+/*
+ * This file is part of the Palacios Virtual Machine Monitor developed
+ * by the V3VEE Project with funding from the United States National
+ * Science Foundation and the Department of Energy.
+ *
+ * The V3VEE Project is a joint project between Northwestern University
+ * and the University of New Mexico. You can find out more at
+ * http://www.v3vee.org
+ *
+ * Copyright (c) 2008, Jack Lange <jarusl@cs.northwestern.edu>
+ * Copyright (c) 2008, The V3VEE Project <http://www.v3vee.org>
+ * All rights reserved.
+ *
+ * Author: Jack Lange <jarusl@cs.northwestern.edu>
+ *
+ * This is free software. You are permitted to use,
+ * redistribute, and modify it as specified in the file "V3VEE_LICENSE".
+ */
+
+
#include <palacios/vmm_shadow_paging.h>
+
#include <palacios/vmm.h>
#include <palacios/vm_guest_mem.h>
+#include <palacios/vmm_decoder.h>
+#include <palacios/vmm_ctrl_regs.h>
-extern struct vmm_os_hooks * os_hooks;
+#include <palacios/vmm_hashtable.h>
+#include <palacios/vmm_direct_paging.h>
-int init_shadow_page_state(struct shadow_page_state * state) {
- state->guest_mode = PDE32;
- state->shadow_mode = PDE32;
-
- state->guest_cr3.r_reg = 0;
- state->shadow_cr3.r_reg = 0;
- return 0;
+
+
+#ifdef V3_CONFIG_SHADOW_PAGING_TELEMETRY
+#include <palacios/vmm_telemetry.h>
+#endif
+
+#ifdef V3_CONFIG_SYMBIOTIC_SWAP
+#include <palacios/vmm_sym_swap.h>
+#endif
+
+#ifndef V3_CONFIG_DEBUG_SHADOW_PAGING
+#undef PrintDebug
+#define PrintDebug(fmt, args...)
+#endif
+
+
+static const char default_strategy[] = "VTLB";
+
+
+static struct hashtable * master_shdw_pg_table = NULL;
+
+
+struct event_callback {
+ int (*callback)(struct guest_info *core, struct v3_shdw_pg_event *event, void *priv_data);
+ void *priv_data;
+
+ struct list_head node;
+};
+
+static uint_t shdw_pg_hash_fn(addr_t key) {
+ char * name = (char *)key;
+ return v3_hash_buffer((uint8_t *)name, strlen(name));
}
-
-int wholesale_update_shadow_page_state(struct guest_info * guest_info) {
- unsigned i, j;
- pde32_t * guest_pde;
- pde32_t * shadow_pde;
+static int shdw_pg_eq_fn(addr_t key1, addr_t key2) {
+ char * name1 = (char *)key1;
+ char * name2 = (char *)key2;
- struct shadow_page_state * state = &(guest_info->shdw_pg_state);
+ return (strcmp(name1, name2) == 0);
+}
+static int have_callbacks(struct guest_info *core)
+{
+ // lock acquistion unnecessary
+ // caller will acquire the lock before *iterating* through the list
+ // so any race will be resolved then
+ return !list_empty(&(core->vm_info->shdw_impl.event_callback_list));
+}
- // For now, we'll only work with PDE32
- if (state->guest_mode != PDE32) {
- return -1;
- }
+static void dispatch_event(struct guest_info *core, struct v3_shdw_pg_event *event)
+{
+ struct event_callback *cb,*temp;
- shadow_pde = (pde32_t *)(CR3_TO_PDE32(state->shadow_cr3.e_reg.low));
+ v3_read_lock(&(core->vm_info->shdw_impl.event_callback_lock));
- if (host_pa_to_host_va(CR3_TO_PDE32(state->guest_cr3.e_reg.low), (addr_t*)&guest_pde) != 0) {
- return -1;
- }
+ list_for_each_entry_safe(cb,
+ temp,
+ &(core->vm_info->shdw_impl.event_callback_list),
+ node) {
+ cb->callback(core,event,cb->priv_data);
+ }
- // Delete the current page table
- delete_page_tables_pde32(shadow_pde);
+ v3_read_unlock(&(core->vm_info->shdw_impl.event_callback_lock));
+}
+
+
+int V3_init_shdw_paging() {
+ extern struct v3_shdw_pg_impl * __start__v3_shdw_pg_impls[];
+ extern struct v3_shdw_pg_impl * __stop__v3_shdw_pg_impls[];
+ struct v3_shdw_pg_impl ** tmp_impl = __start__v3_shdw_pg_impls;
+ int i = 0;
- shadow_pde = os_hooks->allocate_pages(1);
+ master_shdw_pg_table = v3_create_htable(0, shdw_pg_hash_fn, shdw_pg_eq_fn);
- state->shadow_cr3.e_reg.low = (addr_t)shadow_pde;
- state->shadow_mode = PDE32;
