Lock and unlock EPT pmaps before page table entry modification.

ok mlarkin@

diff --git a/sys/arch/amd64/amd64/pmap.c b/sys/arch/amd64/amd64/pmap.c
index c66389d..3a980ba 100644 (file)
--- a/sys/arch/amd64/amd64/pmap.c
+++ b/sys/arch/amd64/amd64/pmap.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: pmap.c,v 1.167 2024/05/03 13:48:29 dv Exp $   */
+/*     $OpenBSD: pmap.c,v 1.168 2024/06/03 20:53:00 dv Exp $   */
 /*     $NetBSD: pmap.c,v 1.3 2003/05/08 18:13:13 thorpej Exp $ */
 
 /*
@@ -2408,6 +2408,8 @@ pmap_remove_ept(struct pmap *pmap, vaddr_t sgpa, vaddr_t egpa)
        struct vmx_invept_descriptor vid;
 #endif /* NVMM > 0 */
 
+       mtx_enter(&pmap->pm_mtx);
+
        DPRINTF("%s: sgpa=0x%llx egpa=0x%llx\n", __func__, (uint64_t)sgpa,
            (uint64_t)egpa);
        for (v = sgpa; v < egpa + PAGE_SIZE; v += PAGE_SIZE)
@@ -2422,6 +2424,8 @@ pmap_remove_ept(struct pmap *pmap, vaddr_t sgpa, vaddr_t egpa)
                invept(IA32_VMX_INVEPT_SINGLE_CTX, &vid);
        }
 #endif /* NVMM > 0 */
+
+       mtx_leave(&pmap->pm_mtx);
 }
 
 void
@@ -2433,6 +2437,8 @@ pmap_do_remove_ept(struct pmap *pmap, paddr_t gpa)
        pd_entry_t *pd4, *pd3, *pd2, *pd1;
        pd_entry_t *pptes;
 
+       MUTEX_ASSERT_LOCKED(&pmap->pm_mtx);
+
        l4idx = (gpa & L4_MASK) >> L4_SHIFT; /* PML4E idx */
        l3idx = (gpa & L3_MASK) >> L3_SHIFT; /* PDPTE idx */
        l2idx = (gpa & L2_MASK) >> L2_SHIFT; /* PDE idx */
@@ -2510,6 +2516,7 @@ pmap_enter_ept(struct pmap *pmap, paddr_t gpa, paddr_t hpa, vm_prot_t prot)
        struct vm_page *ptp, *pptp;
        paddr_t npa;
        struct uvm_object *obj;
+       int ret = 0;
 
        if (gpa > MAXDSIZ)
                return ENOMEM;
@@ -2519,11 +2526,15 @@ pmap_enter_ept(struct pmap *pmap, paddr_t gpa, paddr_t hpa, vm_prot_t prot)
        l2idx = (gpa & L2_MASK) >> L2_SHIFT; /* PDE idx */
        l1idx = (gpa & L1_MASK) >> L1_SHIFT; /* PTE idx */
 
+       mtx_enter(&pmap->pm_mtx);
+
        /* Start at PML4 / top level */
        pd = (pd_entry_t *)pmap->pm_pdir;
 
-       if (pd == NULL)
-               return ENOMEM;
+       if (pd == NULL) {
+               ret = ENOMEM;
+               goto unlock;
+       }
 
        /* npa = physaddr of PDPT */
        npa = pd[l4idx] & PMAP_PA_MASK;
@@ -2535,8 +2546,11 @@ pmap_enter_ept(struct pmap *pmap, paddr_t gpa, paddr_t hpa, vm_prot_t prot)
                ptp = uvm_pagealloc(obj, ptp_va2o(gpa, 3), NULL,
                    UVM_PGA_USERESERVE|UVM_PGA_ZERO);
 
-               if (ptp == NULL)
-                       return ENOMEM;
+               if (ptp == NULL) {
+                       ret = ENOMEM;
+                       goto unlock;
+               }
+               atomic_clearbits_int(&ptp->pg_flags, PG_BUSY);
 
                /*
                 * New PDPT page - we are setting the first entry, so set
@@ -2576,8 +2590,11 @@ pmap_enter_ept(struct pmap *pmap, paddr_t gpa, paddr_t hpa, vm_prot_t prot)
                ptp = uvm_pagealloc(obj, ptp_va2o(gpa, 2), NULL,
                    UVM_PGA_USERESERVE|UVM_PGA_ZERO);
 
-               if (ptp == NULL)
-                       return ENOMEM;
+               if (ptp == NULL) {
+                       ret = ENOMEM;
+                       goto unlock;
+               }
+               atomic_clearbits_int(&ptp->pg_flags, PG_BUSY);
 
                /*
                 * New PD page - we are setting the first entry, so set
@@ -2617,8 +2634,11 @@ pmap_enter_ept(struct pmap *pmap, paddr_t gpa, paddr_t hpa, vm_prot_t prot)
                ptp = uvm_pagealloc(obj, ptp_va2o(gpa, 1), NULL,
                    UVM_PGA_USERESERVE|UVM_PGA_ZERO);
 
-               if (ptp == NULL)
-                       return ENOMEM;
+               if (ptp == NULL) {
+                       ret = ENOMEM;
+                       goto unlock;
+               }
+               atomic_clearbits_int(&ptp->pg_flags, PG_BUSY);
 
                pptp->wire_count++;
 
@@ -2661,7 +2681,10 @@ pmap_enter_ept(struct pmap *pmap, paddr_t gpa, paddr_t hpa, vm_prot_t prot)
 
        pd[l1idx] = npte;
 
-       return 0;
+unlock:
+       mtx_leave(&pmap->pm_mtx);
+
+       return ret;
 }
 
 /*