Re: [PATCH v4 3/3] Inter-VM shared memory PCI device
On 04/15/2010 02:30 AM, Cam Macdonell wrote:
Sample programs, init scripts and the shared memory server are available
in a
git repo here:
www.gitorious.org/nahanni
Please consider qemu.git/contrib.
Should the compilation be tied into Qemu's regular build with a switch
(e.g. --enable-ivshmem-server)? Or should it be its own separate
build?
It can have its own makefile.
---
Makefile.target |3 +
hw/ivshmem.c| 700
+++
qemu-char.c |6 +
qemu-char.h |3 +
qemu-doc.texi | 45 +
Seems to be light on qdev devices. I notice there is a section named
Data Type Index that could be used for qdev device names and
options, but is currently empty. Should I place documentation there
of device there or just add it to 3.3 Invocation?
I think those are in qemu-options.hx. Just put it somewhere where it
seems appropriate.
4 files changed, 712 insertions(+), 0 deletions(-)
create mode 100644 hw/ivshmem.c
diff --git a/Makefile.target b/Makefile.target
index 1ffd802..bc9a681 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -199,6 +199,9 @@ obj-$(CONFIG_USB_OHCI) += usb-ohci.o
obj-y += rtl8139.o
obj-y += e1000.o
+# Inter-VM PCI shared memory
+obj-y += ivshmem.o
+
depends on CONFIG_PCI
as in
obj-($CONFIG_PCI) += ivshmem.o
the variable CONFIG_PCI doesn't seem to be set during configuration.
I don't see any other PCI devices that depend on it.
My mistake, keep as is.
Do we also want
to depend on CONFIG_KVM?
No real need.
+static void create_shared_memory_BAR(IVShmemState *s, int fd) {
+
+s-shm_fd = fd;
+
+s-ivshmem_offset = qemu_ram_mmap(s-shm_fd, s-ivshmem_size,
+ MAP_SHARED, 0);
Where did the offset go?
0 is the offset. I include the offset parameter in qemu_ram_mmap() to
make it flexible for other uses.
Makes sense.
Are you suggesting to take an
optional offset as an argument to -device?
No need.
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Re: [PATCH v4 3/3] Inter-VM shared memory PCI device
On Mon, Apr 12, 2010 at 2:56 PM, Avi Kivity a...@redhat.com wrote:
On 04/08/2010 01:52 AM, Cam Macdonell wrote:
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 MB[,shm=shm name]
Can that be size in format accepted by -m (2M, 4G, 19T, ...).
Interrupts are supported between multiple VMs by using a shared memory
server
by using a chardev socket.
-device ivshmem,size=size in MB[,shm=shm
name][,chardev=id][,msi=on]
[,irqfd=on][,vectors=n]
-chardev socket,path=path,id=id
Do we need the irqfd parameter? Should be on by default.
On the other hand, it may fail with older kernels with limited irqfd slots,
so better keep it there.
Sample programs, init scripts and the shared memory server are available
in a
git repo here:
www.gitorious.org/nahanni
Please consider qemu.git/contrib.
Should the compilation be tied into Qemu's regular build with a switch
(e.g. --enable-ivshmem-server)? Or should it be its own separate
build?
Cam
---
Makefile.target | 3 +
hw/ivshmem.c | 700
+++
qemu-char.c | 6 +
qemu-char.h | 3 +
qemu-doc.texi | 45 +
Seems to be light on qdev devices. I notice there is a section named
Data Type Index that could be used for qdev device names and
options, but is currently empty. Should I place documentation there
of device there or just add it to 3.3 Invocation?
4 files changed, 712 insertions(+), 0 deletions(-)
create mode 100644 hw/ivshmem.c
diff --git a/Makefile.target b/Makefile.target
index 1ffd802..bc9a681 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -199,6 +199,9 @@ obj-$(CONFIG_USB_OHCI) += usb-ohci.o
obj-y += rtl8139.o
obj-y += e1000.o
+# Inter-VM PCI shared memory
+obj-y += ivshmem.o
+
depends on CONFIG_PCI
as in
obj-($CONFIG_PCI) += ivshmem.o
the variable CONFIG_PCI doesn't seem to be set during configuration.
I don't see any other PCI devices that depend on it. Do we also want
to depend on CONFIG_KVM?
+static void create_shared_memory_BAR(IVShmemState *s, int fd) {
+
+ s-shm_fd = fd;
+
+ s-ivshmem_offset = qemu_ram_mmap(s-shm_fd, s-ivshmem_size,
+ MAP_SHARED, 0);
Where did the offset go?
0 is the offset. I include the offset parameter in qemu_ram_mmap() to
make it flexible for other uses. Are you suggesting to take an
optional offset as an argument to -device?
