On 26.09.2018 10:26, Maxime Coquelin wrote:
> This patch opens a userfaultfd and sends it back to Qemu's
> VHOST_USER_POSTCOPY_ADVISE request.
>
> Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
> Signed-off-by: Maxime Coquelin <maxime.coque...@redhat.com>
> ---
> lib/librte_vhost/vhost.h | 2 ++
> lib/librte_vhost/vhost_user.c | 37 +++++++++++++++++++++++++++++++++++
> lib/librte_vhost/vhost_user.h | 3 ++-
> 3 files changed, 41 insertions(+), 1 deletion(-)
>
> diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
> index 25ffd7614..21722d8a8 100644
> --- a/lib/librte_vhost/vhost.h
> +++ b/lib/librte_vhost/vhost.h
> @@ -363,6 +363,8 @@ struct virtio_net {
> int slave_req_fd;
> rte_spinlock_t slave_req_lock;
>
> + int postcopy_ufd;
> +
> /*
> * Device id to identify a specific backend device.
> * It's set to -1 for the default software implementation.
> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
> index a9b429598..bdfe2cac0 100644
> --- a/lib/librte_vhost/vhost_user.c
> +++ b/lib/librte_vhost/vhost_user.c
> @@ -24,9 +24,13 @@
> #include <stdlib.h>
> #include <string.h>
> #include <unistd.h>
> +#include <fcntl.h>
> +#include <linux/userfaultfd.h>
Maybe we need compile time check for this header existence?
Otherwise, this will bump minimal kernel version for default linux build
to something like 4.3.
> +#include <sys/ioctl.h>
> #include <sys/mman.h>
> #include <sys/types.h>
> #include <sys/stat.h>
> +#include <sys/syscall.h>
> #include <assert.h>
> #ifdef RTE_LIBRTE_VHOST_NUMA
> #include <numaif.h>
> @@ -69,6 +73,7 @@ static const char *vhost_message_str[VHOST_USER_MAX] = {
> [VHOST_USER_IOTLB_MSG] = "VHOST_USER_IOTLB_MSG",
> [VHOST_USER_CRYPTO_CREATE_SESS] = "VHOST_USER_CRYPTO_CREATE_SESS",
> [VHOST_USER_CRYPTO_CLOSE_SESS] = "VHOST_USER_CRYPTO_CLOSE_SESS",
> + [VHOST_USER_POSTCOPY_ADVISE] = "VHOST_USER_POSTCOPY_ADVISE",
> };
>
> static uint64_t
> @@ -1412,6 +1417,33 @@ vhost_user_iotlb_msg(struct virtio_net **pdev, struct
> VhostUserMsg *msg)
> return 0;
> }
>
> +static int
> +vhost_user_set_postcopy_advise(struct virtio_net *dev, struct VhostUserMsg
> *msg)
> +{
> + struct uffdio_api api_struct;
> +
> +
> + dev->postcopy_ufd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK);
> +
> + if (dev->postcopy_ufd == -1) {
> + RTE_LOG(ERR, VHOST_CONFIG, "Userfaultfd not available: %s\n",
> + strerror(errno));
> + return -1;
> + }
> + api_struct.api = UFFD_API;
> + api_struct.features = 0;
> + if (ioctl(dev->postcopy_ufd, UFFDIO_API, &api_struct)) {
> + RTE_LOG(ERR, VHOST_CONFIG, "UFFDIO_API ioctl failure: %s\n",
> + strerror(errno));
> + close(dev->postcopy_ufd);
> + return -1;
> + }
> + msg->fds[0] = dev->postcopy_ufd;
> + msg->fd_num = 1;
> +
> + return 0;
> +}
> +
> /* return bytes# of read on success or negative val on failure. */
> static int
> read_vhost_message(int sockfd, struct VhostUserMsg *msg)
> @@ -1756,6 +1788,11 @@ vhost_user_msg_handler(int vid, int fd)
> ret = vhost_user_iotlb_msg(&dev, &msg);
> break;
>
> + case VHOST_USER_POSTCOPY_ADVISE:
> + vhost_user_set_postcopy_advise(dev, &msg);
> + send_vhost_reply(fd, &msg);
> + break;
> +
> default:
> ret = -1;
> break;
> diff --git a/lib/librte_vhost/vhost_user.h b/lib/librte_vhost/vhost_user.h
> index dd0262f8f..2030b40a5 100644
> --- a/lib/librte_vhost/vhost_user.h
> +++ b/lib/librte_vhost/vhost_user.h
> @@ -50,7 +50,8 @@ typedef enum VhostUserRequest {
> VHOST_USER_IOTLB_MSG = 22,
> VHOST_USER_CRYPTO_CREATE_SESS = 26,
> VHOST_USER_CRYPTO_CLOSE_SESS = 27,
> - VHOST_USER_MAX = 28
> + VHOST_USER_POSTCOPY_ADVISE = 28,
> + VHOST_USER_MAX = 29
> } VhostUserRequest;
>
> typedef enum VhostUserSlaveRequest {
>
