@@ -603,6 +603,9 @@ obj-y += pcnet.o
obj-y += rtl8139.o
obj-y += e1000.o
+# Inter-VM PCI shared memory
+obj-y += ivshmem.o
+
# Generic watchdog support and some watchdog devices
obj-y += wdt_ib700.o wdt_i6300esb.o
new file mode 100644
@@ -0,0 +1,591 @@
+/*
+ * Inter-VM Shared Memory PCI device.
+ *
+ * Author:
+ * Cam Macdonell <cam@cs.ualberta.ca>
+ *
+ * Based On: cirrus_vga.c and rtl8139.c
+ *
+ * This code is licensed under the GNU GPL v2.
+ */
+
+#include "hw.h"
+#include "console.h"
+#include "pc.h"
+#include "pci.h"
+#include "sysemu.h"
+
+#include "qemu-common.h"
+#include <sys/mman.h>
+#include <sys/socket.h>
+
+#define PCI_COMMAND_IOACCESS 0x0001
+#define PCI_COMMAND_MEMACCESS 0x0002
+#define PCI_COMMAND_BUSMASTER 0x0004
+
+#define DEBUG_IVSHMEM
+#define MAX_EVENT_FDS 16
+
+#ifdef DEBUG_IVSHMEM
+#define IVSHMEM_DPRINTF(fmt, args...) \
+ do {printf("IVSHMEM: " fmt, ##args); } while (0)
+#else
+#define IVSHMEM_DPRINTF(fmt, args...)
+#endif
+
+#define BROADCAST_VAL ((1 << 8) - 1)
+
+typedef struct IVShmemState {
+ uint16_t intrmask;
+ uint16_t intrstatus;
+ uint16_t doorbell;
+ uint8_t *ivshmem_ptr;
+ unsigned long ivshmem_offset;
+ unsigned int ivshmem_size;
+ unsigned long bios_offset;
+ unsigned int bios_size;
+ target_phys_addr_t base_ctrl;
+ int it_shift;
+ PCIDevice *pci_dev;
+ CharDriverState * chr;
+ CharDriverState * eventfd_chr;
+ unsigned long map_addr;
+ unsigned long map_end;
+ int ivshmem_mmio_io_addr;
+ int * eventfds;
+ int eventfd_posn;
+ uint16_t eventfd_bitvec;
+ int num_eventfds;
+} IVShmemState;
+
+typedef struct PCI_IVShmemState {
+ PCIDevice dev;
+ IVShmemState ivshmem_state;
+} PCI_IVShmemState;
+
+typedef struct IVShmemDesc {
+ char name[1024];
+ char * chrdev;
+ int size;
+} IVShmemDesc;
+
+/* registers for the Inter-VM shared memory device */
+enum ivshmem_registers {
+ IntrMask = 0,
+ IntrStatus = 16,
+ Doorbell = 32,
+ IVPosition = 48,
+ IVLiveList = 64,
+ MemSize = 80
+};
+
+static int num_ivshmem_devices = 0;
+static IVShmemDesc ivshmem_desc;
+
+static void ivshmem_map(PCIDevice *pci_dev, int region_num,
+ uint32_t addr, uint32_t size, int type)
+{
+ PCI_IVShmemState *d = (PCI_IVShmemState *)pci_dev;
+ IVShmemState *s = &d->ivshmem_state;
+
+ IVSHMEM_DPRINTF("addr = %u size = %u\n", addr, size);
+ cpu_register_physical_memory(addr, s->ivshmem_size, s->ivshmem_offset);
+
+}
+
+void ivshmem_init(const char * optarg) {
+
+ char * temp;
+ char * ivshmem_sz;
+ int size;
+
+ num_ivshmem_devices++;
+
+ /* currently we only support 1 device */
+ if (num_ivshmem_devices > MAX_IVSHMEM_DEVICES) {
+ return;
+ }
+
+ temp = strdup(optarg);
+/*
+ snprintf(ivshmem_desc.name, 1024, "/%s", strsep(&temp,","));
+*/
+ ivshmem_sz=strsep(&temp,",");
+
+ if (ivshmem_sz != NULL) {
+ size = atol(ivshmem_sz);
+ } else {
+ size = -1;
+ }
+
+ ivshmem_desc.chrdev = strsep(&temp,"\0");
+
+ if ( size == -1) {
+ ivshmem_desc.size = TARGET_PAGE_SIZE;
+ } else {
+ ivshmem_desc.size = size*1024*1024;
+ }
