The patch adds an ivshmem device which can be used to share memory between
guests on the same host.
This implementation is lacking inter-guest communication which should be
implemented later once information regarding the client-server protocol is
gathered, though infrastructure used to add and remove clients already exists
in the patch (but isn't used anywhere).
Patch is based on David Evansky's shmem device.
Signed-off-by: David Evensky <evensky@xxxxxxxxxx>
Signed-off-by: Sasha Levin <levinsasha928@xxxxxxxxx>
---
tools/kvm/Makefile | 1 +
tools/kvm/builtin-run.c | 134 ++++++++++++++++
tools/kvm/hw/pci-shmem.c | 266 ++++++++++++++++++++++++++++++++
tools/kvm/include/kvm/pci-shmem.h | 28 ++++
tools/kvm/include/kvm/pci.h | 3 +-
tools/kvm/include/kvm/virtio-pci-dev.h | 3 +
tools/kvm/pci.c | 5 +-
tools/kvm/virtio/pci.c | 4 +-
8 files changed, 438 insertions(+), 6 deletions(-)
create mode 100644 tools/kvm/hw/pci-shmem.c
create mode 100644 tools/kvm/include/kvm/pci-shmem.h
diff --git a/tools/kvm/Makefile b/tools/kvm/Makefile
index 25cbd7e..efa032d 100644
--- a/tools/kvm/Makefile
+++ b/tools/kvm/Makefile
@@ -81,6 +81,7 @@ 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 --git a/tools/kvm/builtin-run.c b/tools/kvm/builtin-run.c
index 38612b6..b9efde2 100644
--- a/tools/kvm/builtin-run.c
+++ b/tools/kvm/builtin-run.c
@@ -28,6 +28,7 @@
#include "kvm/sdl.h"
#include "kvm/vnc.h"
#include "kvm/guest_compat.h"
+#include "kvm/pci-shmem.h"
#include <linux/types.h>
@@ -52,6 +53,8 @@
#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 +154,131 @@ static int virtio_9p_rootdir_parser(const struct option *opt, const char *arg, i
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;
+ struct shmem_info *si = malloc(sizeof(struct shmem_info));
+ 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);
+ }
+
+ 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 **argv, const char *prefix)
kbd__init(kvm);
+ pci_shmem__init(kvm);
+
if (vnc || sdl)
fb = vesa__init(kvm);
diff --git a/tools/kvm/hw/pci-shmem.c b/tools/kvm/hw/pci-shmem.c
new file mode 100644
index 0000000..295f5cd
--- /dev/null
+++ b/tools/kvm/hw/pci-shmem.c
@@ -0,0 +1,266 @@
+#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"
+#include "kvm/ioport.h"
+#include "kvm/ioeventfd.h"
+
+#include <linux/kvm.h>
+#include <sys/ioctl.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+
+static struct pci_device_header pci_shmem_pci_device = {
+ .vendor_id = PCI_VENDOR_ID_REDHAT_QUMRANET,
+ .device_id = 0x1110,
+ .header_type = PCI_HEADER_TYPE_NORMAL,
+ .class = 0xFF0000, /* misc pci device */
+ .status = PCI_STATUS_CAP_LIST,
+ .capabilities = (void *)&pci_shmem_pci_device.msix - (void *)&pci_shmem_pci_device,
+ .msix.cap = PCI_CAP_ID_MSIX,
+ .msix.ctrl = 1,
+ .msix.table_offset = 1, /* Use BAR 1 */
