xen: factor out common functions

So common functions used by both HVM and PV are factored out from
xen-all.c to xen-common.c.

Finally rename xen-all.c to xen-hvm.c, as those functions are only
useful to HVM guest.

Create *-stub files and modify Makefile.target to reflect the changes.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

1 files changed, 1129 insertions, 0 deletions

diff --git a/xen-hvm.c b/xen-hvm.c
new file mode 100644
index 0000000000..0a49055180
--- /dev/null
+++ b/xen-hvm.c
@@ -0,0 +1,1129 @@
+/*
+ * Copyright (C) 2010       Citrix Ltd.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ * Contributions after 2012-01-13 are licensed under the terms of the
+ * GNU GPL, version 2 or (at your option) any later version.
+ */
+
+#include <sys/mman.h>
+
+#include "hw/pci/pci.h"
+#include "hw/i386/pc.h"
+#include "hw/xen/xen_common.h"
+#include "hw/xen/xen_backend.h"
+#include "qmp-commands.h"
+
+#include "sysemu/char.h"
+#include "qemu/range.h"
+#include "sysemu/xen-mapcache.h"
+#include "trace.h"
+#include "exec/address-spaces.h"
+
+#include <xen/hvm/ioreq.h>
+#include <xen/hvm/params.h>
+#include <xen/hvm/e820.h>
+
+//#define DEBUG_XEN_HVM
+
+#ifdef DEBUG_XEN_HVM
+#define DPRINTF(fmt, ...) \
+    do { fprintf(stderr, "xen: " fmt, ## __VA_ARGS__); } while (0)
+#else
+#define DPRINTF(fmt, ...) \
+    do { } while (0)
+#endif
+
+static MemoryRegion ram_memory, ram_640k, ram_lo, ram_hi;
+static MemoryRegion *framebuffer;
+static bool xen_in_migration;
+
+/* Compatibility with older version */
+#if __XEN_LATEST_INTERFACE_VERSION__ < 0x0003020a
+static inline uint32_t xen_vcpu_eport(shared_iopage_t *shared_page, int i)
+{
+    return shared_page->vcpu_iodata[i].vp_eport;
+}
+static inline ioreq_t *xen_vcpu_ioreq(shared_iopage_t *shared_page, int vcpu)
+{
+    return &shared_page->vcpu_iodata[vcpu].vp_ioreq;
+}
+#  define FMT_ioreq_size PRIx64
+#else
+static inline uint32_t xen_vcpu_eport(shared_iopage_t *shared_page, int i)
+{
+    return shared_page->vcpu_ioreq[i].vp_eport;
+}
+static inline ioreq_t *xen_vcpu_ioreq(shared_iopage_t *shared_page, int vcpu)
+{
+    return &shared_page->vcpu_ioreq[vcpu];
+}
+#  define FMT_ioreq_size "u"
+#endif
+#ifndef HVM_PARAM_BUFIOREQ_EVTCHN
+#define HVM_PARAM_BUFIOREQ_EVTCHN 26
+#endif
+
+#define BUFFER_IO_MAX_DELAY  100
+
+typedef struct XenPhysmap {
+    hwaddr start_addr;
+    ram_addr_t size;
+    char *name;
+    hwaddr phys_offset;
+
+    QLIST_ENTRY(XenPhysmap) list;
+} XenPhysmap;
+
+typedef struct XenIOState {
+    shared_iopage_t *shared_page;
+    buffered_iopage_t *buffered_io_page;
+    QEMUTimer *buffered_io_timer;
+    /* the evtchn port for polling the notification, */
+    evtchn_port_t *ioreq_local_port;
+    /* evtchn local port for buffered io */
+    evtchn_port_t bufioreq_local_port;
+    /* the evtchn fd for polling */
+    XenEvtchn xce_handle;
+    /* which vcpu we are serving */
+    int send_vcpu;
+
+    struct xs_handle *xenstore;
+    MemoryListener memory_listener;
+    QLIST_HEAD(, XenPhysmap) physmap;
+    hwaddr free_phys_offset;
+    const XenPhysmap *log_for_dirtybit;
+
+    Notifier exit;
+    Notifier suspend;
+    Notifier wakeup;
+} XenIOState;
+
+/* Xen specific function for piix pci */
+
+int xen_pci_slot_get_pirq(PCIDevice *pci_dev, int irq_num)
+{
+    return irq_num + ((pci_dev->devfn >> 3) << 2);
+}
+
+void xen_piix3_set_irq(void *opaque, int irq_num, int level)
+{
+    xc_hvm_set_pci_intx_level(xen_xc, xen_domid, 0, 0, irq_num >> 2,
+                              irq_num & 3, level);
+}
+
+void xen_piix_pci_write_config_client(uint32_t address, uint32_t val, int len)
+{
+    int i;
+
+    /* Scan for updates to PCI link routes (0x60-0x63). */
+    for (i = 0; i < len; i++) {
+        uint8_t v = (val >> (8 * i)) & 0xff;
+        if (v & 0x80) {
+            v = 0;
+        }
+        v &= 0xf;
+        if (((address + i) >= 0x60) && ((address + i) <= 0x63)) {
+            xc_hvm_set_pci_link_route(xen_xc, xen_domid, address + i - 0x60, v);
+        }
+    }
+}
+
+void xen_hvm_inject_msi(uint64_t addr, uint32_t data)
+{
+    xen_xc_hvm_inject_msi(xen_xc, xen_domid, addr, data);
+}
+
+static void xen_suspend_notifier(Notifier *notifier, void *data)
+{
+    xc_set_hvm_param(xen_xc, xen_domid, HVM_PARAM_ACPI_S_STATE, 3);
+}
+
+/* Xen Interrupt Controller */
+
+static void xen_set_irq(void *opaque, int irq, int level)
+{
+    xc_hvm_set_isa_irq_level(xen_xc, xen_domid, irq, level);
+}
+
+qemu_irq *xen_interrupt_controller_init(void)