+ while (tmp_impl != __stop__v3_shdw_pg_impls) {
+ V3_Print(VM_NONE, VCORE_NONE, "Registering Shadow Paging Impl (%s)\n", (*tmp_impl)->name);
- for (i = 0; i < MAX_PDE32_ENTRIES; i++) {
- shadow_pde[i] = guest_pde[i];
+ if (v3_htable_search(master_shdw_pg_table, (addr_t)((*tmp_impl)->name))) {
+ PrintError(VM_NONE, VCORE_NONE, "Multiple instances of shadow paging impl (%s)\n", (*tmp_impl)->name);
+ return -1;
+ }
+
+ if (v3_htable_insert(master_shdw_pg_table,
+ (addr_t)((*tmp_impl)->name),
+ (addr_t)(*tmp_impl)) == 0) {
+ PrintError(VM_NONE, VCORE_NONE, "Could not register shadow paging impl (%s)\n", (*tmp_impl)->name);
+ return -1;
+ }
- // The shadow can be identical to the guest if it's not present
- if (!shadow_pde[i].present) {
- continue;
+ tmp_impl = &(__start__v3_shdw_pg_impls[++i]);
}
- if (shadow_pde[i].large_pages) {
- // large page - just map it through shadow map to generate its physical location
- addr_t guest_addr = PAGE_ADDR(shadow_pde[i].pt_base_addr);
- addr_t host_addr;
- shadow_region_t * ent;
+ return 0;
+}
+
+int V3_deinit_shdw_paging() {
+ v3_free_htable(master_shdw_pg_table, 0, 0);
+ return 0;
+}
+
+
+
+/***
+ *** There be dragons
+ ***/
+
+
+#ifdef V3_CONFIG_SHADOW_PAGING_TELEMETRY
+static void telemetry_cb(struct v3_vm_info * vm, void * private_data, char * hdr) {
+ int i = 0;
+ for (i = 0; i < vm->num_cores; i++) {
+ struct guest_info * core = &(vm->cores[i]);
+
+ V3_Print(vm, core, "%s Guest Page faults: %d\n", hdr, core->shdw_pg_state.guest_faults);
+ }
+}
+#endif
+
+
+
+int v3_init_shdw_pg_state(struct guest_info * core) {
+ struct v3_shdw_pg_state * state = &(core->shdw_pg_state);
+ struct v3_shdw_pg_impl * impl = core->vm_info->shdw_impl.current_impl;
+
- ent = get_shadow_region_by_addr(&(guest_info->mem_map), guest_addr);
-
- if (!ent) {
- // FIXME Panic here - guest is trying to map to physical memory
- // it does not own in any way!
+ state->guest_cr3 = 0;
+ state->guest_cr0 = 0;
+ state->guest_efer.value = 0x0LL;
+
+ if (impl->local_init(core) == -1) {
+ PrintError(core->vm_info, core, "Error in Shadow paging local initialization (%s)\n", impl->name);
return -1;
- }
-
- // FIXME Bounds check here to see if it's trying to trick us
-
- switch (ent->host_type) {
- case HOST_REGION_PHYSICAL_MEMORY:
- // points into currently allocated physical memory, so we just
- // set up the shadow to point to the mapped location
- if (guest_pa_to_host_pa(guest_info, guest_addr, &host_addr)) {
- // Panic here
- return -1;
+ }
+
+
+#ifdef V3_CONFIG_SHADOW_PAGING_TELEMETRY
+ v3_add_telemetry_cb(core->vm_info, telemetry_cb, NULL);
+#endif
+
+
+ return 0;
+}
+
+
+int v3_deinit_shdw_pg_state(struct guest_info * core) {
+ struct v3_shdw_pg_impl * impl = NULL;
+
+ if (!core || !core->vm_info) {
+ return -1;
+ }
+
+ impl = core->vm_info->shdw_impl.current_impl;
+
+ if (impl && impl->local_deinit(core) == -1) {
+ PrintError(core->vm_info, core, "Error deinitializing shadow paging state\n");
+ return -1;
+ }
+
+
+ return 0;
+}
+
+
+
+int v3_init_shdw_impl(struct v3_vm_info * vm) {
+ struct v3_shdw_impl_state * impl_state = &(vm->shdw_impl);
+ v3_cfg_tree_t * pg_cfg = v3_cfg_subtree(vm->cfg_data->cfg, "paging");
+ char * pg_mode = v3_cfg_val(pg_cfg, "mode");
+ char * pg_strat = v3_cfg_val(pg_cfg, "strategy");
+ struct v3_shdw_pg_impl * impl = NULL;
+
+ PrintDebug(vm, VCORE_NONE, "Checking if shadow paging requested.\n");
+ if (pg_mode == NULL) {
+ V3_Print(vm, VCORE_NONE, "No paging mode specified, assuming shadow with defaults\n");
+ pg_mode = "shadow";
+ } else {
+ if (strcasecmp(pg_mode, "nested") == 0) {
+ // this check is repeated here (compare to vmm_config's determine paging mode) since
+ // shadow paging initialization *precedes* per-core pre-config.
