From: Hongyong Zang <zanghongyong@xxxxxxxxxx>
This patch, adds a PIO BAR3 for guest notifying qemu. And we find the new notification way of PIO BAR3 reduces 30% time in comparison with the original MMIO BAR0 way.
Signed-off-by: Hongyong Zang <zanghongyong@xxxxxxxxxx>
---
hw/ivshmem.c | 24 ++++++++++++++++++++++--
kvm-all.c | 23 +++++++++++++++++++++++
kvm.h | 1 +
3 files changed, 46 insertions(+), 2 deletions(-)
diff --git a/hw/ivshmem.c b/hw/ivshmem.c
index 242fbea..031cdd8 100644
--- a/hw/ivshmem.c
+++ b/hw/ivshmem.c
@@ -29,6 +29,7 @@
#define IVSHMEM_MASTER 1
#define IVSHMEM_REG_BAR_SIZE 0x100
+#define IVSHIO_REG_BAR_SIZE 0x10
//#define DEBUG_IVSHMEM
#ifdef DEBUG_IVSHMEM
@@ -57,8 +58,10 @@ typedef struct IVShmemState {
CharDriverState **eventfd_chr;
CharDriverState *server_chr;
MemoryRegion ivshmem_mmio;
+ MemoryRegion ivshmem_pio;
pcibus_t mmio_addr;
+ pcibus_t pio_addr;
/* We might need to register the BAR before we actually have the memory.
* So prepare a container MemoryRegion for the BAR immediately and
* add a subregion when we have the memory.
@@ -234,7 +237,7 @@ 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,
@@ -348,6 +351,8 @@ static void close_guest_eventfds(IVShmemState *s, int posn)
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);
+ kvm_set_ioeventfd_pio_long(s->peers[posn].eventfds[i],
+ s->pio_addr + DOORBELL, (posn << 16) | i, 0);
close(s->peers[posn].eventfds[i]);
}
@@ -367,6 +372,12 @@ static void setup_ioeventfds(IVShmemState *s) {
true,
(i << 16) | j,
s->peers[i].eventfds[j]);
+ memory_region_add_eventfd(&s->ivshmem_pio,
+ DOORBELL,
+ 4,
+ true,
+ (i << 16) | j,
+ s->peers[i].eventfds[j]);
}
}
}
@@ -495,6 +506,10 @@ static void ivshmem_read(void *opaque, const uint8_t * buf, int flags)
(incoming_posn << 16) | guest_max_eventfd, 1) < 0) {
fprintf(stderr, "ivshmem: ioeventfd not available\n");
}
+ if (kvm_set_ioeventfd_pio_long(incoming_fd, s->pio_addr + DOORBELL,
+ (incoming_posn << 16) | guest_max_eventfd, 1) < 0) {
+ fprintf(stderr, "ivshmem: ioeventfd not available\n");
+ }
}
return;
@@ -656,8 +671,10 @@ 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);
+ memory_region_init_io(&s->ivshmem_pio, &ivshmem_io_ops, s,
+ "ivshmem-pio", IVSHIO_REG_BAR_SIZE);
if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) {
setup_ioeventfds(s);
@@ -666,6 +683,8 @@ static int pci_ivshmem_init(PCIDevice *dev)
/* region for registers*/
pci_register_bar(&s->dev, 0, PCI_BASE_ADDRESS_SPACE_MEMORY,
&s->ivshmem_mmio);
+ pci_register_bar(&s->dev, 3, PCI_BASE_ADDRESS_SPACE_IO,
+ &s->ivshmem_pio);
memory_region_init(&s->bar, "ivshmem-bar2-container", s->ivshmem_size);
@@ -742,6 +761,7 @@ static int pci_ivshmem_uninit(PCIDevice *dev)
IVShmemState *s = DO_UPCAST(IVShmemState, dev, dev);
memory_region_destroy(&s->ivshmem_mmio);
+ memory_region_destroy(&s->ivshmem_pio);
memory_region_del_subregion(&s->bar, &s->ivshmem);
memory_region_destroy(&s->ivshmem);
memory_region_destroy(&s->bar);
diff --git a/kvm-all.c b/kvm-all.c
index 5d500e1..737c2e2 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -1396,6 +1396,29 @@ int kvm_set_ioeventfd_mmio_long(int fd, uint32_t addr, uint32_t val, bool assign
return 0;
}
+int kvm_set_ioeventfd_pio_long(int fd, uint32_t addr, uint32_t val, bool assign)
+{
+ struct kvm_ioeventfd kick = {
+ .datamatch = val,
+ .addr = addr,
+ .len = 4,
+ .flags = KVM_IOEVENTFD_FLAG_DATAMATCH | KVM_IOEVENTFD_FLAG_PIO,
+ .fd = fd,
+ };
+ int r;
+ if (!kvm_enabled()) {
+ return -ENOSYS;
+ }
+ if (!assign) {
+ kick.flags |= KVM_IOEVENTFD_FLAG_DEASSIGN;
+ }
+ r = kvm_vm_ioctl(kvm_state, KVM_IOEVENTFD, &kick);
+ if (r < 0) {
+ return r;
+ }
+ return 0;
+}
+
int kvm_set_ioeventfd_pio_word(int fd, uint16_t addr, uint16_t val, bool assign)
{
struct kvm_ioeventfd kick = {
diff --git a/kvm.h b/kvm.h
index b15e1dd..c2373c9 100644
--- a/kvm.h
+++ b/kvm.h
@@ -198,6 +198,7 @@ int kvm_set_ioeventfd_mmio_long(int fd, uint32_t adr, uint32_t val, bool assign)
int kvm_set_irqfd(int gsi, int fd, bool assigned);
+int kvm_set_ioeventfd_pio_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);
typedef struct KVMMsiMessage {
--
1.7.1
--
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