+{
+    return qemu_allocate_irqs(xen_set_irq, NULL, 16);
+}
+
+/* Memory Ops */
+
+static void xen_ram_init(ram_addr_t ram_size, MemoryRegion **ram_memory_p)
+{
+    MemoryRegion *sysmem = get_system_memory();
+    ram_addr_t below_4g_mem_size, above_4g_mem_size = 0;
+    ram_addr_t block_len;
+
+    block_len = ram_size;
+    if (ram_size >= HVM_BELOW_4G_RAM_END) {
+        /* Xen does not allocate the memory continuously, and keep a hole at
+         * HVM_BELOW_4G_MMIO_START of HVM_BELOW_4G_MMIO_LENGTH
+         */
+        block_len += HVM_BELOW_4G_MMIO_LENGTH;
+    }
+    memory_region_init_ram(&ram_memory, NULL, "xen.ram", block_len);
+    *ram_memory_p = &ram_memory;
+    vmstate_register_ram_global(&ram_memory);
+
+    if (ram_size >= HVM_BELOW_4G_RAM_END) {
+        above_4g_mem_size = ram_size - HVM_BELOW_4G_RAM_END;
+        below_4g_mem_size = HVM_BELOW_4G_RAM_END;
+    } else {
+        below_4g_mem_size = ram_size;
+    }
+
+    memory_region_init_alias(&ram_640k, NULL, "xen.ram.640k",
+                             &ram_memory, 0, 0xa0000);
+    memory_region_add_subregion(sysmem, 0, &ram_640k);
+    /* Skip of the VGA IO memory space, it will be registered later by the VGA
+     * emulated device.
+     *
+     * The area between 0xc0000 and 0x100000 will be used by SeaBIOS to load
+     * the Options ROM, so it is registered here as RAM.
+     */
+    memory_region_init_alias(&ram_lo, NULL, "xen.ram.lo",
+                             &ram_memory, 0xc0000, below_4g_mem_size - 0xc0000);
+    memory_region_add_subregion(sysmem, 0xc0000, &ram_lo);
+    if (above_4g_mem_size > 0) {
+        memory_region_init_alias(&ram_hi, NULL, "xen.ram.hi",
+                                 &ram_memory, 0x100000000ULL,
+                                 above_4g_mem_size);
+        memory_region_add_subregion(sysmem, 0x100000000ULL, &ram_hi);
+    }
+}
+
+void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size, MemoryRegion *mr)
+{
+    unsigned long nr_pfn;
+    xen_pfn_t *pfn_list;
+    int i;
+
+    if (runstate_check(RUN_STATE_INMIGRATE)) {
+        /* RAM already populated in Xen */
+        fprintf(stderr, "%s: do not alloc "RAM_ADDR_FMT
+                " bytes of ram at "RAM_ADDR_FMT" when runstate is INMIGRATE\n",
+                __func__, size, ram_addr); 
+        return;
+    }
+
+    if (mr == &ram_memory) {
+        return;
+    }
+
+    trace_xen_ram_alloc(ram_addr, size);
+
+    nr_pfn = size >> TARGET_PAGE_BITS;
+    pfn_list = g_malloc(sizeof (*pfn_list) * nr_pfn);
+
+    for (i = 0; i < nr_pfn; i++) {
+        pfn_list[i] = (ram_addr >> TARGET_PAGE_BITS) + i;
+    }
+
+    if (xc_domain_populate_physmap_exact(xen_xc, xen_domid, nr_pfn, 0, 0, pfn_list)) {
+        hw_error("xen: failed to populate ram at " RAM_ADDR_FMT, ram_addr);
+    }
+
+    g_free(pfn_list);
+}
+
+static XenPhysmap *get_physmapping(XenIOState *state,
+                                   hwaddr start_addr, ram_addr_t size)
+{
+    XenPhysmap *physmap = NULL;
+
+    start_addr &= TARGET_PAGE_MASK;
+
+    QLIST_FOREACH(physmap, &state->physmap, list) {
+        if (range_covers_byte(physmap->start_addr, physmap->size, start_addr)) {
+            return physmap;
+        }
+    }
+    return NULL;
+}
+
+static hwaddr xen_phys_offset_to_gaddr(hwaddr start_addr,
+                                                   ram_addr_t size, void *opaque)
+{
+    hwaddr addr = start_addr & TARGET_PAGE_MASK;
+    XenIOState *xen_io_state = opaque;
+    XenPhysmap *physmap = NULL;
+
+    QLIST_FOREACH(physmap, &xen_io_state->physmap, list) {
+        if (range_covers_byte(physmap->phys_offset, physmap->size, addr)) {
+            return physmap->start_addr;
+        }
+    }
+
+    return start_addr;
+}
+
+#if CONFIG_XEN_CTRL_INTERFACE_VERSION >= 340
+static int xen_add_to_physmap(XenIOState *state,
+                              hwaddr start_addr,
+                              ram_addr_t size,
+                              MemoryRegion *mr,
+                              hwaddr offset_within_region)
+{
+    unsigned long i = 0;
+    int rc = 0;
+    XenPhysmap *physmap = NULL;
+    hwaddr pfn, start_gpfn;
+    hwaddr phys_offset = memory_region_get_ram_addr(mr);
+    char path[80], value[17];
+
+    if (get_physmapping(state, start_addr, size)) {
+        return 0;
+    }
+    if (size <= 0) {
+        return -1;
+    }
+
+    /* Xen can only handle a single dirty log region for now and we want
+     * the linear framebuffer to be that region.
