* [Qemu-devel] [PATCH v8 0/5] Inter-VM Shared Memory Device
@ 2010-07-27 0:10 Cam Macdonell
2010-07-27 0:10 ` [Qemu-devel] [PATCH v8 1/5] Add qemu_ram_alloc_from_ptr function Cam Macdonell
0 siblings, 1 reply; 12+ messages in thread
From: Cam Macdonell @ 2010-07-27 0:10 UTC (permalink / raw)
To: qemu-devel; +Cc: Cam Macdonell, kvm
Latest patch for PCI shared memory device that maps a host shared memory object
to be shared between guests
new in this series
v8
- rebased to qemu.git
- added qemu_ram_alloc_from_ptr() function
- removed irqfd support as support functions are not yet in qemu
v7
- replace marking memory from v6 with marking device as unmigratable indicating
that it should be unplugged before migration and re-added after.
- 'peer' case changed to require removal before migration, only 'master'
devices can be migrated while attached.
v6
- migration support with 'master' and 'peer' roles for guest to determine
who "owns" memory
- modified phys_ram_dirty array for marking memory as not to be migrated
v5:
- fixed segfault for non-server case
- code style fixes
- removed limit on the number of guests
- shared memory server is now in qemu.git/contrib
- made ioeventfd setup function generic
- removed interrupts when guest joined (let application handle it)
v4:
- moved to single Doorbell register and use datamatch to trigger different
VMs rather than one register per eventfd
- remove writing arbitrary values to eventfds. Only values of 1 are now
written to ensure correct usage
Cam Macdonell (5):
Provide a function to add an allocated region of memory to the qemu
RAM.
Device specification for shared memory PCI device
Add function to assign ioeventfd to MMIO.
Support marking a device as non-migratable
Inter-VM shared memory PCI device
Makefile.target | 3 +
cpu-common.h | 2 +
docs/specs/ivshmem_device_spec.txt | 96 ++++
exec.c | 43 ++
hw/hw.h | 2 +
hw/ivshmem.c | 834 ++++++++++++++++++++++++++++++++++++
kvm-all.c | 32 ++
kvm.h | 1 +
qemu-char.c | 6 +
qemu-char.h | 3 +
qemu-doc.texi | 43 ++
savevm.c | 44 ++-
12 files changed, 1106 insertions(+), 3 deletions(-)
create mode 100644 docs/specs/ivshmem_device_spec.txt
create mode 100644 hw/ivshmem.c
^ permalink raw reply [flat|nested] 12+ messages in thread* [Qemu-devel] [PATCH v8 1/5] Add qemu_ram_alloc_from_ptr function 2010-07-27 0:10 [Qemu-devel] [PATCH v8 0/5] Inter-VM Shared Memory Device Cam Macdonell @ 2010-07-27 0:10 ` Cam Macdonell 2010-07-27 0:10 ` [Qemu-devel] [PATCH v8 2/5] Device specification for shared memory PCI device Cam Macdonell 2010-08-10 21:28 ` [Qemu-devel] [PATCH v8 1/5] Add qemu_ram_alloc_from_ptr function Anthony Liguori 0 siblings, 2 replies; 12+ messages in thread From: Cam Macdonell @ 2010-07-27 0:10 UTC (permalink / raw) To: qemu-devel; +Cc: Cam Macdonell, kvm Provide a function to add an allocated region of memory to the qemu RAM. This patch is copied from Marcelo's qemu_ram_map() in qemu-kvm and given the clearer name qemu_ram_alloc_from_ptr(). Signed-off-by: Cam Macdonell <cam@cs.ualberta.ca> --- cpu-common.h | 2 ++ exec.c | 43 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 45 insertions(+), 0 deletions(-) diff --git a/cpu-common.h b/cpu-common.h index 71e7933..0426bc8 100644 --- a/cpu-common.h +++ b/cpu-common.h @@ -40,6 +40,8 @@ static inline void cpu_register_physical_memory(target_phys_addr_t start_addr, } ram_addr_t cpu_get_physical_page_desc(target_phys_addr_t addr); +ram_addr_t qemu_ram_alloc_from_ptr(DeviceState *dev, const char *name, + ram_addr_t size, void *host); ram_addr_t qemu_ram_alloc(DeviceState *dev, const char *name, ram_addr_t size); void qemu_ram_free(ram_addr_t addr); /* This should only be used for ram local to a device. */ diff --git a/exec.c b/exec.c index 868cd7f..8636316 100644 --- a/exec.c +++ b/exec.c @@ -2808,6 +2808,49 @@ static ram_addr_t last_ram_offset(void) return last; } +ram_addr_t qemu_ram_alloc_from_ptr(DeviceState *dev, const char *name, + ram_addr_t size, void *host) +{ + RAMBlock *new_block, *block; + + size = TARGET_PAGE_ALIGN(size); + new_block = qemu_mallocz(sizeof(*new_block)); + + if (dev && dev->parent_bus && dev->parent_bus->info->get_dev_path) { + char *id = dev->parent_bus->info->get_dev_path(dev); + if (id) { + snprintf(new_block->idstr, sizeof(new_block->idstr), "%s/", id); + qemu_free(id); + } + } + pstrcat(new_block->idstr, sizeof(new_block->idstr), name); + + QLIST_FOREACH(block, &ram_list.blocks, next) { + if (!strcmp(block->idstr, new_block->idstr)) { + fprintf(stderr, "RAMBlock \"%s\" already registered, abort!\n", + new_block->idstr); + abort(); + } + } + + new_block->host = host; + + new_block->offset = find_ram_offset(size); + new_block->length = size; + + QLIST_INSERT_HEAD(&ram_list.blocks, new_block, next); + + ram_list.phys_dirty = qemu_realloc(ram_list.phys_dirty, + last_ram_offset() >> TARGET_PAGE_BITS); + memset(ram_list.phys_dirty + (new_block->offset >> TARGET_PAGE_BITS), + 0xff, size >> TARGET_PAGE_BITS); + + if (kvm_enabled()) + kvm_setup_guest_memory(new_block->host, size); + + return new_block->offset; +} + ram_addr_t qemu_ram_alloc(DeviceState *dev, const char *name, ram_addr_t size) { RAMBlock *new_block, *block; -- 1.6.3.2.198.g6096d ^ permalink raw reply related [flat|nested] 12+ messages in thread
* [Qemu-devel] [PATCH v8 2/5] Device specification for shared memory PCI device 2010-07-27 0:10 ` [Qemu-devel] [PATCH v8 1/5] Add qemu_ram_alloc_from_ptr function Cam Macdonell @ 2010-07-27 0:10 ` Cam Macdonell 2010-07-27 0:10 ` [Qemu-devel] [PATCH v8 3/5] Add function to assign ioeventfd to MMIO Cam Macdonell 2010-08-10 21:28 ` [Qemu-devel] [PATCH v8 1/5] Add qemu_ram_alloc_from_ptr function Anthony Liguori 1 sibling, 1 reply; 12+ messages in thread From: Cam Macdonell @ 2010-07-27 0:10 UTC (permalink / raw) To: qemu-devel; +Cc: Cam Macdonell, kvm Signed-off-by: Cam Macdonell <cam@cs.ualberta.ca> --- docs/specs/ivshmem_device_spec.txt | 96 ++++++++++++++++++++++++++++++++++++ 1 files changed, 96 insertions(+), 0 deletions(-) create mode 100644 docs/specs/ivshmem_device_spec.txt diff --git a/docs/specs/ivshmem_device_spec.txt b/docs/specs/ivshmem_device_spec.txt new file mode 100644 index 0000000..23dd2ba --- /dev/null +++ b/docs/specs/ivshmem_device_spec.txt @@ -0,0 +1,96 @@ + +Device Specification for Inter-VM shared memory device +------------------------------------------------------ + +The Inter-VM shared memory device is designed to share a region of memory to +userspace in multiple virtual guests. The memory region does not belong to any +guest, but is a POSIX memory object on the host. Optionally, the device may +support sending interrupts to other guests sharing the same memory region. + + +The Inter-VM PCI device +----------------------- + +*BARs* + +The device supports three BARs. BAR0 is a 1 Kbyte MMIO region to support +registers. BAR1 is used for MSI-X when it is enabled in the device. BAR2 is +used to map the shared memory object from the host. The size of BAR2 is +specified when the guest is started and must be a power of 2 in size. + +*Registers* + +The device currently supports 4 registers of 32-bits each. Registers +are used for synchronization between guests sharing the same memory object when +interrupts are supported (this requires using the shared memory server). + +The server assigns each VM an ID number and sends this ID number to the Qemu +process when the guest starts. + +enum ivshmem_registers { + IntrMask = 0, + IntrStatus = 4, + IVPosition = 8, + Doorbell = 12 +}; + +The first two registers are the interrupt mask and status registers. Mask and +status are only used with pin-based interrupts. They are unused with MSI +interrupts. + +Status Register: The status register is set to 1 when an interrupt occurs. + +Mask Register: The mask register is bitwise ANDed with the interrupt status +and the result will raise an interrupt if it is non-zero. However, since 1 is +the only value the status will be set to, it is only the first bit of the mask +that has any effect. Therefore interrupts can be masked by setting the first +bit to 0 and unmasked by setting the first bit to 1. + +IVPosition Register: The IVPosition register is read-only and reports the +guest's ID number. The guest IDs are non-negative integers. When using the +server, since the server is a separate process, the VM ID will only be set when +the device is ready (shared memory is received from the server and accessible via +the device). If the device is not ready, the IVPosition will return -1. +Applications should ensure that they have a valid VM ID before accessing the +shared memory. + +Doorbell Register: To interrupt another guest, a guest must write to the +Doorbell register. The doorbell register is 32-bits, logically divided into +two 16-bit fields. The high 16-bits are the guest ID to interrupt and the low +16-bits are the interrupt vector to trigger. The semantics of the value +written to the doorbell depends on whether the device is using MSI or a regular +pin-based interrupt. In short, MSI uses vectors while regular interrupts set the +status register. + +Regular Interrupts + +If regular interrupts are used (due to either a guest not supporting MSI or the +user specifying not to use them on startup) then the value written to the lower +16-bits of the Doorbell register results is arbitrary and will trigger an +interrupt in the destination guest. + +Message Signalled Interrupts + +A ivshmem device may support multiple MSI vectors. If so, the lower 16-bits +written to the Doorbell register must be between 0 and the maximum number of +vectors the guest supports. The lower 16 bits written to the doorbell is the +MSI vector that will be raised in the destination guest. The number of MSI +vectors is configurable but it is set when the VM is started. + +The important thing to remember with MSI is that it is only a signal, no status +is set (since MSI interrupts are not shared). All information other than the +interrupt itself should be communicated via the shared memory region. Devices +supporting multiple MSI vectors can use different vectors to indicate different +events have occurred. The semantics of interrupt vectors are left to the +user's discretion. + + +Usage in the Guest +------------------ + +The shared memory device is intended to be used with the provided UIO driver. +Very little configuration is needed. The guest should map BAR0 to access the +registers (an array of 32-bit ints allows simple writing) and map BAR2 to +access the shared memory region itself. The size of the shared memory region +is specified when the guest (or shared memory server) is started. A guest may +map the whole shared memory region or only part of it. -- 1.6.3.2.198.g6096d ^ permalink raw reply related [flat|nested] 12+ messages in thread