+ extern v3_cpu_arch_t v3_mach_type;
+ if ((v3_mach_type == V3_SVM_REV3_CPU) ||
+ (v3_mach_type == V3_VMX_EPT_CPU) ||
+ (v3_mach_type == V3_VMX_EPT_UG_CPU)) {
+ PrintDebug(vm, VCORE_NONE, "Nested paging specified on machine that supports it - not initializing shadow paging\n");
+ return 0;
+ } else {
+ V3_Print(vm, VCORE_NONE, "Nested paging specified but machine does not support it - falling back to shadow paging with defaults\n");
+ pg_mode = "shadow";
+ }
+ } else if (strcasecmp(pg_mode, "shadow") != 0) {
+ V3_Print(vm, VCORE_NONE, "Unknown paging mode '%s' specified - falling back to shadow paging with defaults\n",pg_mode);
+ pg_mode = "shadow";
}
+ }
+
+ if (pg_strat == NULL) {
+ pg_strat = (char *)default_strategy;
+ }
+
+ V3_Print(vm, VCORE_NONE,"Initialization of Shadow Paging implementation\n");
+
+ impl = (struct v3_shdw_pg_impl *)v3_htable_search(master_shdw_pg_table, (addr_t)pg_strat);
+
+ if (impl == NULL) {
+ PrintError(vm, VCORE_NONE, "Could not find shadow paging impl (%s)\n", pg_strat);
+ return -1;
+ }
+
+ INIT_LIST_HEAD(&(impl_state->event_callback_list));
+ v3_rw_lock_init(&(impl_state->event_callback_lock));
+
+ impl_state->current_impl = impl;
+
+ if (impl->init(vm, pg_cfg) == -1) {
+ PrintError(vm, VCORE_NONE, "Could not initialize Shadow paging implemenation (%s)\n", impl->name);
+ return -1;
+ }
+
+
+
+ return 0;
+}
+
+int v3_deinit_shdw_impl(struct v3_vm_info * vm) {
+ struct v3_shdw_pg_impl * impl = vm->shdw_impl.current_impl;
+ struct event_callback *cb,*temp;
+ addr_t flags;
+
+ if (impl == NULL) {
+ // Shadow paging not implemented
+ return 0;
+ }
- shadow_pde[i].pt_base_addr = PAGE_ALIGNED_ADDR(host_addr);
- // FIXME set vmm_info bits here
- break;
- case HOST_REGION_UNALLOCATED:
- // points to physical memory that is *allowed* but that we
- // have not yet allocated. We mark as not present and set a
- // bit to remind us to allocate it later
- shadow_pde[i].present = 0;
- // FIXME Set vminfo bits here so that we know that we will be
- // allocating it later
- break;
- case HOST_REGION_NOTHING:
- // points to physical memory that is NOT ALLOWED.
