[PATCH v4 01/28] KVM: selftests: Add function to allow one-to-one GVA to GPA mappings

[Ryan Afranji <afranji@google.com>]

From: Ackerley Tng <ackerleytng@google.com>

One-to-one GVA to GPA mappings can be used in the guest to set up boot
sequences during which paging is enabled, hence requiring a transition
from using physical to virtual addresses in consecutive instructions.

Signed-off-by: Ackerley Tng <ackerleytng@google.com>
Change-Id: I5a15e241b3ce9014e17a794478bbfa65b9d8e0a1
Signed-off-by: Ryan Afranji <afranji@google.com>
---
 .../selftests/kvm/include/kvm_util_base.h     |  3 +
 tools/testing/selftests/kvm/lib/kvm_util.c    | 81 ++++++++++++++++++-
 2 files changed, 83 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
index af26c5687d86..a07ce5f5244a 100644
--- a/tools/testing/selftests/kvm/include/kvm_util_base.h
+++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
@@ -513,6 +513,9 @@ vm_vaddr_t vm_vaddr_unused_gap(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_mi
 vm_vaddr_t vm_vaddr_alloc(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min);
 vm_vaddr_t __vm_vaddr_alloc(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min,
 			    enum kvm_mem_region_type type);
+vm_vaddr_t vm_vaddr_alloc_shared(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min);
+vm_vaddr_t vm_vaddr_alloc_1to1(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min,
+			       uint32_t data_memslot);
 vm_vaddr_t vm_vaddr_alloc_pages(struct kvm_vm *vm, int nr_pages);
 vm_vaddr_t __vm_vaddr_alloc_page(struct kvm_vm *vm,
 				 enum kvm_mem_region_type type);
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 518990ca408d..5bbcddcd6796 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -1371,6 +1371,58 @@ vm_vaddr_t __vm_vaddr_alloc(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min,
 	return vaddr_start;
 }
 
+/*
+ * VM Virtual Address Allocate Shared/Encrypted
+ *
+ * Input Args:
+ *   vm - Virtual Machine
+ *   sz - Size in bytes
+ *   vaddr_min - Minimum starting virtual address
+ *   paddr_min - Minimum starting physical address
+ *   data_memslot - memslot number to allocate in
+ *   encrypt - Whether the region should be handled as encrypted
+ *
+ * Output Args: None
+ *
+ * Return:
+ *   Starting guest virtual address
+ *
+ * Allocates at least sz bytes within the virtual address space of the vm
+ * given by vm.  The allocated bytes are mapped to a virtual address >=
+ * the address given by vaddr_min.  Note that each allocation uses a
+ * a unique set of pages, with the minimum real allocation being at least
+ * a page.
+ */
+static vm_vaddr_t
+_vm_vaddr_alloc(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min,
+		vm_paddr_t paddr_min, uint32_t data_memslot, bool encrypt)
+{
+	uint64_t pages = (sz >> vm->page_shift) + ((sz % vm->page_size) != 0);
+
+	virt_pgd_alloc(vm);
+	vm_paddr_t paddr = _vm_phy_pages_alloc(vm, pages,
+					       paddr_min,
+					       data_memslot, encrypt);
+
+	/*
+	 * Find an unused range of virtual page addresses of at least
+	 * pages in length.
+	 */
+	vm_vaddr_t vaddr_start = vm_vaddr_unused_gap(vm, sz, vaddr_min);
+
+	/* Map the virtual pages. */
+	for (vm_vaddr_t vaddr = vaddr_start; pages > 0;
+		pages--, vaddr += vm->page_size, paddr += vm->page_size) {
+
+		virt_pg_map(vm, vaddr, paddr);
+
+		sparsebit_set(vm->vpages_mapped,
+			vaddr >> vm->page_shift);
+	}
+
+	return vaddr_start;
+}
+
 /*
  * VM Virtual Address Allocate
  *
@@ -1392,7 +1444,34 @@ vm_vaddr_t __vm_vaddr_alloc(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min,
  */
 vm_vaddr_t vm_vaddr_alloc(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min)
 {
-	return __vm_vaddr_alloc(vm, sz, vaddr_min, MEM_REGION_TEST_DATA);
+	return _vm_vaddr_alloc(vm, sz, vaddr_min,
+			       KVM_UTIL_MIN_PFN * vm->page_size, 0,
+			       vm->protected);
+}
+
+vm_vaddr_t vm_vaddr_alloc_shared(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min)
+{
+	return _vm_vaddr_alloc(vm, sz, vaddr_min,
+			       KVM_UTIL_MIN_PFN * vm->page_size, 0, false);
+}
+
+/**
+ * Allocate memory in @vm of size @sz in memslot with id @data_memslot,
+ * beginning with the desired address of @vaddr_min.
+ *
+ * If there isn't enough memory at @vaddr_min, find the next possible address
+ * that can meet the requested size in the given memslot.
+ *
+ * Return the address where the memory is allocated.
+ */
+vm_vaddr_t vm_vaddr_alloc_1to1(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min,
+			       uint32_t data_memslot)
+{
+	vm_vaddr_t gva = _vm_vaddr_alloc(vm, sz, vaddr_min, (vm_paddr_t) vaddr_min,
+					 data_memslot, vm->protected);
+	ASSERT_EQ(gva, addr_gva2gpa(vm, gva));
+
+	return gva;
 }
 
 /*
-- 
2.41.0.487.g6d72f3e995-goog