* [Qemu-devel] [PATCH v8 3/5] Add function to assign ioeventfd to MMIO. 2010-07-27 0:10 ` [Qemu-devel] [PATCH v8 2/5] Device specification for shared memory PCI device Cam Macdonell @ 2010-07-27 0:10 ` Cam Macdonell 2010-07-27 0:11 ` [Qemu-devel] [PATCH v8 4/5] Support marking a device as non-migratable Cam Macdonell 0 siblings, 1 reply; 12+ messages in thread From: Cam Macdonell @ 2010-07-27 0:10 UTC (permalink / raw) To: qemu-devel; +Cc: Cam Macdonell, kvm Signed-off-by: Cam Macdonell <cam@cs.ualberta.ca> --- kvm-all.c | 32 ++++++++++++++++++++++++++++++++ kvm.h | 1 + 2 files changed, 33 insertions(+), 0 deletions(-) diff --git a/kvm-all.c b/kvm-all.c index 7635f2f..d9a5dd0 100644 --- a/kvm-all.c +++ b/kvm-all.c @@ -1241,6 +1241,38 @@ int kvm_set_signal_mask(CPUState *env, const sigset_t *sigset) return r; } +int kvm_set_ioeventfd_mmio_long(int fd, uint32_t addr, uint32_t val, bool assign) +{ +#ifdef KVM_IOEVENTFD + int ret; + struct kvm_ioeventfd iofd; + + iofd.datamatch = val; + iofd.addr = addr; + iofd.len = 4; + iofd.flags = KVM_IOEVENTFD_FLAG_DATAMATCH; + iofd.fd = fd; + + if (!kvm_enabled()) { + return -ENOSYS; + } + + if (!assign) { + iofd.flags |= KVM_IOEVENTFD_FLAG_DEASSIGN; + } + + ret = kvm_vm_ioctl(kvm_state, KVM_IOEVENTFD, &iofd); + + if (ret < 0) { + return -errno; + } + + return 0; +#else + return -ENOSYS; +#endif +} + int kvm_set_ioeventfd_pio_word(int fd, uint16_t addr, uint16_t val, bool assign) { #ifdef KVM_IOEVENTFD diff --git a/kvm.h b/kvm.h index 93f8187..50b6c01 100644 --- a/kvm.h +++ b/kvm.h @@ -175,6 +175,7 @@ static inline void cpu_synchronize_post_init(CPUState *env) } #endif +int kvm_set_ioeventfd_mmio_long(int fd, uint32_t adr, uint32_t val, bool assign); int kvm_set_ioeventfd_pio_word(int fd, uint16_t adr, uint16_t val, bool assign); #endif -- 1.6.3.2.198.g6096d ^ permalink raw reply related [flat|nested] 12+ messages in thread
* [Qemu-devel] [PATCH v8 4/5] Support marking a device as non-migratable 2010-07-27 0:10 ` [Qemu-devel] [PATCH v8 3/5] Add function to assign ioeventfd to MMIO Cam Macdonell @ 2010-07-27 0:11 ` Cam Macdonell 2010-07-27 0:11 ` [Qemu-devel] [PATCH v8 5/5] Inter-VM shared memory PCI device Cam Macdonell 0 siblings, 1 reply; 12+ messages in thread From: Cam Macdonell @ 2010-07-27 0:11 UTC (permalink / raw) To: qemu-devel; +Cc: Cam Macdonell, kvm A non-migratable device should be removed before migration and re-added after. Signed-off-by: Cam Macdonell <cam@cs.ualberta.ca> --- hw/hw.h | 2 ++ savevm.c | 44 +++++++++++++++++++++++++++++++++++++++++--- 2 files changed, 43 insertions(+), 3 deletions(-) diff --git a/hw/hw.h b/hw/hw.h index c2de6fe..28b4204 100644 --- a/hw/hw.h +++ b/hw/hw.h @@ -264,6 +264,8 @@ int register_savevm_live(DeviceState *dev, void *opaque); void unregister_savevm(DeviceState *dev, const char *idstr, void *opaque); +void register_device_unmigratable(DeviceState *dev, const char *idstr, + void *opaque); typedef void QEMUResetHandler(void *opaque); diff --git a/savevm.c b/savevm.c index ee27989..6d55d28 100644 --- a/savevm.c +++ b/savevm.c @@ -1005,6 +1005,7 @@ typedef struct SaveStateEntry { const VMStateDescription *vmsd; void *opaque; CompatEntry *compat; + int no_migrate; } SaveStateEntry; @@ -1068,6 +1069,7 @@ int register_savevm_live(DeviceState *dev, se->load_state = load_state; se->opaque = opaque; se->vmsd = NULL; + se->no_migrate = 0; if (dev && dev->parent_bus && dev->parent_bus->info->get_dev_path) { char *id = dev->parent_bus->info->get_dev_path(dev); @@ -1131,6 +1133,31 @@ void unregister_savevm(DeviceState *dev, const char *idstr, void *opaque) } } +/* mark a device as not to be migrated, that is the device should be + unplugged before migration */ +void register_device_unmigratable(DeviceState *dev, const char *idstr, + void *opaque) +{ + SaveStateEntry *se; + char id[256] = ""; + + if (dev && dev->parent_bus && dev->parent_bus->info->get_dev_path) { + char *path = dev->parent_bus->info->get_dev_path(dev); + if (path) { + pstrcpy(id, sizeof(id), path); + pstrcat(id, sizeof(id), "/"); + qemu_free(path); + } + } + pstrcat(id, sizeof(id), idstr); + + QTAILQ_FOREACH(se, &savevm_handlers, entry) { + if (strcmp(se->idstr, id) == 0 && se->opaque == opaque) { + se->no_migrate = 1; + } + } +} + int vmstate_register_with_alias_id(DeviceState *dev, int instance_id, const VMStateDescription *vmsd, void *opaque, int alias_id, @@ -1323,13 +1350,19 @@ static int vmstate_load(QEMUFile *f, SaveStateEntry *se, int version_id) return vmstate_load_state(f, se->vmsd, se->opaque, version_id); } -static void vmstate_save(QEMUFile *f, SaveStateEntry *se) +static int vmstate_save(QEMUFile *f, SaveStateEntry *se) { + if (se->no_migrate) { + return -1; + } + if (!se->vmsd) { /* Old style */ se->save_state(f, se->opaque); - return; + return 0; } vmstate_save_state(f,se->vmsd, se->opaque); + + return 0; } #define QEMU_VM_FILE_MAGIC 0x5145564d @@ -1423,6 +1456,7 @@ int qemu_savevm_state_iterate(Monitor *mon, QEMUFile *f) int qemu_savevm_state_complete(Monitor *mon, QEMUFile *f) { SaveStateEntry *se; + int r; cpu_synchronize_all_states(); @@ -1455,7 +1489,11 @@ int qemu_savevm_state_complete(Monitor *mon, QEMUFile *f) qemu_put_be32(f, se->instance_id); qemu_put_be32(f, se->version_id); - vmstate_save(f, se); + r = vmstate_save(f, se); + if (r < 0) { + monitor_printf(mon, "cannot migrate with device '%s'\n", se->idstr); + return r; + } } qemu_put_byte(f, QEMU_VM_EOF); -- 1.6.3.2.198.g6096d ^ permalink raw reply related [flat|nested] 12+ messages in thread
* [Qemu-devel] [PATCH v8 5/5] Inter-VM shared memory PCI device 2010-07-27 0:11 ` [Qemu-devel] [PATCH v8 4/5] Support marking a device as non-migratable Cam Macdonell @ 2010-07-27 0:11 ` Cam Macdonell 2010-07-27 16:54 ` [Qemu-devel] [PATCH v8 5/5] RESEND: " Cam Macdonell 0 siblings, 1 reply; 12+ messages in thread From: Cam Macdonell @ 2010-07-27 0:11 UTC (permalink / raw) To: qemu-devel; +Cc: Cam Macdonell, kvm Support an inter-vm shared memory device that maps a shared-memory object as a PCI device in the guest. This patch also supports interrupts between guest by communicating over a unix domain socket. This patch applies to the qemu-kvm repository. -device ivshmem,size=<size in format accepted by -m>[,shm=<shm name>] Interrupts are supported between multiple VMs by using a shared memory server by using a chardev socket. -device ivshmem,size=<size in format accepted by -m>[,shm=<shm name>] [,chardev=<id>][,msi=on][,ioeventfd=on][,vectors=n][,role=peer|master] -chardev socket,path=<path>,id=<id> The shared memory server, sample programs and init scripts are in a git repo here: www.gitorious.org/nahanni Signed-off-by: Cam Macdonell <cam@cs.ualberta.ca> --- Makefile.target | 3 + hw/ivshmem.c | 834 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ qemu-char.c | 6 + qemu-char.h | 3 + qemu-doc.texi | 43 +++ 5 files changed, 889 insertions(+), 0 deletions(-) create mode 100644 hw/ivshmem.c diff --git a/Makefile.target b/Makefile.target index 3ef4666..4cb3a00 100644 --- a/Makefile.target +++ b/Makefile.target @@ -188,6 +188,9 @@ obj-$(CONFIG_USB_OHCI) += usb-ohci.o obj-y += rtl8139.o obj-y += e1000.o +# Inter-VM PCI shared memory +obj-y += ivshmem.o + # Hardware support obj-i386-y += vga.o obj-i386-y += mc146818rtc.o i8259.o pc.o diff --git a/hw/ivshmem.c b/hw/ivshmem.c new file mode 100644 index 0000000..3f197ae --- /dev/null +++ b/hw/ivshmem.c @@ -0,0 +1,834 @@ +/* + * Inter-VM Shared Memory PCI device. + * + * Author: + * Cam Macdonell <cam@cs.ualberta.ca> + * + * Based On: cirrus_vga.c + * Copyright (c) 2004 Fabrice Bellard + * Copyright (c) 2004 Makoto Suzuki (suzu) + * + * and rtl8139.c + * Copyright (c) 2006 Igor Kovalenko + * + * This code is licensed under the GNU GPL v2. + */ +#include "hw.h" +#include "pc.h" +#include "pci.h" +#include "msix.h" +#include "kvm.h" + +#include <sys/mman.h> +#include <sys/types.h> + +#define IVSHMEM_IOEVENTFD 0 +#define IVSHMEM_MSI 1 + +#define IVSHMEM_PEER 0 +#define IVSHMEM_MASTER 1 + +#define IVSHMEM_REG_BAR_SIZE 0x100 + +//#define DEBUG_IVSHMEM +#ifdef DEBUG_IVSHMEM +#define IVSHMEM_DPRINTF(fmt, ...) \ + do {printf("IVSHMEM: " fmt, ## __VA_ARGS__); } while (0) +#else +#define IVSHMEM_DPRINTF(fmt, ...) +#endif + +typedef struct Peer { + int nb_eventfds; + int *eventfds; +} Peer; + +typedef struct EventfdEntry { + PCIDevice *pdev; + int vector; +} EventfdEntry; + +typedef struct IVShmemState { + PCIDevice dev; + uint32_t intrmask; + uint32_t intrstatus; + uint32_t doorbell; + + CharDriverState **eventfd_chr; + CharDriverState *server_chr; + int ivshmem_mmio_io_addr; + + pcibus_t mmio_addr; + pcibus_t shm_pci_addr; + uint64_t ivshmem_offset; + uint64_t ivshmem_size; /* size of shared memory region */ + int shm_fd; /* shared memory file descriptor */ + + Peer *peers; + int nb_peers; /* how many guests we have space for */ + int max_peer; /* maximum numbered peer */ + + int vm_id; + uint32_t vectors; + uint32_t features; + EventfdEntry *eventfd_table; + + char * shmobj; + char * sizearg; + char * role; + int role_val; /* scalar to avoid multiple string comparisons */ +} IVShmemState; + +/* registers for the Inter-VM shared memory device */ +enum ivshmem_registers { + INTRMASK = 0, + INTRSTATUS = 4, + IVPOSITION = 8, + DOORBELL = 12, +}; + +static inline uint32_t ivshmem_has_feature(IVShmemState *ivs, + unsigned int feature) { + return (ivs->features & (1 << feature)); +} + +static inline bool is_power_of_two(uint64_t x) { + return (x & (x - 1)) == 0; +} + +static void ivshmem_map(PCIDevice *pci_dev, int region_num, + pcibus_t addr, pcibus_t size, int type) +{ + IVShmemState *s = DO_UPCAST(IVShmemState, dev, pci_dev); + + s->shm_pci_addr = addr; + + if (s->ivshmem_offset > 0) { + cpu_register_physical_memory(s->shm_pci_addr, s->ivshmem_size, + s->ivshmem_offset); + } + + IVSHMEM_DPRINTF("guest pci addr = %" FMT_PCIBUS ", guest h/w addr = %" + PRIu64 ", size = %" FMT_PCIBUS "\n", addr, s->ivshmem_offset, size); + +} + +/* accessing registers - based on rtl8139 */ +static void ivshmem_update_irq(IVShmemState *s, int val) +{ + int isr; + isr = (s->intrstatus & s->intrmask) & 0xffffffff; + + /* 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->dev.irq[0], (isr != 0)); +} + +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, val); +} + +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, val); + 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, 0); + + return ret; +} + +static void ivshmem_io_writew(void *opaque, target_phys_addr_t addr, + uint32_t val) +{ + + IVSHMEM_DPRINTF("We shouldn't be writing words\n"); +} + +static void ivshmem_io_writel(void *opaque, target_phys_addr_t addr, + uint32_t val) +{ + IVShmemState *s = opaque; + + uint64_t write_one = 1; + uint16_t dest = val >> 16; + uint16_t vector = val & 0xff; + + addr &= 0xfc; + + IVSHMEM_DPRINTF("writing to addr " TARGET_FMT_plx "\n", addr); + switch (addr) + { + case INTRMASK: + ivshmem_IntrMask_write(s, val); + break; + + case INTRSTATUS: + ivshmem_IntrStatus_write(s, val); + break; + + case DOORBELL: + /* check that dest VM ID is reasonable */ + if ((dest < 0) || (dest > s->max_peer)) { + IVSHMEM_DPRINTF("Invalid destination VM ID (%d)\n", dest); + break; + } + + /* check doorbell range */ + if ((vector >= 0) && (vector < s->peers[dest].nb_eventfds)) { + IVSHMEM_DPRINTF("Writing %" PRId64 " to VM %d on vector %d\n", + write_one, dest, vector); + if (write(s->peers[dest].eventfds[vector], + &(write_one), 8) != 8) { + IVSHMEM_DPRINTF("error writing to eventfd\n"); + } + } + break; + default: + IVSHMEM_DPRINTF("Invalid VM Doorbell VM %d\n", dest); + } +} + +static void ivshmem_io_writeb(void *opaque, target_phys_addr_t addr, + uint32_t val) +{ + IVSHMEM_DPRINTF("We shouldn't be writing bytes\n"); +} + +static uint32_t ivshmem_io_readw(void *opaque, target_phys_addr_t addr) +{ + + IVSHMEM_DPRINTF("We shouldn't be reading words\n"); + return 0; +} + +static uint32_t ivshmem_io_readl(void *opaque, target_phys_addr_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 VM ID if the memory is mapped */ + if (s->shm_fd > 0) { + ret = s->vm_id; + } else { + ret = -1; + } + break; + + default: + IVSHMEM_DPRINTF("why are we reading " TARGET_FMT_plx "\n", addr); + ret = 0; + } + + return ret; +} + +static uint32_t ivshmem_io_readb(void *opaque, target_phys_addr_t addr) +{ + IVSHMEM_DPRINTF("We shouldn't be reading bytes\n"); + + return 0; +} + +static CPUReadMemoryFunc * const ivshmem_mmio_read[3] = { + ivshmem_io_readb, + ivshmem_io_readw, + ivshmem_io_readl, +}; + +static CPUWriteMemoryFunc * const ivshmem_mmio_write[3] = { + ivshmem_io_writeb, + ivshmem_io_writew, + ivshmem_io_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 int ivshmem_can_receive(void * opaque) +{ + return 8; +} + +static void ivshmem_event(void *opaque, int event) +{ + IVSHMEM_DPRINTF("ivshmem_event %d\n", event); +} + +static void fake_irqfd(void *opaque, const uint8_t *buf, int size) { + + EventfdEntry *entry = opaque; + PCIDevice *pdev = entry->pdev; + + IVSHMEM_DPRINTF("interrupt on vector %p %d\n", pdev, entry->vector); + msix_notify(pdev, entry->vector); +} + +static CharDriverState* create_eventfd_chr_device(void * opaque, int eventfd, + int vector) +{ + /* create a event character device based on the passed eventfd */ + IVShmemState *s = opaque; + CharDriverState * chr; + + chr = qemu_chr_open_eventfd(eventfd); + + if (chr == NULL) { + fprintf(stderr, "creating eventfd for eventfd %d failed\n", eventfd); + exit(-1); + } + + /* if MSI is supported we need multiple interrupts */ + if (ivshmem_has_feature(s, IVSHMEM_MSI)) { + s->eventfd_table[vector].pdev = &s->dev; + s->eventfd_table[vector].vector = vector; + + qemu_chr_add_handlers(chr, ivshmem_can_receive, fake_irqfd, + ivshmem_event, &s->eventfd_table[vector]); + } else { + qemu_chr_add_handlers(chr, ivshmem_can_receive, ivshmem_receive, + ivshmem_event, s); + } + + return chr; + +} + +static int check_shm_size(IVShmemState *s, int fd) { + /* check that the guest isn't going to try and map more memory than the + * the object has allocated return -1 to indicate error */ + + struct stat buf; + + fstat(fd, &buf); + + if (s->ivshmem_size > buf.st_size) { + fprintf(stderr, "IVSHMEM ERROR: Requested memory size greater"); + fprintf(stderr, " than shared object size (%" PRIu64 " > %ld)\n", + s->ivshmem_size, buf.st_size); + return -1; + } else { + return 0; + } +} + +/* create the shared memory BAR when we are not using the server, so we can + * create the BAR and map the memory immediately */ +static void create_shared_memory_BAR(IVShmemState *s, int fd) { + + void * ptr; + + s->shm_fd = fd; + + ptr = mmap(0, s->ivshmem_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); + + s->ivshmem_offset = qemu_ram_alloc_from_ptr(&s->dev.qdev, "ivshmem.bar2", + s->ivshmem_size, ptr); + + /* region for shared memory */ + pci_register_bar(&s->dev, 2, s->ivshmem_size, + PCI_BASE_ADDRESS_SPACE_MEMORY, ivshmem_map); +} + +static void close_guest_eventfds(IVShmemState *s, int posn) +{ + int i, guest_curr_max; + + guest_curr_max = s->peers[posn].nb_eventfds; + + for (i = 0; i < guest_curr_max; i++) { + kvm_set_ioeventfd_mmio_long(s->peers[posn].eventfds[i], + s->mmio_addr + DOORBELL, (posn << 16) | i, 0); + close(s->peers[posn].eventfds[i]); + } + + qemu_free(s->peers[posn].eventfds); + s->peers[posn].nb_eventfds = 0; +} + +static void setup_ioeventfds(IVShmemState *s) { + + int i, j; + + for (i = 0; i <= s->max_peer; i++) { + for (j = 0; j < s->peers[i].nb_eventfds; j++) { + kvm_set_ioeventfd_mmio_long(s->peers[i].eventfds[j], + s->mmio_addr + DOORBELL, (i << 16) | j, 1); + } + } +} + +/* this function increase the dynamic storage need to store data about other + * guests */ +static void increase_dynamic_storage(IVShmemState *s, int new_min_size) { + + int j, old_nb_alloc; + + old_nb_alloc = s->nb_peers; + + while (new_min_size >= s->nb_peers) + s->nb_peers = s->nb_peers * 2; + + IVSHMEM_DPRINTF("bumping storage to %d guests\n", s->nb_peers); + s->peers = qemu_realloc(s->peers, s->nb_peers * sizeof(Peer)); + + /* zero out new pointers */ + for (j = old_nb_alloc; j < s->nb_peers; j++) { + s->peers[j].eventfds = NULL; + s->peers[j].nb_eventfds = 0; + } +} + +static void ivshmem_read(void *opaque, const uint8_t * buf, int flags) +{ + IVShmemState *s = opaque; + int incoming_fd, tmp_fd; + int guest_max_eventfd; + long incoming_posn; + + memcpy(&incoming_posn, buf, sizeof(long)); + /* pick off s->server_chr->msgfd and store it, posn should accompany msg */ + tmp_fd = qemu_chr_get_msgfd(s->server_chr); + IVSHMEM_DPRINTF("posn is %ld, fd is %d\n", incoming_posn, tmp_fd); + + /* make sure we have enough space for this guest */ + if (incoming_posn >= s->nb_peers) { + increase_dynamic_storage(s, incoming_posn); + } + + if (tmp_fd == -1) { + /* if posn is positive and unseen before then this is our posn*/ + if ((incoming_posn >= 0) && + (s->peers[incoming_posn].eventfds == NULL)) { + /* receive our posn */ + s->vm_id = incoming_posn; + return; + } else { + /* otherwise an fd == -1 means an existing guest has gone away */ + IVSHMEM_DPRINTF("posn %ld has gone away\n", incoming_posn); + close_guest_eventfds(s, incoming_posn); + return; + } + } + + /* because of the implementation of get_msgfd, we need a dup */ + incoming_fd = dup(tmp_fd); + + if (incoming_fd == -1) { + fprintf(stderr, "could not allocate file descriptor %s\n", + strerror(errno)); + return; + } + + /* if the position is -1, then it's