// Reference: AMD Software Developer Manual Vol.2 Ch.5 "Page Translation and Protection"
-static int get_page_size() {
-
- // Need to fix this....
- return PAGE_SIZE_4KB;
-
-
-#if 0
- struct v3_mem_region * base_reg = &(info->vm_info->mem_map.base_region);
+static uint32_t get_page_size(struct guest_info * core, addr_t fault_addr) {
+ addr_t pg_start = 0UL, pg_end = 0UL; // 2MiB page containing the faulting address
+ struct v3_mem_region * pg_next_reg = NULL; // next immediate mem reg after page start addr
+ uint32_t page_size = PAGE_SIZE_4KB;
/* If the guest has been configured for 2MiB pages, then we must check for hooked regions of
* memory which may overlap with the 2MiB page containing the faulting address (due to
* |----|----|----|----|----|page|----|----|----| 2MB pages
* >>>>>>>>>>>>>>>>>>>> search space
*/
- addr_t pg_start = 0UL, pg_end = 0UL; // 2MiB page containing the faulting address
- struct v3_mem_region * pg_next_reg = NULL; // next immediate mem reg after page start addr
- bool use_large_page = false;
- if (region == NULL) {
- PrintError("%s: invalid region, addr=%p\n", __FUNCTION__, (void *)fault_addr);
- return -1;
- }
- // set use_large_page here
- if (info->vm_info->paging_size == PAGING_2MB) {
+ // guest page maps to a host page + offset (so when we shift, it aligns with a host page)
+ pg_start = PAGE_ADDR_2MB(fault_addr);
+ pg_end = (pg_start + PAGE_SIZE_2MB);
- // guest page maps to a host page + offset (so when we shift, it aligns with a host page)
- pg_start = PAGE_ADDR_2MB(fault_addr);
- pg_end = (pg_start + PAGE_SIZE_2MB);
+ PrintDebug("%s: page [%p,%p) contains address\n", __FUNCTION__, (void *)pg_start, (void *)pg_end);
- PrintDebug("%s: page [%p,%p) contains address\n", __FUNCTION__, (void *)pg_start, (void *)pg_end);
+ pg_next_reg = v3_get_next_mem_region(core->vm_info, core->cpu_id, pg_start);
- pg_next_reg = v3_get_next_mem_region(info->vm_info, info->cpu_id, pg_start);
+ if (pg_next_reg == NULL) {
+ PrintError("%s: Error: address not in base region, %p\n", __FUNCTION__, (void *)fault_addr);
+ return PAGE_SIZE_4KB;
+ }
- if (pg_next_reg == NULL) {
- PrintError("%s: Error: address not in base region, %p\n", __FUNCTION__, (void *)fault_addr);
- return -1;
+ if (pg_next_reg->flags.base == 1) {
+ page_size = PAGE_SIZE_2MB; // State A
+ } else {
+#if 0 // State B/C and D optimization
+ if ((pg_next_reg->guest_end >= pg_end) &&
+ ((pg_next_reg->guest_start >= pg_end) || (pg_next_reg->guest_start <= pg_start))) {
+ page_size = PAGE_SIZE_2MB;
}
- if (pg_next_reg->base == 1) {
- use_large_page = 1; // State A
- } else {
-#if 0 // State B/C and D optimization
- use_large_page = (pg_next_reg->guest_end >= pg_end) &&
- ((pg_next_reg->guest_start >= pg_end) || (pg_next_reg->guest_start <= pg_start));
- PrintDebug("%s: region [%p,%p) %s partial overlap with page\n", __FUNCTION__,
- (void *)pg_next_reg->guest_start, (void *)pg_next_reg->guest_end,
- (use_large_page ? "does not have" : "has"));
+ PrintDebug("%s: region [%p,%p) %s partially overlap with page\n", __FUNCTION__,
+ (void *)pg_next_reg->guest_start, (void *)pg_next_reg->guest_end,
+ (page_size == PAGE_SIZE_2MB) ? "does not" : "does");
+
#else // State B/C
- use_large_page = (pg_next_reg->guest_start >= pg_end);
- PrintDebug("%s: region [%p,%p) %s overlap with page\n", __FUNCTION__,
- (void *)pg_next_reg->guest_start, (void *)pg_next_reg->guest_end,
- (use_large_page ? "does not have" : "has"));
-#endif
+ if (pg_next_reg->guest_start >= pg_end) {
+
+ page_size = PAGE_SIZE_2MB;
}
- }
- PrintDebug("%s: Address gets a 2MiB page? %s\n", __FUNCTION__, (use_large_page ? "yes" : "no"));
+ PrintDebug("%s: region [%p,%p) %s overlap with page\n", __FUNCTION__,
+ (void *)pg_next_reg->guest_start, (void *)pg_next_reg->guest_end,
+ (page_size == PAGE_SIZE_2MB) ? "does not" : "does");
+
#endif
+ }
+
+ return page_size;
}
* 2. the memory regions can be referenced by a large page
*/
if ((core->use_large_pages == 1) ) {
- page_size = get_page_size();
+ page_size = get_page_size(core, fault_addr);
}
+ PrintDebug("Using page size of %dKB\n", page_size / 1024);
+
// Lookup the correct PML address based on the PAGING MODE
if (core->shdw_pg_mode == SHADOW_PAGING) {