xen-hvm: reorganize xen-hvm and move common function to xen-hvm-common

This patch does following:
1. creates arch_handle_ioreq() and arch_xen_set_memory(). This is done in
    preparation for moving most of xen-hvm code to an arch-neutral location,
    move the x86-specific portion of xen_set_memory to arch_xen_set_memory.
    Also, move handle_vmport_ioreq to arch_handle_ioreq.

2. Pure code movement: move common functions to hw/xen/xen-hvm-common.c
    Extract common functionalities from hw/i386/xen/xen-hvm.c and move them to
    hw/xen/xen-hvm-common.c. These common functions are useful for creating
    an IOREQ server.

    xen_hvm_init_pc() contains the architecture independent code for creating
    and mapping a IOREQ server, connecting memory and IO listeners, initializing
    a xen bus and registering backends. Moved this common xen code to a new
    function xen_register_ioreq() which can be used by both x86 and ARM machines.

    Following functions are moved to hw/xen/xen-hvm-common.c:
        xen_vcpu_eport(), xen_vcpu_ioreq(), xen_ram_alloc(), xen_set_memory(),
        xen_region_add(), xen_region_del(), xen_io_add(), xen_io_del(),
        xen_device_realize(), xen_device_unrealize(),
        cpu_get_ioreq_from_shared_memory(), cpu_get_ioreq(), do_inp(),
        do_outp(), rw_phys_req_item(), read_phys_req_item(),
        write_phys_req_item(), cpu_ioreq_pio(), cpu_ioreq_move(),
        cpu_ioreq_config(), handle_ioreq(), handle_buffered_iopage(),
        handle_buffered_io(), cpu_handle_ioreq(), xen_main_loop_prepare(),
        xen_hvm_change_state_handler(), xen_exit_notifier(),
        xen_map_ioreq_server(), destroy_hvm_domain() and
        xen_shutdown_fatal_error()

3. Removed static type from below functions:
    1. xen_region_add()
    2. xen_region_del()
    3. xen_io_add()
    4. xen_io_del()
    5. xen_device_realize()
    6. xen_device_unrealize()
    7. xen_hvm_change_state_handler()
    8. cpu_ioreq_pio()
    9. xen_exit_notifier()

4. Replace TARGET_PAGE_SIZE with XC_PAGE_SIZE to match the page side with Xen.

Signed-off-by: Vikram Garhwal <vikram.garhwal@amd.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>

3 files changed, 878 insertions, 1 deletions

diff --git a/hw/xen/meson.build b/hw/xen/meson.build
index 202752e..afd2075 100644
--- a/hw/xen/meson.build
+++ b/hw/xen/meson.build
@@ -29,4 +29,7 @@ specific_ss.add_all(when: ['CONFIG_XEN', xen], if_true: xen_specific_ss)
 
 xen_ss = ss.source_set()
 
-xen_ss.add(when: 'CONFIG_XEN', if_true: files('xen-mapcache.c'))
+xen_ss.add(when: 'CONFIG_XEN', if_true: files(
+  'xen-mapcache.c',
+  'xen-hvm-common.c',
+))
diff --git a/hw/xen/trace-events b/hw/xen/trace-events
index f977c7c..67a6c41 100644
--- a/hw/xen/trace-events
+++ b/hw/xen/trace-events
@@ -42,6 +42,20 @@ xs_node_vscanf(char *path, char *value) "%s %s"
 xs_node_watch(char *path) "%s"
 xs_node_unwatch(char *path) "%s"
 
+# xen-hvm.c
+xen_ram_alloc(unsigned long ram_addr, unsigned long size) "requested: 0x%lx, size 0x%lx"
+xen_client_set_memory(uint64_t start_addr, unsigned long size, bool log_dirty) "0x%"PRIx64" size 0x%lx, log_dirty %i"
+handle_ioreq(void *req, uint32_t type, uint32_t dir, uint32_t df, uint32_t data_is_ptr, uint64_t addr, uint64_t data, uint32_t count, uint32_t size) "I/O=%p type=%d dir=%d df=%d ptr=%d port=0x%"PRIx64" data=0x%"PRIx64" count=%d size=%d"
+handle_ioreq_read(void *req, uint32_t type, uint32_t df, uint32_t data_is_ptr, uint64_t addr, uint64_t data, uint32_t count, uint32_t size) "I/O=%p read type=%d df=%d ptr=%d port=0x%"PRIx64" data=0x%"PRIx64" count=%d size=%d"