shared memory region fd */ + if (incoming_posn == -1) { + + void * map_ptr; + + s->max_peer = 0; + + if (check_shm_size(s, incoming_fd) == -1) { + exit(-1); + } + + /* mmap the region and map into the BAR2 */ + map_ptr = mmap(0, s->ivshmem_size, PROT_READ|PROT_WRITE, MAP_SHARED, + incoming_fd, 0); + s->ivshmem_offset = qemu_ram_alloc_from_ptr(&s->dev.qdev, + "ivshmem.bar2", s->ivshmem_size, map_ptr); + + IVSHMEM_DPRINTF("guest pci addr = %" FMT_PCIBUS ", guest h/w addr = %" + PRIu64 ", size = %" PRIu64 "\n", s->shm_pci_addr, + s->ivshmem_offset, s->ivshmem_size); + + if (s->shm_pci_addr > 0) { + /* map memory into BAR2 */ + cpu_register_physical_memory(s->shm_pci_addr, s->ivshmem_size, + s->ivshmem_offset); + } + + /* only store the fd if it is successfully mapped */ + s->shm_fd = incoming_fd; + + return; + } + + /* each guest has an array of eventfds, and we keep track of how many + * guests for each VM */ + guest_max_eventfd = s->peers[incoming_posn].nb_eventfds; + + if (guest_max_eventfd == 0) { + /* one eventfd per MSI vector */ + s->peers[incoming_posn].eventfds = (int *) qemu_malloc(s->vectors * + sizeof(int)); + } + + /* this is an eventfd for a particular guest VM */ + IVSHMEM_DPRINTF("eventfds[%ld][%d] = %d\n", incoming_posn, + guest_max_eventfd, incoming_fd); + s->peers[incoming_posn].eventfds[guest_max_eventfd] = incoming_fd; + + /* increment count for particular guest */ + s->peers[incoming_posn].nb_eventfds++; + + /* keep track of the maximum VM ID */ + if (incoming_posn > s->max_peer) { + s->max_peer = incoming_posn; + } + + if (incoming_posn == s->vm_id) { + if (!ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) { + /* initialize char device for callback + * if this is one of my eventfds */ + s->eventfd_chr[guest_max_eventfd] = create_eventfd_chr_device(s, + s->peers[s->vm_id].eventfds[guest_max_eventfd], + guest_max_eventfd); + } + } + + if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) { + kvm_set_ioeventfd_mmio_long(incoming_fd, s->mmio_addr + DOORBELL, + (incoming_posn << 16) | guest_max_eventfd, 1); + } + + return; +} + +static void ivshmem_reset(DeviceState *d) +{ + IVShmemState *s = DO_UPCAST(IVShmemState, dev.qdev, d); + + s->intrstatus = 0; + return; +} + +static void ivshmem_mmio_map(PCIDevice *pci_dev, int region_num, + pcibus_t addr, pcibus_t size, int type) +{ + IVShmemState *s = DO_UPCAST(IVShmemState, dev, pci_dev); + + s->mmio_addr = addr; + cpu_register_physical_memory(addr + 0, IVSHMEM_REG_BAR_SIZE, + s->ivshmem_mmio_io_addr); + + if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) { + setup_ioeventfds(s); + } +} + +static uint64_t ivshmem_get_size(IVShmemState * s) { + + uint64_t value; + char *ptr; + + value = strtoull(s->sizearg, &ptr, 10); + switch (*ptr) { + case 0: case 'M': case 'm': + value <<= 20; + break; + case 'G': case 'g': + value <<= 30; + break; + default: + fprintf(stderr, "qemu: invalid ram size: %s\n", s->sizearg); + exit(1); + } + + /* BARs must be a power of 2 */ + if (!is_power_of_two(value)) { + fprintf(stderr, "ivshmem: size must be power of 2\n"); + exit(1); + } + + return value; +} + +static void ivshmem_setup_msi(IVShmemState * s) { + + int i; + + /* allocate the MSI-X vectors */ + + if (!msix_init(&s->dev, s->vectors, 1, 0)) { + pci_register_bar(&s->dev, 1, + msix_bar_size(&s->dev), + PCI_BASE_ADDRESS_SPACE_MEMORY, + msix_mmio_map); + IVSHMEM_DPRINTF("msix initialized (%d vectors)\n", s->vectors); + } else { + IVSHMEM_DPRINTF("msix initialization failed\n"); + exit(1); + } + + /* 'activate' the vectors */ + for (i = 0; i < s->vectors; i++) { + msix_vector_use(&s->dev, i); + } + + /* if IRQFDs are not supported, we'll have to trigger the interrupts + * via Qemu char devices */ + if (!ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) { + /* for handling interrupts when IRQFD is not available */ + s->eventfd_table = qemu_mallocz(s->vectors * sizeof(EventfdEntry)); + } +} + +static void ivshmem_save(QEMUFile* f, void *opaque) +{ + IVShmemState *proxy = opaque; + + IVSHMEM_DPRINTF("ivshmem_save\n"); + pci_device_save(&proxy->dev, f); + + if (ivshmem_has_feature(proxy, IVSHMEM_MSI)) { + msix_save(&proxy->dev, f); + } else { + qemu_put_be32(f, proxy->intrstatus); + qemu_put_be32(f, proxy->intrmask); + } + +} + +static int ivshmem_load(QEMUFile* f, void *opaque, int version_id) +{ + IVSHMEM_DPRINTF("ivshmem_load\n"); + + IVShmemState *proxy = opaque; + int ret, i; + + if (version_id > 0) { + return -EINVAL; + } + + if (proxy->role_val == IVSHMEM_PEER) { + fprintf(stderr, "ivshmem: 'peer' devices are not migratable\n"); + return -EINVAL; + } + + ret = pci_device_load(&proxy->dev, f); + if (ret) { + return ret; + } + + if (ivshmem_has_feature(proxy, IVSHMEM_MSI)) { + msix_load(&proxy->dev, f); + for (i = 0; i < proxy->vectors; i++) { + msix_vector_use(&proxy->dev, i); + } + } else { + proxy->intrstatus = qemu_get_be32(f); + proxy->intrmask = qemu_get_be32(f); + } + + return 0; +} + +static int pci_ivshmem_init(PCIDevice *dev) +{ + IVShmemState *s = DO_UPCAST(IVShmemState, dev, dev); + uint8_t *pci_conf; + + if (s->sizearg == NULL) + s->ivshmem_size = 4 << 20; /* 4 MB default */ + else { + s->ivshmem_size = ivshmem_get_size(s); + } + + register_savevm(&s->dev.qdev, "ivshmem", 0, 0, ivshmem_save, ivshmem_load, + dev); + + /* IRQFD requires MSI */ + if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD) && + !ivshmem_has_feature(s, IVSHMEM_MSI)) { + fprintf(stderr, "ivshmem: ioeventfd/irqfd requires MSI\n"); + exit(1); + } + + /* check that role is reasonable */ + if (s->role) { + if (strncmp(s->role, "peer", 5) == 0) { + s->role_val = IVSHMEM_PEER; + } else if (strncmp(s->role, "master", 7) == 0) { + s->role_val = IVSHMEM_MASTER; + } else { + fprintf(stderr, "ivshmem: 'role' must be 'peer' or 'master'\n"); + exit(1); + } + } else { + s->role_val = IVSHMEM_MASTER; /* default */ + } + + if (s->role_val == IVSHMEM_PEER) { + register_device_unmigratable(&s->dev.qdev, "ivshmem", s); + } + + pci_conf = s->dev.config; + pci_config_set_vendor_id(pci_conf, PCI_VENDOR_ID_REDHAT_QUMRANET); + pci_conf[0x02] = 0x10; + pci_conf[0x03] = 0x11; + pci_conf[PCI_COMMAND] = PCI_COMMAND_IO | PCI_COMMAND_MEMORY; + pci_config_set_class(pci_conf, PCI_CLASS_MEMORY_RAM); + pci_conf[PCI_HEADER_TYPE] = PCI_HEADER_TYPE_NORMAL; + + pci_config_set_interrupt_pin(pci_conf, 1); + + s->shm_pci_addr = 0; + s->ivshmem_offset = 0; + s->shm_fd = 0; + + s->ivshmem_mmio_io_addr = cpu_register_io_memory(ivshmem_mmio_read, + ivshmem_mmio_write, s); + /* region for registers*/ + pci_register_bar(&s->dev, 0, IVSHMEM_REG_BAR_SIZE, + PCI_BASE_ADDRESS_SPACE_MEMORY, ivshmem_mmio_map); + + if ((s->server_chr != NULL) && + (strncmp(s->server_chr->filename, "unix:", 5) == 0)) { + /* if we get a UNIX socket as the parameter we will talk + * to the ivshmem server to receive the memory region */ + + if (s->shmobj != NULL) { + fprintf(stderr, "WARNING: do not specify both 'chardev' " + "and 'shm' with ivshmem\n"); + } + + IVSHMEM_DPRINTF("using shared memory server (socket = %s)\n", + s->server_chr->filename); + + if (ivshmem_has_feature(s, IVSHMEM_MSI)) { + ivshmem_setup_msi(s); + } + + /* we allocate enough space for 16 guests and grow as needed */ + s->nb_peers = 16; + s->vm_id = -1; + + /* allocate/initialize space for interrupt handling */ + s->peers = qemu_mallocz(s->nb_peers * sizeof(Peer)); + + pci_register_bar(&s->dev, 2, s->ivshmem_size, + PCI_BASE_ADDRESS_SPACE_MEMORY, ivshmem_map); + + s->eventfd_chr = qemu_mallocz(s->vectors * sizeof(CharDriverState *)); + + qemu_chr_add_handlers(s->server_chr, ivshmem_can_receive, ivshmem_read, + ivshmem_event, s); + } else { + /* just map the file immediately, we're not using a server */ + int fd; + + if (s->shmobj == NULL) { + fprintf(stderr, "Must specify 'chardev' or 'shm' to ivshmem\n"); + } + + IVSHMEM_DPRINTF("using shm_open (shm object = %s)\n", s->shmobj); + + /* try opening with O_EXCL and if it succeeds zero the memory + * by truncating to 0 */ + if ((fd = shm_open(s->shmobj, O_CREAT|O_RDWR|O_EXCL, + S_IRWXU|S_IRWXG|S_IRWXO)) > 0) { + /* truncate file to length PCI device's memory */ + if (ftruncate(fd, s->ivshmem_size) != 0) { + fprintf(stderr, "ivshmem: could not truncate shared file\n"); + } + + } else if ((fd = shm_open(s->shmobj, O_CREAT|O_RDWR, + S_IRWXU|S_IRWXG|S_IRWXO)) < 0) { + fprintf(stderr, "ivshmem: could not open shared file\n"); + exit(-1); + + } + + if (check_shm_size(s, fd) == -1) { + exit(-1); + } + + create_shared_memory_BAR(s, fd); + + } + + return 0; +} + +static int pci_ivshmem_uninit(PCIDevice *dev) +{ + IVShmemState *s = DO_UPCAST(IVShmemState, dev, dev); + + cpu_unregister_io_memory(s->ivshmem_mmio_io_addr); + unregister_savevm(&dev->qdev, "ivshmem", s); + + return 0; +} + +static PCIDeviceInfo ivshmem_info = { + .qdev.name = "ivshmem", + .qdev.size = sizeof(IVShmemState), + .qdev.reset = ivshmem_reset, + .init = pci_ivshmem_init, + .exit = pci_ivshmem_uninit, + .qdev.props = (Property[]) { + DEFINE_PROP_CHR("chardev", IVShmemState, server_chr), + DEFINE_PROP_STRING("size", IVShmemState, sizearg), + DEFINE_PROP_UINT32("vectors", IVShmemState, vectors, 1), + DEFINE_PROP_BIT("ioeventfd", IVShmemState, features, IVSHMEM_IOEVENTFD, false), + DEFINE_PROP_BIT("msi", IVShmemState, features, IVSHMEM_MSI, true), + DEFINE_PROP_STRING("shm", IVShmemState, shmobj), + DEFINE_PROP_STRING("role", IVShmemState, role), + DEFINE_PROP_END_OF_LIST(), + } +}; + +static