Cam
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Re: [PATCH v4 3/3] Inter-VM shared memory PCI device
On 04/08/2010 01:52 AM, Cam Macdonell wrote:
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 MB[,shm=shm name]
Can that be size in format accepted by -m (2M, 4G, 19T, ...).
Interrupts are supported between multiple VMs by using a shared memory server
by using a chardev socket.
-device ivshmem,size=size in MB[,shm=shm name][,chardev=id][,msi=on]
[,irqfd=on][,vectors=n]
-chardev socket,path=path,id=id
Do we need the irqfd parameter? Should be on by default.
On the other hand, it may fail with older kernels with limited irqfd
slots, so better keep it there.
Sample programs, init scripts and the shared memory server are available in a
git repo here:
www.gitorious.org/nahanni
Please consider qemu.git/contrib.
---
Makefile.target |3 +
hw/ivshmem.c| 700 +++
qemu-char.c |6 +
qemu-char.h |3 +
qemu-doc.texi | 45 +
4 files changed, 712 insertions(+), 0 deletions(-)
create mode 100644 hw/ivshmem.c
diff --git a/Makefile.target b/Makefile.target
index 1ffd802..bc9a681 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -199,6 +199,9 @@ obj-$(CONFIG_USB_OHCI) += usb-ohci.o
obj-y += rtl8139.o
obj-y += e1000.o
+# Inter-VM PCI shared memory
+obj-y += ivshmem.o
+
depends on CONFIG_PCI
# Hardware support
+
+#define PCI_COMMAND_IOACCESS0x0001
+#define PCI_COMMAND_MEMACCESS 0x0002
Should be in pci.h?
+
+#define DEBUG_IVSHMEM
Disable for production.
+
+#define IVSHMEM_IRQFD 0
+#define IVSHMEM_MSI 1
+#define IVSHMEM_MAX_EVENTFDS 16
Too low? why limit?
+
+struct eventfd_entry {
+PCIDevice *pdev;
+int vector;
+};
Coding style: EventfdEntry, and a typedef.
+
+typedef struct IVShmemState {
+PCIDevice dev;
+uint32_t intrmask;
+uint32_t intrstatus;
+uint32_t doorbell;
+
+CharDriverState * chr;
+CharDriverState ** eventfd_chr;
+int ivshmem_mmio_io_addr;
+
+pcibus_t mmio_addr;
+uint8_t *ivshmem_ptr;
+unsigned long ivshmem_offset;
off_t
+unsigned int ivshmem_size;
ram_addr_t
+
+/* accessing registers - based on rtl8139 */
+static void ivshmem_update_irq(IVShmemState *s, int val)
+{
+int isr;
+isr = (s-intrstatus s-intrmask) 0x;
This is highly undocumented, but fits my suggested 'status is bitmap'.
'isr' needs to be uint32_t if you mask it like that.
+
+/* 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 create_shared_memory_BAR(IVShmemState *s, int fd) {
+
+s-shm_fd = fd;
+
+s-ivshmem_offset = qemu_ram_mmap(s-shm_fd, s-ivshmem_size,
+ MAP_SHARED, 0);
Where did the offset go?
+
+s-ivshmem_ptr = qemu_get_ram_ptr(s-ivshmem_offset);
Never used, please drop.
+
+/* region for shared memory */
+pci_register_bar(s-dev, 2, s-ivshmem_size,
+ PCI_BASE_ADDRESS_SPACE_MEMORY, ivshmem_map);
Might be worthwhile to mark it as a 64-bit BAR. Please test with
ridiculous shared memory sizes.
+}
+
+static int ivshmem_irqfd(PCIDevice* pdev, uint16_t vector, int fd)
+{
+struct kvm_irqfd call = { };
+int r;
+
+IVSHMEM_DPRINTF(inside irqfd\n);
+if (vector= pdev-msix_entries_nr)
+return -EINVAL;
+call.fd = fd;
+call.gsi = pdev-msix_irq_entries[vector].gsi;
+r = kvm_vm_ioctl(kvm_state, KVM_IRQFD,call);
+if (r 0) {
+IVSHMEM_DPRINTF(allocating irqfd failed %d\n, r);
+return r;
+}
+return 0;
+}
should be in kvm.c for reuse.
+
+static int ivshmem_ioeventfd(IVShmemState* s, int posn, int fd, int vector)
+{
+
+int ret;
+struct kvm_ioeventfd iofd;
+
+iofd.datamatch = (posn 16) | vector;
+iofd.addr = s-mmio_addr + Doorbell;
+iofd.len = 4;
+iofd.flags = KVM_IOEVENTFD_FLAG_DATAMATCH;
+iofd.fd = fd;
+
+ret = kvm_vm_ioctl(kvm_state, KVM_IOEVENTFD,iofd);
Ditto.
