Pkvm v6.18 helpers

arch/x86/kvm/pkvm/memory.h

@@ -44,6 +44,12 @@ extern u64 __pkvm_vmemmap;
 #define pkvm_page_to_virt(page)	__pkvm_va(pkvm_page_to_phys(page))
 #define pkvm_page_to_pool(page)	(((struct pkvm_page *)page)->pool)
 
+/* Caution: __st is evaluated twice. */
+#define for_each_pkvm_page(__p, __st, __sz)						\
+	for (struct pkvm_page *__p = pkvm_phys_to_page(PAGE_ALIGN_DOWN(__st)),		\
+			      *__e = pkvm_phys_to_page(PAGE_ALIGN((__st) + (__sz)));	\
+	     __p < __e; __p++)
+
 /*
  * Refcounting for 'struct pkvm_page'.
  * pkvm_pool::lock must be held if atomic access to the refcount is required.

arch/x86/kvm/pkvm/mmu.c

@@ -181,7 +181,7 @@ static int fix_hyp_mmu_page_refcnt(void)
 	 * Calculate the max address space, then walk the [0, size) address
 	 * range to fixup refcount of every page-table page.
 	 */
-	size = hyp_mmu.pgt_ops->level_to_size(hyp_mmu.cap.level + 1);
+	size = pkvm_pgtable_max_size(&hyp_mmu);
 #endif
 
 	return pkvm_pgtable_walk(&hyp_mmu, 0, size, &walker);
@@ -190,26 +190,17 @@ static int fix_hyp_mmu_page_refcnt(void)
 static void set_host_mem_pgstate(unsigned long phys, unsigned long size,
 				 enum pkvm_page_state pgstate)
 {
-	unsigned long end = PAGE_ALIGN(phys + size);
-	struct pkvm_page *page;
-
-	for (phys = PAGE_ALIGN_DOWN(phys); phys < end; phys += PAGE_SIZE) {
-		page = pkvm_phys_to_page(phys);
+	for_each_pkvm_page(page, phys, size)
 		page->host_state = pgstate;
-	}
 }
 
 static int check_host_mem_pgstate(unsigned long phys, unsigned long size,
 				  enum pkvm_page_state pgstate)
 {
-	unsigned long end = PAGE_ALIGN(phys + size);
-	struct pkvm_page *page;
-
 	if (!is_memory_range(phys, size))
 		return -EINVAL;
 
-	for (phys = PAGE_ALIGN_DOWN(phys); phys < end; phys += PAGE_SIZE) {
-		page = pkvm_phys_to_page(phys);
+	for_each_pkvm_page(page, phys, size) {
 		if (page->host_state != pgstate)
 			return -EPERM;
 	}
@@ -278,6 +269,12 @@ static int check_page_owner_and_state(struct pkvm_pgtable *pgt, unsigned long va
 	return pkvm_pgtable_walk(pgt, vaddr, size, &walker);
 }
 
+static u64 host_mmu_pte_prot(bool mmio)
+{
+	return host_mmu.pgt_ops->calc_pte_perm(true, true, true) |
+	       host_mmu.pgt_ops->calc_pte_memtype(mmio);
+}
+
 static int fix_host_mmu_pgstate_walker(struct pkvm_pgtable_visit_ctx *ctx,
 				       unsigned long walk_flags,
 				       void *const arg)
@@ -329,23 +326,21 @@ static int fix_host_mmu_pgstate_walker(struct pkvm_pgtable_visit_ctx *ctx,
 
 static int fix_host_mmu_pgstate(void)
 {
-	unsigned long size = host_mmu.pgt_ops->level_to_size(host_mmu.cap.level + 1);
 	struct pkvm_pgtable_walker walker = {
 		.cb = fix_host_mmu_pgstate_walker,
 		.arg = NULL,
 		.walk_flags = PKVM_PGTABLE_WALK_LEAF,
 	};
 
-	return pkvm_pgtable_walk(&host_mmu, 0, size, &walker);
+	return pkvm_pgtable_walk(&host_mmu, 0, pkvm_pgtable_max_size(&host_mmu),
+				 &walker);
 }
 
 static int host_mmu_map(unsigned long phys, unsigned long size, bool mmio)
 {
-	u64 prot = host_mmu.pgt_ops->calc_pte_perm(true, true, true) |
-		   host_mmu.pgt_ops->calc_pte_memtype(mmio);
-
 	/* The vaddr == phys for the host MMU */
-	return pkvm_pgtable_map(&host_mmu, phys, phys, size, prot);
+	return pkvm_pgtable_map(&host_mmu, phys, phys, size,
+				host_mmu_pte_prot(mmio));
 }
 
 int pkvm_hyp_mmu_init(void *pool_base, unsigned long pool_pages)
@@ -541,8 +536,6 @@ int pkvm_host_donate_hyp(unsigned long phys, unsigned long size, bool clear)
  */
 void pkvm_hyp_donate_host(unsigned long phys, unsigned long size, bool clear)
 {
-	u64 prot = host_mmu.pgt_ops->calc_pte_perm(true, true, true) |
-		   host_mmu.pgt_ops->calc_pte_memtype(false);
 	void *va = __pkvm_va(phys);
 	int ret;
 