+ IVSHMEM_DPRINTF("optarg is %s, name is %s, size is %d, chrdev is %s\n",
+ optarg, ivshmem_desc.name,
+ ivshmem_desc.size, ivshmem_desc.chrdev);
+}
+
+int ivshmem_get_size(void) {
+ return ivshmem_desc.size;
+}
+
+static void broadcast_eventfds(int val, IVShmemState *s)
+{
+
+ int dest = val >> 4;
+ u_int64_t writelong = val & 0xff;
+
+ for (dest = 1; dest < s->num_eventfds; dest++) {
+
+ if (s->eventfds[dest] != -1) {
+ IVSHMEM_DPRINTF("Writing %ld to VM %d\n", writelong, dest);
+ write(s->eventfds[dest], &(writelong), 8);
+ }
+
+ }
+
+}
+
+/* accessing registers - based on rtl8139 */
+static void ivshmem_update_irq(IVShmemState *s)
+{
+ int isr;
+ isr = (s->intrstatus & s->intrmask) & 0xffff;
+
+ /* don't print ISR resets */
+ if (isr) {
+ IVSHMEM_DPRINTF("Set IRQ to %d (%04x %04x)\n",
+ isr ? 1 : 0, s->intrstatus, s->intrmask);
+ }
+
+ qemu_set_irq(s->pci_dev->irq[0], (isr != 0));
+}
+
+static void ivshmem_mmio_map(PCIDevice *pci_dev, int region_num,
+ uint32_t addr, uint32_t size, int type)
+{
+ PCI_IVShmemState *d = (PCI_IVShmemState *)pci_dev;
+ IVShmemState *s = &d->ivshmem_state;
+
+ cpu_register_physical_memory(addr + 0, 0x100, s->ivshmem_mmio_io_addr);
+}
+
+static void ivshmem_IntrMask_write(IVShmemState *s, uint32_t val)
+{
+ IVSHMEM_DPRINTF("IntrMask write(w) val = 0x%04x\n", val);
+
+ s->intrmask = val;
+
+ ivshmem_update_irq(s);
+}
+
+static uint32_t ivshmem_IntrMask_read(IVShmemState *s)
+{
+ uint32_t ret = s->intrmask;
+
+ IVSHMEM_DPRINTF("intrmask read(w) val = 0x%04x\n", ret);
+
+ return ret;
+}
+
+static void ivshmem_IntrStatus_write(IVShmemState *s, uint32_t val)
+{
+ IVSHMEM_DPRINTF("IntrStatus write(w) val = 0x%04x\n", val);
+
+ s->intrstatus = val;
+
+ ivshmem_update_irq(s);
+ return;
+}
+
+static uint32_t ivshmem_IntrStatus_read(IVShmemState *s)
+{
+ uint32_t ret = s->intrstatus;
+
+ /* reading ISR clears all interrupts */
+ s->intrstatus = 0;
+
+ ivshmem_update_irq(s);
+
+ return ret;
+}
+
+static void ivshmem_io_writew(void *opaque, uint8_t addr, uint32_t val)
+{
+ IVShmemState *s = opaque;
+
+ // 32-bits are written to the address
+ int dest = val >> 8;
+ u_int64_t writelong = val & 0xff;
+
+ IVSHMEM_DPRINTF("writing 0x%x to 0x%lx\n", addr, (unsigned long) opaque);
+
+ addr &= 0xfe;
+
+ switch (addr)
+ {
+ case IntrMask:
+ ivshmem_IntrMask_write(s, val);
+ break;
+
+ case IntrStatus:
+ ivshmem_IntrStatus_write(s, val);
+ break;
+
+ case Doorbell:
+ IVSHMEM_DPRINTF("val is %d\n", val);
+
+ if (dest == BROADCAST_VAL) {
+ broadcast_eventfds(val, s);
+ } else if (dest <= s->num_eventfds) {
+ IVSHMEM_DPRINTF("Writing %ld to VM %d\n", writelong, dest);
+ write(s->eventfds[dest], &(writelong), 8);
+ } else {
+ IVSHMEM_DPRINTF("Invalid %ld to VM %d\n", writelong, dest);
+ }
+
+ break;
+ default:
+ IVSHMEM_DPRINTF("why are we writing 0x%x\n", addr);
+ }
+}
+
+static void ivshmem_io_writel(void *opaque, uint8_t addr, uint32_t val)
+{
+ IVSHMEM_DPRINTF("We shouldn't be writing longs\n");
+}
+
