[PATCH v5 02/10] KVM: arm64: Introduce for_each_hyp_page

[Vincent Donnefort <vdonnefort@google.com>]

Add a helper to iterate over the hypervisor vmemmap. This will be
particularly handy with the introduction of huge mapping support
for the np-guest stage-2.

Signed-off-by: Vincent Donnefort <vdonnefort@google.com>

diff --git a/arch/arm64/kvm/hyp/include/nvhe/memory.h b/arch/arm64/kvm/hyp/include/nvhe/memory.h
index eb0c2ebd1743..dee1a406b0c2 100644
--- a/arch/arm64/kvm/hyp/include/nvhe/memory.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/memory.h
@@ -96,24 +96,24 @@ static inline struct hyp_page *hyp_phys_to_page(phys_addr_t phys)
 #define hyp_page_to_virt(page)	__hyp_va(hyp_page_to_phys(page))
 #define hyp_page_to_pool(page)	(((struct hyp_page *)page)->pool)
 
-static inline enum pkvm_page_state get_host_state(phys_addr_t phys)
+static inline enum pkvm_page_state get_host_state(struct hyp_page *p)
 {
-	return (enum pkvm_page_state)hyp_phys_to_page(phys)->__host_state;
+	return p->__host_state;
 }
 
-static inline void set_host_state(phys_addr_t phys, enum pkvm_page_state state)
+static inline void set_host_state(struct hyp_page *p, enum pkvm_page_state state)
 {
-	hyp_phys_to_page(phys)->__host_state = state;
+	p->__host_state = state;
 }
 
-static inline enum pkvm_page_state get_hyp_state(phys_addr_t phys)
+static inline enum pkvm_page_state get_hyp_state(struct hyp_page *p)
 {
-	return hyp_phys_to_page(phys)->__hyp_state_comp ^ PKVM_PAGE_STATE_MASK;
+	return p->__hyp_state_comp ^ PKVM_PAGE_STATE_MASK;
 }
 
-static inline void set_hyp_state(phys_addr_t phys, enum pkvm_page_state state)
+static inline void set_hyp_state(struct hyp_page *p, enum pkvm_page_state state)
 {
-	hyp_phys_to_page(phys)->__hyp_state_comp = state ^ PKVM_PAGE_STATE_MASK;
+	p->__hyp_state_comp = state ^ PKVM_PAGE_STATE_MASK;
 }
 
 /*
diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
index be4f7c5612f8..1018a6f66359 100644
--- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
+++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
@@ -60,6 +60,11 @@ static void hyp_unlock_component(void)
 	hyp_spin_unlock(&pkvm_pgd_lock);
 }
 
+#define for_each_hyp_page(__p, __st, __sz)				\
+	for (struct hyp_page *__p = hyp_phys_to_page(__st),		\
+			     *__e = __p + ((__sz) >> PAGE_SHIFT);	\
+	     __p < __e; __p++)
+
 static void *host_s2_zalloc_pages_exact(size_t size)
 {
 	void *addr = hyp_alloc_pages(&host_s2_pool, get_order(size));
@@ -485,7 +490,8 @@ static int host_stage2_adjust_range(u64 addr, struct kvm_mem_range *range)
 		return -EAGAIN;
 
 	if (pte) {
-		WARN_ON(addr_is_memory(addr) && get_host_state(addr) != PKVM_NOPAGE);
+		WARN_ON(addr_is_memory(addr) &&
+			get_host_state(hyp_phys_to_page(addr)) != PKVM_NOPAGE);
 		return -EPERM;
 	}
 
@@ -511,10 +517,8 @@ int host_stage2_idmap_locked(phys_addr_t addr, u64 size,
 
 static void __host_update_page_state(phys_addr_t addr, u64 size, enum pkvm_page_state state)
 {
-	phys_addr_t end = addr + size;
-
-	for (; addr < end; addr += PAGE_SIZE)
-		set_host_state(addr, state);
+	for_each_hyp_page(page, addr, size)
+		set_host_state(page, state);
 }
 
 int host_stage2_set_owner_locked(phys_addr_t addr, u64 size, u8 owner_id)
@@ -636,16 +640,16 @@ static int check_page_state_range(struct kvm_pgtable *pgt, u64 addr, u64 size,
 static int __host_check_page_state_range(u64 addr, u64 size,
 					 enum pkvm_page_state state)
 {
-	u64 end = addr + size;
 	int ret;
 
-	ret = check_range_allowed_memory(addr, end);
+	ret = check_range_allowed_memory(addr, addr + size);
 	if (ret)
 		return ret;
 
 	hyp_assert_lock_held(&host_mmu.lock);
-	for (; addr < end; addr += PAGE_SIZE) {
-		if (get_host_state(addr) != state)
+
+	for_each_hyp_page(page, addr, size) {
+		if (get_host_state(page) != state)
 			return -EPERM;
 	}
 