void ivshmem_register_devices(void) +{ + pci_qdev_register(&ivshmem_info); +} + +device_init(ivshmem_register_devices) diff --git a/qemu-char.c b/qemu-char.c index 9b69d92..6a3952c 100644 --- a/qemu-char.c +++ b/qemu-char.c @@ -2087,6 +2087,12 @@ static void tcp_chr_read(void *opaque) } } +CharDriverState *qemu_chr_open_eventfd(int eventfd){ + + return qemu_chr_open_fd(eventfd, eventfd); + +} + static void tcp_chr_connect(void *opaque) { CharDriverState *chr = opaque; diff --git a/qemu-char.h b/qemu-char.h index e3a0783..6ea01ba 100644 --- a/qemu-char.h +++ b/qemu-char.h @@ -94,6 +94,9 @@ void qemu_chr_info_print(Monitor *mon, const QObject *ret_data); void qemu_chr_info(Monitor *mon, QObject **ret_data); CharDriverState *qemu_chr_find(const char *name); +/* add an eventfd to the qemu devices that are polled */ +CharDriverState *qemu_chr_open_eventfd(int eventfd); + extern int term_escape_char; /* async I/O support */ diff --git a/qemu-doc.texi b/qemu-doc.texi index e67bf44..55a966f 100644 --- a/qemu-doc.texi +++ b/qemu-doc.texi @@ -706,6 +706,49 @@ Using the @option{-net socket} option, it is possible to make VLANs that span several QEMU instances. See @ref{sec_invocation} to have a basic example. +@section Other Devices + +@subsection Inter-VM Shared Memory device + +With KVM enabled on a Linux host, a shared memory device is available. Guests +map a POSIX shared memory region into the guest as a PCI device that enables +zero-copy communication to the application level of the guests. The basic +syntax is: + +@example +qemu -device ivshmem,size=<size in format accepted by -m>[,shm=<shm name>] +@end example + +If desired, interrupts can be sent between guest VMs accessing the same shared +memory region. Interrupt support requires using a shared memory server and +using a chardev socket to connect to it. The code for the shared memory server +is qemu.git/contrib/ivshmem-server. An example syntax when using the shared +memory server is: + +@example +qemu -device ivshmem,size=<size in format accepted by -m>[,chardev=<id>] + [,msi=on][,ioeventfd=on][,vectors=n][,role=peer|master] +qemu -chardev socket,path=<path>,id=<id> +@end example + +When using the server, the guest will be assigned a VM ID (>=0) that allows guests +using the same server to communicate via interrupts. Guests can read their +VM ID from a device register (see example code). Since receiving the shared +memory region from the server is asynchronous, there is a (small) chance the +guest may boot before the shared memory is attached. To allow an application +to ensure shared memory is attached, the VM ID register will return -1 (an +invalid VM ID) until the memory is attached. Once the shared memory is +attached, the VM ID will return the guest's valid VM ID. With these semantics, +the guest application can check to ensure the shared memory is attached to the +guest before proceeding. + +The @option{role} argument can be set to either master or peer and will affect +how the shared memory is migrated. With @option{role=master}, the guest will +copy the shared memory on migration to the destination host. With +@option{role=peer}, the guest will not be able to migrate with the device attached. +With the @option{peer} case, the device should be detached and then reattached +after migration using the PCI hotplug support. + @node direct_linux_boot @section Direct Linux Boot -- 1.6.3.2.198.g6096d ^ permalink raw reply related [flat|nested] 12+ messages in thread
* [Qemu-devel] [PATCH v8 5/5] RESEND: Inter-VM shared memory PCI device 2010-07-27 0:11 ` [Qemu-devel] [PATCH v8 5/5] Inter-VM shared memory PCI device Cam Macdonell @ 2010-07-27 16:54 ` Cam Macdonell 2010-08-11 8:35 ` Stefan Weil 0 siblings, 1 reply; 12+ messages in thread From: Cam Macdonell @ 2010-07-27 16:54 UTC (permalink / raw) To: qemu-devel; +Cc: Cam Macdonell, kvm resend for bug fix related to removal of irqfd Support an inter-vm shared memory device that maps a shared-memory object as a PCI device in the guest. This patch also supports interrupts between guest by communicating over a unix domain socket. This patch applies to the qemu-kvm repository. -device ivshmem,size=<size in format accepted by -m>[,shm=<shm name>] Interrupts are supported between multiple VMs by using a shared memory server by using a chardev socket. -device ivshmem,size=<size in format accepted by -m>[,shm=<shm name>] [,chardev=<id>][,msi=on][,ioeventfd=on][,vectors=n][,role=peer|master] -chardev socket,path=<path>,id=<id> The shared memory server, sample programs and init scripts are in a git repo here: www.gitorious.org/nahanni Signed-off-by: Cam Macdonell <cam@cs.ualberta.ca> --- Makefile.target | 3 + hw/ivshmem.c | 828 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ qemu-char.c | 6 + qemu-char.h | 3 + qemu-doc.texi | 43 +++ 5 files changed, 883 insertions(+), 0 deletions(-) create mode 100644 hw/ivshmem.c diff --git a/Makefile.target b/Makefile.target index 8a9c427..b791492 100644 --- a/Makefile.target +++ b/Makefile.target @@ -190,6 +190,9 @@ obj-$(CONFIG_USB_OHCI) += usb-ohci.o obj-y += rtl8139.o obj-y += e1000.o +# Inter-VM PCI shared memory +obj-y += ivshmem.o + # Hardware support obj-i386-y += vga.o obj-i386-y += mc146818rtc.o i8259.o pc.o diff --git a/hw/ivshmem.c b/hw/ivshmem.c new file mode 100644 index 0000000..bbb5cba --- /dev/null +++ b/hw/ivshmem.c @@ -0,0 +1,828 @@ +/* + * Inter-VM Shared Memory PCI device. + * + * Author: + * Cam Macdonell <cam@cs.ualberta.ca> + * + * Based On: cirrus_vga.c + * Copyright (c) 2004 Fabrice Bellard + * Copyright (c) 2004 Makoto Suzuki (suzu) + * + * and rtl8139.c + * Copyright (c) 2006 Igor Kovalenko + * + * This code is licensed under the GNU GPL v2. + */ +#include "hw.h" +#include "pc.h" +#include "pci.h" +#include "msix.h" +#include "kvm.h" + +#include <sys/mman.h> +#include <sys/types.h> + +#define IVSHMEM_IOEVENTFD 0 +#define IVSHMEM_MSI 1 + +#define IVSHMEM_PEER 0 +#define IVSHMEM_MASTER 1 + +#define IVSHMEM_REG_BAR_SIZE 0x100 + +//#define DEBUG_IVSHMEM +#ifdef DEBUG_IVSHMEM +#define IVSHMEM_DPRINTF(fmt, ...) \ + do {printf("IVSHMEM: " fmt, ## __VA_ARGS__); } while (0) +#else +#define IVSHMEM_DPRINTF(fmt, ...) +#endif + +typedef struct Peer { + int nb_eventfds; + int *eventfds; +} Peer; + +typedef struct EventfdEntry { + PCIDevice *pdev; + int vector; +} EventfdEntry; + +typedef struct IVShmemState { + PCIDevice dev; + uint32_t intrmask; + uint32_t intrstatus; + uint32_t doorbell; + + CharDriverState **eventfd_chr; + CharDriverState *server_chr; + int ivshmem_mmio_io_addr; + + pcibus_t mmio_addr; + pcibus_t shm_pci_addr; + uint64_t ivshmem_offset; + uint64_t ivshmem_size; /* size of shared memory region */ + int shm_fd; /* shared memory file descriptor */ + + Peer *peers; + int nb_peers; /* how many guests we have space for */ + int max_peer; /* maximum numbered peer */ + + int vm_id; + uint32_t vectors; + uint32_t features; + EventfdEntry *eventfd_table; + + char * shmobj; + char * sizearg; + char * role; + int role_val; /* scalar to avoid multiple string comparisons */ +} IVShmemState; + +/* registers for the Inter-VM shared memory device */ +enum ivshmem_registers { + INTRMASK = 0, + INTRSTATUS = 4, + IVPOSITION = 8, + DOORBELL = 12, +}; + +static inline uint32_t ivshmem_has_feature(IVShmemState *ivs, + unsigned int feature) { + return (ivs->features & (1 << feature)); +} + +static inline bool is_power_of_two(uint64_t x) { + return (x & (x - 1)) == 0; +} + +static void ivshmem_map(PCIDevice *pci_dev, int region_num, + pcibus_t addr, pcibus_t size, int type) +{ + IVShmemState *s = DO_UPCAST(IVShmemState, dev, pci_dev); + + s->shm_pci_addr = addr; + + if (s->ivshmem_offset > 0) { + cpu_register_physical_memory(s->shm_pci_addr, s->ivshmem_size, + s->ivshmem_offset); + } + + IVSHMEM_DPRINTF("guest pci addr = %" FMT_PCIBUS ", guest h/w addr = %" + PRIu64 ", size = %" FMT_PCIBUS "\n", addr, s->ivshmem_offset, size); + +} + +/* accessing registers - based on rtl8139 */ +static void ivshmem_update_irq(IVShmemState *s, int val) +{ + int isr; + isr = (s->intrstatus & s->intrmask) & 0xffffffff; + + /* 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->dev.irq[0], (isr != 0)); +} + +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, val); +} + +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, val); + 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, 0); + + return ret; +} + +static void ivshmem_io_writew(void *opaque, target_phys_addr_t addr, + uint32_t val) +{ + + IVSHMEM_DPRINTF("We shouldn't be writing words\n"); +} + +static void ivshmem_io_writel(void *opaque, target_phys_addr_t addr, + uint32_t val) +{ + IVShmemState *s = opaque; + + uint64_t write_one = 1; + uint16_t dest = val >> 16; + uint16_t vector = val & 0xff; + + addr &= 0xfc; + + IVSHMEM_DPRINTF("writing to addr " TARGET_FMT_plx "\n", addr); + switch (addr) + { + case INTRMASK: + ivshmem_IntrMask_write(s, val); + break; + + case INTRSTATUS: + ivshmem_IntrStatus_write(s, val); + break; + + case DOORBELL: + /* check that dest VM ID is reasonable */ + if ((dest < 0) || (dest > s->max_peer)) { + IVSHMEM_DPRINTF("Invalid destination VM ID (%d)\n", dest); + break; + } + + /* check doorbell range */ + if ((vector >= 0) && (vector < s->peers[dest].nb_eventfds)) { + IVSHMEM_DPRINTF("Writing %" PRId64 " to VM %d on vector %d\n", + write_one, dest, vector); + if (write(s->peers[dest].eventfds[vector], + &(write_one), 