+handle_ioreq_write(void *req, uint32_t type, uint32_t df, uint32_t data_is_ptr, uint64_t addr, uint64_t data, uint32_t count, uint32_t size) "I/O=%p write type=%d df=%d ptr=%d port=0x%"PRIx64" data=0x%"PRIx64" count=%d size=%d"
+cpu_ioreq_pio(void *req, uint32_t dir, uint32_t df, uint32_t data_is_ptr, uint64_t addr, uint64_t data, uint32_t count, uint32_t size) "I/O=%p pio dir=%d df=%d ptr=%d port=0x%"PRIx64" data=0x%"PRIx64" count=%d size=%d"
+cpu_ioreq_pio_read_reg(void *req, uint64_t data, uint64_t addr, uint32_t size) "I/O=%p pio read reg data=0x%"PRIx64" port=0x%"PRIx64" size=%d"
+cpu_ioreq_pio_write_reg(void *req, uint64_t data, uint64_t addr, uint32_t size) "I/O=%p pio write reg data=0x%"PRIx64" port=0x%"PRIx64" size=%d"
+cpu_ioreq_move(void *req, uint32_t dir, uint32_t df, uint32_t data_is_ptr, uint64_t addr, uint64_t data, uint32_t count, uint32_t size) "I/O=%p copy dir=%d df=%d ptr=%d port=0x%"PRIx64" data=0x%"PRIx64" count=%d size=%d"
+xen_map_resource_ioreq(uint32_t id, void *addr) "id: %u addr: %p"
+cpu_ioreq_config_read(void *req, uint32_t sbdf, uint32_t reg, uint32_t size, uint32_t data) "I/O=%p sbdf=0x%x reg=%u size=%u data=0x%x"
+cpu_ioreq_config_write(void *req, uint32_t sbdf, uint32_t reg, uint32_t size, uint32_t data) "I/O=%p sbdf=0x%x reg=%u size=%u data=0x%x"
+
 # xen-mapcache.c
 xen_map_cache(uint64_t phys_addr) "want 0x%"PRIx64
 xen_remap_bucket(uint64_t index) "index 0x%"PRIx64
diff --git a/hw/xen/xen-hvm-common.c b/hw/xen/xen-hvm-common.c
new file mode 100644
index 0000000..a31b067
--- /dev/null
+++ b/hw/xen/xen-hvm-common.c
@@ -0,0 +1,860 @@
+#include "qemu/osdep.h"
+#include "qemu/units.h"
+#include "qapi/error.h"
+#include "trace.h"
+
+#include "hw/pci/pci_host.h"
+#include "hw/xen/xen-hvm-common.h"
+#include "hw/xen/xen-bus.h"
+#include "hw/boards.h"
+#include "hw/xen/arch_hvm.h"
+
+MemoryRegion ram_memory;
+
+void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size, MemoryRegion *mr,
+                   Error **errp)
+{
+    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)) {
+        error_setg(errp, "xen: failed to populate ram at " RAM_ADDR_FMT,
+                   ram_addr);
+    }
+
+    g_free(pfn_list);
+}
+
+static void xen_set_memory(struct MemoryListener *listener,
+                           MemoryRegionSection *section,
+                           bool add)
+{
+    XenIOState *state = container_of(listener, XenIOState, memory_listener);
+
+    if (section->mr == &ram_memory) {
+        return;
+    } else {
+        if (add) {
+            xen_map_memory_section(xen_domid, state->ioservid,
+                                   section);
+        } else {
+            xen_unmap_memory_section(xen_domid, state->ioservid,
+                                     section);
+        }
+    }
+
+    arch_xen_set_memory(state, section, add);
+}
+
+void xen_region_add(MemoryListener *listener,
+                           MemoryRegionSection *section)
+{
+    memory_region_ref(section->mr);
+    xen_set_memory(listener, section, true);
+}
+
+void xen_region_del(MemoryListener *listener,
+                           MemoryRegionSection *section)
+{
+    xen_set_memory(listener, section, false);
+    memory_region_unref(section->mr);
+}
+
+void xen_io_add(MemoryListener *listener,
+                       MemoryRegionSection *section)
+{
+    XenIOState *state = container_of(listener, XenIOState, io_listener);
+    MemoryRegion *mr = section->mr;
+
+    if (mr->ops == &unassigned_io_ops) {
+        return;
+    }
+
+    memory_region_ref(mr);
+
+    xen_map_io_section(xen_domid, state->ioservid, section);