+
+if (ret 0) {
+fprintf(stderr, error assigning ioeventfd (%d)\n, ret);
+perror(strerror(ret));
+} else {
+IVSHMEM_DPRINTF(success assigning ioeventfd (%d:%d)\n, posn, vector);
+}
+
+return ret;
+}
blank line here.
--
Do not meddle in the internals of kernels, for they are subtle and quick to
panic.
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[PATCH v4 3/3] Inter-VM shared memory PCI device
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 MB[,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 MB[,shm=shm name][,chardev=id][,msi=on]
[,irqfd=on][,vectors=n]
-chardev socket,path=path,id=id
Sample programs, init scripts and the shared memory server are available in a
git repo here:
www.gitorious.org/nahanni
---
Makefile.target |3 +
hw/ivshmem.c| 700 +++
qemu-char.c |6 +
qemu-char.h |3 +
4 files changed, 712 insertions(+), 0 deletions(-)
create mode 100644 hw/ivshmem.c
diff --git a/Makefile.target b/Makefile.target
index 1ffd802..bc9a681 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -199,6 +199,9 @@ 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 = pckbd.o dma.o
obj-i386-y += vga.o
diff --git a/hw/ivshmem.c b/hw/ivshmem.c
new file mode 100644
index 000..2ec6c2c
--- /dev/null
+++ b/hw/ivshmem.c
@@ -0,0 +1,700 @@
+/*
+ * Inter-VM Shared Memory PCI device.
+ *
+ * Author:
+ * Cam Macdonell c...@cs.ualberta.ca
+ *
+ * Based On: cirrus_vga.c and rtl8139.c
+ *
+ * This code is licensed under the GNU GPL v2.
+ */
+#include sys/mman.h
+#include sys/types.h
+#include sys/socket.h
+#include sys/io.h
+#include sys/ioctl.h
+#include sys/eventfd.h
+#include hw.h
+#include console.h
+#include pc.h
+#include pci.h
+#include sysemu.h
+
+#include msix.h
+#include qemu-kvm.h
+#include libkvm.h
+
+#include sys/eventfd.h
+#include sys/mman.h
+#include sys/socket.h
+#include sys/ioctl.h
+
+#define PCI_COMMAND_IOACCESS0x0001
+#define PCI_COMMAND_MEMACCESS 0x0002
+
+#define DEBUG_IVSHMEM
+
+#define IVSHMEM_IRQFD 0
+#define IVSHMEM_MSI 1
+#define IVSHMEM_MAX_EVENTFDS 16
+
+#ifdef DEBUG_IVSHMEM
+#define IVSHMEM_DPRINTF(fmt, args...)\
+do {printf(IVSHMEM: fmt, ##args); } while (0)
+#else
+#define IVSHMEM_DPRINTF(fmt, args...)
+#endif
+
+#define NEW_GUEST_VAL UINT_MAX
+
+struct eventfd_entry {
+PCIDevice *pdev;
+int vector;
+};
+
+typedef struct IVShmemState {
+PCIDevice dev;
+uint32_t intrmask;
+uint32_t intrstatus;
+uint32_t doorbell;
+
+CharDriverState * chr;
+CharDriverState ** eventfd_chr;
+int ivshmem_mmio_io_addr;
+
+pcibus_t mmio_addr;
+uint8_t *ivshmem_ptr;
+unsigned long ivshmem_offset;
+unsigned int ivshmem_size;
+int shm_fd; /* shared memory file descriptor */
+
+/* array of eventfds for each guest */
+int * eventfds[IVSHMEM_MAX_EVENTFDS];
+/* keep track of # of eventfds for each guest*/
+int * eventfds_posn_count;
+
+int vm_id;
+int num_eventfds;
+uint32_t vectors;
+uint32_t features;
+struct eventfd_entry eventfd_table[IVSHMEM_MAX_EVENTFDS];
+
+char * shmobj;
+uint32_t size; /*size of shared memory in MB*/
+} 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, int feature) {
+return (ivs-features (1 feature));
+}
+
+static inline int is_power_of_two(int 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);
+
+IVSHMEM_DPRINTF(addr = %u size = %u\n, (uint32_t)addr, (uint32_t)size);
+cpu_register_physical_memory(addr, s-ivshmem_size, s-ivshmem_offset);
+
+}
+
+/* accessing registers - based on rtl8139 */
+static void ivshmem_update_irq(IVShmemState *s, int val)
+{
+int isr;
+isr = (s-intrstatus s-intrmask) 0x;
+
+/* 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