+ .msix.pba_offset = 0x1001, /* Use BAR 1 */
+};
+
+/* registers for the Inter-VM shared memory device */
+enum ivshmem_registers {
+ INTRMASK = 0,
+ INTRSTATUS = 4,
+ IVPOSITION = 8,
+ DOORBELL = 12,
+};
+
+static struct shmem_info *shmem_region;
+static u16 ivshmem_registers;
+static int local_fd;
+static u32 local_id;
+static u64 msix_block;
+static u64 msix_pba;
+static struct msix_table msix_table[2];
+
+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;
+}
+
+static bool shmem_pci__io_in(struct ioport *ioport, struct kvm *kvm, u16 port, void *data, int size)
+{
+ u16 offset = port - ivshmem_registers;
+
+ switch (offset) {
+ case INTRMASK:
+ break;
+ case INTRSTATUS:
+ break;
+ case IVPOSITION:
+ ioport__write32(data, local_id);
+ break;
+ case DOORBELL:
+ break;
+ };
+
+ return true;
+}
+
+static bool shmem_pci__io_out(struct ioport *ioport, struct kvm *kvm, u16 port, void *data, int size)
+{
+ u16 offset = port - ivshmem_registers;
+
+ switch (offset) {
+ case INTRMASK:
+ break;
+ case INTRSTATUS:
+ break;
+ case IVPOSITION:
+ break;
+ case DOORBELL:
+ break;
+ };
+
+ return true;
+}
+
+static struct ioport_operations shmem_pci__io_ops = {
+ .io_in = shmem_pci__io_in,
+ .io_out = shmem_pci__io_out,
+};
+
+static void callback_mmio_msix(u64 addr, u8 *data, u32 len, u8 is_write, void *ptr)
+{
+ void *mem;
+
+ if (addr - msix_block < 0x1000)
+ mem = &msix_table;
+ else
+ mem = &msix_pba;
+
+ if (is_write)
+ memcpy(mem + addr - msix_block, data, len);
+ else
+ memcpy(data, mem + addr - msix_block, len);
+}
+
+/*
+ * Return an irqfd which can be used by other guests to signal this guest
+ * whenever they need to poke it
+ */
+int pci_shmem__get_local_irqfd(struct kvm *kvm)
+{
+ int fd, gsi, r;
+ struct kvm_irqfd irqfd;
+
+ if (local_fd == 0) {
+ fd = eventfd(0, 0);
+ if (fd < 0)
+ return fd;
+
+ if (pci_shmem_pci_device.msix.ctrl & PCI_MSIX_FLAGS_ENABLE) {
+ gsi = irq__add_msix_route(kvm,
+ msix_table[0].low,
+ msix_table[0].high,
+ msix_table[0].data);
+ } else {
+ gsi = pci_shmem_pci_device.irq_line;
+ }
+
+ irqfd = (struct kvm_irqfd) {
+ .fd = fd,
+ .gsi = gsi,
+ };
+
+ r = ioctl(kvm->vm_fd, KVM_IRQFD, &irqfd);
+ if (r < 0)
+ return r;
+
+ local_fd = fd;
+ }
+
+ return local_fd;
+}
+
+/*
+ * Connect a new client to ivshmem by adding the appropriate datamatch
+ * to the DOORBELL
+ */
+int pci_shmem__add_client(struct kvm *kvm, u32 id, int fd)
+{
+ struct kvm_ioeventfd ioevent;
+
+ ioevent = (struct kvm_ioeventfd) {
+ .addr = ivshmem_registers + DOORBELL,
+ .len = sizeof(u32),
+ .datamatch = id,
+ .fd = fd,
+ .flags = KVM_IOEVENTFD_FLAG_PIO | KVM_IOEVENTFD_FLAG_DATAMATCH,
+ };
+
+ return ioctl(kvm->vm_fd, KVM_IOEVENTFD, &ioevent);
+}
+
+/*
+ * Remove a client connected to ivshmem by removing the appropriate datamatch