+}
+
+void xen_io_del(MemoryListener *listener,
+                       MemoryRegionSection *section)
+{
+    XenIOState *state = container_of(listener, XenIOState, io_listener);
+    MemoryRegion *mr = section->mr;
+
+    if (mr->ops == &unassigned_io_ops) {
+        return;
+    }
+
+    xen_unmap_io_section(xen_domid, state->ioservid, section);
+
+    memory_region_unref(mr);
+}
+
+void xen_device_realize(DeviceListener *listener,
+                               DeviceState *dev)
+{
+    XenIOState *state = container_of(listener, XenIOState, device_listener);
+
+    if (object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) {
+        PCIDevice *pci_dev = PCI_DEVICE(dev);
+        XenPciDevice *xendev = g_new(XenPciDevice, 1);
+
+        xendev->pci_dev = pci_dev;
+        xendev->sbdf = PCI_BUILD_BDF(pci_dev_bus_num(pci_dev),
+                                     pci_dev->devfn);
+        QLIST_INSERT_HEAD(&state->dev_list, xendev, entry);
+
+        xen_map_pcidev(xen_domid, state->ioservid, pci_dev);
+    }
+}
+
+void xen_device_unrealize(DeviceListener *listener,
+                                 DeviceState *dev)
+{
+    XenIOState *state = container_of(listener, XenIOState, device_listener);
+
+    if (object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) {
+        PCIDevice *pci_dev = PCI_DEVICE(dev);
+        XenPciDevice *xendev, *next;
+
+        xen_unmap_pcidev(xen_domid, state->ioservid, pci_dev);
+
+        QLIST_FOREACH_SAFE(xendev, &state->dev_list, entry, next) {
+            if (xendev->pci_dev == pci_dev) {
+                QLIST_REMOVE(xendev, entry);
+                g_free(xendev);
+                break;
+            }
+        }
+    }
+}
+
+MemoryListener xen_io_listener = {
+    .name = "xen-io",
+    .region_add = xen_io_add,
+    .region_del = xen_io_del,
+    .priority = 10,
+};
+
+DeviceListener xen_device_listener = {
+    .realize = xen_device_realize,
+    .unrealize = xen_device_unrealize,
+};
+
+/* 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: %u, size: %u\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)
+{
+    MachineState *ms = MACHINE(qdev_get_machine());
+    unsigned int max_cpus = ms->smp.max_cpus;
+    int i;
+    evtchn_port_t port;
+
+    port = qemu_xen_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 */
+        qemu_xen_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(uint32_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: %04x %lx", addr, size);
+    }
+}
+
+static void do_outp(uint32_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: %04x %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);
+}
+
+
+void cpu_ioreq_pio(ioreq_t *req)
+{
+    uint32_t i;
+
+    trace_cpu_ioreq_pio(req, req->dir, req->df, req->data_is_ptr, req->addr,
+                         req->data, req->count, req->size);
+
+    if (req->size > sizeof(uint32_t)) {
+        hw_error("PIO: bad size (%u)", req->size);
+    }
+
+    if (req->dir == IOREQ_READ) {
+        if (!req->data_is_ptr) {
+            req->data = do_inp(req->addr, req->size);
+            trace_cpu_ioreq_pio_read_reg(req, req->data, 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) {
+            trace_cpu_ioreq_pio_write_reg(req, req->data, req->addr,
+                                          req->size);
+            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;
+
+    trace_cpu_ioreq_move(req, req->dir, req->df, req->data_is_ptr, req->addr,
+                         req->data, req->count, req->size);
+
+    if (req->size > sizeof(req->data)) {
