From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by dpdk.org (Postfix) with ESMTP id BCA1D2BBD; Thu, 29 Mar 2018 15:20:55 +0200 (CEST) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 29 Mar 2018 06:20:54 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.48,376,1517904000"; d="scan'208";a="39155411" Received: from tanjianf-mobl.ccr.corp.intel.com (HELO [10.255.29.250]) ([10.255.29.250]) by orsmga003.jf.intel.com with ESMTP; 29 Mar 2018 06:20:51 -0700 To: "Wodkowski, PawelX" , Maxime Coquelin , Victor Kaplansky References: <1510746068-143223-1-git-send-email-jianfeng.tan@intel.com> <20171205141954.GF9111@yliu-dev> <1c5d3010-c7a9-a2b1-909e-dd43cde24af1@redhat.com> Cc: "dev@dpdk.org" , "stable@dpdk.org" , "Yang, Yi Y" , "Harris, James R" , "Yang, Ziye" , "Liu, Changpeng" , "Stojaczyk, DariuszX" , Yuanhan Liu From: "Tan, Jianfeng" Message-ID: <24ff3c96-df78-b2f0-a8ae-0edaef6f31e0@intel.com> Date: Thu, 29 Mar 2018 21:20:50 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [PATCH] vhost: fix segfault as handle set_mem_table message X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 29 Mar 2018 13:20:56 -0000 On 3/29/2018 8:57 PM, Wodkowski, PawelX wrote: >>>>>>> DPDK vhost-user handles this message rudely by unmap all existing >>>>>>> regions and map new ones. This might lead to segfault if there >>>>>>> is pmd thread just trying to touch those unmapped memory regions. >>>>>>> >>>>>>> But for most cases, except VM memory hotplug, >>>> FYI, Victor is working on implementing a lock-less protection mechanism >>>> to prevent crashes in such cases. It is intended first to protect >>>> log_base in case of multiqueue + live-migration, but would solve thi >>>> issue too. >>> Bring this issue back for discussion. >>> >>> Reported by SPDK guys, even with per-queue lock, they could still run into >> crash as of memory hot plug or unplug. >>> In detail, you add the lock in an internal struct, vhost_queue which is, >> unfortunately, not visible to the external datapath, like vhost-scsi in SPDK. >> >> Yes, I agree current solution is not enough >> >>> The memory hot plug and unplug would be the main issue from SPDK side so >> far. For this specific issue, I think we can continue this patch to filter out the >> changed regions, and keep unchanged regions not remapped. >>> But I know that the per-vq lock is not only to resolve the memory table issue, >> some other vhost-user messages could also lead to problems? If yes, shall we >> take a step back, to think about how to solve this kind of issues for backends, >> like vhost-scsi. >> >> Right, any message that can change the device or virtqueue states can be >> problematic. >> >>> Thoughts? >> In another thread, SPDK people proposed to destroy and re-create the >> device for every message. I think this is not acceptable. > Backend must know which part of device is outdated (memory table, ring > position etc) so it can take right action here. I don't insist on destroy/create > scheme but this solve most of those problems (if not all). if we will have another > working solution this is perfectly fine for me. > >> I proposed an alternative that I think would work: >> - external backends & applications implements the .vring_state_changed() >> callback. On disable it stops processing the rings and only return >> once all descriptor buffers are processed. On enable, they resume the >> rings processing. >> - In vhost lib, we implement vhost_vring_pause and vhost_vring_resume >> functions. In pause function, we save device state (enable or >> disable) in a variable, and if the ring is enabled at device level it >> calls .vring_state_changed() with disabled state. In resume, it checks >> the vring state in the device and call .vring_state_changed() with >> enable state if it was enabled in device state. > This will be not enough. We need to know what exactly changed. As for ring > state it is straight forward to save/fetch new ring state but eg. for set mem > table we need to finish all IO, remove currently registered RDMA memory. > Then, when new memory table is available we need to register it again for > RDMA then resume IO. That's easy to do, just add a parameter for the ops to indicate the reason of state changing. But, actually, your code below remind me of that, we can let external backends & applications to intercept messages, by the new pre msg handler. > >> So, I think that would work but I hadn't had a clear reply from SPDK >> people proving it wouldn't. >> >> They asked we revert Victor's patch, but I don't see the need as it does >> not hurt SPDK (but doesn't protect anything for them I agree), while it >> really fixes real issues with internal Net backend. >> >> What do you think of my proposal? Do you see other alternative? >> > As Victor is already working on the solution, can you post some info about how > you plan to solve it? I was thinking about something like code bellow (sorry for > how this code look like but this is my work-in-progress to see if this make any > sense here). This code allow to: > 1. not introducing changes like http://dpdk.org/ml/archives/dev/2018-March/093922.html > because backend will handle this by its own. > 2. virtio-net specific messages can be moved out of generic vhost_user.c file This sounds like a refactor. I cannot wait to see it :-) > 3. virtqueue locking stuff can be moved to virito-net specific backend. It is net specific now. > > Pls let me know what you think. > > --- > lib/librte_vhost/Makefile | 2 +- > lib/librte_vhost/rte_vhost.h | 60 ++++++++++++++++++- > lib/librte_vhost/rte_vhost_user.h | 120 ++++++++++++++++++++++++++++++++++++++ > lib/librte_vhost/vhost.h | 14 ----- > lib/librte_vhost/vhost_user.c | 30 ++++++++++ > lib/librte_vhost/vhost_user.h | 88 ---------------------------- > 6 files changed, 209 insertions(+), 105 deletions(-) > create mode 100644 lib/librte_vhost/rte_vhost_user.h > > diff --git a/lib/librte_vhost/Makefile b/lib/librte_vhost/Makefile > index 5d6c6abaed51..07439a186d91 100644 > --- a/lib/librte_vhost/Makefile > +++ b/lib/librte_vhost/Makefile > @@ -25,6 +25,6 @@ SRCS-$(CONFIG_RTE_LIBRTE_VHOST) := fd_man.c iotlb.c socket.c vhost.c \ > vhost_user.c virtio_net.c > > # install includes > -SYMLINK-$(CONFIG_RTE_LIBRTE_VHOST)-include += rte_vhost.h > +SYMLINK-$(CONFIG_RTE_LIBRTE_VHOST)-include += rte_vhost.h rte_vhost_user.h > > include $(RTE_SDK)/mk/rte.lib.mk > diff --git a/lib/librte_vhost/rte_vhost.h b/lib/librte_vhost/rte_vhost.h > index d33206997453..7b76952638dc 100644 > --- a/lib/librte_vhost/rte_vhost.h > +++ b/lib/librte_vhost/rte_vhost.h > @@ -16,12 +16,13 @@ > #include > #include > > +#include > + > #ifdef __cplusplus > extern "C" { > #endif > > /* These are not C++-aware. */ > -#include > #include > > #define RTE_VHOST_USER_CLIENT (1ULL << 0) > @@ -65,6 +66,51 @@ struct rte_vhost_vring { > }; > > /** > + * Vhost library started processing given vhost user message. > + * > + * This state should be used eg. to stop rings processing in case of > + * SET_MEM_TABLE message. > + * > + * Backend is allowed to return any result of RTE_VHOST_USER_MESSAGE_RESULT_*. > + */ > +#define RTE_VHOST_USER_MSG_START 0 > + > +/** > + * Vhost library is finishing processing given vhost user message. > + * If