First attempt at speculative paging around the address that faulted

It only attempts to fill the leaf page table

diff --git a/geekos/src/geekos/main.c b/geekos/src/geekos/main.c
index 5d71341..310fcf9 100644 (file)
--- a/geekos/src/geekos/main.c
+++ b/geekos/src/geekos/main.c
@@ -241,7 +241,7 @@ void Main(struct Boot_Info* bootInfo)
 #endif
 
 
-#if 1
+#if 0
   struct Kernel_Thread *spin_thread;
 
   spin_thread=Start_Kernel_Thread(Spin,0,PRIORITY_NORMAL,false);

diff --git a/manual/manual.pdf b/manual/manual.pdf
index 887fd33..78e5043 100644 (file)
Binary files a/manual/manual.pdf and b/manual/manual.pdf differ

diff --git a/palacios/src/palacios/vmm_shadow_paging.c b/palacios/src/palacios/vmm_shadow_paging.c
index 8074c16..91004f9 100644 (file)
--- a/palacios/src/palacios/vmm_shadow_paging.c
+++ b/palacios/src/palacios/vmm_shadow_paging.c
@@ -30,6 +30,14 @@
 
 #include <palacios/vmm_direct_paging.h>
 
+
+// set this to 1 if you want us to attempt to
+// fetch multiple entries on a page fault
+#define SPECULATIVE_PAGING 1
+
+#define REGULAR_PAGE_FAULT 0
+#define SPECULATIVE_PAGE_FAULT 1
+
 #ifndef DEBUG_SHADOW_PAGING
 #undef PrintDebug
 #define PrintDebug(fmt, args...)
@@ -126,6 +134,7 @@ int v3_activate_passthrough_pt(struct guest_info * info) {
 
 
 int v3_handle_shadow_pagefault(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) {
+  int rc;
   
     if (v3_get_mem_mode(info) == PHYSICAL_MEM) {
        // If paging is not turned on we need to handle the special cases
@@ -134,14 +143,38 @@ int v3_handle_shadow_pagefault(struct guest_info * info, addr_t fault_addr, pf_e
 
        switch (v3_get_cpu_mode(info)) {
            case PROTECTED:
-               return handle_shadow_pagefault_32(info, fault_addr, error_code);
+             return handle_shadow_pagefault_32(info, fault_addr, error_code);
                break;
            case PROTECTED_PAE:
                return handle_shadow_pagefault_32pae(info, fault_addr, error_code);
            case LONG:
            case LONG_32_COMPAT:
-           case LONG_16_COMPAT:
-               return handle_shadow_pagefault_64(info, fault_addr, error_code);
+       case LONG_16_COMPAT: {
+             addr_t curr_addr;
+             addr_t fault_addr_base;
+             // first, we will handle the actual fault, non-speculatively
+             rc=handle_shadow_pagefault_64(info, fault_addr, error_code, REGULAR_PAGE_FAULT);
+             if (rc) {
+               return -1;
+             } 
+             if (!SPECULATIVE_PAGING) { 
+               return 0;
+             }
+             fault_addr_base=PAGE_ADDR_4KB(fault_addr);
+             PrintDebug("Attempting speculative paging around %p\n",(void*)fault_addr_base);
+             for (curr_addr = (fault_addr_base & (~0x1fffffLL)) ; 
+                  curr_addr < (fault_addr_base | (0x1fffffLL)) ;
+                  curr_addr+=PAGE_SIZE) {
+               if (curr_addr!=fault_addr_base) { 
+                 rc=handle_shadow_pagefault_64(info, curr_addr, error_code, SPECULATIVE_PAGE_FAULT);
+                 if (rc) {
+                   PrintDebug("Speculative page fault handler failed at %p\n",(void*)curr_addr);
+                   return -1;
+                 } 
+               }
+             }
+             return 0;
+           }
                break;
            default:
                PrintError("Unhandled CPU Mode: %s\n", v3_cpu_mode_to_str(v3_get_cpu_mode(info)));