+     * Avoid tracking any regions that is not videoram and avoid tracking
+     * the legacy vga region. */
+    if (mr == framebuffer && start_addr > 0xbffff) {
+        goto go_physmap;
+    }
+    return -1;
+
+go_physmap:
+    DPRINTF("mapping vram to %"HWADDR_PRIx" - %"HWADDR_PRIx"\n",
+            start_addr, start_addr + size);
+
+    pfn = phys_offset >> TARGET_PAGE_BITS;
+    start_gpfn = start_addr >> TARGET_PAGE_BITS;
+    for (i = 0; i < size >> TARGET_PAGE_BITS; i++) {
+        unsigned long idx = pfn + i;
+        xen_pfn_t gpfn = start_gpfn + i;
+
+        rc = xc_domain_add_to_physmap(xen_xc, xen_domid, XENMAPSPACE_gmfn, idx, gpfn);
+        if (rc) {
+            DPRINTF("add_to_physmap MFN %"PRI_xen_pfn" to PFN %"
+                    PRI_xen_pfn" failed: %d\n", idx, gpfn, rc);
+            return -rc;
+        }
+    }
+
+    physmap = g_malloc(sizeof (XenPhysmap));
+
+    physmap->start_addr = start_addr;
+    physmap->size = size;
+    physmap->name = (char *)mr->name;
+    physmap->phys_offset = phys_offset;
+
+    QLIST_INSERT_HEAD(&state->physmap, physmap, list);
+
+    xc_domain_pin_memory_cacheattr(xen_xc, xen_domid,
+                                   start_addr >> TARGET_PAGE_BITS,
+                                   (start_addr + size) >> TARGET_PAGE_BITS,
+                                   XEN_DOMCTL_MEM_CACHEATTR_WB);
+
+    snprintf(path, sizeof(path),
+            "/local/domain/0/device-model/%d/physmap/%"PRIx64"/start_addr",
+            xen_domid, (uint64_t)phys_offset);
+    snprintf(value, sizeof(value), "%"PRIx64, (uint64_t)start_addr);
+    if (!xs_write(state->xenstore, 0, path, value, strlen(value))) {
+        return -1;
+    }
+    snprintf(path, sizeof(path),
+            "/local/domain/0/device-model/%d/physmap/%"PRIx64"/size",
+            xen_domid, (uint64_t)phys_offset);
+    snprintf(value, sizeof(value), "%"PRIx64, (uint64_t)size);
+    if (!xs_write(state->xenstore, 0, path, value, strlen(value))) {
+        return -1;
+    }
+    if (mr->name) {
+        snprintf(path, sizeof(path),
+                "/local/domain/0/device-model/%d/physmap/%"PRIx64"/name",
+                xen_domid, (uint64_t)phys_offset);
+        if (!xs_write(state->xenstore, 0, path, mr->name, strlen(mr->name))) {
+            return -1;
+        }
+    }
+
+    return 0;
+}
+
+static int xen_remove_from_physmap(XenIOState *state,
+                                   hwaddr start_addr,
+                                   ram_addr_t size)
+{
+    unsigned long i = 0;
+    int rc = 0;
+    XenPhysmap *physmap = NULL;
+    hwaddr phys_offset = 0;
+
+    physmap = get_physmapping(state, start_addr, size);
+    if (physmap == NULL) {
+        return -1;
+    }
+
+    phys_offset = physmap->phys_offset;
+    size = physmap->size;
+
+    DPRINTF("unmapping vram to %"HWADDR_PRIx" - %"HWADDR_PRIx", at "
+            "%"HWADDR_PRIx"\n", start_addr, start_addr + size, phys_offset);
+
+    size >>= TARGET_PAGE_BITS;
+    start_addr >>= TARGET_PAGE_BITS;
+    phys_offset >>= TARGET_PAGE_BITS;
+    for (i = 0; i < size; i++) {
+        unsigned long idx = start_addr + i;
+        xen_pfn_t gpfn = phys_offset + i;
+
+        rc = xc_domain_add_to_physmap(xen_xc, xen_domid, XENMAPSPACE_gmfn, idx, gpfn);
+        if (rc) {
+            fprintf(stderr, "add_to_physmap MFN %"PRI_xen_pfn" to PFN %"
+                    PRI_xen_pfn" failed: %d\n", idx, gpfn, rc);
+            return -rc;
+        }
+    }
+
+    QLIST_REMOVE(physmap, list);
+    if (state->log_for_dirtybit == physmap) {
+        state->log_for_dirtybit = NULL;
+    }
+    g_free(physmap);
+
+    return 0;
+}
+
+#else
+static int xen_add_to_physmap(XenIOState *state,
+                              hwaddr start_addr,
+                              ram_addr_t size,
+                              MemoryRegion *mr,
+                              hwaddr offset_within_region)
+{
+    return -ENOSYS;
+}
+
+static int xen_remove_from_physmap(XenIOState *state,