+static void ivshmem_io_writeb(void *opaque, uint8_t addr, uint32_t val)
+{
+ IVSHMEM_DPRINTF("We shouldn't be writing bytes\n");
+}
+
+static uint32_t ivshmem_io_readw(void *opaque, uint8_t addr)
+{
+
+ IVShmemState *s = opaque;
+ uint32_t ret;
+
+ switch (addr)
+ {
+ case IntrMask:
+ ret = ivshmem_IntrMask_read(s);
+ break;
+ case IntrStatus:
+ ret = ivshmem_IntrStatus_read(s);
+ break;
+
+ case IVPosition:
+ /* return my id in the ivshmem list */
+ ret = s->eventfd_posn;
+ break;
+ case IVLiveList:
+ /* return the list of live VMs id for ivshmem */
+ ret = s->eventfd_bitvec;
+ break;
+
+ default:
+ IVSHMEM_DPRINTF("why are we reading 0x%x\n", addr);
+ ret = 0;
+ }
+
+ return ret;
+}
+
+static uint32_t ivshmem_io_readl(void *opaque, uint8_t addr)
+{
+ IVSHMEM_DPRINTF("We shouldn't be reading longs\n");
+ return 0;
+}
+
+static uint32_t ivshmem_io_readb(void *opaque, uint8_t addr)
+{
+ IVSHMEM_DPRINTF("We shouldn't be reading bytes\n");
+
+ return 0;
+}
+
+static void ivshmem_mmio_writeb(void *opaque,
+ target_phys_addr_t addr, uint32_t val)
+{
+ ivshmem_io_writeb(opaque, addr & 0xFF, val);
+}
+
+static void ivshmem_mmio_writew(void *opaque,
+ target_phys_addr_t addr, uint32_t val)
+{
+ ivshmem_io_writew(opaque, addr & 0xFF, val);
+}
+
+static void ivshmem_mmio_writel(void *opaque,
+ target_phys_addr_t addr, uint32_t val)
+{
+ ivshmem_io_writel(opaque, addr & 0xFF, val);
+}
+
+static uint32_t ivshmem_mmio_readb(void *opaque, target_phys_addr_t addr)
+{
+ return ivshmem_io_readb(opaque, addr & 0xFF);
+}
+
+static uint32_t ivshmem_mmio_readw(void *opaque, target_phys_addr_t addr)
+{
+ uint32_t val = ivshmem_io_readw(opaque, addr & 0xFF);
+ return val;
+}
+
+static uint32_t ivshmem_mmio_readl(void *opaque, target_phys_addr_t addr)
+{
+ uint32_t val = ivshmem_io_readl(opaque, addr & 0xFF);
+ return val;
+}
+
+static CPUReadMemoryFunc *ivshmem_mmio_read[3] = {
+ ivshmem_mmio_readb,
+ ivshmem_mmio_readw,
+ ivshmem_mmio_readl,
+};
+
+static CPUWriteMemoryFunc *ivshmem_mmio_write[3] = {
+ ivshmem_mmio_writeb,
+ ivshmem_mmio_writew,
+ ivshmem_mmio_writel,
+};
+
+
+static void ivshmem_receive(void *opaque, const uint8_t *buf, int size)
+{
+ IVShmemState *s = opaque;
+
+ ivshmem_IntrStatus_write(s, *buf);
+
+ IVSHMEM_DPRINTF("ivshmem_receive 0x%02x\n", *buf);
+}
+
+static void ivshmem_event(void *opaque, int event)
+{
+// IVShmemState *s = opaque;
+ IVSHMEM_DPRINTF("ivshmem_event %d\n", event);
+}
+
+static int ivshmem_can_receive(void * opaque)
+{
+ return 8;
+}
+
+static CharDriverState* create_eventfd_chr_device(void * opaque, int eventfd)
+{
+ // create a event character device based on the passed eventfd
+ IVShmemState *s = opaque;
+ CharDriverState * chr;
+
+ chr = qemu_chr_open_eventfd(eventfd);
+
+ if (chr == NULL) {
+ IVSHMEM_DPRINTF("creating eventfd for eventfd %d failed\n", eventfd);
+ exit(-1);
+ }
+
+ qemu_chr_add_handlers(chr, ivshmem_can_receive, ivshmem_receive,
+ ivshmem_event, s);
+
+ return chr;
+
+}
+
+static int check_shm_size(IVShmemState *s, int shmemfd) {
