This patch adds a PCI device that provides PCI device memory to the
guest. This memory in the guest exists as a shared memory segment in
the host. This is similar memory sharing capability of Nahanni
(ivshmem) available in QEMU. In this case, the shared memory segment
is exposed as a PCI BAR only.
A new command line argument is added as:
--shmem pci:0xc8000000:16MB:handle=/newmem:create
which will set the PCI BAR at 0xc8000000, the shared memory segment
and the region pointed to by the BAR will be 16MB. On the host side
the shm_open handle will be '/newmem', and the kvm tool will create
the shared segment, set its size, and initialize it. If the size,
handle, or create flag are absent, they will default to 16MB,
handle=/kvm_shmem, and create will be false. The address family,
'pci:' is also optional as it is the only address family currently
supported. Only a single --shmem is supported at this time.
Signed-off-by: David Evensky <evensky@xxxxxxxxxx>
diff -uprN -X linux-kvm/Documentation/dontdiff linux-kvm/tools/kvm/builtin-run.c linux-kvm_pci_shmem/tools/kvm/builtin-run.c
--- linux-kvm/tools/kvm/builtin-run.c 2011-08-24 10:21:22.342077674 -0700
+++ linux-kvm_pci_shmem/tools/kvm/builtin-run.c 2011-08-24 14:17:33.190451297 -0700
@@ -28,6 +28,8 @@
#include "kvm/sdl.h"
#include "kvm/vnc.h"
#include "kvm/guest_compat.h"
+#include "shmem-util.h"
+#include "kvm/pci-shmem.h"
#include <linux/types.h>
@@ -52,6 +54,8 @@
#define DEFAULT_SCRIPT "none"
#define MB_SHIFT (20)
+#define KB_SHIFT (10)
+#define GB_SHIFT (30)
#define MIN_RAM_SIZE_MB (64ULL)
#define MIN_RAM_SIZE_BYTE (MIN_RAM_SIZE_MB << MB_SHIFT)
@@ -151,6 +155,130 @@ static int virtio_9p_rootdir_parser(cons
return 0;
}
+static int shmem_parser(const struct option *opt, const char *arg, int unset)
+{
+ const uint64_t default_size = SHMEM_DEFAULT_SIZE;
+ const uint64_t default_phys_addr = SHMEM_DEFAULT_ADDR;
+ const char *default_handle = SHMEM_DEFAULT_HANDLE;
+ enum { PCI, UNK } addr_type = PCI;
+ uint64_t phys_addr;
+ uint64_t size;
+ char *handle = NULL;
+ int create = 0;
+ const char *p = arg;
+ char *next;
+ int base = 10;
+ int verbose = 0;
+
+ const int skip_pci = strlen("pci:");
+ if (verbose)
+ pr_info("shmem_parser(%p,%s,%d)", opt, arg, unset);
+ /* parse out optional addr family */
+ if (strcasestr(p, "pci:")) {
+ p += skip_pci;
+ addr_type = PCI;
+ } else if (strcasestr(p, "mem:")) {
+ die("I can't add to E820 map yet.\n");
+ }
+ /* parse out physical addr */
+ base = 10;
+ if (strcasestr(p, "0x"))
+ base = 16;
+ phys_addr = strtoll(p, &next, base);
+ if (next == p && phys_addr == 0) {
+ pr_info("shmem: no physical addr specified, using default.");
+ phys_addr = default_phys_addr;
+ }
+ if (*next != ':' && *next != '\0')
+ die("shmem: unexpected chars after phys addr.\n");
+ if (*next == '\0')
+ p = next;
+ else
+ p = next + 1;
+ /* parse out size */
+ base = 10;
+ if (strcasestr(p, "0x"))
+ base = 16;
+ size = strtoll(p, &next, base);
+ if (next == p && size == 0) {
+ pr_info("shmem: no size specified, using default.");