+        hw_error("MMIO: bad size (%u)", req->size);
+    }
+
+    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 cpu_ioreq_config(XenIOState *state, ioreq_t *req)
+{
+    uint32_t sbdf = req->addr >> 32;
+    uint32_t reg = req->addr;
+    XenPciDevice *xendev;
+
+    if (req->size != sizeof(uint8_t) && req->size != sizeof(uint16_t) &&
+        req->size != sizeof(uint32_t)) {
+        hw_error("PCI config access: bad size (%u)", req->size);
+    }
+
+    if (req->count != 1) {
+        hw_error("PCI config access: bad count (%u)", req->count);
+    }
+
+    QLIST_FOREACH(xendev, &state->dev_list, entry) {
+        if (xendev->sbdf != sbdf) {
+            continue;
+        }
+
+        if (!req->data_is_ptr) {
+            if (req->dir == IOREQ_READ) {
+                req->data = pci_host_config_read_common(
+                    xendev->pci_dev, reg, PCI_CONFIG_SPACE_SIZE,
+                    req->size);
+                trace_cpu_ioreq_config_read(req, xendev->sbdf, reg,
+                                            req->size, req->data);
+            } else if (req->dir == IOREQ_WRITE) {
+                trace_cpu_ioreq_config_write(req, xendev->sbdf, reg,
+                                             req->size, req->data);
+                pci_host_config_write_common(
+                    xendev->pci_dev, reg, PCI_CONFIG_SPACE_SIZE,
+                    req->data, req->size);
+            }
+        } else {
+            uint32_t tmp;
+
+            if (req->dir == IOREQ_READ) {
+                tmp = pci_host_config_read_common(
+                    xendev->pci_dev, reg, PCI_CONFIG_SPACE_SIZE,
+                    req->size);
+                trace_cpu_ioreq_config_read(req, xendev->sbdf, reg,
+                                            req->size, tmp);
+                write_phys_req_item(req->data, req, 0, &tmp);
+            } else if (req->dir == IOREQ_WRITE) {
+                read_phys_req_item(req->data, req, 0, &tmp);
+                trace_cpu_ioreq_config_write(req, xendev->sbdf, reg,
+                                             req->size, tmp);
+                pci_host_config_write_common(
+                    xendev->pci_dev, reg, PCI_CONFIG_SPACE_SIZE,
+                    tmp, req->size);
+            }
+        }
+    }
+}
+
+static void handle_ioreq(XenIOState *state, ioreq_t *req)
+{
+    trace_handle_ioreq(req, req->type, req->dir, req->df, req->data_is_ptr,
+                       req->addr, req->data, req->count, req->size);
+
+    if (!req->data_is_ptr && (req->dir == IOREQ_WRITE) &&
+            (req->size < sizeof (target_ulong))) {
+        req->data &= ((target_ulong) 1 << (8 * req->size)) - 1;
+    }
+
+    if (req->dir == IOREQ_WRITE)
+        trace_handle_ioreq_write(req, req->type, req->df, req->data_is_ptr,
+                                 req->addr, req->data, req->count, req->size);
+
+    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;
+        case IOREQ_TYPE_PCI_CONFIG:
+            cpu_ioreq_config(state, req);
+            break;
+        default:
+            arch_handle_ioreq(state, req);
+    }
+    if (req->dir == IOREQ_READ) {
+        trace_handle_ioreq_read(req, req->type, req->df, req->data_is_ptr,
+                                req->addr, req->data, req->count, req->size);
+    }
+}
+
+static bool handle_buffered_iopage(XenIOState *state)
+{
+    buffered_iopage_t *buf_page = state->buffered_io_page;
+    buf_ioreq_t *buf_req = NULL;
+    bool handled_ioreq = false;
+    ioreq_t req;
+    int qw;
+
+    if (!buf_page) {
+        return 0;
+    }
+
+    memset(&req, 0x00, sizeof(req));