+ /* check that the guest isn't going to try and map more memory than the
+ * card server allocated return -1 to indicate error */
+
+ struct stat buf;
+
+ fstat(shmemfd, &buf);
+
+ if (s->ivshmem_size > buf.st_size) {
+ fprintf(stderr, "IVSHMEM ERROR: Requested memory size greater");
+ fprintf(stderr, " than shared object size (%d > %ld)\n",
+ s->ivshmem_size, buf.st_size);
+ return -1;
+ } else {
+ return 0;
+ }
+}
+
+static void ivshmem_recvmsg(void *opaque, struct msghdr * msg, int flags)
+{
+
+ IVShmemState *s = opaque;
+ struct cmsghdr *cmptr;
+ struct iovec *iov;
+ long param;
+ long msg_size;
+
+ iov = msg->msg_iov;
+
+ memcpy(¶m, iov->iov_base, sizeof param);
+
+ IVSHMEM_DPRINTF("Inside Recvmsg (%ld)\n", param);
+ for (cmptr = CMSG_FIRSTHDR(msg); cmptr != NULL;
+ cmptr = CMSG_NXTHDR(msg, cmptr)) {
+ if (cmptr->cmsg_level != SOL_SOCKET ||
+ cmptr->cmsg_type != SCM_RIGHTS) {
+ printf("read msg_size = %ld\n", msg_size);
+ continue;
+ }
+
+ // is eventfd_posn uninitialized? Then this is the initial list of eventfds
+ if (s->eventfd_posn == -1) {
+
+ s->eventfd_bitvec = 0;
+ msg_size = sizeof(int) * (param + 1);
+ s->eventfds = (int *)malloc(msg_size);
+ s->num_eventfds = param + 1;
+ s->eventfd_posn = param;
+
+ memcpy(s->eventfds, CMSG_DATA(cmptr), msg_size);
+ IVSHMEM_DPRINTF("I am %d, receiving %d fds\n", s->eventfd_posn, s->num_eventfds);
+ IVSHMEM_DPRINTF("broadcast enabled - %d\n", BROADCAST_VAL);
+ IVSHMEM_DPRINTF("shmemfd is %d\n", s->eventfds[0]);
+ IVSHMEM_DPRINTF("My fd is %d\n", s->eventfds[s->eventfd_posn]);
+
+ /* presume all eventfds are live, we will be notified of dead ones */
+ s->eventfd_bitvec = (1 << (s->num_eventfds)) - 1;
+ s->eventfd_bitvec &= ~1; /* posn 0 is not an eventfd, it's the shared memory fd */
+
+ if (check_shm_size(s, s->eventfds[0]) == -1) {
+ exit(-1);
+ }
+
+ if (mmap(s->ivshmem_ptr, ivshmem_desc.size, PROT_READ|PROT_WRITE,
+ MAP_SHARED|MAP_FIXED, s->eventfds[0], 0) == MAP_FAILED)
+ {
+ fprintf(stderr, "kvm_ivshmem: could not mmap shared file\n");
+ exit(-1);
+ }
+
+
+ // initialize char device for callback on my eventfd
+ s->eventfd_chr = create_eventfd_chr_device(s, s->eventfds[s->eventfd_posn]);
+
+ return;
+ }
+
+ // at this point we know this is an update
+ // the param is then the position of a new fd
+ if (param >= s->num_eventfds) {
+ s->eventfds = realloc(s->eventfds, sizeof(int) * (param + 1));
+ }
+
+ msg_size = sizeof(int);
+
+ // copy the new fd into its posn
+ memcpy(&(s->eventfds[param]), CMSG_DATA(cmptr), msg_size);
+
+ s->num_eventfds = param + 1;
+ s->eventfd_bitvec |= 1 << param;
+
+ IVSHMEM_DPRINTF("[update] new bitvec is %d\n", s->eventfd_bitvec);
+ IVSHMEM_DPRINTF("[update] s->eventfds[%ld] is %d\n", param,s->eventfds[param]);
+
+ }
+
+ // notification of a dead guest
+ // a negative number indicates a kill
+
+ if (param < 0) {
+ int index = -param;
+
+ IVSHMEM_DPRINTF("%d < %d || %d > 0\n", index, s->eventfds[index], s->num_eventfds);
