xen/x86: streamline set_pte_mfn()

In preparation for restoring xen_set_pte_init()'s original behavior of avoiding hypercalls, make set_pte_mfn() no longer use the standard set_pte() code path. That one is more complicated than the alternative of simply using an available hypercall directly. This way we can avoid introducing a fair number (2k on my test system) of cases where the hypervisor would trap-and-emulate page table updates. Signed-off-by: Jan Beulich <[email protected]> Reviewed-by: Boris Ostrovsky <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Boris Ostrovsky <[email protected]>
josf · Nov 2, 2021 · dc4bd2a · dc4bd2a
1 parent bfc484f
commit dc4bd2a
Showing 1 changed file with 4 additions and 2 deletions.
diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c
@@ -241,9 +241,11 @@ static void xen_set_pmd(pmd_t *ptr, pmd_t val)
  * Associate a virtual page frame with a given physical page frame
  * and protection flags for that frame.
  */
-void set_pte_mfn(unsigned long vaddr, unsigned long mfn, pgprot_t flags)
+void __init set_pte_mfn(unsigned long vaddr, unsigned long mfn, pgprot_t flags)
 {
-	set_pte_vaddr(vaddr, mfn_pte(mfn, flags));
+	if (HYPERVISOR_update_va_mapping(vaddr, mfn_pte(mfn, flags),
+					 UVMF_INVLPG))
+		BUG();
 }
 
 static bool xen_batched_set_pte(pte_t *ptep, pte_t pteval)