- // We will mark it as not present and set a bit to remind
- // us that it's bad later and insert a GPF then
- shadow_pde[i].present = 0;
- break;
- case HOST_REGION_MEMORY_MAPPED_DEVICE:
- case HOST_REGION_REMOTE:
- case HOST_REGION_SWAPPED:
- default:
- // Panic. Currently unhandled
+ if (impl->deinit(vm) == -1) {
+ PrintError(vm, VCORE_NONE,"Error deinitializing shadow paging implementation\n");
return -1;
- break;
- }
+ }
+
+ flags=v3_write_lock_irqsave(&(vm->shdw_impl.event_callback_lock));
+
+ list_for_each_entry_safe(cb,
+ temp,
+ &(vm->shdw_impl.event_callback_list),
+ node) {
+ list_del(&(cb->node));
+ V3_Free(cb);
+ }
+
+ v3_write_unlock_irqrestore(&(vm->shdw_impl.event_callback_lock),flags);
+
+ v3_rw_lock_deinit(&(vm->shdw_impl.event_callback_lock));
+
+ return 0;
+}
+
+
+// Reads the guest CR3 register
+// creates new shadow page tables
+// updates the shadow CR3 register to point to the new pts
+int v3_activate_shadow_pt(struct guest_info * core) {
+ struct v3_shdw_impl_state * state = &(core->vm_info->shdw_impl);
+ struct v3_shdw_pg_impl * impl = state->current_impl;
+
+ if (!have_callbacks(core)) {
+ return impl->activate_shdw_pt(core);
+ } else {
+ int rc;
+ struct v3_shdw_pg_event event_pre={SHADOW_ACTIVATE,SHADOW_PREIMPL,0,{0,0,0,0,0,0}};
+ struct v3_shdw_pg_event event_post={SHADOW_ACTIVATE,SHADOW_POSTIMPL,0,{0,0,0,0,0,0}};
+
+ dispatch_event(core,&event_pre);
+
+ rc =impl->activate_shdw_pt(core);
+
+ dispatch_event(core,&event_post);
+
+ return rc;
+ }
+}
+
+
+
+// This must flush any caches
+// and reset the cr3 value to the correct value
+int v3_invalidate_shadow_pts(struct guest_info * core) {
+ struct v3_shdw_impl_state * state = &(core->vm_info->shdw_impl);
+ struct v3_shdw_pg_impl * impl = state->current_impl;
+
+ if (!have_callbacks(core)) {
+ return impl->invalidate_shdw_pt(core);
} else {
- pte32_t * guest_pte;
- pte32_t * shadow_pte;
- addr_t guest_addr;
- addr_t guest_pte_host_addr;
- shadow_region_t * ent;
+ int rc;
+ struct v3_shdw_pg_event event_pre={SHADOW_INVALIDATE,SHADOW_PREIMPL,0,{0,0,0,0,0,0}};
+ struct v3_shdw_pg_event event_post={SHADOW_INVALIDATE,SHADOW_POSTIMPL,0,{0,0,0,0,0,0}};
+
+ dispatch_event(core,&event_pre);
+
+ rc = impl->invalidate_shdw_pt(core);
- // small page - set PDE and follow down to the child table
- shadow_pde[i] = guest_pde[i];
+ dispatch_event(core,&event_post);
+
+ return rc;
+ }
+}
- guest_addr = PAGE_ADDR(guest_pde[i].pt_base_addr);
- // Allocate a new second level page table for the shadow
- shadow_pte = os_hooks->allocate_pages(1);
+int v3_handle_shadow_pagefault(struct guest_info * core, addr_t fault_addr, pf_error_t error_code)
+{
+ int rc;
+
- // make our first level page table in the shadow point to it
- shadow_pde[i].pt_base_addr = PAGE_ALIGNED_ADDR(shadow_pte);
-
- ent = get_shadow_region_by_addr(&(guest_info->mem_map), guest_addr);
-
+ if (have_callbacks(core)) {
+ struct v3_shdw_pg_event event={SHADOW_PAGEFAULT,SHADOW_PREIMPL,fault_addr,error_code};
+ dispatch_event(core,&event);
+ }
+
+ if (v3_get_vm_mem_mode(core) == PHYSICAL_MEM) {
+ // If paging is not turned on we need to handle the special cases
+ rc = v3_handle_passthrough_pagefault(core, fault_addr, error_code,NULL,NULL);
+ } else if (v3_get_vm_mem_mode(core) == VIRTUAL_MEM) {
+ struct v3_shdw_impl_state * state = &(core->vm_info->shdw_impl);
+ struct v3_shdw_pg_impl * impl = state->current_impl;
+
+ rc = impl->handle_pagefault(core, fault_addr, error_code);
+ } else {
+ PrintError(core->vm_info, core, "Invalid Memory mode\n");
+ rc = -1;
+ }
+
+ if (have_callbacks(core)) {
+ struct v3_shdw_pg_event event={SHADOW_PAGEFAULT,SHADOW_POSTIMPL,fault_addr,error_code};
+ dispatch_event(core,&event);
+ }
+
+ return rc;
+}
- /* JRL: This is bad.... */
- // For now the guest Page Table must always be mapped to host physical memory
- /* If we swap out a page table or if it isn't present for some reason, this turns real ugly */
- if ((!ent) || (ent->host_type != HOST_REGION_PHYSICAL_MEMORY)) {
- // FIXME Panic here - guest is trying to map to physical memory
- // it does not own in any way!