8) != 8) { + IVSHMEM_DPRINTF("error writing to eventfd\n"); + } + } + break; + default: + IVSHMEM_DPRINTF("Invalid VM Doorbell VM %d\n", dest); + } +} + +static void ivshmem_io_writeb(void *opaque, target_phys_addr_t addr, + uint32_t val) +{ + IVSHMEM_DPRINTF("We shouldn't be writing bytes\n"); +} + +static uint32_t ivshmem_io_readw(void *opaque, target_phys_addr_t addr) +{ + + IVSHMEM_DPRINTF("We shouldn't be reading words\n"); + return 0; +} + +static uint32_t ivshmem_io_readl(void *opaque, target_phys_addr_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 VM ID if the memory is mapped */ + if (s->shm_fd > 0) { + ret = s->vm_id; + } else { + ret = -1; + } + break; + + default: + IVSHMEM_DPRINTF("why are we reading " TARGET_FMT_plx "\n", addr); + ret = 0; + } + + return ret; +} + +static uint32_t ivshmem_io_readb(void *opaque, target_phys_addr_t addr) +{ + IVSHMEM_DPRINTF("We shouldn't be reading bytes\n"); + + return 0; +} + +static CPUReadMemoryFunc * const ivshmem_mmio_read[3] = { + ivshmem_io_readb, + ivshmem_io_readw, + ivshmem_io_readl, +}; + +static CPUWriteMemoryFunc * const ivshmem_mmio_write[3] = { + ivshmem_io_writeb, + ivshmem_io_writew, + ivshmem_io_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 int ivshmem_can_receive(void * opaque) +{ + return 8; +} + +static void ivshmem_event(void *opaque, int event) +{ + IVSHMEM_DPRINTF("ivshmem_event %d\n", event); +} + +static void fake_irqfd(void *opaque, const uint8_t *buf, int size) { + + EventfdEntry *entry = opaque; + PCIDevice *pdev = entry->pdev; + + IVSHMEM_DPRINTF("interrupt on vector %p %d\n", pdev, entry->vector); + msix_notify(pdev, entry->vector); +} + +static CharDriverState* create_eventfd_chr_device(void * opaque, int eventfd, + int vector) +{ + /* create a event character device based on the passed eventfd */ + IVShmemState *s = opaque; + CharDriverState * chr; + + chr = qemu_chr_open_eventfd(eventfd); + + if (chr == NULL) { + fprintf(stderr, "creating eventfd for eventfd %d failed\n", eventfd); + exit(-1); + } + + /* if MSI is supported we need multiple interrupts */ + if (ivshmem_has_feature(s, IVSHMEM_MSI)) { + s->eventfd_table[vector].pdev = &s->dev; + s->eventfd_table[vector].vector = vector; + + qemu_chr_add_handlers(chr, ivshmem_can_receive, fake_irqfd, + ivshmem_event, &s->eventfd_table[vector]); + } else { + qemu_chr_add_handlers(chr, ivshmem_can_receive, ivshmem_receive, + ivshmem_event, s); + } + + return chr; + +} + +static int check_shm_size(IVShmemState *s, int fd) { + /* check that the guest isn't going to try and map more memory than the + * the object has allocated return -1 to indicate error */ + + struct stat buf; + + fstat(fd, &buf); + + if (s->ivshmem_size > buf.st_size) { + fprintf(stderr, "IVSHMEM ERROR: Requested memory size greater"); + fprintf(stderr, " than shared object size (%" PRIu64 " > %ld)\n", + s->ivshmem_size, buf.st_size); + return -1; + } else { + return 0; + } +} + +/* create the shared memory BAR when we are not using the server, so we can + * create the BAR and map the memory immediately */ +static void create_shared_memory_BAR(IVShmemState *s, int fd) { + + void * ptr; + + s->shm_fd = fd; + + ptr = mmap(0, s->ivshmem_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); + + s->ivshmem_offset = qemu_ram_alloc_from_ptr(&s->dev.qdev, "ivshmem.bar2", + s->ivshmem_size, ptr); + + /* region for shared memory */ + pci_register_bar(&s->dev, 2, s->ivshmem_size, + PCI_BASE_ADDRESS_SPACE_MEMORY, ivshmem_map); +} + +static void close_guest_eventfds(IVShmemState *s, int posn) +{ + int i, guest_curr_max; + + guest_curr_max = s->peers[posn].nb_eventfds; + + for (i = 0; i < guest_curr_max; i++) { + kvm_set_ioeventfd_mmio_long(s->peers[posn].eventfds[i], + s->mmio_addr + DOORBELL, (posn << 16) | i, 0); + close(s->peers[posn].eventfds[i]); + } + + qemu_free(s->peers[posn].eventfds); + s->peers[posn].nb_eventfds = 0; +} + +static void setup_ioeventfds(IVShmemState *s) { + + int i, j; + + for (i = 0; i <= s->max_peer; i++) { + for (j = 0; j < s->peers[i].nb_eventfds; j++) { + kvm_set_ioeventfd_mmio_long(s->peers[i].eventfds[j], + s->mmio_addr + DOORBELL, (i << 16) | j, 1); + } + } +} + +/* this function increase the dynamic storage need to store data about other + * guests */ +static void increase_dynamic_storage(IVShmemState *s, int new_min_size) { + + int j, old_nb_alloc; + + old_nb_alloc = s->nb_peers; + + while (new_min_size >= s->nb_peers) + s->nb_peers = s->nb_peers * 2; + + IVSHMEM_DPRINTF("bumping storage to %d guests\n", s->nb_peers); + s->peers = qemu_realloc(s->peers, s->nb_peers * sizeof(Peer)); + + /* zero out new pointers */ + for (j = old_nb_alloc; j < s->nb_peers; j++) { + s->peers[j].eventfds = NULL; + s->peers[j].nb_eventfds = 0; + } +} + +static void ivshmem_read(void *opaque, const uint8_t * buf, int flags) +{ + IVShmemState *s = opaque; + int incoming_fd, tmp_fd; + int guest_max_eventfd; + long incoming_posn; + + memcpy(&incoming_posn, buf, sizeof(long)); + /* pick off s->server_chr->msgfd and store it, posn should accompany msg */ + tmp_fd = qemu_chr_get_msgfd(s->server_chr); + IVSHMEM_DPRINTF("posn is %ld, fd is %d\n", incoming_posn, tmp_fd); + + /* make sure we have enough space for this guest */ + if (incoming_posn >= s->nb_peers) { + increase_dynamic_storage(s, incoming_posn); + } + + if (tmp_fd == -1) { + /* if posn is positive and unseen before then this is our posn*/ + if ((incoming_posn >= 0) && + (s->peers[incoming_posn].eventfds == NULL)) { + /* receive our posn */ + s->vm_id = incoming_posn; + return; + } else { + /* otherwise an fd == -1 means an existing guest has gone away */ + IVSHMEM_DPRINTF("posn %ld has gone away\n", incoming_posn); + close_guest_eventfds(s, incoming_posn); + return; + } + } + + /* because of the implementation of get_msgfd, we need a dup */ + incoming_fd = dup(tmp_fd); + + if (incoming_fd == -1) { + fprintf(stderr, "could not allocate file descriptor %s\n", + strerror(errno)); + return; + } + + /* if the position is -1, then it's shared memory region fd */ + if (incoming_posn == -1) { + + void * map_ptr; + + s->max_peer = 0; + + if (check_shm_size(s, incoming_fd) == -1) { + exit(-1); + } + + /* mmap the region and map into the BAR2 */ + map_ptr = mmap(0, s->ivshmem_size, PROT_READ|PROT_WRITE, MAP_SHARED, + incoming_fd, 0); + s->ivshmem_offset = qemu_ram_alloc_from_ptr(&s->dev.qdev, + "ivshmem.bar2", s->ivshmem_size, map_ptr); + + IVSHMEM_DPRINTF("guest pci addr = %" FMT_PCIBUS ", guest h/w addr = %" + PRIu64 ", size = %" PRIu64 "\n", s->shm_pci_addr, + s->ivshmem_offset, s->ivshmem_size); + + if (s->shm_pci_addr > 0) { + /* map memory into BAR2 */ + cpu_register_physical_memory(s->shm_pci_addr, s->ivshmem_size, + s->ivshmem_offset); + } + + /* only store the fd if it is successfully mapped */ + s->shm_fd = incoming_fd; + + return; + } + + /* each guest has an array of eventfds, and we keep track of how many + * guests for each VM */ + guest_max_eventfd = s->peers[incoming_posn].nb_eventfds; + + if (guest_max_eventfd == 0) { + /* one eventfd per MSI vector */ + s->peers[incoming_posn].eventfds = (int *) qemu_malloc(s->vectors * + sizeof(int)); + } + + /* this is an eventfd for a particular guest VM */ + IVSHMEM_DPRINTF("eventfds[%ld][%d] = %d\n", incoming_posn, + guest_max_eventfd, incoming_fd); + s->peers[incoming_posn].eventfds[guest_max_eventfd] = incoming_fd; + + /* increment count for particular guest */ + s->peers[incoming_posn].nb_eventfds++; + + /* keep track of the maximum VM ID */ + if (incoming_posn > s->max_peer) { + s->max_peer = incoming_posn; + } + + if (incoming_posn == s->vm_id) { + s->eventfd_chr[guest_max_eventfd] = create_eventfd_chr_device(s, + s->peers[s->vm_id].eventfds[guest_max_eventfd], + guest_max_eventfd); + } + + if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) { + if (kvm_set_ioeventfd_mmio_long(incoming_fd, s->mmio_addr + DOORBELL, + (incoming_posn << 16) | guest_max_eventfd, 1) < 0) { + fprintf(stderr, "ivshmem: ioeventfd not available\n"); + } + } + + return; +} + +static void ivshmem_reset(DeviceState *d) +{ + IVShmemState *s = DO_UPCAST(IVShmemState, dev.qdev, d); + + s->intrstatus = 0; + return; +} + +static void ivshmem_mmio_map(PCIDevice *pci_dev, int region_num, + pcibus_t addr, pcibus_t size, int type) +{ + IVShmemState *s = DO_UPCAST(IVShmemState, dev, pci_dev); + + s->mmio_addr = addr; + cpu_register_physical_memory(addr + 0, IVSHMEM_REG_BAR_SIZE, + s->ivshmem_mmio_io_addr); + + if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) { + setup_ioeventfds(s); + } +} + +static uint64_t ivshmem_get_size(IVShmemState * s) { + + uint64_t value; + char *ptr; + + value = strtoull(s->sizearg, &ptr, 10); + switch (*ptr) { + case 0: case 'M': case 'm': + value <<= 20; + break; + case 'G': case 'g': + value <<= 30; + break; + default: + fprintf(stderr, "qemu: invalid ram size: %s\n", s->sizearg); + exit(1); + } + + /* BARs must be a power of 2 */ + if (!is_power_of_two(value)) { + fprintf(stderr, "ivshmem: size must be power of 2\n"); + exit(1); + } + + return value; +} + +static void ivshmem_setup_msi(IVShmemState * s) { + + int i; + + /* allocate the MSI-X vectors */ + + if (!msix_init(&s->dev, s->vectors, 1, 0)) { + pci_register_bar(&s->dev, 1, + msix_bar_size(&s->dev), + PCI_BASE_ADDRESS_SPACE_MEMORY, + msix_mmio_map); + IVSHMEM_DPRINTF("msix initialized (%d vectors)\n", s->vectors); + } else { + IVSHMEM_DPRINTF("msix initialization failed\n"); + exit(1); + } + + /* 'activate' the vectors */ + for (i = 0; i < s->vectors; i++) { + msix_vector_use(&s->dev, i); + } + + /* allocate Qemu char devices for receiving interrupts */ + s->eventfd_table = qemu_mallocz(s->vectors * sizeof(EventfdEntry)); +} + +static void ivshmem_save(QEMUFile* f, void *opaque) +{ + IVShmemState *proxy = opaque; + + IVSHMEM_DPRINTF("ivshmem_save\n"); + pci_device_save(&proxy->dev, f); + + if (ivshmem_has_feature(proxy, IVSHMEM_MSI)) { + msix_save(&proxy->dev, f); + } else { + qemu_put_be32(f, proxy->intrstatus); + qemu_put_be32(f, proxy->intrmask); + } + +} + +static int ivshmem_load(QEMUFile* f, void *opaque, int version_id) +{ + IVSHMEM_DPRINTF("ivshmem_load\n"); + + IVShmemState *proxy = opaque; + int ret, i; + + if (version_id > 0) { + return -EINVAL; + } + + if (proxy->role_val == IVSHMEM_PEER) { + fprintf(stderr, "ivshmem: 'peer' devices are not migratable\n"); + return -EINVAL; + } + + ret = pci_device_load(&proxy->dev, f); + if (ret) { + return ret; + } + + if (ivshmem_has_feature(proxy, IVSHMEM_MSI)) { + msix_load(&proxy->dev, f); + for (i = 0; i < proxy->vectors; i++) { + msix_vector_use(&proxy->dev, i); + } + } else { + proxy->intrstatus = qemu_get_be32(f); + proxy->intrmask = qemu_get_be32(f); + } + + return 0; +} + +static int pci_ivshmem_init(PCIDevice *dev) +{ + IVShmemState *s = DO_UPCAST(IVShmemState, dev, dev); + uint8_t *pci_conf; + + if (s->sizearg == NULL) + s->ivshmem_size = 4 << 20; /* 4 MB default */ + else { + s->ivshmem_size = ivshmem_get_size(s); + } + + register_savevm(&s->dev.qdev, "ivshmem", 0, 0, ivshmem_save, ivshmem_load, + dev); + + /* IRQFD requires MSI */ + if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD) && + !ivshmem_has_feature(s, IVSHMEM_MSI)) { + fprintf(stderr, "ivshmem: ioeventfd/irqfd requires MSI\n"); + exit(1); + } + + /* check that role is reasonable */ + if (s->role) { + if (strncmp(s->role, "peer", 5) == 0) { + s->role_val = IVSHMEM_PEER; + } else if (strncmp(s->role, "master", 7) == 0) { + s->role_val = IVSHMEM_MASTER; + } else { + fprintf(stderr, "ivshmem: 'role' must be 'peer' or 'master'\n"); + exit(1); + } + } else { + s->role_val = IVSHMEM_MASTER; /* default */ + } + + if (s->role_val == IVSHMEM_PEER) { + register_device_unmigratable(&s->dev.qdev, "ivshmem", s); + } + + pci_conf = s->dev.config; + pci_config_set_vendor_id(pci_conf, PCI_VENDOR_ID_REDHAT_QUMRANET); + pci_conf[0x02] = 0x10; + pci_conf[0x03] = 0x11; + pci_conf[PCI_COMMAND] = PCI_COMMAND_IO | PCI_COMMAND_MEMORY; + pci_config_set_class(pci_conf, PCI_CLASS_MEMORY_RAM); + pci_conf[PCI_HEADER_TYPE] = PCI_HEADER_TYPE_NORMAL; + + pci_config_set_interrupt_pin(pci_conf, 1); + + s->shm_pci_addr = 0; + s->ivshmem_offset = 0; + s->shm_fd = 0; + + s->ivshmem_mmio_io_addr = cpu_register_io_memory(ivshmem_mmio_read, + ivshmem_mmio_write, s); + /* region for registers*/ + pci_register_bar(&s->dev, 0, IVSHMEM_REG_BAR_SIZE, + PCI_BASE_ADDRESS_SPACE_MEMORY, ivshmem_mmio_map); + + if ((s->server_chr != NULL) && + (strncmp(s->server_chr->filename, "unix:", 5) == 0)) { + /* if we get a UNIX socket as the parameter we will talk + * to the ivshmem server to receive the memory region */ + + if (s->shmobj != NULL) { + fprintf(stderr, "WARNING: do not specify both 'chardev' " + "and 'shm' with ivshmem\n"); + } + + IVSHMEM_DPRINTF("using shared memory server (socket = %s)\n", + s->server_chr->filename); + + if (ivshmem_has_feature(s, IVSHMEM_MSI)) { + ivshmem_setup_msi(s); + } + + /* we allocate enough space for 16 guests and grow as needed */ + s->nb_peers = 16; + s->vm_id = -1; + + /* allocate/initialize space for interrupt handling */ + s->peers = qemu_mallocz(s->nb_peers * sizeof(Peer)); + + pci_register_bar(&s->dev, 2, s->ivshmem_size, + PCI_BASE_ADDRESS_SPACE_MEMORY, ivshmem_map); + + s->eventfd_chr = qemu_mallocz(s->vectors * sizeof(CharDriverState *)); + + qemu_chr_add_handlers(s->server_chr, ivshmem_can_receive, ivshmem_read, + ivshmem_event, s); + } else { + /* just map the file immediately, we're not using a server */ + int fd; + + if (s->shmobj == NULL) { + fprintf(stderr, "Must specify 'chardev' or 'shm' to ivshmem\n"); + } + + IVSHMEM_DPRINTF("using shm_open (shm object = %s)\n", s->shmobj); + + /* try opening with O_EXCL and if it succeeds zero the memory + * by truncating to 0 */ + if ((fd = shm_open(s->shmobj, O_CREAT|O_RDWR|O_EXCL, + S_IRWXU|S_IRWXG|S_IRWXO)) > 0) { + /* truncate file to length PCI device's memory */ + if (ftruncate(fd, s->ivshmem_size) != 0) { + fprintf(stderr, "ivshmem: could not truncate shared file\n"); + } + + } else if ((fd = shm_open(s->shmobj, O_CREAT|O_RDWR, + S_IRWXU|S_IRWXG|S_IRWXO)) < 0) { + fprintf(stderr, "ivshmem: could not open shared file\n"); + exit(-1); + + } + + if (check_shm_size(s, fd) == -1) { + exit(-1); + } + + create_shared_memory_BAR(s, fd); + + } + + return 0; +} + +static int pci_ivshmem_uninit(PCIDevice *dev) +{ + IVShmemState *s = DO_UPCAST(IVShmemState, dev, dev); + + cpu_unregister_io_memory(s->ivshmem_mmio_io_addr); + unregister_savevm(&dev->qdev, "ivshmem", s); + + return 0; +} + +static PCIDeviceInfo ivshmem_info = { + .qdev.name = "ivshmem", + .qdev.size = sizeof(IVShmemState), + .qdev.reset = ivshmem_reset, + .init = pci_ivshmem_init, + .exit = pci_ivshmem_uninit, + .qdev.props = (Property[]) { + DEFINE_PROP_CHR("chardev", IVShmemState, server_chr), + DEFINE_PROP_STRING("size", IVShmemState, sizearg), + DEFINE_PROP_UINT32("vectors", IVShmemState, vectors, 1), + DEFINE_PROP_BIT("ioeventfd", IVShmemState, features, IVSHMEM_IOEVENTFD, false), + DEFINE_PROP_BIT("msi", IVShmemState, features, IVSHMEM_MSI, true), + DEFINE_PROP_STRING("shm", IVShmemState, shmobj), + DEFINE_PROP_STRING("role", IVShmemState, role), + DEFINE_PROP_END_OF_LIST(), + } +}; + +static void ivshmem_register_devices(void) +{ + pci_qdev_register(&ivshmem_info); +} + +device_init(ivshmem_register_devices) diff --git a/qemu-char.c b/qemu-char.c index 9b69d92..6a3952c 100644 --- a/qemu-char.c +++ b/qemu-char.c @@ -2087,6 +2087,12 @@ static void tcp_chr_read(void *opaque) } } +CharDriverState *qemu_chr_open_eventfd(int eventfd){ + + return qemu_chr_open_fd(eventfd, eventfd); + +} + static void tcp_chr_connect(void *opaque) { CharDriverState *chr = opaque; diff --git a/qemu-char.h b/qemu-char.h index e3a0783..6ea01ba 100644 --- a/qemu-char.h +++ b/qemu-char.h @@ -94,6 +94,9 @@ void qemu_chr_info_print(Monitor *mon, const QObject *ret_data); void qemu_chr_info(Monitor *mon, QObject **ret_data); CharDriverState *qemu_chr_find(const char *name); +/* add an eventfd to the qemu devices that are polled */ +CharDriverState *qemu_chr_open_eventfd(int eventfd); + extern int term_escape_char; /* async I/O support */ diff --git a/qemu-doc.texi b/qemu-doc.texi index e67bf44..55a966f 100644 --- a/qemu-doc.texi +++ b/qemu-doc.texi @@ -706,6 +706,49 @@ Using the @option{-net socket} option, it is possible to make VLANs that span several QEMU instances. See @ref{sec_invocation} to have a basic example. +@section Other Devices + +@subsection Inter-VM Shared Memory device + +With KVM enabled on a Linux host, a shared memory device is available. Guests +map a POSIX shared memory region into the guest as a PCI device that enables +zero-copy communication to the application level of the guests. The basic +syntax is: + +@example +qemu -device ivshmem,size=<size in format accepted by -m>[,shm=<shm name>] +@end example + +If desired, interrupts can be sent between guest VMs accessing the same shared +memory region. Interrupt support requires using a shared memory server and +using a chardev socket to connect to it. The code for the shared memory server +is qemu.git/contrib/ivshmem-server. An example syntax when using the shared +memory server is: + +@example +qemu -device ivshmem,size=<size in format accepted by -m>[,chardev=<id>] + [,msi=on][,ioeventfd=on][,vectors=n][,role=peer|master] +qemu -chardev socket,path=<path>,id=<id> +@end example + +When using the server, the guest will be assigned a VM ID (>=0) that allows guests +using the same server to communicate via interrupts. Guests can read their +VM ID from a device register (see example code). Since receiving the shared +memory region from the server is asynchronous, there is a (small) chance the +guest may boot before the shared memory is attached. To allow an application +to ensure shared memory is attached, the VM ID register will return -1 (an +invalid VM ID) until the memory is attached. Once the shared memory is +attached, the VM ID will return the guest's valid VM ID. With these semantics, +the guest application can check to ensure the shared memory is attached to the +guest before proceeding. + +The @option{role} argument can be set to either master or peer and will affect +how the shared memory is migrated. With @option{role=master}, the guest will +copy the shared memory on migration to the destination host. With +@option{role=peer}, the guest will not be able to migrate with the device attached. +With the @option{peer} case, the device should be detached and then reattached +after migration using the PCI hotplug support. + @node direct_linux_boot @section Direct Linux Boot -- 1.6.3.2.198.g6096d ^ permalink raw reply related [flat|nested] 12+ messages in thread
