* *
* *
*/
-static int handle_4MB_shadow_pagefault_32(struct guest_info * info, addr_t fault_addr, pf_error_t error_code,
- pte32_t * shadow_pt, pde32_4MB_t * large_guest_pde);
+static int handle_4MB_shadow_pagefault_pde_32(struct guest_info * info, addr_t fault_addr, pf_error_t error_code,
+ pt_access_status_t shadow_pde_access, pde32_4MB_t * large_shadow_pde,
+ pde32_4MB_t * large_guest_pde);
+static int handle_4MB_shadow_pagefault_pte_32(struct guest_info * info, addr_t fault_addr, pf_error_t error_code,
+ pte32_t * shadow_pt, pde32_4MB_t * large_guest_pde);
static int handle_pte_shadow_pagefault_32(struct guest_info * info, addr_t fault_addr, pf_error_t error_code,
pte32_t * shadow_pt, pte32_t * guest_pt);
// Get the next shadow page level, allocate if not present
if (shadow_pde_access == PT_ACCESS_NOT_PRESENT) {
+
+ if (info->use_large_pages && guest_pde->large_page) {
+ // Check underlying physical memory map to see if a large page is viable
+ addr_t guest_pa = BASE_TO_PAGE_ADDR_4MB(((pde32_4MB_t *)guest_pde)->page_base_addr);
+ addr_t host_pa;
+ if (v3_get_max_page_size(info, guest_pa, PAGE_SIZE_4MB) < PAGE_SIZE_4MB) {
+ PrintDebug("Underlying physical memory map doesn't allow use of a large page.\n");
+ // Fallthrough to small pages
+ } else if ((v3_gpa_to_hpa(info, guest_pa, &host_pa) != 0)
+ || (v3_compute_page_alignment(host_pa) < PAGE_SIZE_4MB)) {
+ PrintDebug("Host memory alignment doesn't allow use of a large page.\n");
+ // Fallthrough to small pages
+ } else if (handle_4MB_shadow_pagefault_pde_32(info, fault_addr, error_code, shadow_pde_access,
+ (pde32_4MB_t *)shadow_pde, (pde32_4MB_t *)guest_pde) == 0) {
+ return 0;
+ } else {
+ PrintError("Error handling large pagefault with large page\n");
+ return -1;
+ }
+ // Fallthrough to handle the region with small pages
+ }
+
struct shadow_page_data * shdw_page = create_new_shadow_pt(info);
shadow_pt = (pte32_t *)V3_VAddr((void *)shdw_page->page_pa);
return -1;
}
} else {
- if (handle_4MB_shadow_pagefault_32(info, fault_addr, error_code, shadow_pt, (pde32_4MB_t *)guest_pde) == -1) {
+ if (handle_4MB_shadow_pagefault_pte_32(info, fault_addr, error_code, shadow_pt, (pde32_4MB_t *)guest_pde) == -1) {
PrintError("Error handling large pagefault\n");
return -1;
}
return 0;
}
-
-
-static int handle_4MB_shadow_pagefault_32(struct guest_info * info,
+// Handle a 4MB page fault with small pages in the PTE
+static int handle_4MB_shadow_pagefault_pte_32(struct guest_info * info,
addr_t fault_addr, pf_error_t error_code,
pte32_t * shadow_pt, pde32_4MB_t * large_guest_pde)
{
return -1;
}
- PrintDebug("Returning from large page fault handler\n");
+ PrintDebug("Returning from large page->small page fault handler\n");
return 0;
}
+// Handle a 4MB page fault with a 4MB page in the PDE
+static int handle_4MB_shadow_pagefault_pde_32(struct guest_info * info,
+ addr_t fault_addr, pf_error_t error_code,
+ pt_access_status_t shadow_pde_access,
+ pde32_4MB_t * large_shadow_pde, pde32_4MB_t * large_guest_pde)
+{
+ addr_t guest_fault_pa = BASE_TO_PAGE_ADDR_4MB(large_guest_pde->page_base_addr) + PAGE_OFFSET_4MB(fault_addr);
+
+
+ PrintDebug("Handling 4MB fault with large page (guest_fault_pa=%p) (error_code=%x)\n", (void *)guest_fault_pa, *(uint_t*)&error_code);
+ PrintDebug("LargeShadowPDE=%p, LargeGuestPDE=%p\n", large_shadow_pde, large_guest_pde);
+
+ struct v3_mem_region * shdw_reg = v3_get_mem_region(info->vm_info, info->cpu_id, guest_fault_pa);
+
+
+ if (shdw_reg == NULL) {
+ // Inject a machine check in the guest
+ PrintDebug("Invalid Guest Address in page table (0x%p)\n", (void *)guest_fault_pa);
+ v3_raise_exception(info, MC_EXCEPTION);
+ return -1;
+ }
+
+ if (shadow_pde_access == PT_ACCESS_OK) {
+ // Inconsistent state...
+ // Guest Re-Entry will flush tables and everything should now workd
+ PrintDebug("Inconsistent state... Guest re-entry should flush tlb\n");
+ return 0;
+ }
+
+
+ if (shadow_pde_access == PT_ACCESS_NOT_PRESENT) {
+ // Get the guest physical address of the fault
+
+ if ((shdw_reg->flags.alloced == 1) &&
+ (shdw_reg->flags.read == 1)) {
+ addr_t shadow_pa = 0;
+
+ if (v3_gpa_to_hpa(info, guest_fault_pa, &shadow_pa) == -1) {
+ PrintError("could not translate page fault address (%p)\n", (void *)guest_fault_pa);
+ return -1;
+ }
+ PrintDebug("\tMapping shadow page (%p)\n", (void *)BASE_TO_PAGE_ADDR(shadow_pte->page_base_addr));
+ large_guest_pde->vmm_info = V3_LARGE_PG; /* For invalidations */
+ large_shadow_pde->page_base_addr = PAGE_BASE_ADDR_4MB(shadow_pa);
+ large_shadow_pde->large_page = 1;
+ large_shadow_pde->present = 1;
+ large_shadow_pde->user_page = 1;
+ if (shdw_reg->flags.write == 0) {
+ large_shadow_pde->writable = 0;
+ } else {
+ large_shadow_pde->writable = 1;
+ }
+ //set according to VMM policy
+ large_shadow_pde->write_through = large_guest_pde->write_through;
+ large_shadow_pde->cache_disable = large_guest_pde->cache_disable;
+ large_shadow_pde->global_page = large_guest_pde->global_page;
+ //
+ } else {
+ if (shdw_reg->unhandled(info, fault_addr, guest_fault_pa, shdw_reg, error_code) == -1) {
+ PrintError("Special Page Fault handler returned error for address: %p\n", (void *)fault_addr);
+ return -1;
+ }
+ }
+ } else if (shadow_pde_access == PT_ACCESS_WRITE_ERROR) {
+ if (shdw_reg->flags.write == 0) {
+ if (shdw_reg->unhandled(info, fault_addr, guest_fault_pa, shdw_reg, error_code) == -1) {
+ PrintError("Special Page Fault handler returned error for address: %p\n", (void *)fault_addr);
+ return -1;
+ }
+ }
+ } else {
+ PrintError("Error in large page fault handler...\n");
+ PrintError("This case should have been handled at the top level handler\n");
+ return -1;
+ }
+ PrintDebug("Returning from large page->large page fault handler\n");
+ return 0;
+}
/* If we start to optimize we should look up the guest pages in the cache... */
static inline int handle_shadow_invlpg_32(struct guest_info * info, addr_t vaddr) {