+    req.state = STATE_IOREQ_READY;
+    req.count = 1;
+    req.dir = IOREQ_WRITE;
+
+    for (;;) {
+        uint32_t rdptr = buf_page->read_pointer, wrptr;
+
+        xen_rmb();
+        wrptr = buf_page->write_pointer;
+        xen_rmb();
+        if (rdptr != buf_page->read_pointer) {
+            continue;
+        }
+        if (rdptr == wrptr) {
+            break;
+        }
+        buf_req = &buf_page->buf_ioreq[rdptr % IOREQ_BUFFER_SLOT_NUM];
+        req.size = 1U << buf_req->size;
+        req.addr = buf_req->addr;
+        req.data = buf_req->data;
+        req.type = buf_req->type;
+        xen_rmb();
+        qw = (req.size == 8);
+        if (qw) {
+            if (rdptr + 1 == wrptr) {
+                hw_error("Incomplete quad word buffered ioreq");
+            }
+            buf_req = &buf_page->buf_ioreq[(rdptr + 1) %
+                                           IOREQ_BUFFER_SLOT_NUM];
+            req.data |= ((uint64_t)buf_req->data) << 32;
+            xen_rmb();
+        }
+
+        handle_ioreq(state, &req);
+
+        /* Only req.data may get updated by handle_ioreq(), albeit even that
+         * should not happen as such data would never make it to the guest (we
+         * can only usefully see writes here after all).
+         */
+        assert(req.state == STATE_IOREQ_READY);
+        assert(req.count == 1);
+        assert(req.dir == IOREQ_WRITE);
+        assert(!req.data_is_ptr);
+
+        qatomic_add(&buf_page->read_pointer, qw + 1);
+        handled_ioreq = true;
+    }
+
+    return handled_ioreq;
+}
+
+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);
+        qemu_xen_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) {
+        ioreq_t copy = *req;
+
+        xen_rmb();
+        handle_ioreq(state, &copy);
+        req->data = copy.data;
+
+        if (req->state != STATE_IOREQ_INPROCESS) {
+            fprintf(stderr, "Badness in I/O request ... not in service?!: "
+                    "%x, ptr: %x, port: %"PRIx64", "
+                    "data: %"PRIx64", count: %u, size: %u, type: %u\n",
+                    req->state, req->data_is_ptr, req->addr,
+                    req->data, req->count, req->size, req->type);
+            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()) {
+            ShutdownCause request;
+
+            if (qemu_shutdown_requested_get()) {
+                destroy_hvm_domain(false);
+            }
+            request = qemu_reset_requested_get();
+            if (request) {
+                qemu_system_reset(request);
+                destroy_hvm_domain(true);
+            }
+        }
+
+        req->state = STATE_IORESP_READY;
+        qemu_xen_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 != NULL) {
+        evtchn_fd = qemu_xen_evtchn_fd(state->xce_handle);
+    }
+
+    state->buffered_io_timer = timer_new_ms(QEMU_CLOCK_REALTIME, handle_buffered_io,
+                                                 state);
+
+    if (evtchn_fd != -1) {
+        CPUState *cpu_state;
+
+        DPRINTF("%s: Init cpu_by_vcpu_id\n", __func__);
+        CPU_FOREACH(cpu_state) {
+            DPRINTF("%s: cpu_by_vcpu_id[%d]=%p\n",
+                    __func__, cpu_state->cpu_index, cpu_state);
+            state->cpu_by_vcpu_id[cpu_state->cpu_index] = cpu_state;
+        }
+        qemu_set_fd_handler(evtchn_fd, cpu_handle_ioreq, NULL, state);
+    }
+}
+
+
+void xen_hvm_change_state_handler(void *opaque, bool running,
+                                         RunState rstate)
+{
+    XenIOState *state = opaque;
+
+    if (running) {