+                                   hwaddr start_addr,
+                                   ram_addr_t size)
+{
+    return -ENOSYS;
+}
+#endif
+
+static void xen_set_memory(struct MemoryListener *listener,
+                           MemoryRegionSection *section,
+                           bool add)
+{
+    XenIOState *state = container_of(listener, XenIOState, memory_listener);
+    hwaddr start_addr = section->offset_within_address_space;
+    ram_addr_t size = int128_get64(section->size);
+    bool log_dirty = memory_region_is_logging(section->mr);
+    hvmmem_type_t mem_type;
+
+    if (!memory_region_is_ram(section->mr)) {
+        return;
+    }
+
+    if (!(section->mr != &ram_memory
+          && ( (log_dirty && add) || (!log_dirty && !add)))) {
+        return;
+    }
+
+    trace_xen_client_set_memory(start_addr, size, log_dirty);
+
+    start_addr &= TARGET_PAGE_MASK;
+    size = TARGET_PAGE_ALIGN(size);
+
+    if (add) {
+        if (!memory_region_is_rom(section->mr)) {
+            xen_add_to_physmap(state, start_addr, size,
+                               section->mr, section->offset_within_region);
+        } else {
+            mem_type = HVMMEM_ram_ro;
+            if (xc_hvm_set_mem_type(xen_xc, xen_domid, mem_type,
+                                    start_addr >> TARGET_PAGE_BITS,
+                                    size >> TARGET_PAGE_BITS)) {
+                DPRINTF("xc_hvm_set_mem_type error, addr: "TARGET_FMT_plx"\n",
+                        start_addr);
+            }
+        }
+    } else {
+        if (xen_remove_from_physmap(state, start_addr, size) < 0) {
+            DPRINTF("physmapping does not exist at "TARGET_FMT_plx"\n", start_addr);
+        }
+    }
+}
+
+static void xen_region_add(MemoryListener *listener,
+                           MemoryRegionSection *section)
+{
+    memory_region_ref(section->mr);
+    xen_set_memory(listener, section, true);
+}
+
+static void xen_region_del(MemoryListener *listener,
+                           MemoryRegionSection *section)
+{
+    xen_set_memory(listener, section, false);
+    memory_region_unref(section->mr);
+}
+
+static void xen_sync_dirty_bitmap(XenIOState *state,
+                                  hwaddr start_addr,
+                                  ram_addr_t size)
+{
+    hwaddr npages = size >> TARGET_PAGE_BITS;
+    const int width = sizeof(unsigned long) * 8;
+    unsigned long bitmap[(npages + width - 1) / width];
+    int rc, i, j;
+    const XenPhysmap *physmap = NULL;
+
+    physmap = get_physmapping(state, start_addr, size);
+    if (physmap == NULL) {
+        /* not handled */
+        return;
+    }
+
+    if (state->log_for_dirtybit == NULL) {
+        state->log_for_dirtybit = physmap;
+    } else if (state->log_for_dirtybit != physmap) {
+        /* Only one range for dirty bitmap can be tracked. */
+        return;
+    }
+
+    rc = xc_hvm_track_dirty_vram(xen_xc, xen_domid,
+                                 start_addr >> TARGET_PAGE_BITS, npages,
+                                 bitmap);
+    if (rc < 0) {
+        if (rc != -ENODATA) {
+            memory_region_set_dirty(framebuffer, 0, size);
+            DPRINTF("xen: track_dirty_vram failed (0x" TARGET_FMT_plx
+                    ", 0x" TARGET_FMT_plx "): %s\n",
+                    start_addr, start_addr + size, strerror(-rc));
+        }
+        return;
+    }
+
+    for (i = 0; i < ARRAY_SIZE(bitmap); i++) {
+        unsigned long map = bitmap[i];
+        while (map != 0) {
+            j = ffsl(map) - 1;
+            map &= ~(1ul << j);
+            memory_region_set_dirty(framebuffer,
+                                    (i * width + j) * TARGET_PAGE_SIZE,
+                                    TARGET_PAGE_SIZE);
+        };
+    }
+}
+
+static void xen_log_start(MemoryListener *listener,
+                          MemoryRegionSection *section)
+{
+    XenIOState *state = container_of(listener, XenIOState, memory_listener);
+
+    xen_sync_dirty_bitmap(state, section->offset_within_address_space,
