On Thu, Nov 17, 2011 at 10:50 PM, <zanghongyong@xxxxxxxxxx> wrote:
> 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.
Come to think of it, should we bump the PIO to BAR4 so that the shared
memory region could be made a 64-bit BAR and therefore take up BAR2
and BAR3?
>
> 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
>
--
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