+        xen_main_loop_prepare(state);
+    }
+
+    xen_set_ioreq_server_state(xen_domid,
+                               state->ioservid,
+                               (rstate == RUN_STATE_RUNNING));
+}
+
+void xen_exit_notifier(Notifier *n, void *data)
+{
+    XenIOState *state = container_of(n, XenIOState, exit);
+
+    xen_destroy_ioreq_server(xen_domid, state->ioservid);
+    if (state->fres != NULL) {
+        xenforeignmemory_unmap_resource(xen_fmem, state->fres);
+    }
+
+    qemu_xen_evtchn_close(state->xce_handle);
+    xs_daemon_close(state->xenstore);
+}
+
+static int xen_map_ioreq_server(XenIOState *state)
+{
+    void *addr = NULL;
+    xen_pfn_t ioreq_pfn;
+    xen_pfn_t bufioreq_pfn;
+    evtchn_port_t bufioreq_evtchn;
+    int rc;
+
+    /*
+     * Attempt to map using the resource API and fall back to normal
+     * foreign mapping if this is not supported.
+     */
+    QEMU_BUILD_BUG_ON(XENMEM_resource_ioreq_server_frame_bufioreq != 0);
+    QEMU_BUILD_BUG_ON(XENMEM_resource_ioreq_server_frame_ioreq(0) != 1);
+    state->fres = xenforeignmemory_map_resource(xen_fmem, xen_domid,
+                                         XENMEM_resource_ioreq_server,
+                                         state->ioservid, 0, 2,
+                                         &addr,
+                                         PROT_READ | PROT_WRITE, 0);
+    if (state->fres != NULL) {
+        trace_xen_map_resource_ioreq(state->ioservid, addr);
+        state->buffered_io_page = addr;
+        state->shared_page = addr + XC_PAGE_SIZE;
+    } else if (errno != EOPNOTSUPP) {
+        error_report("failed to map ioreq server resources: error %d handle=%p",
+                     errno, xen_xc);
+        return -1;
+    }
+
+    rc = xen_get_ioreq_server_info(xen_domid, state->ioservid,
+                                   (state->shared_page == NULL) ?
+                                   &ioreq_pfn : NULL,
+                                   (state->buffered_io_page == NULL) ?
+                                   &bufioreq_pfn : NULL,
+                                   &bufioreq_evtchn);
+    if (rc < 0) {
+        error_report("failed to get ioreq server info: error %d handle=%p",
+                     errno, xen_xc);
+        return rc;
+    }
+
+    if (state->shared_page == NULL) {
+        DPRINTF("shared page at pfn %lx\n", ioreq_pfn);
+
+        state->shared_page = xenforeignmemory_map(xen_fmem, xen_domid,
+                                                  PROT_READ | PROT_WRITE,
+                                                  1, &ioreq_pfn, NULL);
+        if (state->shared_page == NULL) {
+            error_report("map shared IO page returned error %d handle=%p",
+                         errno, xen_xc);
+        }
+    }
+
+    if (state->buffered_io_page == NULL) {
+        DPRINTF("buffered io page at pfn %lx\n", bufioreq_pfn);
+
+        state->buffered_io_page = xenforeignmemory_map(xen_fmem, xen_domid,
+                                                       PROT_READ | PROT_WRITE,
+                                                       1, &bufioreq_pfn,
+                                                       NULL);
+        if (state->buffered_io_page == NULL) {
+            error_report("map buffered IO page returned error %d", errno);
+            return -1;
+        }
+    }
+
+    if (state->shared_page == NULL || state->buffered_io_page == NULL) {
+        return -1;
+    }
+
+    DPRINTF("buffered io evtchn is %x\n", bufioreq_evtchn);
+
+    state->bufioreq_remote_port = bufioreq_evtchn;
+
+    return 0;
+}
+