+                          int128_get64(section->size));
+}
+
+static void xen_log_stop(MemoryListener *listener, MemoryRegionSection *section)
+{
+    XenIOState *state = container_of(listener, XenIOState, memory_listener);
+
+    state->log_for_dirtybit = NULL;
+    /* Disable dirty bit tracking */
+    xc_hvm_track_dirty_vram(xen_xc, xen_domid, 0, 0, NULL);
+}
+
+static void xen_log_sync(MemoryListener *listener, MemoryRegionSection *section)
+{
+    XenIOState *state = container_of(listener, XenIOState, memory_listener);
+
+    xen_sync_dirty_bitmap(state, section->offset_within_address_space,
+                          int128_get64(section->size));
+}
+
+static void xen_log_global_start(MemoryListener *listener)
+{
+    if (xen_enabled()) {
+        xen_in_migration = true;
+    }
+}
+
+static void xen_log_global_stop(MemoryListener *listener)
+{
+    xen_in_migration = false;
+}
+
+static MemoryListener xen_memory_listener = {
+    .region_add = xen_region_add,
+    .region_del = xen_region_del,
+    .log_start = xen_log_start,
+    .log_stop = xen_log_stop,
+    .log_sync = xen_log_sync,
+    .log_global_start = xen_log_global_start,
+    .log_global_stop = xen_log_global_stop,
+    .priority = 10,
+};
+
+/* get the ioreq packets from share mem */
+static ioreq_t *cpu_get_ioreq_from_shared_memory(XenIOState *state, int vcpu)
+{
+    ioreq_t *req = xen_vcpu_ioreq(state->shared_page, vcpu);
+
+    if (req->state != STATE_IOREQ_READY) {
+        DPRINTF("I/O request not ready: "
+                "%x, ptr: %x, port: %"PRIx64", "
+                "data: %"PRIx64", count: %" FMT_ioreq_size ", size: %" FMT_ioreq_size "\n",
+                req->state, req->data_is_ptr, req->addr,
+                req->data, req->count, req->size);
+        return NULL;
+    }
+
+    xen_rmb(); /* see IOREQ_READY /then/ read contents of ioreq */
+
+    req->state = STATE_IOREQ_INPROCESS;
+    return req;
+}
+
+/* use poll to get the port notification */
+/* ioreq_vec--out,the */
+/* retval--the number of ioreq packet */
+static ioreq_t *cpu_get_ioreq(XenIOState *state)
+{
+    int i;
+    evtchn_port_t port;
+
+    port = xc_evtchn_pending(state->xce_handle);
+    if (port == state->bufioreq_local_port) {
+        timer_mod(state->buffered_io_timer,
+                BUFFER_IO_MAX_DELAY + qemu_clock_get_ms(QEMU_CLOCK_REALTIME));
+        return NULL;
+    }
+
+    if (port != -1) {
+        for (i = 0; i < max_cpus; i++) {
+            if (state->ioreq_local_port[i] == port) {
+                break;
+            }
+        }
+
+        if (i == max_cpus) {
+            hw_error("Fatal error while trying to get io event!\n");
+        }
+
+        /* unmask the wanted port again */
+        xc_evtchn_unmask(state->xce_handle, port);
+
+        /* get the io packet from shared memory */
+        state->send_vcpu = i;
+        return cpu_get_ioreq_from_shared_memory(state, i);
+    }
+
+    /* read error or read nothing */
+    return NULL;
+}
+
+static uint32_t do_inp(pio_addr_t addr, unsigned long size)
+{
+    switch (size) {
+        case 1:
+            return cpu_inb(addr);
+        case 2:
+            return cpu_inw(addr);
+        case 4:
+            return cpu_inl(addr);
+        default:
+            hw_error("inp: bad size: %04"FMT_pioaddr" %lx", addr, size);
+    }
+}
+
+static void do_outp(pio_addr_t addr,
+        unsigned long size, uint32_t val)
+{
+    switch (size) {
+        case 1:
+            return cpu_outb(addr, val);
+        case 2:
+            return cpu_outw(addr, val);
+        case 4:
+            return cpu_outl(addr, val);
+        default:
+            hw_error("outp: bad size: %04"FMT_pioaddr" %lx", addr, size);
+    }
+}
+
+/*
+ * Helper functions which read/write an object from/to physical guest
+ * memory, as part of the implementation of an ioreq.
+ *
+ * Equivalent to
+ *   cpu_physical_memory_rw(addr + (req->df ? -1 : +1) * req->size * i,
+ *                          val, req->size, 0/1)
+ * except without the integer overflow problems.