@@ -655,7 +659,7 @@ static int __host_check_page_state_range(u64 addr, u64 size,
 static int __host_set_page_state_range(u64 addr, u64 size,
 				       enum pkvm_page_state state)
 {
-	if (get_host_state(addr) == PKVM_NOPAGE) {
+	if (get_host_state(hyp_phys_to_page(addr)) == PKVM_NOPAGE) {
 		int ret = host_stage2_idmap_locked(addr, size, PKVM_HOST_MEM_PROT);
 
 		if (ret)
@@ -669,18 +673,14 @@ static int __host_set_page_state_range(u64 addr, u64 size,
 
 static void __hyp_set_page_state_range(phys_addr_t phys, u64 size, enum pkvm_page_state state)
 {
-	phys_addr_t end = phys + size;
-
-	for (; phys < end; phys += PAGE_SIZE)
-		set_hyp_state(phys, state);
+	for_each_hyp_page(page, phys, size)
+		set_hyp_state(page, state);
 }
 
 static int __hyp_check_page_state_range(phys_addr_t phys, u64 size, enum pkvm_page_state state)
 {
-	phys_addr_t end = phys + size;
-
-	for (; phys < end; phys += PAGE_SIZE) {
-		if (get_hyp_state(phys) != state)
+	for_each_hyp_page(page, phys, size) {
+		if (get_hyp_state(page) != state)
 			return -EPERM;
 	}
 
@@ -931,7 +931,7 @@ int __pkvm_host_share_guest(u64 pfn, u64 gfn, struct pkvm_hyp_vcpu *vcpu,
 		goto unlock;
 
 	page = hyp_phys_to_page(phys);
-	switch (get_host_state(phys)) {
+	switch (get_host_state(page)) {
 	case PKVM_PAGE_OWNED:
 		WARN_ON(__host_set_page_state_range(phys, PAGE_SIZE, PKVM_PAGE_SHARED_OWNED));
 		break;
@@ -983,9 +983,9 @@ static int __check_host_shared_guest(struct pkvm_hyp_vm *vm, u64 *__phys, u64 ip
 	if (WARN_ON(ret))
 		return ret;
 
-	if (get_host_state(phys) != PKVM_PAGE_SHARED_OWNED)
-		return -EPERM;
 	page = hyp_phys_to_page(phys);
+	if (get_host_state(page) != PKVM_PAGE_SHARED_OWNED)
+		return -EPERM;
 	if (WARN_ON(!page->host_share_guest_count))
 		return -EINVAL;
 
diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c
index 6d513a4b3763..c19860fc8183 100644
--- a/arch/arm64/kvm/hyp/nvhe/setup.c
+++ b/arch/arm64/kvm/hyp/nvhe/setup.c
@@ -190,6 +190,7 @@ static int fix_host_ownership_walker(const struct kvm_pgtable_visit_ctx *ctx,
 				     enum kvm_pgtable_walk_flags visit)
 {
 	enum pkvm_page_state state;
+	struct hyp_page *page;
 	phys_addr_t phys;
 
 	if (!kvm_pte_valid(ctx->old))
@@ -202,6 +203,8 @@ static int fix_host_ownership_walker(const struct kvm_pgtable_visit_ctx *ctx,
 	if (!addr_is_memory(phys))
 		return -EINVAL;
 
+	page = hyp_phys_to_page(phys);
+
 	/*
 	 * Adjust the host stage-2 mappings to match the ownership attributes
 	 * configured in the hypervisor stage-1, and make sure to propagate them
@@ -210,15 +213,15 @@ static int fix_host_ownership_walker(const struct kvm_pgtable_visit_ctx *ctx,
 	state = pkvm_getstate(kvm_pgtable_hyp_pte_prot(ctx->old));
 	switch (state) {
 	case PKVM_PAGE_OWNED:
-		set_hyp_state(phys, PKVM_PAGE_OWNED);
+		set_hyp_state(page, PKVM_PAGE_OWNED);
 		return host_stage2_set_owner_locked(phys, PAGE_SIZE, PKVM_ID_HYP);
 	case PKVM_PAGE_SHARED_OWNED:
-		set_hyp_state(phys, PKVM_PAGE_SHARED_OWNED);
-		set_host_state(phys, PKVM_PAGE_SHARED_BORROWED);
+		set_hyp_state(page, PKVM_PAGE_SHARED_OWNED);
+		set_host_state(page, PKVM_PAGE_SHARED_BORROWED);
 		break;
 	case PKVM_PAGE_SHARED_BORROWED:
-		set_hyp_state(phys, PKVM_PAGE_SHARED_BORROWED);
-		set_host_state(phys, PKVM_PAGE_SHARED_OWNED);
+		set_hyp_state(page, PKVM_PAGE_SHARED_BORROWED);
+		set_host_state(page, PKVM_PAGE_SHARED_OWNED);
 		break;
 	default:
 		return -EINVAL;
-- 
2.49.0.1143.g0be31eac6b-goog