+void destroy_hvm_domain(bool reboot)
+{
+    xc_interface *xc_handle;
+    int sts;
+    int rc;
+
+    unsigned int reason = reboot ? SHUTDOWN_reboot : SHUTDOWN_poweroff;
+
+    if (xen_dmod) {
+        rc = xendevicemodel_shutdown(xen_dmod, xen_domid, reason);
+        if (!rc) {
+            return;
+        }
+        if (errno != ENOTTY /* old Xen */) {
+            perror("xendevicemodel_shutdown failed");
+        }
+        /* well, try the old thing then */
+    }
+
+    xc_handle = xc_interface_open(0, 0, 0);
+    if (xc_handle == NULL) {
+        fprintf(stderr, "Cannot acquire xenctrl handle\n");
+    } else {
+        sts = xc_domain_shutdown(xc_handle, xen_domid, reason);
+        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_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(SHUTDOWN_CAUSE_HOST_ERROR);
+}
+
+void xen_register_ioreq(XenIOState *state, unsigned int max_cpus,
+                        MemoryListener xen_memory_listener)
+{
+    int i, rc;
+
+    setup_xen_backend_ops();
+
+    state->xce_handle = qemu_xen_evtchn_open();
+    if (state->xce_handle == NULL) {
+        perror("xen: event channel open");
+        goto err;
+    }
+
+    state->xenstore = xs_daemon_open();
+    if (state->xenstore == NULL) {
+        perror("xen: xenstore open");
+        goto err;
+    }
+
+    xen_create_ioreq_server(xen_domid, &state->ioservid);
+
+    state->exit.notify = xen_exit_notifier;
+    qemu_add_exit_notifier(&state->exit);
+
+    /*
+     * Register wake-up support in QMP query-current-machine API
+     */
+    qemu_register_wakeup_support();
+
+    rc = xen_map_ioreq_server(state);
+    if (rc < 0) {
+        goto err;
+    }
+
+    /* Note: cpus is empty at this point in init */
+    state->cpu_by_vcpu_id = g_malloc0(max_cpus * sizeof(CPUState *));
+
+    rc = xen_set_ioreq_server_state(xen_domid, state->ioservid, true);
+    if (rc < 0) {
+        error_report("failed to enable ioreq server info: error %d handle=%p",
+                     errno, xen_xc);
+        goto err;
+    }
+
+    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 = qemu_xen_evtchn_bind_interdomain(state->xce_handle, xen_domid,
+                                              xen_vcpu_eport(state->shared_page,
+                                                             i));
+        if (rc == -1) {
+            error_report("shared evtchn %d bind error %d", i, errno);
+            goto err;
+        }
+        state->ioreq_local_port[i] = rc;
+    }
+
+    rc = qemu_xen_evtchn_bind_interdomain(state->xce_handle, xen_domid,
+                                          state->bufioreq_remote_port);
+    if (rc == -1) {
+        error_report("buffered evtchn bind error %d", errno);
+        goto err;
+    }
+    state->bufioreq_local_port = rc;
+
+    /* Init RAM management */
+#ifdef XEN_COMPAT_PHYSMAP
+    xen_map_cache_init(xen_phys_offset_to_gaddr, state);
+#else
+    xen_map_cache_init(NULL, state);
+#endif
+
+    qemu_add_vm_change_state_handler(xen_hvm_change_state_handler, state);
+
+    state->memory_listener = xen_memory_listener;
+    memory_listener_register(&state->memory_listener, &address_space_memory);
+
+    state->io_listener = xen_io_listener;
+    memory_listener_register(&state->io_listener, &address_space_io);
+
+    state->device_listener = xen_device_listener;
+    QLIST_INIT(&state->dev_list);
+    device_listener_register(&state->device_listener);
+
+    xen_bus_init();
+
+    xen_be_init();
+
+    return;
+err:
+    error_report("xen hardware virtual machine initialisation failed");
+    exit(1);
+}