+ */
+static void rw_phys_req_item(hwaddr addr,
+                             ioreq_t *req, uint32_t i, void *val, int rw)
+{
+    /* Do everything unsigned so overflow just results in a truncated result
+     * and accesses to undesired parts of guest memory, which is up
+     * to the guest */
+    hwaddr offset = (hwaddr)req->size * i;
+    if (req->df) {
+        addr -= offset;
+    } else {
+        addr += offset;
+    }
+    cpu_physical_memory_rw(addr, val, req->size, rw);
+}
+
+static inline void read_phys_req_item(hwaddr addr,
+                                      ioreq_t *req, uint32_t i, void *val)
+{
+    rw_phys_req_item(addr, req, i, val, 0);
+}
+static inline void write_phys_req_item(hwaddr addr,
+                                       ioreq_t *req, uint32_t i, void *val)
+{
+    rw_phys_req_item(addr, req, i, val, 1);
+}
+
+
+static void cpu_ioreq_pio(ioreq_t *req)
+{
+    uint32_t i;
+
+    if (req->dir == IOREQ_READ) {
+        if (!req->data_is_ptr) {
+            req->data = do_inp(req->addr, req->size);
+        } else {
+            uint32_t tmp;
+
+            for (i = 0; i < req->count; i++) {
+                tmp = do_inp(req->addr, req->size);
+                write_phys_req_item(req->data, req, i, &tmp);
+            }
+        }
+    } else if (req->dir == IOREQ_WRITE) {
+        if (!req->data_is_ptr) {
+            do_outp(req->addr, req->size, req->data);
+        } else {
+            for (i = 0; i < req->count; i++) {
+                uint32_t tmp = 0;
+
+                read_phys_req_item(req->data, req, i, &tmp);
+                do_outp(req->addr, req->size, tmp);
+            }
+        }
+    }
+}
+
+static void cpu_ioreq_move(ioreq_t *req)
+{
+    uint32_t i;
+
+    if (!req->data_is_ptr) {
+        if (req->dir == IOREQ_READ) {
+            for (i = 0; i < req->count; i++) {
+                read_phys_req_item(req->addr, req, i, &req->data);
+            }
+        } else if (req->dir == IOREQ_WRITE) {
+            for (i = 0; i < req->count; i++) {
+                write_phys_req_item(req->addr, req, i, &req->data);
+            }
+        }
+    } else {
+        uint64_t tmp;
+
+        if (req->dir == IOREQ_READ) {
+            for (i = 0; i < req->count; i++) {
+                read_phys_req_item(req->addr, req, i, &tmp);
+                write_phys_req_item(req->data, req, i, &tmp);
+            }
+        } else if (req->dir == IOREQ_WRITE) {
+            for (i = 0; i < req->count; i++) {
+                read_phys_req_item(req->data, req, i, &tmp);
+                write_phys_req_item(req->addr, req, i, &tmp);
+            }
+        }
+    }
+}
+
+static void handle_ioreq(ioreq_t *req)
+{
+    if (!req->data_is_ptr && (req->dir == IOREQ_WRITE) &&
+            (req->size < sizeof (target_ulong))) {
+        req->data &= ((target_ulong) 1 << (8 * req->size)) - 1;
+    }
+
+    switch (req->type) {
+        case IOREQ_TYPE_PIO:
+            cpu_ioreq_pio(req);
+            break;
+        case IOREQ_TYPE_COPY:
+            cpu_ioreq_move(req);
+            break;
+        case IOREQ_TYPE_TIMEOFFSET:
+            break;
+        case IOREQ_TYPE_INVALIDATE:
+            xen_invalidate_map_cache();
+            break;
+        default:
+            hw_error("Invalid ioreq type 0x%x\n", req->type);
+    }
+}
+
+static int handle_buffered_iopage(XenIOState *state)
+{
+    buf_ioreq_t *buf_req = NULL;
+    ioreq_t req;
+    int qw;
+
+    if (!state->buffered_io_page) {
+        return 0;
+    }
+
+    memset(&req, 0x00, sizeof(req));
+
+    while (state->buffered_io_page->read_pointer != state->buffered_io_page->write_pointer) {
+        buf_req = &state->buffered_io_page->buf_ioreq[
+            state->buffered_io_page->read_pointer % IOREQ_BUFFER_SLOT_NUM];
+        req.size = 1UL << buf_req->size;
+        req.count = 1;
+        req.addr = buf_req->addr;
+        req.data = buf_req->data;
+        req.state = STATE_IOREQ_READY;
+        req.dir = buf_req->dir;
+        req.df = 1;
+        req.type = buf_req->type;
+        req.data_is_ptr = 0;
+        qw = (req.size == 8);
+        if (qw) {
+            buf_req = &state->buffered_io_page->buf_ioreq[
+                (state->buffered_io_page->read_pointer + 1) % IOREQ_BUFFER_SLOT_NUM];
+            req.data |= ((uint64_t)buf_req->data) << 32;
+        }
+
+        handle_ioreq(&req);
+
+        xen_mb();
+        state->buffered_io_page->read_pointer += qw ? 2 : 1;
+    }
+
+    return req.count;
+}
+
+static void handle_buffered_io(void *opaque)
+{
+    XenIOState *state = opaque;
+
+    if (handle_buffered_iopage(state)) {
+        timer_mod(state->buffered_io_timer,
+                BUFFER_IO_MAX_DELAY + qemu_clock_get_ms(QEMU_CLOCK_REALTIME));
+    } else {
+        timer_del(state->buffered_io_timer);
+        xc_evtchn_unmask(state->xce_handle, state->bufioreq_local_port);
+    }
+}
+
+static void cpu_handle_ioreq(void *opaque)
+{
+    XenIOState *state = opaque;
+    ioreq_t *req = cpu_get_ioreq(state);
+
+    handle_buffered_iopage(state);
+    if (req) {
+        handle_ioreq(req);
+
+        if (req->state != STATE_IOREQ_INPROCESS) {
+            fprintf(stderr, "Badness in I/O request ... not in service?!: "
+                    "%x, ptr: %x, port: %"PRIx64", "
+                    "data: %"PRIx64", count: %" FMT_ioreq_size ", size: %" FMT_ioreq_size "\n",
+                    req->state, req->data_is_ptr, req->addr,
+                    req->data, req->count, req->size);
+            destroy_hvm_domain(false);
+            return;
+        }
+
+        xen_wmb(); /* Update ioreq contents /then/ update state. */
+
+        /*
+         * We do this before we send the response so that the tools
+         * have the opportunity to pick up on the reset before the
+         * guest resumes and does a hlt with interrupts disabled which
+         * causes Xen to powerdown the domain.
