Large page TLB flush

QEMU uses a fixed page size for the CPU TLB.  If the guest uses large
pages then we effectively split these into multiple smaller pages, and
populate the corresponding TLB entries on demand.

When the guest invalidates the TLB by virtual address we must invalidate
all entries covered by the large page.  However the address used to
invalidate the entry may not be present in the QEMU TLB, so we do not
know which regions to clear.

Implementing a full vaiable size TLB is hard and slow, so just keep a
simple address/mask pair to record which addresses may have been mapped by
large pages.  If the guest invalidates this region then flush the
whole TLB.

Signed-off-by: Paul Brook <paul@codesourcery.com>

1 files changed, 27 insertions, 21 deletions

diff --git a/target-arm/helper.c b/target-arm/helper.c
index 1a181acce3..18e22b1afc 100644
--- a/target-arm/helper.c
+++ b/target-arm/helper.c
@@ -894,7 +894,8 @@ static uint32_t get_level1_table_address(CPUState *env, uint32_t address)
 }
 
 static int get_phys_addr_v5(CPUState *env, uint32_t address, int access_type,
-			    int is_user, uint32_t *phys_ptr, int *prot)
+			    int is_user, uint32_t *phys_ptr, int *prot,
+                            target_ulong *page_size)
 {
     int code;
     uint32_t table;
@@ -927,6 +928,7 @@ static int get_phys_addr_v5(CPUState *env, uint32_t address, int access_type,
         phys_addr = (desc & 0xfff00000) | (address & 0x000fffff);
         ap = (desc >> 10) & 3;
         code = 13;
+        *page_size = 1024 * 1024;
     } else {
         /* Lookup l2 entry.  */
 	if (type == 1) {
@@ -944,10 +946,12 @@ static int get_phys_addr_v5(CPUState *env, uint32_t address, int access_type,
         case 1: /* 64k page.  */
             phys_addr = (desc & 0xffff0000) | (address & 0xffff);
             ap = (desc >> (4 + ((address >> 13) & 6))) & 3;
+            *page_size = 0x10000;
             break;
         case 2: /* 4k page.  */
             phys_addr = (desc & 0xfffff000) | (address & 0xfff);
             ap = (desc >> (4 + ((address >> 13) & 6))) & 3;
+            *page_size = 0x1000;
             break;
         case 3: /* 1k page.  */
 	    if (type == 1) {
@@ -962,6 +966,7 @@ static int get_phys_addr_v5(CPUState *env, uint32_t address, int access_type,
 		phys_addr = (desc & 0xfffffc00) | (address & 0x3ff);
 	    }
             ap = (desc >> 4) & 3;
+            *page_size = 0x400;
             break;
         default:
             /* Never happens, but compiler isn't smart enough to tell.  */
@@ -981,7 +986,8 @@ do_fault:
 }
 
 static int get_phys_addr_v6(CPUState *env, uint32_t address, int access_type,
-			    int is_user, uint32_t *phys_ptr, int *prot)
+			    int is_user, uint32_t *phys_ptr, int *prot,
+                            target_ulong *page_size)
 {
     int code;
     uint32_t table;
@@ -1021,9 +1027,11 @@ static int get_phys_addr_v6(CPUState *env, uint32_t address, int access_type,
         if (desc & (1 << 18)) {
             /* Supersection.  */
             phys_addr = (desc & 0xff000000) | (address & 0x00ffffff);
+            *page_size = 0x1000000;
         } else {
             /* Section.  */
             phys_addr = (desc & 0xfff00000) | (address & 0x000fffff);
+            *page_size = 0x100000;
         }
         ap = ((desc >> 10) & 3) | ((desc >> 13) & 4);
         xn = desc & (1 << 4);
@@ -1040,10 +1048,12 @@ static int get_phys_addr_v6(CPUState *env, uint32_t address, int access_type,
         case 1: /* 64k page.  */
             phys_addr = (desc & 0xffff0000) | (address & 0xffff);
             xn = desc & (1 << 15);
+            *page_size = 0x10000;
             break;
         case 2: case 3: /* 4k page.  */
             phys_addr = (desc & 0xfffff000) | (address & 0xfff);
             xn = desc & 1;
+            *page_size = 0x1000;
             break;
         default:
             /* Never happens, but compiler isn't smart enough to tell.  */
@@ -1132,7 +1142,8 @@ static int get_phys_addr_mpu(CPUState *env, uint32_t address, int access_type,
 
