Perform the translation of a guest virtual address to a guest physical
address using the currently installed page tables. This must be used for
virtual addresses that are not identity mapped addresses, e.g. a virtual
address returned by alloc_vpage(), where virt_to_phys() won't work.
Signed-off-by: Pavan Kumar Paluri <papaluri@xxxxxxx>
---
lib/x86/vm.c | 24 ++++++++++++++++++++++++
lib/x86/vm.h | 1 +
2 files changed, 25 insertions(+)
diff --git a/lib/x86/vm.c b/lib/x86/vm.c
index ce2063aee75d..078665b2faf4 100644
--- a/lib/x86/vm.c
+++ b/lib/x86/vm.c
@@ -332,3 +332,27 @@ void walk_pte(void *virt, size_t len, pte_callback_t callback)
callback(search, (void *)curr);
}
}
+
+unsigned long pgtable_va_to_pa(unsigned long va)
+{
+ pteval_t *pt = (pgd_t *)read_cr3();
+ unsigned long offset, paddr;
+ int level;
+
+ for (level = PAGE_LEVEL; level; level--) {
+ offset = PGDIR_OFFSET((uintptr_t)va, level);
+ assert_msg(pt[offset], "PTE absent");
+
+ if (level == 1 ||
+ (level <= 3 && (pt[offset] & PT_PAGE_SIZE_MASK))) {
+ paddr = pt[offset] & PT_ADDR_MASK;
+ paddr += va & ((1UL << PGDIR_BITS(level)) - 1);
+
+ return paddr;
+ }
+
+ pt = phys_to_virt(pt[offset] & PT_ADDR_MASK);
+ }
+
+ __builtin_unreachable();
+}
diff --git a/lib/x86/vm.h b/lib/x86/vm.h
index a5bd8d4ecf7c..9f72c267086d 100644
--- a/lib/x86/vm.h
+++ b/lib/x86/vm.h
@@ -59,6 +59,7 @@ static inline void *current_page_table(void)
void split_large_page(unsigned long *ptep, int level);
void force_4k_page(void *addr);
+unsigned long pgtable_va_to_pa(unsigned long vaddr);
struct vm_vcpu_info {
u64 cr3;
--
2.34.1