@@ -573,7 +566,8 @@ void pkvm_hyp_donate_host(unsigned long phys, unsigned long size, bool clear)
 	 * the page state and the mapping, which may lead to unexpected
 	 * behavior. So panic if it fails.
 	 */
-	BUG_ON(ret = pkvm_pgtable_map(&host_mmu, phys, phys, size, prot));
+	BUG_ON(ret = pkvm_pgtable_map(&host_mmu, phys, phys, size,
+				      host_mmu_pte_prot(false)));
 
 	set_host_mem_pgstate(phys, size, PKVM_PAGE_OWNED);
 unlock:
@@ -611,8 +605,7 @@ void pkvm_hyp_donate_host(unsigned long phys, unsigned long size, bool clear)
  */
 int pkvm_hyp_donate_host_mmio_locked(unsigned long phys, unsigned long size)
 {
-	u64 prot = host_mmu.pgt_ops->calc_pte_perm(true, true, true) |
-		   host_mmu.pgt_ops->calc_pte_memtype(true) |
+	u64 prot = host_mmu_pte_prot(true) |
 		   host_mmu.pgt_ops->pte_mk_pgstate(PKVM_PAGE_OWNED);
 	int ret;
 
@@ -647,19 +640,14 @@ int pkvm_hyp_donate_host_mmio_locked(unsigned long phys, unsigned long size)
  */
 int pkvm_host_share_hyp(unsigned long phys, unsigned long size)
 {
-	unsigned long start = PAGE_ALIGN_DOWN(phys);
-	unsigned long end = PAGE_ALIGN(phys + size);
-	struct pkvm_page *page;
 	int ret;
 
 	if (size == 0 || !is_memory_range(phys, size))
 		return -EINVAL;
 
 	pkvm_host_mmu_lock();
 
-	for (phys = start; phys < end; phys += PAGE_SIZE) {
-		page = pkvm_phys_to_page(phys);
-
+	for_each_pkvm_page(page, phys, size) {
 		switch (page->host_state) {
 		case PKVM_PAGE_OWNED:
 			BUG_ON(page->host_share_hyp_count);
@@ -684,9 +672,7 @@ int pkvm_host_share_hyp(unsigned long phys, unsigned long size)
 		}
 	}
 
-	for (phys = start; phys < end; phys += PAGE_SIZE) {
-		page = pkvm_phys_to_page(phys);
-
+	for_each_pkvm_page(page, phys, size) {
 		page->host_state = PKVM_PAGE_SHARED_OWNED;
 		page->host_share_hyp_count++;
 	}
@@ -713,8 +699,6 @@ int pkvm_host_share_hyp(unsigned long phys, unsigned long size)
  */
 void pkvm_host_unshare_hyp(unsigned long phys, unsigned long size)
 {
-	unsigned long end = PAGE_ALIGN(phys + size);
-	struct pkvm_page *page;
 	int ret;
 
 	if (size == 0) {
@@ -728,9 +712,7 @@ void pkvm_host_unshare_hyp(unsigned long phys, unsigned long size)
 	if (ret)
 		goto unlock;
 
-	for (phys = PAGE_ALIGN_DOWN(phys); phys < end; phys += PAGE_SIZE) {
-		page = pkvm_phys_to_page(phys);
-
+	for_each_pkvm_page(page, phys, size) {
 		/*
 		 * Even if host_share_hyp_count is 0 because the page is
 		 * shared with a guest, not with the hypervisor, it still

arch/x86/kvm/pkvm/pgtable.h

@@ -200,4 +200,13 @@ static inline enum pkvm_owner_id pkvm_pte_owner_id(struct pkvm_pgtable *pgt, voi
 	return FIELD_GET(PKVM_INVALID_PTE_OWNER_MASK, pgt->pgt_ops->pte_get(ptep));
 }
 
+/*
+ * Return the max size of the virtual address space that can be
+ * mapped by the page table @pgt.
+ */
+static inline unsigned long pkvm_pgtable_max_size(struct pkvm_pgtable *pgt)
+{
+	return pgt->pgt_ops->level_to_size(pgt->cap.level + 1);
+}
+
 #endif /* __PKVM_X86_PGTABLE_H */