size);
@@ -1823,7 +1831,7 @@ int __pkvm_ownership_selftest(u64 pfn, u64 pgtable_pfn, unsigned long pgtable_nr
 	assert_transition_res(-EPERM,	__pkvm_hyp_donate_host, pfn, 1);
 	assert_transition_res(-EPERM,	__pkvm_host_share_guest, pfn, gfn, 1, vcpu, prot);
 	assert_transition_res(-ENOENT,	__pkvm_host_unshare_guest, gfn, 1, vm);
-	assert_transition_res(-EPERM,   __pkvm_host_donate_guest, pfn, gfn, vcpu);
+	assert_transition_res(-EPERM,   __pkvm_host_donate_guest, pfn, gfn, 1, vcpu);
 
 	hyp_unpin_shared_mem(virt, virt + size);
 	assert_page_state();
@@ -1843,7 +1851,7 @@ int __pkvm_ownership_selftest(u64 pfn, u64 pgtable_pfn, unsigned long pgtable_nr
 	assert_transition_res(-EPERM,	__pkvm_hyp_donate_host, pfn, 1);
 	assert_transition_res(-EPERM,	__pkvm_host_share_guest, pfn, gfn, 1, vcpu, prot);
 	assert_transition_res(-ENOENT,	__pkvm_host_unshare_guest, gfn, 1, vm);
-	assert_transition_res(-EPERM,   __pkvm_host_donate_guest, pfn, gfn, vcpu);
+	assert_transition_res(-EPERM,   __pkvm_host_donate_guest, pfn, gfn, 1, vcpu);
 	assert_transition_res(-EPERM,	hyp_pin_shared_mem, virt, virt + size);
 
 	selftest_state.host = PKVM_PAGE_OWNED;
@@ -1860,7 +1868,7 @@ int __pkvm_ownership_selftest(u64 pfn, u64 pgtable_pfn, unsigned long pgtable_nr
 	assert_transition_res(-EPERM,	__pkvm_host_share_hyp, pfn, 1);
 	assert_transition_res(-EPERM,	__pkvm_host_unshare_hyp, pfn, 1);
 	assert_transition_res(-EPERM,	__pkvm_hyp_donate_host, pfn, 1);
-	assert_transition_res(-EPERM,   __pkvm_host_donate_guest, pfn, gfn, vcpu);
+	assert_transition_res(-EPERM,   __pkvm_host_donate_guest, pfn, gfn, 1, vcpu);
 	assert_transition_res(-EPERM,	hyp_pin_shared_mem, virt, virt + size);
 
 	selftest_state.guest[1] = PKVM_PAGE_SHARED_BORROWED;
@@ -1876,9 +1884,9 @@ int __pkvm_ownership_selftest(u64 pfn, u64 pgtable_pfn, unsigned long pgtable_nr
 
