From: Ackerley Tng <ackerley...@google.com>

virt_map() enforces a private mapping for private memory. Introduce
virt_map_shared() that creates a shared mapping for private as
well as shared memory. This way, the TD does not have to remap its
page tables at runtime.

Signed-off-by: Ackerley Tng <ackerley...@google.com>
Signed-off-by: Sagi Shahar <sa...@google.com>
---
 .../testing/selftests/kvm/include/kvm_util.h  | 23 +++++++++++++
 tools/testing/selftests/kvm/lib/kvm_util.c    | 34 +++++++++++++++++++
 .../testing/selftests/kvm/lib/x86/processor.c | 15 ++++++--
 3 files changed, 70 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/kvm_util.h 
b/tools/testing/selftests/kvm/include/kvm_util.h
index 813ba634dc49..442e34c6ed84 100644
--- a/tools/testing/selftests/kvm/include/kvm_util.h
+++ b/tools/testing/selftests/kvm/include/kvm_util.h
@@ -621,6 +621,8 @@ vm_vaddr_t vm_vaddr_alloc_page(struct kvm_vm *vm);
 
 void virt_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
              unsigned int npages);
+void virt_map_shared(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
+                    unsigned int npages);
 void *addr_gpa2hva(struct kvm_vm *vm, vm_paddr_t gpa);
 void *addr_gva2hva(struct kvm_vm *vm, vm_vaddr_t gva);
 vm_paddr_t addr_hva2gpa(struct kvm_vm *vm, void *hva);
@@ -1096,6 +1098,27 @@ static inline void virt_pg_map(struct kvm_vm *vm, 
uint64_t vaddr, uint64_t paddr
        virt_arch_pg_map(vm, vaddr, paddr);
 }
 
+/*
+ * VM Virtual Page Map as Shared
+ *
+ * Input Args:
+ *   vm - Virtual Machine
+ *   vaddr - VM Virtual Address
+ *   paddr - VM Physical Address
+ *
+ * Output Args: None
+ *
+ * Return: None
+ *
+ * Within @vm, creates a virtual translation for the page starting
+ * at @vaddr to the page starting at @paddr.
+ */
+void virt_arch_pg_map_shared(struct kvm_vm *vm, uint64_t vaddr, uint64_t 
paddr);
+
+static inline void virt_pg_map_shared(struct kvm_vm *vm, uint64_t vaddr, 
uint64_t paddr)
+{
+       virt_arch_pg_map_shared(vm, vaddr, paddr);
+}
 
 /*
  * Address Guest Virtual to Guest Physical
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c 
b/tools/testing/selftests/kvm/lib/kvm_util.c
index f8cf49794eed..008f01831036 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -7,6 +7,7 @@
 #include "test_util.h"
 #include "kvm_util.h"
 #include "processor.h"
+#include "sparsebit.h"
 #include "ucall_common.h"
 
 #include <assert.h>
@@ -1604,6 +1605,39 @@ void virt_map(struct kvm_vm *vm, uint64_t vaddr, 
uint64_t paddr,
        }
 }
 
+/*
+ * Map a range of VM virtual address to the VM's physical address as shared
+ *
+ * Input Args:
+ *   vm - Virtual Machine
+ *   vaddr - Virtual address to map
+ *   paddr - VM Physical Address
+ *   npages - The number of pages to map
+ *
+ * Output Args: None
+ *
+ * Return: None
+ *
+ * Within the VM given by @vm, creates a virtual translation for
+ * @npages starting at @vaddr to the page range starting at @paddr.
+ */
+void virt_map_shared(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
+                    unsigned int npages)
+{
+       size_t page_size = vm->page_size;
+       size_t size = npages * page_size;
+
+       TEST_ASSERT(vaddr + size > vaddr, "Vaddr overflow");
+       TEST_ASSERT(paddr + size > paddr, "Paddr overflow");
+
+       while (npages--) {
+               virt_pg_map_shared(vm, vaddr, paddr);
+               sparsebit_set(vm->vpages_mapped, vaddr >> vm->page_shift);
+               vaddr += page_size;
+               paddr += page_size;
+       }
+}
+
 /*
  * Address VM Physical to Host Virtual
  *
diff --git a/tools/testing/selftests/kvm/lib/x86/processor.c 
b/tools/testing/selftests/kvm/lib/x86/processor.c
index 9b2c236e723a..fef63d807c91 100644
--- a/tools/testing/selftests/kvm/lib/x86/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86/processor.c
@@ -181,7 +181,8 @@ static uint64_t *virt_create_upper_pte(struct kvm_vm *vm,
        return pte;
 }
 
-void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, int 
level)
+static void ___virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
+                          int level, bool protected)
 {
        const uint64_t pg_size = PG_LEVEL_SIZE(level);
        uint64_t *pml4e, *pdpe, *pde;
@@ -231,17 +232,27 @@ void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, 
uint64_t paddr, int level)
         * Neither SEV nor TDX supports shared page tables, so only the final
         * leaf PTE needs manually set the C/S-bit.
         */
-       if (vm_is_gpa_protected(vm, paddr))
+       if (protected)
                *pte |= vm->arch.c_bit;
        else
                *pte |= vm->arch.s_bit;
 }
 
+void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, int 
level)
+{
+       ___virt_pg_map(vm, vaddr, paddr, level, vm_is_gpa_protected(vm, paddr));
+}
+
 void virt_arch_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr)
 {
        __virt_pg_map(vm, vaddr, paddr, PG_LEVEL_4K);
 }
 
+void virt_arch_pg_map_shared(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr)
+{
+       ___virt_pg_map(vm, vaddr, paddr, PG_LEVEL_4K, false);
+}
+
 void virt_map_level(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
                    uint64_t nr_bytes, int level)
 {
-- 
2.49.0.504.g3bcea36a83-goog


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