+ size = default_size;
+ }
+ /* look for [KMGkmg][Bb]* uses base 2. */
+ int skip_B = 0;
+ if (strspn(next, "KMGkmg")) { /* might have a prefix */
+ if (*(next + 1) == 'B' || *(next + 1) == 'b')
+ skip_B = 1;
+ switch (*next) {
+ case 'K':
+ case 'k':
+ size = size << KB_SHIFT;
+ break;
+ case 'M':
+ case 'm':
+ size = size << MB_SHIFT;
+ break;
+ case 'G':
+ case 'g':
+ size = size << GB_SHIFT;
+ break;
+ default:
+ die("shmem: bug in detecting size prefix.");
+ break;
+ }
+ next += 1 + skip_B;
+ }
+ if (*next != ':' && *next != '\0') {
+ die("shmem: unexpected chars after phys size. <%c><%c>\n",
+ *next, *p);
+ }
+ if (*next == '\0')
+ p = next;
+ else
+ p = next + 1;
+ /* parse out optional shmem handle */
+ const int skip_handle = strlen("handle=");
+ next = strcasestr(p, "handle=");
+ if (*p && next) {
+ if (p != next)
+ die("unexpected chars before handle\n");
+ p += skip_handle;
+ next = strchrnul(p, ':');
+ if (next - p) {
+ handle = malloc(next - p + 1);
+ strncpy(handle, p, next - p);
+ handle[next - p] = '\0'; /* just in case. */
+ }
+ if (*next == '\0')
+ p = next;
+ else
+ p = next + 1;
+ }
+ /* parse optional create flag to see if we should create shm seg. */
+ if (*p && strcasestr(p, "create")) {
+ create = 1;
+ p += strlen("create");
+ }
+ if (*p != '\0')
+ die("shmem: unexpected trailing chars\n");
+ if (handle == NULL) {
+ handle = malloc(strlen(default_handle) + 1);
+ strcpy(handle, default_handle);
+ }
+ if (verbose) {
+ pr_info("shmem: phys_addr = %lx", phys_addr);
+ pr_info("shmem: size = %lx", size);
+ pr_info("shmem: handle = %s", handle);
+ pr_info("shmem: create = %d", create);
+ }
+ struct shmem_info *si = malloc(sizeof(struct shmem_info));
+ si->phys_addr = phys_addr;
+ si->size = size;
+ si->handle = handle;
+ si->create = create;
+ pci_shmem__register_mem(si); /* ownership of si, etc. passed on. */
+ return 0;
+}
static const struct option options[] = {
OPT_GROUP("Basic options:"),
@@ -158,6 +286,10 @@ static const struct option options[] = {
"A name for the guest"),
OPT_INTEGER('c', "cpus", &nrcpus, "Number of CPUs"),
OPT_U64('m', "mem", &ram_size, "Virtual machine memory size in MiB."),
+ OPT_CALLBACK('\0', "shmem", NULL,
+ "[pci:]<addr>:<size>[:handle=<handle>][:create]",
+ "Share host shmem with guest via pci device",
+ shmem_parser),
OPT_CALLBACK('d', "disk", NULL, "image or rootfs_dir", "Disk image or rootfs directory", img_name_parser),
OPT_BOOLEAN('\0', "balloon", &balloon, "Enable virtio balloon"),
OPT_BOOLEAN('\0', "vnc", &vnc, "Enable VNC framebuffer"),
@@ -695,6 +827,8 @@ int kvm_cmd_run(int argc, const char **a
kbd__init(kvm);
+ pci_shmem__init(kvm);
+
if (vnc || sdl)
fb = vesa__init(kvm);
diff -uprN -X linux-kvm/Documentation/dontdiff linux-kvm/tools/kvm/hw/pci-shmem.c linux-kvm_pci_shmem/tools/kvm/hw/pci-shmem.c
--- linux-kvm/tools/kvm/hw/pci-shmem.c 1969-12-31 16:00:00.000000000 -0800
+++ linux-kvm_pci_shmem/tools/kvm/hw/pci-shmem.c 2011-08-24 14:18:09.227234167 -0700
@@ -0,0 +1,59 @@
+#include "shmem-util.h"
+#include "kvm/pci-shmem.h"