+ * from the DOORBELL
+ */
+int pci_shmem__remove_client(struct kvm *kvm, u32 id)
+{
+ struct kvm_ioeventfd ioevent;
+
+ ioevent = (struct kvm_ioeventfd) {
+ .addr = ivshmem_registers + DOORBELL,
+ .len = sizeof(u32),
+ .datamatch = id,
+ .flags = KVM_IOEVENTFD_FLAG_PIO
+ | KVM_IOEVENTFD_FLAG_DATAMATCH
+ | KVM_IOEVENTFD_FLAG_DEASSIGN,
+ };
+
+ return ioctl(kvm->vm_fd, KVM_IOEVENTFD, &ioevent);
+}
+
+static void *setup_shmem(const char *key, size_t len, int creating)
+{
+ 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 < 0) {
+ pr_warning("Failed to open shared memory file %s\n", key);
+ return NULL;
+ }
+
+ if (creating) {
+ rtn = ftruncate(fd, (off_t) len);
+ if (rtn < 0)
+ pr_warning("Can't ftruncate(fd,%ld)\n", len);
+ }
+ mem = mmap(NULL, len,
+ PROT_READ | PROT_WRITE, MAP_SHARED | MAP_NORESERVE, fd, 0);
+ close(fd);
+
+ if (mem == NULL)
+ pr_warning("Failed to mmap shared memory file");
+
+ return mem;
+}
+
+int pci_shmem__init(struct kvm *kvm)
+{
+ u8 dev, line, pin;
+ char *mem;
+
+ if (shmem_region == 0) {
+ pr_warning("pci_shmem_init: memory region not registered\n");
+ return 0;
+ }
+
+ /* Register good old INTx */
+ if (irq__register_device(PCI_DEVICE_ID_PCI_SHMEM, &dev, &pin, &line) < 0)
+ return 0;
+
+ pci_shmem_pci_device.irq_pin = pin;
+ pci_shmem_pci_device.irq_line = line;
+
+ /* Register MMIO space for MSI-X */
+ ivshmem_registers = ioport__register(IOPORT_EMPTY, &shmem_pci__io_ops, IOPORT_SIZE, NULL);
+ msix_block = pci_get_io_space_block(0x1010);
+ kvm__register_mmio(kvm, msix_block, 0x1010, callback_mmio_msix, NULL);
+
+ /*
+ * This registers 3 BARs:
+ *
+ * 0 - ivshmem registers
+ * 1 - MSI-X MMIO space
+ * 2 - Shared memory block
+ */
+ pci_shmem_pci_device.bar[0] = ivshmem_registers | PCI_BASE_ADDRESS_SPACE_IO;
+ pci_shmem_pci_device.bar_size[0] = shmem_region->size;
+ pci_shmem_pci_device.bar[1] = msix_block | PCI_BASE_ADDRESS_SPACE_MEMORY;
+ pci_shmem_pci_device.bar_size[1] = 0x1010;
+ pci_shmem_pci_device.bar[2] = shmem_region->phys_addr | PCI_BASE_ADDRESS_SPACE_MEMORY;
+ pci_shmem_pci_device.bar_size[2] = shmem_region->size;
+
+ pci__register(&pci_shmem_pci_device, dev);
+
+ /* Open shared memory and plug it into the guest */
+ mem = setup_shmem(shmem_region->handle, shmem_region->size,
+ shmem_region->create);
+ if (mem == NULL)
+ return 0;
+ kvm__register_mem(kvm, shmem_region->phys_addr, shmem_region->size,
+ mem);
+ return 1;
+}
diff --git a/tools/kvm/include/kvm/pci-shmem.h b/tools/kvm/include/kvm/pci-shmem.h
new file mode 100644
index 0000000..599ab37
--- /dev/null
+++ b/tools/kvm/include/kvm/pci-shmem.h
@@ -0,0 +1,28 @@
+#ifndef KVM__PCI_SHMEM_H
+#define KVM__PCI_SHMEM_H
+
+#include <linux/types.h>
+#include <linux/list.h>
+
+#define SHMEM_DEFAULT_SIZE (16 << MB_SHIFT)