+ if ((index < s->num_eventfds) || (s->eventfds[index] > 0)) {
+ s->eventfds[index] = -1;
+ // turn off the bit in the bit vector
+ s->eventfd_bitvec &= ~(1 << index);
+ IVSHMEM_DPRINTF("[kill] s->eventfds[%d] is %d\n", index,s->eventfds[index]);
+ }
+
+ return;
+
+ }
+
+
+}
+
+
+int pci_ivshmem_init(PCIBus *bus)
+{
+ PCI_IVShmemState *d;
+ IVShmemState *s;
+ uint8_t *pci_conf;
+
+ IVSHMEM_DPRINTF("shared file is %s\n", ivshmem_desc.name);
+ d = (PCI_IVShmemState *)pci_register_device(bus, "kvm_ivshmem",
+ sizeof(PCI_IVShmemState),
+ -1, NULL, NULL);
+ if (!d) {
+ return -1;
+ }
+
+ s = &d->ivshmem_state;
+
+ /* allocate shared memory RAM */
+ s->ivshmem_offset = qemu_ram_alloc(ivshmem_desc.size);
+ IVSHMEM_DPRINTF("size is = %d\n", ivshmem_desc.size);
+ IVSHMEM_DPRINTF("ivshmem ram offset = %ld\n", s->ivshmem_offset);
+
+ s->ivshmem_ptr = qemu_get_ram_ptr(s->ivshmem_offset);
+
+ s->pci_dev = &d->dev;
+ s->ivshmem_size = ivshmem_desc.size;
+
+ pci_conf = d->dev.config;
+ pci_conf[0x00] = 0xf4; // Qumranet vendor ID 0x5002
+ pci_conf[0x01] = 0x1a;
+ pci_conf[0x02] = 0x10;
+ pci_conf[0x03] = 0x11;
+ pci_conf[0x04] = PCI_COMMAND_IOACCESS | PCI_COMMAND_MEMACCESS;
+ pci_conf[0x0a] = 0x00; // RAM controller
+ pci_conf[0x0b] = 0x05;
+ pci_conf[0x0e] = 0x00; // header_type
+
+ pci_conf[PCI_INTERRUPT_PIN] = 1; // we are going to support interrupts
+
+ /* XXX: ivshmem_desc.size must be a power of two */
+
+ s->ivshmem_mmio_io_addr = cpu_register_io_memory(ivshmem_mmio_read,
+ ivshmem_mmio_write, s);
+
+ /* region for registers*/
+ pci_register_bar(&d->dev, 0, 0x100,
+ PCI_ADDRESS_SPACE_MEM, ivshmem_mmio_map);
+
+ /* region for shared memory */
+ pci_register_bar(&d->dev, 1, ivshmem_desc.size,
+ PCI_ADDRESS_SPACE_MEM, ivshmem_map);
+
+ if (ivshmem_desc.chrdev != NULL) {
+ char label[32];
+
+ s->eventfd_posn = -1;
+
+ snprintf(label, 32, "ivshmem_chardev");
+ s->chr = qemu_chr_open(label, ivshmem_desc.chrdev, NULL);
+ if (s->chr == NULL) {
+ fprintf(stderr, "No server listening on %s\n", ivshmem_desc.chrdev);
+ exit(-1);
+ }
+
+ tcp_switch_to_recvmsg_handlers(s->chr);
+
+ qemu_chr_add_handlers(s->chr, ivshmem_can_receive, ivshmem_recvmsg,
+ ivshmem_event, s);
+
+ }
+
+ return 0;
+}
+
@@ -68,6 +68,8 @@ static PITState *pit;
static IOAPICState *ioapic;
static PCIDevice *i440fx_state;
+extern int ivshmem_enabled;
+
typedef struct rom_reset_data {
uint8_t *data;
target_phys_addr_t addr;
@@ -1293,6 +1295,10 @@ static void pc_init1(ram_addr_t ram_size,
}
}
+ if (pci_enabled && ivshmem_enabled) {
+ pci_ivshmem_init(pci_bus);
+ }
+
rtc_state = rtc_init(0x70, i8259[8], 2000);
qemu_register_boot_set(pc_boot_set, rtc_state);
@@ -183,6 +183,9 @@ void isa_ne2000_init(int base, qemu_irq irq, NICInfo *nd);
void extboot_init(BlockDriverState *bs, int cmd);
+/* ivshmem.c */
+int pci_ivshmem_init(PCIBus *bus);
+
int cpu_is_bsp(CPUState *env);
#endif
@@ -1310,6 +1310,18 @@ The default device is @code{vc} in graphical mode and @code{stdio} in
non graphical mode.