+         */
+        if (runstate_is_running()) {
+            if (qemu_shutdown_requested_get()) {
+                destroy_hvm_domain(false);
+            }
+            if (qemu_reset_requested_get()) {
+                qemu_system_reset(VMRESET_REPORT);
+                destroy_hvm_domain(true);
+            }
+        }
+
+        req->state = STATE_IORESP_READY;
+        xc_evtchn_notify(state->xce_handle, state->ioreq_local_port[state->send_vcpu]);
+    }
+}
+
+static void xen_main_loop_prepare(XenIOState *state)
+{
+    int evtchn_fd = -1;
+
+    if (state->xce_handle != XC_HANDLER_INITIAL_VALUE) {
+        evtchn_fd = xc_evtchn_fd(state->xce_handle);
+    }
+
+    state->buffered_io_timer = timer_new_ms(QEMU_CLOCK_REALTIME, handle_buffered_io,
+                                                 state);
+
+    if (evtchn_fd != -1) {
+        qemu_set_fd_handler(evtchn_fd, cpu_handle_ioreq, NULL, state);
+    }
+}
+
+
+static void xen_hvm_change_state_handler(void *opaque, int running,
+                                         RunState rstate)
+{
+    XenIOState *xstate = opaque;
+    if (running) {
+        xen_main_loop_prepare(xstate);
+    }
+}
+
+static void xen_exit_notifier(Notifier *n, void *data)
+{
+    XenIOState *state = container_of(n, XenIOState, exit);
+
+    xc_evtchn_close(state->xce_handle);
+    xs_daemon_close(state->xenstore);
+}
+
+static void xen_read_physmap(XenIOState *state)
+{
+    XenPhysmap *physmap = NULL;
+    unsigned int len, num, i;
+    char path[80], *value = NULL;
+    char **entries = NULL;
+
+    snprintf(path, sizeof(path),
+            "/local/domain/0/device-model/%d/physmap", xen_domid);
+    entries = xs_directory(state->xenstore, 0, path, &num);
+    if (entries == NULL)
+        return;
+
+    for (i = 0; i < num; i++) {
+        physmap = g_malloc(sizeof (XenPhysmap));
+        physmap->phys_offset = strtoull(entries[i], NULL, 16);
+        snprintf(path, sizeof(path),
+                "/local/domain/0/device-model/%d/physmap/%s/start_addr",
+                xen_domid, entries[i]);
+        value = xs_read(state->xenstore, 0, path, &len);
+        if (value == NULL) {
+            g_free(physmap);
+            continue;
+        }
+        physmap->start_addr = strtoull(value, NULL, 16);
+        free(value);
+
+        snprintf(path, sizeof(path),
+                "/local/domain/0/device-model/%d/physmap/%s/size",
+                xen_domid, entries[i]);
+        value = xs_read(state->xenstore, 0, path, &len);
+        if (value == NULL) {
+            g_free(physmap);
+            continue;
+        }
+        physmap->size = strtoull(value, NULL, 16);
+        free(value);
+
+        snprintf(path, sizeof(path),
+                "/local/domain/0/device-model/%d/physmap/%s/name",
+                xen_domid, entries[i]);
+        physmap->name = xs_read(state->xenstore, 0, path, &len);
+
+        QLIST_INSERT_HEAD(&state->physmap, physmap, list);
+    }
+    free(entries);
+}
+
+static void xen_wakeup_notifier(Notifier *notifier, void *data)
+{
+    xc_set_hvm_param(xen_xc, xen_domid, HVM_PARAM_ACPI_S_STATE, 0);
+}
+
+int xen_hvm_init(MemoryRegion **ram_memory)
+{
+    int i, rc;
+    unsigned long ioreq_pfn;
+    unsigned long bufioreq_evtchn;
+    XenIOState *state;
+
+    state = g_malloc0(sizeof (XenIOState));
+
+    state->xce_handle = xen_xc_evtchn_open(NULL, 0);
+    if (state->xce_handle == XC_HANDLER_INITIAL_VALUE) {
+        perror("xen: event channel open");
+        g_free(state);
+        return -errno;
+    }
+
+    state->xenstore = xs_daemon_open();
+    if (state->xenstore == NULL) {
+        perror("xen: xenstore open");
+        g_free(state);
+        return -errno;
+    }
+
+    state->exit.notify = xen_exit_notifier;
+    qemu_add_exit_notifier(&state->exit);
+
+    state->suspend.notify = xen_suspend_notifier;
+    qemu_register_suspend_notifier(&state->suspend);
+
+    state->wakeup.notify = xen_wakeup_notifier;
+    qemu_register_wakeup_notifier(&state->wakeup);
+
+    xc_get_hvm_param(xen_xc, xen_domid, HVM_PARAM_IOREQ_PFN, &ioreq_pfn);
+    DPRINTF("shared page at pfn %lx\n", ioreq_pfn);
+    state->shared_page = xc_map_foreign_range(xen_xc, xen_domid, XC_PAGE_SIZE,
+                                              PROT_READ|PROT_WRITE, ioreq_pfn);
+    if (state->shared_page == NULL) {
