1 files changed, 59 insertions, 14 deletions

diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
index f7fe724c14f4..d8ea68b78e9c 100644
--- a/virt/kvm/arm/mmu.c
+++ b/virt/kvm/arm/mmu.c
@@ -43,6 +43,8 @@ static unsigned long hyp_idmap_start;
 static unsigned long hyp_idmap_end;
 static phys_addr_t hyp_idmap_vector;
 
+static unsigned long io_map_base;
+
 #define S2_PGD_SIZE	(PTRS_PER_S2_PGD * sizeof(pgd_t))
 #define hyp_pgd_order get_order(PTRS_PER_PGD * sizeof(pgd_t))
 
@@ -518,27 +520,35 @@ static void unmap_hyp_idmap_range(pgd_t *pgdp, phys_addr_t start, u64 size)
  *
  * Assumes hyp_pgd is a page table used strictly in Hyp-mode and
  * therefore contains either mappings in the kernel memory area (above
- * PAGE_OFFSET), or device mappings in the vmalloc range (from
- * VMALLOC_START to VMALLOC_END).
+ * PAGE_OFFSET), or device mappings in the idmap range.
  *
- * boot_hyp_pgd should only map two pages for the init code.
+ * boot_hyp_pgd should only map the idmap range, and is only used in
+ * the extended idmap case.
  */
 void free_hyp_pgds(void)
 {
+	pgd_t *id_pgd;
+
 	mutex_lock(&kvm_hyp_pgd_mutex);
 
+	id_pgd = boot_hyp_pgd ? boot_hyp_pgd : hyp_pgd;
+
+	if (id_pgd) {
+		/* In case we never called hyp_mmu_init() */
+		if (!io_map_base)
+			io_map_base = hyp_idmap_start;
+		unmap_hyp_idmap_range(id_pgd, io_map_base,
+				      hyp_idmap_start + PAGE_SIZE - io_map_base);
+	}
+
 	if (boot_hyp_pgd) {
-		unmap_hyp_idmap_range(boot_hyp_pgd, hyp_idmap_start, PAGE_SIZE);
 		free_pages((unsigned long)boot_hyp_pgd, hyp_pgd_order);
 		boot_hyp_pgd = NULL;
 	}
 
 	if (hyp_pgd) {
-		unmap_hyp_idmap_range(hyp_pgd, hyp_idmap_start, PAGE_SIZE);
 		unmap_hyp_range(hyp_pgd, kern_hyp_va(PAGE_OFFSET),
 				(uintptr_t)high_memory - PAGE_OFFSET);
-		unmap_hyp_range(hyp_pgd, kern_hyp_va(VMALLOC_START),
-				VMALLOC_END - VMALLOC_START);
 
 		free_pages((unsigned long)hyp_pgd, hyp_pgd_order);
 		hyp_pgd = NULL;
@@ -735,8 +745,9 @@ int create_hyp_io_mappings(phys_addr_t phys_addr, size_t size,
 			   void __iomem **kaddr,
 			   void __iomem **haddr)
 {
-	unsigned long start, end;
-	int ret;
+	pgd_t *pgd = hyp_pgd;
+	unsigned long base;
+	int ret = 0;
 
 	*kaddr = ioremap(phys_addr, size);
 	if (!*kaddr)
@@ -747,19 +758,52 @@ int create_hyp_io_mappings(phys_addr_t phys_addr, size_t size,
 		return 0;
 	}
 
+	mutex_lock(&kvm_hyp_pgd_mutex);
 
-	start = kern_hyp_va((unsigned long)*kaddr);
-	end = kern_hyp_va((unsigned long)*kaddr + size);
-	ret = __create_hyp_mappings(hyp_pgd, PTRS_PER_PGD, start, end,
-				     __phys_to_pfn(phys_addr), PAGE_HYP_DEVICE);
+	/*
+	 * This assumes that we we have enough space below the idmap
+	 * page to allocate our VAs. If not, the check below will
+	 * kick. A potential alternative would be to detect that
+	 * overflow and switch to an allocation above the idmap.
+	 *
+	 * The allocated size is always a multiple of PAGE_SIZE.
+	 */
+	size = PAGE_ALIGN(size + offset_in_page(phys_addr));
+	base = io_map_base - size;
 
+	/*
+	 * Verify that BIT(VA_BITS - 1) hasn't been flipped by
+	 * allocating the new area, as it would indicate we've
+	 * overflowed the idmap/IO address range.
+	 */
+	if ((base ^ io_map_base) & BIT(VA_BITS - 1))
+		ret = -ENOMEM;
+	else
+		io_map_base = base;
+
+	mutex_unlock(&kvm_hyp_pgd_mutex);
+
+	if (ret)
+		goto out;
+
+	if (__kvm_cpu_uses_extended_idmap())
+		pgd = boot_hyp_pgd;
+
+	ret = __create_hyp_mappings(pgd, __kvm_idmap_ptrs_per_pgd(),
+				    base, base + size,
+				    __phys_to_pfn(phys_addr), PAGE_HYP_DEVICE);
+	if (ret)
+		goto out;
+
+	*haddr = (void __iomem *)base + offset_in_page(phys_addr);
+
+out:
 	if (ret) {
 		iounmap(*kaddr);
 		*kaddr = NULL;
 		return ret;
 	}
 
-	*haddr = (void __iomem *)start;
 	return 0;
 }
 
@@ -1892,6 +1936,7 @@ int kvm_mmu_init(void)
 			goto out;
 	}
 
+	io_map_base = hyp_idmap_start;
 	return 0;
 out:
 	free_hyp_pgds();