On Wed, Apr 24, 2013 at 01:32:56PM +0800, Asias He wrote: > On Mon, Apr 22, 2013 at 08:32:27PM -0400, Sasha Levin wrote: > > Support mergable rx buffers for virtio-net. This helps reduce the amount > > of memory the guest kernel has to allocate per rx vq. > > With this, we always do an extra copy of the rx data into a linear buffer. > I am thinking about whether we should keep the non MRG_RXBUF code. For > tap use case, it is fine, user can use vhost. But for uip use case, we > can not use vhost.
You have to keep it but it might be ok not to optimize it. > > Signed-off-by: Sasha Levin <[email protected]> > > --- > > tools/kvm/include/kvm/uip.h | 4 ++-- > > tools/kvm/include/kvm/util.h | 3 +++ > > tools/kvm/net/uip/core.c | 54 > > +++++--------------------------------------- > > tools/kvm/net/uip/tcp.c | 2 +- > > tools/kvm/net/uip/udp.c | 2 +- > > tools/kvm/util/util.c | 15 ++++++++++++ > > tools/kvm/virtio/net.c | 37 ++++++++++++++++++++++-------- > > 7 files changed, 55 insertions(+), 62 deletions(-) > > > > diff --git a/tools/kvm/include/kvm/uip.h b/tools/kvm/include/kvm/uip.h > > index ac248d2..fa82f10 100644 > > --- a/tools/kvm/include/kvm/uip.h > > +++ b/tools/kvm/include/kvm/uip.h > > @@ -252,7 +252,7 @@ struct uip_tcp_socket { > > }; > > > > struct uip_tx_arg { > > - struct virtio_net_hdr *vnet; > > + struct virtio_net_hdr_mrg_rxbuf *vnet; > > struct uip_info *info; > > struct uip_eth *eth; > > int vnet_len; > > @@ -332,7 +332,7 @@ static inline u16 uip_eth_hdrlen(struct uip_eth *eth) > > } > > > > int uip_tx(struct iovec *iov, u16 out, struct uip_info *info); > > -int uip_rx(struct iovec *iov, u16 in, struct uip_info *info); > > +int uip_rx(unsigned char *buffer, u32 length, struct uip_info *info); > > int uip_init(struct uip_info *info); > > > > int uip_tx_do_ipv4_udp_dhcp(struct uip_tx_arg *arg); > > diff --git a/tools/kvm/include/kvm/util.h b/tools/kvm/include/kvm/util.h > > index 0df9f0d..6f8ac83 100644 > > --- a/tools/kvm/include/kvm/util.h > > +++ b/tools/kvm/include/kvm/util.h > > @@ -22,6 +22,7 @@ > > #include <sys/param.h> > > #include <sys/types.h> > > #include <linux/types.h> > > +#include <sys/uio.h> > > > > #ifdef __GNUC__ > > #define NORETURN __attribute__((__noreturn__)) > > @@ -94,4 +95,6 @@ struct kvm; > > void *mmap_hugetlbfs(struct kvm *kvm, const char *htlbfs_path, u64 size); > > void *mmap_anon_or_hugetlbfs(struct kvm *kvm, const char *hugetlbfs_path, > > u64 size); > > > > +int memcpy_toiovecend(const struct iovec *iov, int iovlen, unsigned char > > *kdata, size_t len); > > + > > #endif /* KVM__UTIL_H */ > > diff --git a/tools/kvm/net/uip/core.c b/tools/kvm/net/uip/core.c > > index 4e5bb82..d9e9993 100644 > > --- a/tools/kvm/net/uip/core.c > > +++ b/tools/kvm/net/uip/core.c > > @@ -7,7 +7,7 @@ > > > > int uip_tx(struct iovec *iov, u16 out, struct uip_info *info) > > { > > - struct virtio_net_hdr *vnet; > > + struct virtio_net_hdr_mrg_rxbuf *vnet; > > struct uip_tx_arg arg; > > int eth_len, vnet_len; > > struct uip_eth *eth; > > @@ -74,63 +74,21 @@ int uip_tx(struct iovec *iov, u16 out, struct uip_info > > *info) > > return vnet_len + eth_len; > > } > > > > -int uip_rx(struct iovec *iov, u16 in, struct uip_info *info) > > +int uip_rx(unsigned char *buffer, u32 length, struct uip_info *info) > > { > > - struct virtio_net_hdr *vnet; > > - struct uip_eth *eth; > > struct uip_buf *buf; > > - int vnet_len; > > - int eth_len; > > - char *p; > > int len; > > - int cnt; > > - int i; > > > > /* > > * Sleep until there is a buffer for guest > > */ > > buf = uip_buf_get_used(info); > > > > - /* > > - * Fill device to guest buffer, vnet hdr fisrt > > - */ > > - vnet_len = iov[0].iov_len; > > - vnet = iov[0].iov_base; > > - if (buf->vnet_len > vnet_len) { > > - len = -1; > > - goto out; > > - } > > - memcpy(vnet, buf->vnet, buf->vnet_len); > > - > > - /* > > - * Then, the real eth data > > - * Note: Be sure buf->eth_len is not bigger than the buffer len that > > guest provides > > - */ > > - cnt = buf->eth_len; > > - p = buf->eth; > > - for (i = 1; i < in; i++) { > > - eth_len = iov[i].iov_len; > > - eth = iov[i].iov_base; > > - if (cnt > eth_len) { > > - memcpy(eth, p, eth_len); > > - cnt -= eth_len; > > - p += eth_len; > > - } else { > > - memcpy(eth, p, cnt); > > - cnt -= cnt; > > - break; > > - } > > - } > > - > > - if (cnt) { > > - pr_warning("uip_rx error"); > > - len = -1; > > - goto out; > > - } > > + memcpy(buffer, buf->vnet, buf->vnet_len); > > + memcpy(buffer + buf->vnet_len, buf->eth, buf->eth_len); > > > > len = buf->vnet_len + buf->eth_len; > > > > -out: > > uip_buf_set_free(info, buf); > > return len; > > } > > @@ -172,8 +130,8 @@ int uip_init(struct uip_info *info) > > } > > > > list_for_each_entry(buf, buf_head, list) { > > - buf->vnet = malloc(sizeof(struct virtio_net_hdr)); > > - buf->vnet_len = sizeof(struct virtio_net_hdr); > > + buf->vnet = malloc(sizeof(struct > > virtio_net_hdr_mrg_rxbuf)); > > + buf->vnet_len = sizeof(struct virtio_net_hdr_mrg_rxbuf); > > buf->eth = malloc(1024*64 + sizeof(struct > > uip_pseudo_hdr)); > > buf->eth_len = 1024*64 + sizeof(struct uip_pseudo_hdr); > > > > diff --git a/tools/kvm/net/uip/tcp.c b/tools/kvm/net/uip/tcp.c > > index 9044f40..a99b95e 100644 > > --- a/tools/kvm/net/uip/tcp.c > > +++ b/tools/kvm/net/uip/tcp.c > > @@ -153,7 +153,7 @@ static int uip_tcp_payload_send(struct uip_tcp_socket > > *sk, u8 flag, u16 payload_ > > /* > > * virtio_net_hdr > > */ > > - buf->vnet_len = sizeof(struct virtio_net_hdr); > > + buf->vnet_len = sizeof(struct virtio_net_hdr_mrg_rxbuf); > > memset(buf->vnet, 0, buf->vnet_len); > > > > buf->eth_len = ntohs(ip2->len) + uip_eth_hdrlen(&ip2->eth); > > diff --git a/tools/kvm/net/uip/udp.c b/tools/kvm/net/uip/udp.c > > index 31c417c..083c221 100644 > > --- a/tools/kvm/net/uip/udp.c > > +++ b/tools/kvm/net/uip/udp.c > > @@ -142,7 +142,7 @@ int uip_udp_make_pkg(struct uip_info *info, struct > > uip_udp_socket *sk, struct ui > > /* > > * virtio_net_hdr > > */ > > - buf->vnet_len = sizeof(struct virtio_net_hdr); > > + buf->vnet_len = sizeof(struct virtio_net_hdr_mrg_rxbuf); > > memset(buf->vnet, 0, buf->vnet_len); > > > > buf->eth_len = ntohs(ip2->len) + uip_eth_hdrlen(&ip2->eth); > > diff --git a/tools/kvm/util/util.c b/tools/kvm/util/util.c > > index c11a15a..4e0069c 100644 > > --- a/tools/kvm/util/util.c > > +++ b/tools/kvm/util/util.c > > @@ -9,6 +9,7 @@ > > #include <sys/mman.h> > > #include <sys/stat.h> > > #include <sys/statfs.h> > > +#include <linux/kernel.h> > > > > static void report(const char *prefix, const char *err, va_list params) > > { > > @@ -131,3 +132,17 @@ void *mmap_anon_or_hugetlbfs(struct kvm *kvm, const > > char *hugetlbfs_path, u64 si > > return mmap(NULL, size, PROT_RW, MAP_ANON_NORESERVE, -1, 0); > > } > > } > > + > > +int memcpy_toiovecend(const struct iovec *iov, int iovlen, unsigned char > > *kdata, size_t len) > > +{ > > + size_t copy, start_len = len; > > + > > + for (; len > 0 && iovlen > 0; ++iov, --iovlen) { > > + copy = min(iov->iov_len, len); > > + memcpy(iov->iov_base, kdata, copy); > > + kdata += copy; > > + len -= copy; > > + } > > + > > + return start_len - len; > > +} > > diff --git a/tools/kvm/virtio/net.c b/tools/kvm/virtio/net.c > > index c0a8f12..c99c5a6 100644 > > --- a/tools/kvm/virtio/net.c > > +++ b/tools/kvm/virtio/net.c > > @@ -32,8 +32,8 @@ > > struct net_dev; > > > > struct net_dev_operations { > > - int (*rx)(struct iovec *iov, u16 in, struct net_dev *ndev); > > - int (*tx)(struct iovec *iov, u16 in, struct net_dev *ndev); > > + int (*rx)(unsigned char *buffer, u32 length, struct net_dev *ndev); > > + int (*tx)(struct iovec *iov, u16 out, struct net_dev *ndev); > > }; > > > > struct net_dev { > > @@ -63,6 +63,8 @@ struct net_dev { > > static LIST_HEAD(ndevs); > > static int compat_id = -1; > > > > +#define MAX_PACKET_SIZE ((u16)(-1)) > > Why 64KB - 1? The package can be 65550 bytes which is max TCP or UDP > plus 14 bytes eth header. > > > + > > static void *virtio_net_rx_thread(void *p) > > { > > struct iovec iov[VIRTIO_NET_QUEUE_SIZE]; > > @@ -90,9 +92,23 @@ static void *virtio_net_rx_thread(void *p) > > mutex_unlock(&ndev->io_lock[id]); > > > > while (virt_queue__available(vq)) { > > + unsigned char buffer[MAX_PACKET_SIZE]; > > The buffer size should at least be: > > MAX_PACKET_SIZE + sizeof(struct virtio_net_hdr_mrg_rxbuf) > > > + struct virtio_net_hdr_mrg_rxbuf *hdr; > > + > > + len = ndev->ops->rx(buffer, MAX_PACKET_SIZE, ndev); > > head = virt_queue__get_iov(vq, iov, &out, &in, kvm); > > - len = ndev->ops->rx(iov, in, ndev); > > - virt_queue__set_used_elem(vq, head, len); > > + hdr = (void *)iov[0].iov_base; > > + while (len) { > > + int copied; > > + > > + copied = memcpy_toiovecend(iov, in, buffer, > > len); > > + len -= copied; > > + hdr->num_buffers++; > > + virt_queue__set_used_elem(vq, head, copied); > > + if (len == 0) > > + break; > > + head = virt_queue__get_iov(vq, iov, &out, &in, > > kvm); > > Here, need to check if we still have available buffer from guest. If not > need to wait for it. > > > + } > > > > /* We should interrupt guest right now, otherwise > > latency is huge. */ > > if (virtio_queue__should_signal(vq)) > > @@ -241,7 +257,7 @@ static bool virtio_net__tap_init(const struct > > virtio_net_params *params, > > goto fail; > > } > > > > - hdr_len = sizeof(struct virtio_net_hdr); > > + hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf); > > if (ioctl(ndev->tap_fd, TUNSETVNETHDRSZ, &hdr_len) < 0) > > pr_warning("Config tap device TUNSETVNETHDRSZ error"); > > > > @@ -300,9 +316,9 @@ static inline int tap_ops_tx(struct iovec *iov, u16 > > out, struct net_dev *ndev) > > return writev(ndev->tap_fd, iov, out); > > } > > > > -static inline int tap_ops_rx(struct iovec *iov, u16 in, struct net_dev > > *ndev) > > +static inline int tap_ops_rx(unsigned char *buffer, u32 length, struct > > net_dev *ndev) > > { > > - return readv(ndev->tap_fd, iov, in); > > + return read(ndev->tap_fd, buffer, length); > > } > > > > static inline int uip_ops_tx(struct iovec *iov, u16 out, struct net_dev > > *ndev) > > @@ -310,9 +326,9 @@ static inline int uip_ops_tx(struct iovec *iov, u16 > > out, struct net_dev *ndev) > > return uip_tx(iov, out, &ndev->info); > > } > > > > -static inline int uip_ops_rx(struct iovec *iov, u16 in, struct net_dev > > *ndev) > > +static inline int uip_ops_rx(unsigned char *buffer, u32 length, struct > > net_dev *ndev) > > { > > - return uip_rx(iov, in, &ndev->info); > > + return uip_rx(buffer, length, &ndev->info); > > } > > > > static struct net_dev_operations tap_ops = { > > @@ -347,7 +363,8 @@ static u32 get_host_features(struct kvm *kvm, void *dev) > > | 1UL << VIRTIO_RING_F_EVENT_IDX > > | 1UL << VIRTIO_RING_F_INDIRECT_DESC > > | 1UL << VIRTIO_NET_F_CTRL_VQ > > - | 1UL << (ndev->queue_pairs > 1 ? VIRTIO_NET_F_MQ : 0); > > + | 1UL << (ndev->queue_pairs > 1 ? VIRTIO_NET_F_MQ : 0) > > + | 1UL << VIRTIO_NET_F_MRG_RXBUF; > > } > > > > static void set_guest_features(struct kvm *kvm, void *dev, u32 features) > > -- > > 1.8.2.1 > > > > -- > Asias -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