 	selftest_state.host = PKVM_NOPAGE;
 	selftest_state.guest[0] = PKVM_PAGE_OWNED;
-	assert_transition_res(0,	__pkvm_host_donate_guest, pfn, gfn, vcpu);
-	assert_transition_res(-EPERM,	__pkvm_host_donate_guest, pfn, gfn, vcpu);
-	assert_transition_res(-EPERM,	__pkvm_host_donate_guest, pfn, gfn + 1, vcpu);
+	assert_transition_res(0,	__pkvm_host_donate_guest, pfn, gfn, 1, vcpu);
+	assert_transition_res(-EPERM,	__pkvm_host_donate_guest, pfn, gfn, 1, vcpu);
+	assert_transition_res(-EPERM,	__pkvm_host_donate_guest, pfn, gfn + 1, 1, vcpu);
 	assert_transition_res(-EPERM,	__pkvm_host_share_guest, pfn, gfn, 1, vcpu, prot);
 	assert_transition_res(-EPERM,	__pkvm_host_share_guest, pfn, gfn + 1, 1, vcpu, prot);
 	assert_transition_res(-EPERM,	__pkvm_host_share_ffa, pfn, 1);
@@ -1891,8 +1899,8 @@ int __pkvm_ownership_selftest(u64 pfn, u64 pgtable_pfn, unsigned long pgtable_nr
 	selftest_state.guest[0] = PKVM_PAGE_SHARED_OWNED;
 	assert_transition_res(0,	__pkvm_guest_share_host, vcpu, gfn);
 	assert_transition_res(-EPERM,	__pkvm_guest_share_host, vcpu, gfn);
-	assert_transition_res(-EPERM,	__pkvm_host_donate_guest, pfn, gfn, vcpu);
-	assert_transition_res(-EPERM,	__pkvm_host_donate_guest, pfn, gfn + 1, vcpu);
+	assert_transition_res(-EPERM,	__pkvm_host_donate_guest, pfn, gfn, 1, vcpu);
+	assert_transition_res(-EPERM,	__pkvm_host_donate_guest, pfn, gfn + 1, 1, vcpu);
 	assert_transition_res(-EPERM,	__pkvm_host_share_guest, pfn, gfn, 1, vcpu, prot);
 	assert_transition_res(-EPERM,	__pkvm_host_share_guest, pfn, gfn + 1, 1, vcpu, prot);
 	assert_transition_res(-EPERM,	__pkvm_host_share_ffa, pfn, 1);
@@ -1905,8 +1913,8 @@ int __pkvm_ownership_selftest(u64 pfn, u64 pgtable_pfn, unsigned long pgtable_nr
 	selftest_state.guest[0] = PKVM_PAGE_OWNED;
 	assert_transition_res(0,	__pkvm_guest_unshare_host, vcpu, gfn);
 	assert_transition_res(-EPERM,	__pkvm_guest_unshare_host, vcpu, gfn);
-	assert_transition_res(-EPERM,	__pkvm_host_donate_guest, pfn, gfn, vcpu);
-	assert_transition_res(-EPERM,	__pkvm_host_donate_guest, pfn, gfn + 1, vcpu);
+	assert_transition_res(-EPERM,	__pkvm_host_donate_guest, pfn, gfn, 1, vcpu);
+	assert_transition_res(-EPERM,	__pkvm_host_donate_guest, pfn, gfn + 1, 1, vcpu);
 	assert_transition_res(-EPERM,	__pkvm_host_share_guest, pfn, gfn, 1, vcpu, prot);
 	assert_transition_res(-EPERM,	__pkvm_host_share_guest, pfn, gfn + 1, 1, vcpu, prot);
 	assert_transition_res(-EPERM,	__pkvm_host_share_ffa, pfn, 1);
@@ -1918,19 +1926,19 @@ int __pkvm_ownership_selftest(u64 pfn, u64 pgtable_pfn, unsigned long pgtable_nr
 	selftest_state.host = PKVM_PAGE_OWNED;
 	selftest_state.guest[0] = PKVM_POISON;
 	assert_transition_res(0,	__pkvm_host_force_reclaim_page_guest, phys);
-	assert_transition_res(-EPERM,	__pkvm_host_donate_guest, pfn, gfn, vcpu);
+	assert_transition_res(-EPERM,	__pkvm_host_donate_guest, pfn, gfn, 1, vcpu);
 	assert_transition_res(-EPERM,	__pkvm_host_share_guest, pfn, gfn, 1, vcpu, prot);
 	assert_transition_res(-EHWPOISON, __pkvm_guest_share_host, vcpu, gfn);
 	assert_transition_res(-EHWPOISON, __pkvm_guest_unshare_host, vcpu, gfn);
 
 	selftest_state.host = PKVM_NOPAGE;
 	selftest_state.guest[1] = PKVM_PAGE_OWNED;
-	assert_transition_res(0,	__pkvm_host_donate_guest, pfn, gfn + 1, vcpu);
+	assert_transition_res(0,	__pkvm_host_donate_guest, pfn, gfn + 1, 1, vcpu);
 
 	selftest_state.host = PKVM_PAGE_OWNED;
 	selftest_state.guest[1] = PKVM_NOPAGE;
 	assert_transition_res(0,	__pkvm_host_reclaim_page_guest, gfn + 1, vm);
-	assert_transition_res(-EPERM,	__pkvm_host_donate_guest, pfn, gfn, vcpu);
+	assert_transition_res(-EPERM,	__pkvm_host_donate_guest, pfn, gfn, 1, vcpu);
 	assert_transition_res(-EPERM,	__pkvm_host_share_guest, pfn, gfn, 1, vcpu, prot);
 
 	selftest_state.host = PKVM_NOPAGE;
diff --git a/arch/arm64/kvm/pkvm.c b/arch/arm64/kvm/pkvm.c
index 047f941fcbb9..58d8474b563e 100644
--- a/arch/arm64/kvm/pkvm.c
+++ b/arch/arm64/kvm/pkvm.c
@@ -465,7 +465,7 @@ int pkvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size,
 			return ret ? -EFAULT : -EAGAIN;
 		}
 
-		ret = kvm_call_hyp_nvhe(__pkvm_host_donate_guest, pfn, gfn);
+		ret = kvm_call_hyp_nvhe(__pkvm_host_donate_guest, pfn, gfn, 1);
 	} else {
 		if (WARN_ON_ONCE(size != PAGE_SIZE && size != PMD_SIZE))
 			return -EINVAL;
-- 
2.55.0.508.g3f0d502094-goog