From: Hongyong Zang <zanghongyong@xxxxxxxxxx>
This patch adds a PIO BAR4 for guest notifying qemu to reduce notification time.
And the new notification way of PIO BAR4 reduces 30% time in comparison with the
original MMIO BAR0 way.
Also, this patch introduces a new feature named IVSHMEM_PIO_NOTIFY to make PIO
BAR4 disappeared for compatible with machine type pc-1.0 or blow.
Signed-off-by: Hongyong Zang <zanghongyong@xxxxxxxxxx>
---
hw/ivshmem.c | 34 ++++++++++++++++++++++++++++++++--
hw/pc_piix.c | 28 ++++++++++++++++++++++++++++
2 files changed, 60 insertions(+), 2 deletions(-)
diff --git a/hw/ivshmem.c b/hw/ivshmem.c
index 80b5db0..6845ade 100644
--- a/hw/ivshmem.c
+++ b/hw/ivshmem.c
@@ -26,11 +26,13 @@
#define IVSHMEM_IOEVENTFD 0
#define IVSHMEM_MSI 1
+#define IVSHMEM_PIO_NOTIFY 2
#define IVSHMEM_PEER 0
#define IVSHMEM_MASTER 1
#define IVSHMEM_REG_BAR_SIZE 0x100
+#define IVSHIO_REG_BAR_SIZE 0x10
//#define DEBUG_IVSHMEM
#ifdef DEBUG_IVSHMEM
@@ -59,6 +61,7 @@ typedef struct IVShmemState {
CharDriverState **eventfd_chr;
CharDriverState *server_chr;
MemoryRegion ivshmem_mmio;
+ MemoryRegion ivshmem_pio;
/* We might need to register the BAR before we actually have the memory.
* So prepare a container MemoryRegion for the BAR immediately and
@@ -237,7 +240,7 @@ static uint64_t ivshmem_io_read(void *opaque, target_phys_addr_t addr,
return ret;
}
-static const MemoryRegionOps ivshmem_mmio_ops = {
+static const MemoryRegionOps ivshmem_io_ops = {
.read = ivshmem_io_read,
.write = ivshmem_io_write,
.endianness = DEVICE_NATIVE_ENDIAN,
@@ -356,6 +359,14 @@ static void close_guest_eventfds(IVShmemState *s, int posn)
true,
(posn << 16) | i,
s->peers[posn].eventfds[i]);
+ if(ivshmem_has_feature(s, IVSHMEM_PIO_NOTIFY)) {
+ memory_region_del_eventfd(&s->ivshmem_pio,
+ DOORBELL,
+ 4,
+ true,
+ (posn << 16) | i,
+ s->peers[posn].eventfds[i]);
+ }
}
close(s->peers[posn].eventfds[i]);
}
@@ -490,6 +501,14 @@ static void ivshmem_read(void *opaque, const uint8_t * buf, int flags)
true,
(incoming_posn << 16) | guest_max_eventfd,
incoming_fd);
+ if(ivshmem_has_feature(s, IVSHMEM_PIO_NOTIFY)) {
+ memory_region_add_eventfd(&s->ivshmem_pio,
+ DOORBELL,
+ 4,
+ true,
+ (incoming_posn << 16) | guest_max_eventfd,
+ incoming_fd);
+ }
}
return;
@@ -652,13 +671,20 @@ static int pci_ivshmem_init(PCIDevice *dev)
s->shm_fd = 0;
- memory_region_init_io(&s->ivshmem_mmio, &ivshmem_mmio_ops, s,
+ memory_region_init_io(&s->ivshmem_mmio, &ivshmem_io_ops, s,
"ivshmem-mmio", IVSHMEM_REG_BAR_SIZE);
/* region for registers*/
pci_register_bar(&s->dev, 0, PCI_BASE_ADDRESS_SPACE_MEMORY,
&s->ivshmem_mmio);
+ if(ivshmem_has_feature(s, IVSHMEM_PIO_NOTIFY)) {
+ memory_region_init_io(&s->ivshmem_pio, &ivshmem_io_ops, s,
+ "ivshmem-pio", IVSHIO_REG_BAR_SIZE);
+ pci_register_bar(&s->dev, 4, PCI_BASE_ADDRESS_SPACE_IO,
+ &s->ivshmem_pio);
+ }
+
memory_region_init(&s->bar, "ivshmem-bar2-container", s->ivshmem_size);
if ((s->server_chr != NULL) &&
@@ -738,6 +764,9 @@ static int pci_ivshmem_uninit(PCIDevice *dev)
error_free(s->migration_blocker);
}
+ if(ivshmem_has_feature(s, IVSHMEM_PIO_NOTIFY)) {
+ memory_region_destroy(&s->ivshmem_pio);
+ }
memory_region_destroy(&s->ivshmem_mmio);
memory_region_del_subregion(&s->bar, &s->ivshmem);
memory_region_destroy(&s->ivshmem);
@@ -762,6 +791,7 @@ static PCIDeviceInfo ivshmem_info = {
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_BIT("pio_notify", IVShmemState, features, IVSHMEM_PIO_NOTIFY, true),
DEFINE_PROP_STRING("shm", IVShmemState, shmobj),
DEFINE_PROP_STRING("role", IVShmemState, role),
DEFINE_PROP_END_OF_LIST(),
diff --git a/hw/pc_piix.c b/hw/pc_piix.c
index 970f43c..fe64874 100644
--- a/hw/pc_piix.c
+++ b/hw/pc_piix.c
@@ -304,6 +304,14 @@ static QEMUMachine pc_machine_v1_0 = {
.init = pc_init_pci,
.max_cpus = 255,
.is_default = 1,
+ .compat_props = (GlobalProperty[]) {
+ {
+ .driver = "ivshmem",
+ .property = "pio_notify",
+ .value = "off",
+ },
+ { /* end of list */ }
+ },
};
static QEMUMachine pc_machine_v0_14 = {
@@ -320,6 +328,10 @@ static QEMUMachine pc_machine_v0_14 = {
.driver = "qxl-vga",
.property = "revision",
.value = stringify(2),
+ },{
+ .driver = "ivshmem",
+ .property = "pio_notify",
+ .value = "off",
},
{ /* end of list */ }
},
@@ -363,6 +375,10 @@ static QEMUMachine pc_machine_v0_13 = {
.driver = "AC97",
.property = "use_broken_id",
.value = stringify(1),
+ },{
+ .driver = "ivshmem",
+ .property = "pio_notify",
+ .value = "off",
},
{ /* end of list */ }
},
@@ -410,6 +426,10 @@ static QEMUMachine pc_machine_v0_12 = {
.driver = "AC97",
.property = "use_broken_id",
.value = stringify(1),
+ },{
+ .driver = "ivshmem",
+ .property = "pio_notify",
+ .value = "off",
},
{ /* end of list */ }
}
@@ -465,6 +485,10 @@ static QEMUMachine pc_machine_v0_11 = {
.driver = "AC97",
.property = "use_broken_id",
.value = stringify(1),
+ },{
+ .driver = "ivshmem",
+ .property = "pio_notify",
+ .value = "off",
},
{ /* end of list */ }
}
@@ -532,6 +556,10 @@ static QEMUMachine pc_machine_v0_10 = {
.driver = "AC97",
.property = "use_broken_id",
.value = stringify(1),
+ },{
+ .driver = "ivshmem",
+ .property = "pio_notify",
+ .value = "off",
},
{ /* end of list */ }
},
--
1.7.1
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
