target/i386/hvf: Use address_space_translate in ept_emulation_fault

The hvf_slot structure is a poor replacement for properly
looking up a memory region in the address space.
Use memory_region_get_dirty_log_mask instead of HVF_SLOT_LOG.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp>
Message-ID: <20251103101034.59039-6-philmd@linaro.org>

target/i386/hvf/hvf.c

@@ -119,9 +119,12 @@ void hvf_handle_io(CPUState *env, uint16_t port, void *buffer,
     }
 }
 
-static bool ept_emulation_fault(hvf_slot *slot, uint64_t gpa, uint64_t ept_qual)
+static bool ept_emulation_fault(CPUState *cs, uint64_t gpa, uint64_t ept_qual)
 {
-    int read, write;
+    bool read, write;
+    MemoryRegion *mr;
+    hwaddr gpa_page = gpa & qemu_real_host_page_mask();
+    hwaddr xlat;
 
     /* EPT fault on an instruction fetch doesn't make sense here */
     if (ept_qual & EPT_VIOLATION_INST_FETCH) {
@@ -129,21 +132,22 @@ static bool ept_emulation_fault(hvf_slot *slot, uint64_t gpa, uint64_t ept_qual)
     }
 
     /* EPT fault must be a read fault or a write fault */
-    read = ept_qual & EPT_VIOLATION_DATA_READ ? 1 : 0;
-    write = ept_qual & EPT_VIOLATION_DATA_WRITE ? 1 : 0;
-    if ((read | write) == 0) {
+    read = ept_qual & EPT_VIOLATION_DATA_READ;
+    write = ept_qual & EPT_VIOLATION_DATA_WRITE;
+    if (!read && !write) {
         return false;
     }
 
-    if (write && slot) {
-        if (slot->flags & HVF_SLOT_LOG) {
-            uintptr_t page_size = qemu_real_host_page_size();
-            intptr_t page_mask = -(intptr_t)page_size;
-            uint64_t dirty_page_start = gpa & page_mask;
+    mr = address_space_translate(cpu_get_address_space(cs, X86ASIdx_MEM),
+                                 gpa_page, &xlat, NULL, write,
+                                 MEMTXATTRS_UNSPECIFIED);
 
-            memory_region_set_dirty(slot->region, gpa - slot->start, 1);
-            hvf_unprotect_dirty_range(dirty_page_start, page_size);
-        }
+    /* Handle dirty page logging for ram. */
+    if (write && memory_region_get_dirty_log_mask(mr)) {
+        uintptr_t page_size = qemu_real_host_page_size();
+
+        memory_region_set_dirty(mr, gpa_page + xlat, page_size);
+        hvf_unprotect_dirty_range(gpa_page, page_size);
     }
 
     /*
@@ -156,11 +160,8 @@ static bool ept_emulation_fault(hvf_slot *slot, uint64_t gpa, uint64_t ept_qual)
         return false;
     }
 
-    if (!slot) {
-        return true;
-    }
-    if (!memory_region_is_ram(slot->region) &&
-        !(read && memory_region_is_romd(slot->region))) {
+    if (!memory_region_is_ram(mr) &&
+        !(read && memory_region_is_romd(mr))) {
         return true;
     }
     return false;
@@ -765,7 +766,6 @@ static int hvf_handle_vmexit(CPUState *cpu)
     /* Need to check if MMIO or unmapped fault */
     case EXIT_REASON_EPT_FAULT:
     {
-        hvf_slot *slot;
         uint64_t gpa = rvmcs(cpu->accel->fd, VMCS_GUEST_PHYSICAL_ADDRESS);
 
         if (((idtvec_info & VMCS_IDT_VEC_VALID) == 0) &&
@@ -773,9 +773,8 @@ static int hvf_handle_vmexit(CPUState *cpu)
             vmx_set_nmi_blocking(cpu);
         }
 
-        slot = hvf_find_overlap_slot(gpa, 1);
         /* mmio */
-        if (ept_emulation_fault(slot, gpa, exit_qual)) {
+        if (ept_emulation_fault(cpu, gpa, exit_qual)) {
             struct x86_decode decode;
 
             hvf_load_regs(cpu);