* Re: [Qemu-devel] [PATCH v8 5/5] RESEND: Inter-VM shared memory PCI device 2010-07-27 16:54 ` [Qemu-devel] [PATCH v8 5/5] RESEND: " Cam Macdonell @ 2010-08-11 8:35 ` Stefan Weil 2010-08-11 15:49 ` Cam Macdonell 0 siblings, 1 reply; 12+ messages in thread From: Stefan Weil @ 2010-08-11 8:35 UTC (permalink / raw) To: Cam Macdonell; +Cc: Anthony Liguori, qemu-devel, kvm Am 27.07.2010 18:54, schrieb Cam Macdonell: > resend for bug fix related to removal of irqfd > > Support an inter-vm shared memory device that maps a shared-memory > object as a > PCI device in the guest. This patch also supports interrupts between > guest by > communicating over a unix domain socket. This patch applies to the > qemu-kvm > repository. > > -device ivshmem,size=<size in format accepted by -m>[,shm=<shm name>] > > Interrupts are supported between multiple VMs by using a shared memory > server > by using a chardev socket. > > -device ivshmem,size=<size in format accepted by -m>[,shm=<shm name>] > [,chardev=<id>][,msi=on][,ioeventfd=on][,vectors=n][,role=peer|master] > -chardev socket,path=<path>,id=<id> > > The shared memory server, sample programs and init scripts are in a > git repo here: > > www.gitorious.org/nahanni > > Signed-off-by: Cam Macdonell <cam@cs.ualberta.ca> > --- > Makefile.target | 3 + > hw/ivshmem.c | 828 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ > qemu-char.c | 6 + > qemu-char.h | 3 + > qemu-doc.texi | 43 +++ > 5 files changed, 883 insertions(+), 0 deletions(-) > create mode 100644 hw/ivshmem.c > Hi, hw/ivshmem.c breaks compilation on 32 bit hosts, for targets without kvm support and for win32 environments. I sent patches to qemu-devel which fix the first two problems. The win32 problems (missing mmap, maybe more) remain. Could you please fix them? Regards Stefan ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [Qemu-devel] [PATCH v8 5/5] RESEND: Inter-VM shared memory PCI device 2010-08-11 8:35 ` Stefan Weil @ 2010-08-11 15:49 ` Cam Macdonell 2010-08-11 17:07 ` Paolo Bonzini 0 siblings, 1 reply; 12+ messages in thread From: Cam Macdonell @ 2010-08-11 15:49 UTC (permalink / raw) To: Stefan Weil; +Cc: Anthony Liguori, qemu-devel, kvm On Wed, Aug 11, 2010 at 4:35 AM, Stefan Weil <weil@mail.berlios.de> wrote: > Am 27.07.2010 18:54, schrieb Cam Macdonell: >> >> resend for bug fix related to removal of irqfd >> >> Support an inter-vm shared memory device that maps a shared-memory object >> as a >> PCI device in the guest. This patch also supports interrupts between guest >> by >> communicating over a unix domain socket. This patch applies to the >> qemu-kvm >> repository. >> >> -device ivshmem,size=<size in format accepted by -m>[,shm=<shm name>] >> >> Interrupts are supported between multiple VMs by using a shared memory >> server >> by using a chardev socket. >> >> -device ivshmem,size=<size in format accepted by -m>[,shm=<shm name>] >> [,chardev=<id>][,msi=on][,ioeventfd=on][,vectors=n][,role=peer|master] >> -chardev socket,path=<path>,id=<id> >> >> The shared memory server, sample programs and init scripts are in a git >> repo here: >> >> www.gitorious.org/nahanni >> >> Signed-off-by: Cam Macdonell <cam@cs.ualberta.ca> >> --- >> Makefile.target | 3 + >> hw/ivshmem.c | 828 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ >> qemu-char.c | 6 + >> qemu-char.h | 3 + >> qemu-doc.texi | 43 +++ >> 5 files changed, 883 insertions(+), 0 deletions(-) >> create mode 100644 hw/ivshmem.c >> > > Hi, > > hw/ivshmem.c breaks compilation on 32 bit hosts, for targets without kvm > support > and for win32 environments. > > I sent patches to qemu-devel which fix the first two problems. > > The win32 problems (missing mmap, maybe more) remain. > Could you please fix them? Could that be accomplished with excluding it on Windows on the makefiles? Thanks, Cam > > Regards > Stefan > > ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [Qemu-devel] [PATCH v8 5/5] RESEND: Inter-VM shared memory PCI device 2010-08-11 15:49 ` Cam Macdonell @ 2010-08-11 17:07 ` Paolo Bonzini 2010-08-11 18:22 ` Stefan Weil 0 siblings, 1 reply; 12+ messages in thread From: Paolo Bonzini @ 2010-08-11 17:07 UTC (permalink / raw) To: Cam Macdonell; +Cc: Anthony Liguori, qemu-devel, kvm On 08/11/2010 11:49 AM, Cam Macdonell wrote: >> The win32 problems (missing mmap, maybe more) remain. >> Could you please fix them? > > Could that be accomplished with excluding it on Windows on the makefiles? Yes, just use obj-$(CONFIG_POSIX). Paolo ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [Qemu-devel] [PATCH v8 5/5] RESEND: Inter-VM shared memory PCI device 2010-08-11 17:07 ` Paolo Bonzini @ 2010-08-11 18:22 ` Stefan Weil 0 siblings, 0 replies; 12+ messages in thread From: Stefan Weil @ 2010-08-11 18:22 UTC (permalink / raw) To: Paolo Bonzini; +Cc: Anthony Liguori, Cam Macdonell, qemu-devel, kvm Am 11.08.2010 19:07, schrieb Paolo Bonzini: > On 08/11/2010 11:49 AM, Cam Macdonell wrote: >>> The win32 problems (missing mmap, maybe more) remain. >>> Could you please fix them? >> >> Could that be accomplished with excluding it on Windows on the >> makefiles? > > Yes, just use obj-$(CONFIG_POSIX). > > Paolo > Or use obj-$(CONFIG_KVM) if that file is only reasonable when KVM is supported. Stefan ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [Qemu-devel] [PATCH v8 1/5] Add qemu_ram_alloc_from_ptr function 2010-07-27 0:10 ` [Qemu-devel] [PATCH v8 1/5] Add qemu_ram_alloc_from_ptr function Cam Macdonell 2010-07-27 0:10 ` [Qemu-devel] [PATCH v8 2/5] Device specification for shared memory PCI device Cam Macdonell @ 2010-08-10 21:28 ` Anthony Liguori 1 sibling, 0 replies; 12+ messages in thread From: Anthony Liguori @ 2010-08-10 21:28 UTC (permalink / raw) To: Cam Macdonell; +Cc: qemu-devel, kvm On 07/26/2010 07:10 PM, Cam Macdonell wrote: > Provide a function to add an allocated region of memory to the qemu RAM. > > This patch is copied from Marcelo's qemu_ram_map() in qemu-kvm and given the > clearer name qemu_ram_alloc_from_ptr(). > > Signed-off-by: Cam Macdonell<cam@cs.ualberta.ca> > Applied all. Thanks. Regards, Anthony Liguori > --- > cpu-common.h | 2 ++ > exec.c | 43 +++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 45 insertions(+), 0 deletions(-) > > diff --git a/cpu-common.h b/cpu-common.h > index 71e7933..0426bc8 100644 > --- a/cpu-common.h > +++ b/cpu-common.h > @@ -40,6 +40,8 @@ static inline void cpu_register_physical_memory(target_phys_addr_t start_addr, > } > > ram_addr_t cpu_get_physical_page_desc(target_phys_addr_t addr); > +ram_addr_t qemu_ram_alloc_from_ptr(DeviceState *dev, const char *name, > + ram_addr_t size, void *host); > ram_addr_t qemu_ram_alloc(DeviceState *dev, const char *name, ram_addr_t size); > void qemu_ram_free(ram_addr_t addr); > /* This should only be used for ram local to a device. */ > diff --git a/exec.c b/exec.c > index 868cd7f..8636316 100644 > --- a/exec.c > +++ b/exec.c > @@ -2808,6 +2808,49 @@ static ram_addr_t last_ram_offset(void) > return last; > } > > +ram_addr_t qemu_ram_alloc_from_ptr(DeviceState *dev, const char *name, > + ram_addr_t size, void *host) > +{ > + RAMBlock *new_block, *block; > + > + size = TARGET_PAGE_ALIGN(size); > + new_block = qemu_mallocz(sizeof(*new_block)); > + > + if (dev&& dev->parent_bus&& dev->parent_bus->info->get_dev_path) { > + char *id = dev->parent_bus->info->get_dev_path(dev); > + if (id) { > + snprintf(new_block->idstr, sizeof(new_block->idstr), "%s/", id); > + qemu_free(id); > + } > + } > + pstrcat(new_block->idstr, sizeof(new_block->idstr), name); > + > + QLIST_FOREACH(block,&ram_list.blocks, next) { > + if (!strcmp(block->idstr, new_block->idstr)) { > + fprintf(stderr, "RAMBlock \"%s\" already registered, abort!\n", > + new_block->idstr); > + abort(); > + } > + } > + > + new_block->host = host; > + > + new_block->offset = find_ram_offset(size); > + new_block->length = size; > + > + QLIST_INSERT_HEAD(&ram_list.blocks, new_block, next); > + > + ram_list.phys_dirty = qemu_realloc(ram_list.phys_dirty, > + last_ram_offset()>> TARGET_PAGE_BITS); > + memset(ram_list.phys_dirty + (new_block->offset>> TARGET_PAGE_BITS), > + 0xff, size>> TARGET_PAGE_BITS); > + > + if (kvm_enabled()) > + kvm_setup_guest_memory(new_block->host, size); > + > + return new_block->offset; > +} > + > ram_addr_t qemu_ram_alloc(DeviceState *dev, const char *name, ram_addr_t size) > { > RAMBlock *new_block, *block; > ^ permalink raw reply [flat|nested] 12+ messages in thread
end of thread, other threads:[~2010-08-11 18:25 UTC | newest] Thread overview: 12+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2010-07-27 0:10 [Qemu-devel] [PATCH v8 0/5] Inter-VM Shared Memory Device Cam Macdonell 2010-07-27 0:10 ` [Qemu-devel] [PATCH v8 1/5] Add qemu_ram_alloc_from_ptr function Cam Macdonell 2010-07-27 0:10 ` [Qemu-devel] [PATCH v8 2/5] Device specification for shared memory PCI device Cam Macdonell 2010-07-27 0:10 ` [Qemu-devel] [PATCH v8 3/5] Add function to assign ioeventfd to MMIO Cam Macdonell 2010-07-27 0:11 ` [Qemu-devel] [PATCH v8 4/5] Support marking a device as non-migratable Cam Macdonell 2010-07-27 0:11 ` [Qemu-devel] [PATCH v8 5/5] Inter-VM shared memory PCI device Cam Macdonell 2010-07-27 16:54 ` [Qemu-devel] [PATCH v8 5/5] RESEND: " Cam Macdonell 2010-08-11 8:35 ` Stefan Weil 2010-08-11 15:49 ` Cam Macdonell 2010-08-11 17:07 ` Paolo Bonzini 2010-08-11 18:22 ` Stefan Weil 2010-08-10 21:28 ` [Qemu-devel] [PATCH v8 1/5] Add qemu_ram_alloc_from_ptr function Anthony Liguori
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