+#include "kvm/virtio-pci-dev.h"
+#include "kvm/irq.h"
+#include "kvm/kvm.h"
+#include "kvm/pci.h"
+#include "kvm/util.h"
+
+static struct pci_device_header pci_shmem_pci_device = {
+ .vendor_id = PCI_VENDOR_ID_PCI_SHMEM,
+ .device_id = PCI_DEVICE_ID_PCI_SHMEM,
+ .header_type = PCI_HEADER_TYPE_NORMAL,
+ .class = 0xFF0000, /* misc pci device */
+};
+
+static struct shmem_info *shmem_region;
+
+int pci_shmem__register_mem(struct shmem_info *si)
+{
+ if (shmem_region == NULL) {
+ shmem_region = si;
+ } else {
+ pr_warning("only single shmem currently avail. ignoring.\n");
+ free(si);
+ }
+ return 0;
+}
+
+int pci_shmem__init(struct kvm *kvm)
+{
+ u8 dev, line, pin;
+ char *mem;
+ int verbose = 0;
+ if (irq__register_device(PCI_DEVICE_ID_PCI_SHMEM, &dev, &pin, &line)
+ < 0)
+ return 0;
+ /* ignore irq stuff, just want bus info for now. */
+ /* pci_shmem_pci_device.irq_pin = pin; */
+ /* pci_shmem_pci_device.irq_line = line; */
+ if (shmem_region == 0) {
+ if (verbose == 1)
+ pr_warning
+ ("pci_shmem_init: memory region not registered\n");
+ return 0;
+ }
+ pci_shmem_pci_device.bar[0] =
+ shmem_region->phys_addr | PCI_BASE_ADDRESS_SPACE_MEMORY;
+ pci_shmem_pci_device.bar_size[0] = shmem_region->size;
+ pci__register(&pci_shmem_pci_device, dev);
+
+ mem =
+ setup_shmem(shmem_region->handle, shmem_region->size,
+ shmem_region->create, verbose);
+ if (mem == NULL)
+ return 0;
+ kvm__register_mem(kvm, shmem_region->phys_addr, shmem_region->size,
+ mem);
+ return 1;
+}
diff -uprN -X linux-kvm/Documentation/dontdiff linux-kvm/tools/kvm/include/kvm/pci-shmem.h linux-kvm_pci_shmem/tools/kvm/include/kvm/pci-shmem.h
--- linux-kvm/tools/kvm/include/kvm/pci-shmem.h 1969-12-31 16:00:00.000000000 -0800
+++ linux-kvm_pci_shmem/tools/kvm/include/kvm/pci-shmem.h 2011-08-13 15:43:01.067953711 -0700
@@ -0,0 +1,13 @@
+#ifndef KVM__PCI_SHMEM_H
+#define KVM__PCI_SHMEM_H
+
+#include <linux/types.h>
+#include <linux/list.h>
+
+struct kvm;
+struct shmem_info;
+
+int pci_shmem__init(struct kvm *self);
+int pci_shmem__register_mem(struct shmem_info *si);
+
+#endif
diff -uprN -X linux-kvm/Documentation/dontdiff linux-kvm/tools/kvm/include/kvm/virtio-pci-dev.h linux-kvm_pci_shmem/tools/kvm/include/kvm/virtio-pci-dev.h
--- linux-kvm/tools/kvm/include/kvm/virtio-pci-dev.h 2011-08-09 15:38:48.760120973 -0700
+++ linux-kvm_pci_shmem/tools/kvm/include/kvm/virtio-pci-dev.h 2011-08-18 10:06:12.171539230 -0700
@@ -15,10 +15,13 @@
#define PCI_DEVICE_ID_VIRTIO_BLN 0x1005
#define PCI_DEVICE_ID_VIRTIO_P9 0x1009
#define PCI_DEVICE_ID_VESA 0x2000
+#define PCI_DEVICE_ID_PCI_SHMEM 0x0001
#define PCI_VENDOR_ID_REDHAT_QUMRANET 0x1af4
+#define PCI_VENDOR_ID_PCI_SHMEM 0x0001
#define PCI_SUBSYSTEM_VENDOR_ID_REDHAT_QUMRANET 0x1af4
#define PCI_SUBSYSTEM_ID_VESA 0x0004
+#define PCI_SUBSYSTEM_ID_PCI_SHMEM 0x0001
#endif /* VIRTIO_PCI_DEV_H_ */
diff -uprN -X linux-kvm/Documentation/dontdiff linux-kvm/tools/kvm/include/shmem-util.h linux-kvm_pci_shmem/tools/kvm/include/shmem-util.h
--- linux-kvm/tools/kvm/include/shmem-util.h 1969-12-31 16:00:00.000000000 -0800