 static inline int get_phys_addr(CPUState *env, uint32_t address,
                                 int access_type, int is_user,
-                                uint32_t *phys_ptr, int *prot)
+                                uint32_t *phys_ptr, int *prot,
+                                target_ulong *page_size)
 {
     /* Fast Context Switch Extension.  */
     if (address < 0x02000000)
@@ -1142,16 +1153,18 @@ static inline int get_phys_addr(CPUState *env, uint32_t address,
         /* MMU/MPU disabled.  */
         *phys_ptr = address;
         *prot = PAGE_READ | PAGE_WRITE;
+        *page_size = TARGET_PAGE_SIZE;
         return 0;
     } else if (arm_feature(env, ARM_FEATURE_MPU)) {
+        *page_size = TARGET_PAGE_SIZE;
 	return get_phys_addr_mpu(env, address, access_type, is_user, phys_ptr,
 				 prot);
     } else if (env->cp15.c1_sys & (1 << 23)) {
         return get_phys_addr_v6(env, address, access_type, is_user, phys_ptr,
-                                prot);
+                                prot, page_size);
     } else {
         return get_phys_addr_v5(env, address, access_type, is_user, phys_ptr,
-                                prot);
+                                prot, page_size);
     }
 }
 
@@ -1159,17 +1172,20 @@ int cpu_arm_handle_mmu_fault (CPUState *env, target_ulong address,
                               int access_type, int mmu_idx, int is_softmmu)
 {
     uint32_t phys_addr;
+    target_ulong page_size;
     int prot;
     int ret, is_user;
 
     is_user = mmu_idx == MMU_USER_IDX;
-    ret = get_phys_addr(env, address, access_type, is_user, &phys_addr, &prot);
+    ret = get_phys_addr(env, address, access_type, is_user, &phys_addr, &prot,
+                        &page_size);
     if (ret == 0) {
         /* Map a single [sub]page.  */
         phys_addr &= ~(uint32_t)0x3ff;
         address &= ~(uint32_t)0x3ff;
-        return tlb_set_page (env, address, phys_addr, prot, mmu_idx,
-                             is_softmmu);
+        tlb_set_page (env, address, phys_addr, prot | PAGE_EXEC, mmu_idx,
+                      page_size);
+        return 0;
     }
 
     if (access_type == 2) {
@@ -1189,10 +1205,11 @@ int cpu_arm_handle_mmu_fault (CPUState *env, target_ulong address,
 target_phys_addr_t cpu_get_phys_page_debug(CPUState *env, target_ulong addr)
 {
     uint32_t phys_addr;
+    target_ulong page_size;
     int prot;
     int ret;
 
-    ret = get_phys_addr(env, addr, 0, 0, &phys_addr, &prot);
+    ret = get_phys_addr(env, addr, 0, 0, &phys_addr, &prot, &page_size);
 
     if (ret != 0)
         return -1;
@@ -1406,18 +1423,7 @@ void HELPER(set_cp15)(CPUState *env, uint32_t insn, uint32_t val)
             tlb_flush(env, 0);
             break;
         case 1: /* Invalidate single TLB entry.  */
-#if 0
-            /* ??? This is wrong for large pages and sections.  */
-            /* As an ugly hack to make linux work we always flush a 4K
-               pages.  */
-            val &= 0xfffff000;
-            tlb_flush_page(env, val);
-            tlb_flush_page(env, val + 0x400);
-            tlb_flush_page(env, val + 0x800);
-            tlb_flush_page(env, val + 0xc00);
-#else
-            tlb_flush(env, 1);
-#endif
+            tlb_flush_page(env, val & TARGET_PAGE_MASK);
             break;
         case 2: /* Invalidate on ASID.  */
             tlb_flush(env, val == 0);