+        hw_error("map shared IO page returned error %d handle=" XC_INTERFACE_FMT,
+                 errno, xen_xc);
+    }
+
+    xc_get_hvm_param(xen_xc, xen_domid, HVM_PARAM_BUFIOREQ_PFN, &ioreq_pfn);
+    DPRINTF("buffered io page at pfn %lx\n", ioreq_pfn);
+    state->buffered_io_page = xc_map_foreign_range(xen_xc, xen_domid, XC_PAGE_SIZE,
+                                                   PROT_READ|PROT_WRITE, ioreq_pfn);
+    if (state->buffered_io_page == NULL) {
+        hw_error("map buffered IO page returned error %d", errno);
+    }
+
+    state->ioreq_local_port = g_malloc0(max_cpus * sizeof (evtchn_port_t));
+
+    /* FIXME: how about if we overflow the page here? */
+    for (i = 0; i < max_cpus; i++) {
+        rc = xc_evtchn_bind_interdomain(state->xce_handle, xen_domid,
+                                        xen_vcpu_eport(state->shared_page, i));
+        if (rc == -1) {
+            fprintf(stderr, "bind interdomain ioctl error %d\n", errno);
+            return -1;
+        }
+        state->ioreq_local_port[i] = rc;
+    }
+
+    rc = xc_get_hvm_param(xen_xc, xen_domid, HVM_PARAM_BUFIOREQ_EVTCHN,
+            &bufioreq_evtchn);
+    if (rc < 0) {
+        fprintf(stderr, "failed to get HVM_PARAM_BUFIOREQ_EVTCHN\n");
+        return -1;
+    }
+    rc = xc_evtchn_bind_interdomain(state->xce_handle, xen_domid,
+            (uint32_t)bufioreq_evtchn);
+    if (rc == -1) {
+        fprintf(stderr, "bind interdomain ioctl error %d\n", errno);
+        return -1;
+    }
+    state->bufioreq_local_port = rc;
+
+    /* Init RAM management */
+    xen_map_cache_init(xen_phys_offset_to_gaddr, state);
+    xen_ram_init(ram_size, ram_memory);
+
+    qemu_add_vm_change_state_handler(xen_hvm_change_state_handler, state);
+
+    state->memory_listener = xen_memory_listener;
+    QLIST_INIT(&state->physmap);
+    memory_listener_register(&state->memory_listener, &address_space_memory);
+    state->log_for_dirtybit = NULL;
+
+    /* Initialize backend core & drivers */
+    if (xen_be_init() != 0) {
+        fprintf(stderr, "%s: xen backend core setup failed\n", __FUNCTION__);
+        exit(1);
+    }
+    xen_be_register("console", &xen_console_ops);
+    xen_be_register("vkbd", &xen_kbdmouse_ops);
+    xen_be_register("qdisk", &xen_blkdev_ops);
+    xen_read_physmap(state);
+
+    return 0;
+}
+
+void destroy_hvm_domain(bool reboot)
+{
+    XenXC xc_handle;
+    int sts;
+
+    xc_handle = xen_xc_interface_open(0, 0, 0);
+    if (xc_handle == XC_HANDLER_INITIAL_VALUE) {
+        fprintf(stderr, "Cannot acquire xenctrl handle\n");
+    } else {
+        sts = xc_domain_shutdown(xc_handle, xen_domid,
+                                 reboot ? SHUTDOWN_reboot : SHUTDOWN_poweroff);
+        if (sts != 0) {
+            fprintf(stderr, "xc_domain_shutdown failed to issue %s, "
+                    "sts %d, %s\n", reboot ? "reboot" : "poweroff",
+                    sts, strerror(errno));
+        } else {
+            fprintf(stderr, "Issued domain %d %s\n", xen_domid,
+                    reboot ? "reboot" : "poweroff");
+        }
+        xc_interface_close(xc_handle);
+    }
+}
+
+void xen_register_framebuffer(MemoryRegion *mr)
+{
+    framebuffer = mr;
+}
+
+void xen_shutdown_fatal_error(const char *fmt, ...)
+{
+    va_list ap;
+
+    va_start(ap, fmt);
+    vfprintf(stderr, fmt, ap);
+    va_end(ap);
+    fprintf(stderr, "Will destroy the domain.\n");
+    /* destroy the domain */
+    qemu_system_shutdown_request();
+}
+
+void xen_modified_memory(ram_addr_t start, ram_addr_t length)
+{
+    if (unlikely(xen_in_migration)) {
+        int rc;
+        ram_addr_t start_pfn, nb_pages;
+
+        if (length == 0) {
+            length = TARGET_PAGE_SIZE;
+        }
+        start_pfn = start >> TARGET_PAGE_BITS;
+        nb_pages = ((start + length + TARGET_PAGE_SIZE - 1) >> TARGET_PAGE_BITS)
+            - start_pfn;
+        rc = xc_hvm_modified_memory(xen_xc, xen_domid, start_pfn, nb_pages);
+        if (rc) {
+            fprintf(stderr,
+                    "%s failed for "RAM_ADDR_FMT" ("RAM_ADDR_FMT"): %i, %s\n",
+                    __func__, start, nb_pages, rc, strerror(-rc));
+        }
+    }
+}
+
+void qmp_xen_set_global_dirty_log(bool enable, Error **errp)
+{
+    if (enable) {
+        memory_global_dirty_log_start();
+    } else {
+        memory_global_dirty_log_stop();
+    }
+}