+#define SHMEM_DEFAULT_ADDR (0xc8000000)
+#define SHMEM_DEFAULT_HANDLE "/kvm_shmem"
+
+struct kvm;
+struct shmem_info;
+
+struct shmem_info {
+ u64 phys_addr;
+ u64 size;
+ char *handle;
+ int create;
+};
+
+int pci_shmem__init(struct kvm *self);
+int pci_shmem__register_mem(struct shmem_info *si);
+
+int pci_shmem__get_local_irqfd(struct kvm *kvm);
+int pci_shmem__add_client(struct kvm *kvm, u32 id, int fd);
+int pci_shmem__remove_client(struct kvm *kvm, u32 id);
+
+#endif
diff --git a/tools/kvm/include/kvm/pci.h b/tools/kvm/include/kvm/pci.h
index e74d3ec..5ee8005 100644
--- a/tools/kvm/include/kvm/pci.h
+++ b/tools/kvm/include/kvm/pci.h
@@ -13,6 +13,7 @@
#define PCI_CONFIG_ADDRESS 0xcf8
#define PCI_CONFIG_DATA 0xcfc
#define PCI_CONFIG_BUS_FORWARD 0xcfa
+#define PCI_IO_SIZE 0x100
struct pci_config_address {
unsigned zeros : 2; /* 1 .. 0 */
@@ -69,6 +70,6 @@ struct pci_device_header {
void pci__init(void);
void pci__register(struct pci_device_header *dev, u8 dev_num);
-u32 pci_get_io_space_block(void);
+u32 pci_get_io_space_block(u32 size);
#endif /* KVM__PCI_H */
diff --git a/tools/kvm/include/kvm/virtio-pci-dev.h b/tools/kvm/include/kvm/virtio-pci-dev.h
index 4eee831..bfcb076 100644
--- a/tools/kvm/include/kvm/virtio-pci-dev.h
+++ b/tools/kvm/include/kvm/virtio-pci-dev.h
@@ -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 --git a/tools/kvm/pci.c b/tools/kvm/pci.c
index a046c19..d1afc05 100644
--- a/tools/kvm/pci.c
+++ b/tools/kvm/pci.c
@@ -6,7 +6,6 @@
#include <assert.h>
#define PCI_MAX_DEVICES 256
-#define PCI_IO_SIZE 0x100
#define PCI_BAR_OFFSET(b) (offsetof(struct pci_device_header, bar[b]))
static struct pci_device_header *pci_devices[PCI_MAX_DEVICES];
@@ -16,10 +15,10 @@ static struct pci_config_address pci_config_address;
/* This is within our PCI gap - in an unused area */
static u32 io_space_blocks = KVM_32BIT_GAP_START + 0x1000000;
-u32 pci_get_io_space_block(void)
+u32 pci_get_io_space_block(u32 size)
{
u32 block = io_space_blocks;
- io_space_blocks += PCI_IO_SIZE;
+ io_space_blocks += size;
return block;
}
diff --git a/tools/kvm/virtio/pci.c b/tools/kvm/virtio/pci.c
index 9e2a1ed..2745b25 100644
--- a/tools/kvm/virtio/pci.c
+++ b/tools/kvm/virtio/pci.c
@@ -266,8 +266,8 @@ int virtio_pci__init(struct kvm *kvm, struct virtio_pci *vpci, void *dev,
u8 pin, line, ndev;
vpci->dev = dev;
- vpci->msix_io_block = pci_get_io_space_block();
- vpci->msix_pba_block = pci_get_io_space_block();
+ vpci->msix_io_block = pci_get_io_space_block(PCI_IO_SIZE);
+ vpci->msix_pba_block = pci_get_io_space_block(PCI_IO_SIZE);
vpci->base_addr = ioport__register(IOPORT_EMPTY, &virtio_pci__io_ops, IOPORT_SIZE, vpci);
kvm__register_mmio(kvm, vpci->msix_io_block, 0x100, callback_mmio_table, vpci);
--
1.7.6.1
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