+int v3_handle_shadow_invlpg(struct guest_info * core) {
+ uchar_t instr[15];
+ struct x86_instr dec_instr;
+ int ret = 0;
+ addr_t vaddr = 0;
+
+ if (v3_get_vm_mem_mode(core) != VIRTUAL_MEM) {
+ // Paging must be turned on...
+ // should handle with some sort of fault I think
+ PrintError(core->vm_info, core, "ERROR: INVLPG called in non paged mode\n");
+ return -1;
+ }
+
+ if (v3_get_vm_mem_mode(core) == PHYSICAL_MEM) {
+ ret = v3_read_gpa_memory(core, get_addr_linear(core, core->rip, &(core->segments.cs)), 15, instr);
+ } else {
+ ret = v3_read_gva_memory(core, get_addr_linear(core, core->rip, &(core->segments.cs)), 15, instr);
+ }
+
+ if (ret == -1) {
+ PrintError(core->vm_info, core, "Could not read instruction into buffer\n");
return -1;
- }
+ }
- // Address of the relevant second level page table in the guest
- if (guest_pa_to_host_pa(guest_info, guest_addr, &guest_pte_host_addr)) {
- // Panic here
+ if (v3_decode(core, (addr_t)instr, &dec_instr) == -1) {
+ PrintError(core->vm_info, core, "Decoding Error\n");
+ return -1;
+ }
+
+ if ((dec_instr.op_type != V3_OP_INVLPG) ||
+ (dec_instr.num_operands != 1) ||
+ (dec_instr.dst_operand.type != MEM_OPERAND)) {
+ PrintError(core->vm_info, core, "Decoder Error: Not a valid INVLPG instruction...\n");
return -1;
- }
+ }
+ vaddr = dec_instr.dst_operand.operand;
- // host_addr now contains the host physical address for the guest's 2nd level page table
- // Now we transform it to relevant virtual address
- guest_pte = os_hooks->paddr_to_vaddr((void *)guest_pte_host_addr);
+ core->rip += dec_instr.instr_length;
- // Now we walk through the second level guest page table
- // and clone it into the shadow
- for (j = 0; j < MAX_PTE32_ENTRIES; j++) {
- shadow_pte[j] = guest_pte[j];
+ {
+ struct v3_shdw_impl_state * state = &(core->vm_info->shdw_impl);
+ struct v3_shdw_pg_impl * impl = state->current_impl;
+ int rc;
- addr_t guest_addr = PAGE_ADDR(shadow_pte[j].page_base_addr);
-
- shadow_region_t * ent;
-
- ent = get_shadow_region_by_addr(&(guest_info->mem_map), guest_addr);
-
- if (!ent) {
- // FIXME Panic here - guest is trying to map to physical memory
- // it does not own in any way!
- return -1;
+ if (have_callbacks(core)) {
+ struct v3_shdw_pg_event event={SHADOW_INVLPG,SHADOW_PREIMPL,vaddr,{0,0,0,0,0,0}};
+ dispatch_event(core,&event);
}
- switch (ent->host_type) {
- case HOST_REGION_PHYSICAL_MEMORY:
- {
- addr_t host_addr;
-
- // points into currently allocated physical memory, so we just
- // set up the shadow to point to the mapped location
- if (guest_pa_to_host_pa(guest_info, guest_addr, &host_addr)) {
- // Panic here
- return -1;
- }
-
- shadow_pte[j].page_base_addr = PAGE_ALIGNED_ADDR(host_addr);
- // FIXME set vmm_info bits here
- break;
+ rc=impl->handle_invlpg(core, vaddr);
+
+ if (have_callbacks(core)) {
+ struct v3_shdw_pg_event event={SHADOW_INVLPG,SHADOW_POSTIMPL,vaddr,{0,0,0,0,0,0}};
+ dispatch_event(core,&event);
+ }
+
+ return rc;
+ }
+}
+
+
+
+
+
+
+int v3_inject_guest_pf(struct guest_info * core, addr_t fault_addr, pf_error_t error_code) {
+ core->ctrl_regs.cr2 = fault_addr;
+
+#ifdef V3_CONFIG_SHADOW_PAGING_TELEMETRY
+ core->shdw_pg_state.guest_faults++;
+#endif
+
+ return v3_raise_exception_with_error(core, PF_EXCEPTION, *(uint_t *)&error_code);
+}
+
+
+int v3_is_guest_pf(pt_access_status_t guest_access, pt_access_status_t shadow_access) {
+ /* basically the reasoning is that there can be multiple reasons for a page fault:
+ If there is a permissions failure for a page present in the guest _BUT_
+ the reason for the fault was that the page is not present in the shadow,
+ _THEN_ we have to map the shadow page in and reexecute, this will generate
+ a permissions fault which is _THEN_ valid to send to the guest
+ _UNLESS_ both the guest and shadow have marked the page as not present
+
+ whew...