backend have handled the message produced response is passed as message > + * parameter. If response is needed it will be send after returning. > + * > + * This state might be used to resume ring processing in case of SET_MEM_TABLE > + * message. > + * > + * Returning RTE_VHOST_USER_MSG_RESULT_FAILED will trigger failure action in > + * vhost library. > + */ > +#define RTE_VHOST_USER_MSG_END 1 > + > +/** > + * Backend understood the message but processing it failed for some reason. > + * vhost library will take the failure action - chance closing existing > + * connection. > + */ > +#define RTE_VHOST_USER_MSG_RESULT_FAILED -1 > + > +/** > + * Backend understood the message and handled it entirly. Backend is responsible > + * for filling message object with right response data. > + */ > +#define RTE_VHOST_USER_MSG_RESULT_HANDLED 0 > + > +/** > + * Backend ignored the message or understood and took some action. In either > + * case the message need to be further processed by vhost library. > + * > + * Backend is not allowed to change passed message. > + */ > +#define RTE_VHOST_USER_MSG_RESULT_OK 1 > + > + > +/** > * Device and vring operations. > */ > struct vhost_device_ops { > @@ -84,7 +130,17 @@ struct vhost_device_ops { > int (*new_connection)(int vid); > void (*destroy_connection)(int vid); > > - void *reserved[2]; /**< Reserved for future extension */ > + /** > + * Backend callback for user message. > + * > + * @param vid id of vhost device > + * @param msg message object. > + * @param phase RTE_VHOST_USER_MSG_START or RTE_VHOST_USER_MSG_END > + * @return one of RTE_VHOST_USER_MESSAGE_RESULT_* > + */ > + int (*user_message_handler)(int vid, struct VhostUserMsg *msg, int phase); We will have a similar handler, actually two, pre and post msg handler, http://dpdk.org/dev/patchwork/patch/36647/. Thanks, Jianfeng > + > + void *reserved[1]; /**< Reserved for future extension */ > }; > > /** > diff --git a/lib/librte_vhost/rte_vhost_user.h b/lib/librte_vhost/rte_vhost_user.h > new file mode 100644 > index 000000000000..f7678d33acc3 > --- /dev/null > +++ b/lib/librte_vhost/rte_vhost_user.h > @@ -0,0 +1,120 @@ > +#ifndef _VHOST_RTE_VHOST_USER_H_ > +#define _VHOST_RTE_VHOST_USER_H_ > + > +#include > + > +#ifdef __cplusplus > +extern "C" { > +#endif > + > +/* These are not C++-aware. */ > +#include > + > +/* refer to hw/virtio/vhost-user.c */ > + > +struct vhost_iotlb_msg { > + __u64 iova; > + __u64 size; > + __u64 uaddr; > +#define VHOST_ACCESS_RO 0x1 > +#define VHOST_ACCESS_WO 0x2 > +#define VHOST_ACCESS_RW 0x3 > + __u8 perm; > +#define VHOST_IOTLB_MISS 1 > +#define VHOST_IOTLB_UPDATE 2 > +#define VHOST_IOTLB_INVALIDATE 3 > +#define VHOST_IOTLB_ACCESS_FAIL 4 > + __u8 type; > +}; > + > +#define VHOST_MEMORY_MAX_NREGIONS 8 > + > +#define VHOST_USER_PROTOCOL_F_MQ 0 > +#define VHOST_USER_PROTOCOL_F_LOG_SHMFD 1 > +#define VHOST_USER_PROTOCOL_F_RARP 2 > +#define VHOST_USER_PROTOCOL_F_REPLY_ACK 3 > +#define VHOST_USER_PROTOCOL_F_NET_MTU 4 > +#define VHOST_USER_PROTOCOL_F_SLAVE_REQ 5 > + > +typedef enum VhostUserRequest { > + VHOST_USER_NONE = 0, > + VHOST_USER_GET_FEATURES = 1, > + VHOST_USER_SET_FEATURES = 2, > + VHOST_USER_SET_OWNER = 3, > + VHOST_USER_RESET_OWNER = 4, > + VHOST_USER_SET_MEM_TABLE = 5, > + VHOST_USER_SET_LOG_BASE = 6, > + VHOST_USER_SET_LOG_FD = 7, > + VHOST_USER_SET_VRING_NUM = 8, > + VHOST_USER_SET_VRING_ADDR = 9, > + VHOST_USER_SET_VRING_BASE = 10, > + VHOST_USER_GET_VRING_BASE = 11, > + VHOST_USER_SET_VRING_KICK = 12, > + VHOST_USER_SET_VRING_CALL = 13, > + VHOST_USER_SET_VRING_ERR = 14, > + VHOST_USER_GET_PROTOCOL_FEATURES = 15, > + VHOST_USER_SET_PROTOCOL_FEATURES = 16, > + VHOST_USER_GET_QUEUE_NUM = 17, > + VHOST_USER_SET_VRING_ENABLE = 18, > + VHOST_USER_SEND_RARP = 19, > + VHOST_USER_NET_SET_MTU = 20, > + VHOST_USER_SET_SLAVE_REQ_FD = 21, > + VHOST_USER_IOTLB_MSG = 22, > + VHOST_USER_MAX > +} VhostUserRequest; > + > +typedef enum VhostUserSlaveRequest { > + VHOST_USER_SLAVE_NONE = 0, > + VHOST_USER_SLAVE_IOTLB_MSG = 1, > + VHOST_USER_SLAVE_MAX > +} VhostUserSlaveRequest; > + > +typedef struct VhostUserMemoryRegion { > + uint64_t guest_phys_addr; > + uint64_t memory_size; > + uint64_t userspace_addr; > + uint64_t mmap_offset; > +} VhostUserMemoryRegion; > + > +typedef struct VhostUserMemory { > + uint32_t nregions; > + uint32_t padding; > + VhostUserMemoryRegion regions[VHOST_MEMORY_MAX_NREGIONS]; > +} VhostUserMemory; > + > +typedef struct VhostUserLog { > + uint64_t mmap_size; > + uint64_t mmap_offset; > +} VhostUserLog; > + > +typedef struct VhostUserMsg { > + union { > + VhostUserRequest master; > + VhostUserSlaveRequest slave; > + } request; > + > +#define VHOST_USER_VERSION_MASK 0x3 > +#define VHOST_USER_REPLY_MASK (0x1 << 2) > +#define VHOST_USER_NEED_REPLY (0x1 << 3) > + uint32_t flags; > + uint32_t size; /* the following payload size */ > + union { > +#define VHOST_USER_VRING_IDX_MASK 0xff > +#define VHOST_USER_VRING_NOFD_MASK (0x1<<8) > + uint64_t u64; > + struct vhost_vring_state state; > + struct vhost_vring_addr addr; > + VhostUserMemory memory; > + VhostUserLog log; > + struct vhost_iotlb_msg iotlb; > + } payload; > + int fds[VHOST_MEMORY_MAX_NREGIONS]; > +} __attribute((packed)) VhostUserMsg; > + > +#define VHOST_USER_HDR_SIZE offsetof(VhostUserMsg, payload.u64) > + > +#ifdef __cplusplus > +} > +#endif > + > +#endif /* _VHOST_RTE_VHOST_USER_H_ */ > diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h > index d947bc9e3b3f..42a1474095a3 100644 > --- a/lib/librte_vhost/vhost.h > +++ b/lib/librte_vhost/vhost.h > @@ -141,20 +141,6 @@ struct vhost_virtqueue { > > #define VIRTIO_F_IOMMU_PLATFORM 33 > > -struct vhost_iotlb_msg { > - __u64 iova; > - __u64 size; > - __u64 uaddr; > -#define VHOST_ACCESS_RO 0x1 > -#define VHOST_ACCESS_WO 0x2 > -#define VHOST_ACCESS_RW 0x3 > - __u8 perm; > -#define VHOST_IOTLB_MISS 1 > -#define VHOST_IOTLB_UPDATE 2 > -#define VHOST_IOTLB_INVALIDATE 3 > -#define VHOST_IOTLB_ACCESS_FAIL 4 > - __u8 type; > -}; > > #define VHOST_IOTLB_MSG 0x1 > > diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c > index 90ed2112e0af..15532e182b58 100644 > --- a/lib/librte_vhost/vhost_user.c > +++ b/lib/librte_vhost/vhost_user.c > @@ -1301,6 +1301,7 @@ vhost_user_msg_handler(int vid, int fd) > struct virtio_net *dev; > struct VhostUserMsg msg; > int ret; > + int user_handler_result; > int unlock_required = 0; > > dev = get_device(vid); > @@ -1347,6 +1348,26 @@ vhost_user_msg_handler(int vid, int fd) > return -1; > } > > + > + if (dev->notify_ops->user_message_handler) { > + user_handler_result = dev->notify_ops->user_message_handler( > + dev->vid, &msg, RTE_VHOST_USER_MSG_START); > + > + switch (user_handler_result) { > + case RTE_VHOST_USER_MSG_RESULT_FAILED: > + RTE_LOG(ERR, VHOST_CONFIG, > + "User message handler failed\n"); > + return -1; > + case RTE_VHOST_USER_MSG_RESULT_HANDLED: > + RTE_LOG(DEBUG, VHOST_CONFIG, > + "User message handled by backend\n"); > + goto msg_handled; > + case RTE_VHOST_USER_MSG_RESULT_OK: > + break; > + } > + } > + > + > /* > * Note: we don't lock all queues on VHOST_USER_GET_VRING_BASE > * and VHOST_USER_RESET_OWNER, since it is sent when virtio stops > @@ -1485,6 +1506,15 @@ vhost_user_msg_handler(int vid, int fd) > if (unlock_required) > vhost_user_unlock_all_queue_pairs(dev); > > +msg_handled: > + if (dev->notify_ops->user_message_handler) { > + user_handler_result = dev->notify_ops->user_message_handler( > + dev->vid, &msg, RTE_VHOST_USER_MSG_END); > + > + if (user_handler_result == RTE_VHOST_USER_MSG_RESULT_FAILED) > + return -1; > + } > + > if (msg.flags & VHOST_USER_NEED_REPLY) { > msg.payload.u64 = !!ret; > msg.size = sizeof(msg.payload.u64); > diff --git a/lib/librte_vhost/vhost_user.h b/lib/librte_vhost/vhost_user.h > index d4bd604b9d6b..cf3f0da0ec41 100644 > --- a/lib/librte_vhost/vhost_user.h > +++ b/lib/librte_vhost/vhost_user.h > @@ -10,17 +10,6 @@ > > #include "rte_vhost.h" > > -/* refer to hw/virtio/vhost-user.c */ > - > -#define VHOST_MEMORY_MAX_NREGIONS 8 > - > -#define VHOST_USER_PROTOCOL_F_MQ 0 > -#define VHOST_USER_PROTOCOL_F_LOG_SHMFD 1 > -#define VHOST_USER_PROTOCOL_F_RARP 2 > -#define VHOST_USER_PROTOCOL_F_REPLY_ACK 3 > -#define VHOST_USER_PROTOCOL_F_NET_MTU 4 > -#define VHOST_USER_PROTOCOL_F_SLAVE_REQ 5 > - > #define VHOST_USER_PROTOCOL_FEATURES ((1ULL << VHOST_USER_PROTOCOL_F_MQ) | \ > (1ULL << VHOST_USER_PROTOCOL_F_LOG_SHMFD) |\ > (1ULL << VHOST_USER_PROTOCOL_F_RARP) | \ > @@ -28,83 +17,6 @@ > (1ULL << VHOST_USER_PROTOCOL_F_NET_MTU) | \ > (1ULL << VHOST_USER_PROTOCOL_F_SLAVE_REQ)) > > -typedef enum VhostUserRequest { > - VHOST_USER_NONE = 0, > - VHOST_USER_GET_FEATURES = 1, > - VHOST_USER_SET_FEATURES = 2, > - VHOST_USER_SET_OWNER = 3, > - VHOST_USER_RESET_OWNER = 4, > - VHOST_USER_SET_MEM_TABLE = 5, > - VHOST_USER_SET_LOG_BASE = 6, > - VHOST_USER_SET_LOG_FD = 7, > - VHOST_USER_SET_VRING_NUM = 8, > - VHOST_USER_SET_VRING_ADDR = 9, > - VHOST_USER_SET_VRING_BASE = 10, > - VHOST_USER_GET_VRING_BASE = 11, > - VHOST_USER_SET_VRING_KICK = 12, > - VHOST_USER_SET_VRING_CALL = 13, > - VHOST_USER_SET_VRING_ERR = 14, > - VHOST_USER_GET_PROTOCOL_FEATURES = 15, > - VHOST_USER_SET_PROTOCOL_FEATURES = 16, > - VHOST_USER_GET_QUEUE_NUM = 17, > - VHOST_USER_SET_VRING_ENABLE = 18, > - VHOST_USER_SEND_RARP = 19, > - VHOST_USER_NET_SET_MTU = 20, > - VHOST_USER_SET_SLAVE_REQ_FD = 21, > - VHOST_USER_IOTLB_MSG = 22, > - VHOST_USER_MAX > -} VhostUserRequest; > - > -typedef enum VhostUserSlaveRequest { > - VHOST_USER_SLAVE_NONE = 0, > - VHOST_USER_SLAVE_IOTLB_MSG = 1, > - VHOST_USER_SLAVE_MAX > -} VhostUserSlaveRequest; > - > -typedef struct VhostUserMemoryRegion { > - uint64_t guest_phys_addr; > - uint64_t memory_size; > - uint64_t userspace_addr; > - uint64_t mmap_offset; > -} VhostUserMemoryRegion; > - > -typedef struct VhostUserMemory { > - uint32_t nregions; > - uint32_t padding; > - VhostUserMemoryRegion regions[VHOST_MEMORY_MAX_NREGIONS]; > -} VhostUserMemory; > - > -typedef struct VhostUserLog { > - uint64_t mmap_size; > - uint64_t mmap_offset; > -} VhostUserLog; > - > -typedef struct VhostUserMsg { > - union { > - VhostUserRequest master; > - VhostUserSlaveRequest slave; > - } request; > - > -#define VHOST_USER_VERSION_MASK 0x3 > -#define VHOST_USER_REPLY_MASK (0x1 << 2) > -#define VHOST_USER_NEED_REPLY (0x1 << 3) > - uint32_t flags; > - uint32_t size; /* the following payload size */ > - union { > -#define VHOST_USER_VRING_IDX_MASK 0xff > -#define VHOST_USER_VRING_NOFD_MASK (0x1<<8) > - uint64_t u64; > - struct vhost_vring_state state; > - struct vhost_vring_addr addr; > - VhostUserMemory memory; > - VhostUserLog log; > - struct vhost_iotlb_msg iotlb; > - } payload; > - int fds[VHOST_MEMORY_MAX_NREGIONS]; > -} __attribute((packed)) VhostUserMsg; > - > -#define VHOST_USER_HDR_SIZE offsetof(VhostUserMsg, payload.u64) > - > /* The version of the protocol we support */ > #define VHOST_USER_VERSION 0x1 >