+++ linux-kvm_pci_shmem/tools/kvm/include/shmem-util.h 2011-08-24 14:15:30.271780710 -0700
@@ -0,0 +1,27 @@
+#ifndef SHMEM_UTIL_H
+#define SHMEM_UTIL_H
+
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#define SHMEM_DEFAULT_SIZE (16 << MB_SHIFT)
+#define SHMEM_DEFAULT_ADDR (0xc8000000)
+#define SHMEM_DEFAULT_HANDLE "/kvm_shmem"
+struct shmem_info {
+ uint64_t phys_addr;
+ uint64_t size;
+ char *handle;
+ int create;
+};
+
+inline void *setup_shmem(const char *key, size_t len, int creating,
+ int verbose);
+inline void fill_mem(void *buf, size_t buf_size, char *fill, size_t fill_len);
+
+#endif /* SHMEM_UTIL_H */
diff -uprN -X linux-kvm/Documentation/dontdiff linux-kvm/tools/kvm/Makefile linux-kvm_pci_shmem/tools/kvm/Makefile
--- linux-kvm/tools/kvm/Makefile 2011-08-24 10:21:22.342077676 -0700
+++ linux-kvm_pci_shmem/tools/kvm/Makefile 2011-08-24 13:55:37.442003451 -0700
@@ -77,10 +77,12 @@ OBJS += threadpool.o
OBJS += util/parse-options.o
OBJS += util/rbtree-interval.o
OBJS += util/strbuf.o
+OBJS += util/shmem-util.o
OBJS += virtio/9p.o
OBJS += virtio/9p-pdu.o
OBJS += hw/vesa.o
OBJS += hw/i8042.o
+OBJS += hw/pci-shmem.o
FLAGS_BFD := $(CFLAGS) -lbfd
has_bfd := $(call try-cc,$(SOURCE_BFD),$(FLAGS_BFD))
diff -uprN -X linux-kvm/Documentation/dontdiff linux-kvm/tools/kvm/util/shmem-util.c linux-kvm_pci_shmem/tools/kvm/util/shmem-util.c
--- linux-kvm/tools/kvm/util/shmem-util.c 1969-12-31 16:00:00.000000000 -0800
+++ linux-kvm_pci_shmem/tools/kvm/util/shmem-util.c 2011-08-24 14:19:31.801027897 -0700
@@ -0,0 +1,64 @@
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <string.h>
+#include "shmem-util.h"
+
+inline void *setup_shmem(const char *key, size_t len, int creating, int verbose)
+{
+ int fd;
+ int rtn;
+ void *mem;
+ int flag = O_RDWR;
+ if (creating)
+ flag |= O_CREAT;
+ fd = shm_open(key, flag, S_IRUSR | S_IWUSR);
+ if (fd == -1) {
+ fprintf(stderr, "Failed to open shared memory file %s\n", key);
+ fflush(stderr);
+ return NULL;
+ }
+ if (creating) {
+ if (verbose)
+ fprintf(stderr, "Truncating file.\n");
+ rtn = ftruncate(fd, (off_t) len);
+ if (rtn == -1) {
+ fprintf(stderr, "Can't ftruncate(fd,%ld)\n", len);
+ fflush(stderr);
+ }
+ }
+ mem = mmap(NULL, len,
+ PROT_READ | PROT_WRITE, MAP_SHARED | MAP_NORESERVE, fd, 0);
+ close(fd);
+ if (mem == NULL) {
+ fprintf(stderr, "Failed to mmap shared memory file\n");
+ fflush(stderr);
+ return NULL;
+ }
+ if (creating) {
+ int fill_bytes = 0xae0dae0d;
+ if (verbose)
+ fprintf(stderr, "Filling buffer\n");
+ fill_mem(mem, len, (char *)&fill_bytes, 4);
+ }
+ return mem;
+}
+
+inline void fill_mem(void *buf, size_t buf_size, char *fill, size_t fill_len)
+{
+ size_t i;
+
+ if (fill_len == 1) {
+ memset(buf, fill[0], buf_size);
+ } else {
+ if (buf_size > fill_len) {
+ for (i = 0; i < buf_size - fill_len; i += fill_len)
+ memcpy(((char *)buf) + i, fill, fill_len);
+ memcpy(buf + i, fill, buf_size - i);
+ } else {
+ memcpy(buf, fill, buf_size);
+ }
+ }
+}
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