+ */
+ if (guest_access != PT_ACCESS_OK) {
+ // Guest Access Error
+
+ if ((shadow_access != PT_ACCESS_NOT_PRESENT) &&
+ (guest_access != PT_ACCESS_NOT_PRESENT)) {
+ // aka (guest permission error)
+ return 1;
+ }
+
+ /*
+ if ((shadow_access == PT_ACCESS_NOT_PRESENT) &&
+ (guest_access == PT_ACCESS_NOT_PRESENT)) {
+ // Page tables completely blank, handle guest first
+ return 1;
}
- case HOST_REGION_UNALLOCATED:
- // points to physical memory that is *allowed* but that we
- // have not yet allocated. We mark as not present and set a
- // bit to remind us to allocate it later
- shadow_pte[j].present = 0;
- // FIXME Set vminfo bits here so that we know that we will be
- // allocating it later
- break;
- case HOST_REGION_NOTHING:
- // points to physical memory that is NOT ALLOWED.
- // We will mark it as not present and set a bit to remind
- // us that it's bad later and insert a GPF then
- shadow_pte[j].present = 0;
- break;
- case HOST_REGION_MEMORY_MAPPED_DEVICE:
- case HOST_REGION_REMOTE:
- case HOST_REGION_SWAPPED:
- default:
- // Panic. Currently unhandled
- return -1;
- break;
+ */
+
+ if (guest_access == PT_ACCESS_NOT_PRESENT) {
+ // Page tables completely blank, handle guest first
+ return 1;
}
- }
+
+ // Otherwise we'll handle the guest fault later...?
}
- }
- return 0;
+
+ return 0;
}
-
+
+
+int v3_register_shadow_paging_event_callback(struct v3_vm_info *vm,
+ int (*callback)(struct guest_info *core,
+ struct v3_shdw_pg_event *event,
+ void *priv_data),
+ void *priv_data)
+{
+ struct event_callback *ec = V3_Malloc(sizeof(struct event_callback));
+ addr_t flags;
+
+ if (!ec) {
+ PrintError(vm, VCORE_NONE, "Unable to allocate for a shadow paging event callback\n");
+ return -1;
+ }
+
+ ec->callback = callback;
+ ec->priv_data = priv_data;
+
+ flags=v3_write_lock_irqsave(&(vm->shdw_impl.event_callback_lock));
+ list_add(&(ec->node),&(vm->shdw_impl.event_callback_list));
+ v3_write_unlock_irqrestore(&(vm->shdw_impl.event_callback_lock),flags);
+
+ return 0;
+
+}
+
+int v3_unregister_shadow_paging_event_callback(struct v3_vm_info *vm,
+ int (*callback)(struct guest_info *core,
+ struct v3_shdw_pg_event *event,
+ void *priv_data),
+ void *priv_data)
+{
+ struct event_callback *cb,*temp;
+ addr_t flags;
+
+ flags=v3_write_lock_irqsave(&(vm->shdw_impl.event_callback_lock));
+
+ list_for_each_entry_safe(cb,
+ temp,
+ &(vm->shdw_impl.event_callback_list),
+ node) {
+ if ((callback == cb->callback) && (priv_data == cb->priv_data)) {
+ list_del(&(cb->node));
+ v3_write_unlock_irqrestore(&(vm->shdw_impl.event_callback_lock),flags);
+ V3_Free(cb);
+ return 0;
+ }
+ }
+
+ v3_write_unlock_irqrestore(&(vm->shdw_impl.event_callback_lock),flags);
+
+ PrintError(vm, VCORE_NONE, "No callback found!\n");
+
+ return -1;
+}
+