ETEXI
+DEF("ivshmem", HAS_ARG, QEMU_OPTION_ivshmem, \
+ "-ivshmem size,unix:file connects to shared memory PCI card server \
+ listening on unix domain socket 'path' of at least 'size' (in MB) and \
+ exposes as a PCI device in the guest\n")
+STEXI
+@item -ivshmem @var{size},unix:@var{file}
+Connects to a shared memory PCI server at UDS @var{file} that shares a POSIX
+shared object of size @var{size} and creates a PCI device of the same size that
+maps the shared object (received from the server) into the device for guests to
+access. The servers also sends eventfds to the guest to support interrupts.
+ETEXI
+
DEF("pidfile", HAS_ARG, QEMU_OPTION_pidfile, \
"-pidfile file write PID to 'file'\n")
STEXI
@@ -240,6 +240,14 @@ extern CharDriverState *parallel_hds[MAX_PARALLEL_PORTS];
extern CharDriverState *virtcon_hds[MAX_VIRTIO_CONSOLES];
+/* inter-VM shared memory devices */
+
+#define MAX_IVSHMEM_DEVICES 1
+
+extern CharDriverState * ivshmem_chardev;
+void ivshmem_init(const char * optarg);
+int ivshmem_get_size(void);
+
#define TFR(expr) do { if ((expr) != -1) break; } while (errno == EINTR)
#ifdef NEED_CPU_H
@@ -203,6 +203,7 @@ static int rtc_date_offset = -1; /* -1 means no change */
int cirrus_vga_enabled = 1;
int std_vga_enabled = 0;
int vmsvga_enabled = 0;
+int ivshmem_enabled = 0;
int xenfb_enabled = 0;
#ifdef TARGET_SPARC
int graphic_width = 1024;
@@ -221,6 +222,8 @@ int no_quit = 0;
CharDriverState *serial_hds[MAX_SERIAL_PORTS];
CharDriverState *parallel_hds[MAX_PARALLEL_PORTS];
CharDriverState *virtcon_hds[MAX_VIRTIO_CONSOLES];
+CharDriverState *ivshmem_chardev;
+const char * ivshmem_device;
#ifdef TARGET_I386
int win2k_install_hack = 0;
int rtc_td_hack = 0;
@@ -4915,6 +4918,8 @@ int main(int argc, char **argv, char **envp)
cyls = heads = secs = 0;
translation = BIOS_ATA_TRANSLATION_AUTO;
monitor_device = "vc:80Cx24C";
+ ivshmem_device = NULL;
+ ivshmem_chardev = NULL;
serial_devices[0] = "vc:80Cx24C";
for(i = 1; i < MAX_SERIAL_PORTS; i++)
@@ -5368,6 +5373,10 @@ int main(int argc, char **argv, char **envp)
parallel_devices[parallel_device_index] = optarg;
parallel_device_index++;
break;
+ case QEMU_OPTION_ivshmem:
+ ivshmem_device = optarg;
+ ivshmem_enabled = 1;
+ break;
case QEMU_OPTION_loadvm:
loadvm = optarg;
break;
@@ -5817,6 +5826,11 @@ int main(int argc, char **argv, char **envp)
if (ram_size == 0)
ram_size = DEFAULT_RAM_SIZE * 1024 * 1024;
+ if (ivshmem_enabled) {
+ ivshmem_init(ivshmem_device);
+ ram_size += ivshmem_get_size();
+ }
+
#ifdef CONFIG_KQEMU
/* FIXME: This is a nasty hack because kqemu can't cope with dynamic
guest ram allocation. It needs to go away. */