From: Patrick Bridges <bridges@apu.cs.unm.edu>
Date: Thu, 12 Aug 2010 17:05:05 +0000 (-0600)
Subject: Actually fixed page alignment computation to be correct, moved into vmm_mem.h for... 
X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?a=commitdiff_plain;h=1fd0d9b438ed24410346ad7a4a23de70a6ad68ea;p=palacios.git

Actually fixed page alignment computation to be correct, moved into vmm_mem.h for use with 4MB pages, too.
---

diff --git a/palacios/include/palacios/vmm_mem.h b/palacios/include/palacios/vmm_mem.h
index 651e82e..32d6ae6 100644
--- a/palacios/include/palacios/vmm_mem.h
+++ b/palacios/include/palacios/vmm_mem.h
@@ -110,7 +110,7 @@ struct v3_mem_region * v3_get_next_mem_region(struct v3_vm_info * vm, uint16_t c
 void v3_print_mem_map(struct v3_vm_info * vm);
 
 uint32_t v3_get_max_page_size(struct guest_info * core, addr_t fault_addr, uint32_t req_size);
-
+uint32_t v3_compute_page_alignment(addr_t addr);
 
 
 #endif // ! __V3VEE__
diff --git a/palacios/src/palacios/mmu/vmm_shdw_pg_tlb_64.h b/palacios/src/palacios/mmu/vmm_shdw_pg_tlb_64.h
index 8b30540..011a882 100644
--- a/palacios/src/palacios/mmu/vmm_shdw_pg_tlb_64.h
+++ b/palacios/src/palacios/mmu/vmm_shdw_pg_tlb_64.h
@@ -271,44 +271,6 @@ static int handle_pdpe_shadow_pagefault_64(struct guest_info * info, addr_t faul
     return 0;
 }
 
-// For an address on a page of size page_size, compute the actual alignment
-// of the physical page it maps to
-int compute_physical_alignment(addr_t va, addr_t pa, uint32_t page_size)
-{
-    addr_t va_offset, pa_base;
-    switch (page_size) {
-	case PAGE_SIZE_1GB:
-	    va_offset = PAGE_OFFSET_1GB(va);
-	    break;
-	case PAGE_SIZE_4MB:
-	    va_offset = PAGE_OFFSET_4MB(va);
-	    break;
-	case PAGE_SIZE_2MB:
-	    va_offset = PAGE_OFFSET_2MB(va);
-	    break;
-	case PAGE_SIZE_4KB:
-	    return 1;
-	default:
-	    PrintError("Invalid page size in %s.\n", __FUNCTION__);
-	    return 0;
-    }
- 
-    pa_base = pa - va_offset;
-
-    if (PAGE_OFFSET_1GB(pa_base) == 0) {
-	 return PAGE_SIZE_1GB;
-    } else if (PAGE_OFFSET_4MB(pa_base) == 0) {
-	 return PAGE_SIZE_4MB;
-    } else if (PAGE_OFFSET_2MB(pa_base) == 0) {
-	return PAGE_SIZE_2MB;
-    } else if (PAGE_OFFSET_4KB(pa_base) == 0) {
-	return PAGE_SIZE_4KB;
-    } else {
-        PrintError("Incorrection alignment setup or calculation in %s.\n", __FUNCTION__);
-	return 0;
-    }
-}
-
 static int handle_pde_shadow_pagefault_64(struct guest_info * info, addr_t fault_addr, pf_error_t error_code,
 					  pde64_t * shadow_pd, pde64_t * guest_pd) {
     pt_access_status_t guest_pde_access;
@@ -379,18 +341,20 @@ static int handle_pde_shadow_pagefault_64(struct guest_info * info, addr_t fault
         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_2MB(((pde64_2MB_t *)guest_pde)->page_base_addr);
-	    if ((compute_physical_alignment(fault_addr, guest_pa, PAGE_SIZE_2MB) >= PAGE_SIZE_2MB)
-	        && (v3_get_max_page_size(info, guest_pa, PAGE_SIZE_2MB) >= PAGE_SIZE_2MB)) {
-	    	// should be able to use a large page.
-	        if (handle_2MB_shadow_pagefault_pde_64(info, fault_addr, error_code, shadow_pde_access,
-		 	 		               (pde64_2MB_t *)shadow_pde, (pde64_2MB_t *)guest_pde) ==  0) {
-	    	    return 0;
-	        } else {
-	            PrintError("Error handling large pagefault with large page\n");
-	            return -1;
-		}
+	    addr_t host_pa;
+	    if (v3_get_max_page_size(info, guest_pa, PAGE_SIZE_2MB) < PAGE_SIZE_2MB) {
+		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_2MB)) {
+		PrintDebug("Host memory alignment doesn't allow use of a large page.\n");
+		// Fallthrough to small pages
+	    } else if (handle_2MB_shadow_pagefault_pde_64(info, fault_addr, error_code, shadow_pde_access,
+		 	 		               (pde64_2MB_t *)shadow_pde, (pde64_2MB_t *)guest_pde) == 0) {
+	    	return 0;
 	    } else {
-		PrintDebug("Alignment or underlying physical memory map doesn't allow use of a large page.\n");
+	        PrintError("Error handling large pagefault with large page\n");
+	        return -1;
 	    }
 	    // Fallthrough to handle the region with small pages
 	}
diff --git a/palacios/src/palacios/vmm_mem.c b/palacios/src/palacios/vmm_mem.c
index 78ee376..4a33825 100644
--- a/palacios/src/palacios/vmm_mem.c
+++ b/palacios/src/palacios/vmm_mem.c
@@ -473,6 +473,23 @@ uint32_t v3_get_max_page_size(struct guest_info * core, addr_t fault_addr, uint3
     return page_size;
 }
 
+// For an address on a page of size page_size, compute the actual alignment
+// of the physical page it maps to
+uint32_t v3_compute_page_alignment(addr_t page_addr)
+{
+    if (PAGE_OFFSET_1GB(page_addr) == 0) {
+	 return PAGE_SIZE_1GB;
+    } else if (PAGE_OFFSET_4MB(page_addr) == 0) {
+	 return PAGE_SIZE_4MB;
+    } else if (PAGE_OFFSET_2MB(page_addr) == 0) {
+	return PAGE_SIZE_2MB;
+    } else if (PAGE_OFFSET_4KB(page_addr) == 0) {
+	return PAGE_SIZE_4KB;
+    } else {
+        PrintError("Non-page aligned address passed to %s.\n", __FUNCTION__);
+	return 0;
+    }
+}
 
 void v3_print_mem_map(struct v3_vm_info * vm) {
     struct rb_node * node = v3_rb_first(&(vm->mem_map.mem_regions));