From: Nick Child nnac123@linux.ibm.com
commit 23cc5f667453ca7645a24c8d21bf84dbf61107b2 upstream.
Perform a partial reset before sending a login request if any of the following are true: 1. If a previous request times out. This can be dangerous because the VIOS could still receive the old login request at any point after the timeout. Therefore, it is best to re-register the CRQ's and sub-CRQ's before retrying. 2. If the previous request returns an error that is not described in PAPR. PAPR provides procedures if the login returns with partial success or aborted return codes (section L.5.1) but other values do not have a defined procedure. Previously, these conditions just returned error from the login function rather than trying to resolve the issue. This can cause further issues since most callers of the login function are not prepared to handle an error when logging in. This improper cleanup can lead to the device being permanently DOWN'd. For example, if the VIOS believes that the device is already logged in then it will return INVALID_STATE (-7). If we never re-register CRQ's then it will always think that the device is already logged in. This leaves the device inoperable.
The partial reset involves freeing the sub-CRQs, freeing the CRQ then registering and initializing a new CRQ and sub-CRQs. This essentially restarts all communication with VIOS to allow for a fresh login attempt that will be unhindered by any previous failed attempts.
Fixes: dff515a3e71d ("ibmvnic: Harden device login requests") Signed-off-by: Nick Child nnac123@linux.ibm.com Reviewed-by: Simon Horman horms@kernel.org Link: https://lore.kernel.org/r/20230809221038.51296-4-nnac123@linux.ibm.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/ibm/ibmvnic.c | 46 ++++++++++++++++++++++++++++++++----- 1 file changed, 40 insertions(+), 6 deletions(-)
--- a/drivers/net/ethernet/ibm/ibmvnic.c +++ b/drivers/net/ethernet/ibm/ibmvnic.c @@ -97,6 +97,8 @@ static int pending_scrq(struct ibmvnic_a static union sub_crq *ibmvnic_next_scrq(struct ibmvnic_adapter *, struct ibmvnic_sub_crq_queue *); static int ibmvnic_poll(struct napi_struct *napi, int data); +static int reset_sub_crq_queues(struct ibmvnic_adapter *adapter); +static inline void reinit_init_done(struct ibmvnic_adapter *adapter); static void send_query_map(struct ibmvnic_adapter *adapter); static int send_request_map(struct ibmvnic_adapter *, dma_addr_t, u32, u8); static int send_request_unmap(struct ibmvnic_adapter *, u8); @@ -1527,11 +1529,9 @@ static int ibmvnic_login(struct net_devi
if (!wait_for_completion_timeout(&adapter->init_done, timeout)) { - netdev_warn(netdev, "Login timed out, retrying...\n"); - retry = true; - adapter->init_done_rc = 0; - retry_count++; - continue; + netdev_warn(netdev, "Login timed out\n"); + adapter->login_pending = false; + goto partial_reset; }
if (adapter->init_done_rc == ABORTED) { @@ -1576,7 +1576,41 @@ static int ibmvnic_login(struct net_devi } else if (adapter->init_done_rc) { netdev_warn(netdev, "Adapter login failed, init_done_rc = %d\n", adapter->init_done_rc); - return -EIO; + +partial_reset: + /* adapter login failed, so free any CRQs or sub-CRQs + * and register again before attempting to login again. + * If we don't do this then the VIOS may think that + * we are already logged in and reject any subsequent + * attempts + */ + netdev_warn(netdev, + "Freeing and re-registering CRQs before attempting to login again\n"); + retry = true; + adapter->init_done_rc = 0; + retry_count++; + release_sub_crqs(adapter, true); + reinit_init_done(adapter); + release_crq_queue(adapter); + /* If we don't sleep here then we risk an unnecessary + * failover event from the VIOS. This is a known VIOS + * issue caused by a vnic device freeing and registering + * a CRQ too quickly. + */ + msleep(1500); + rc = init_crq_queue(adapter); + if (rc) { + netdev_err(netdev, "login recovery: init CRQ failed %d\n", + rc); + return -EIO; + } + + rc = ibmvnic_reset_init(adapter, false); + if (rc) { + netdev_err(netdev, "login recovery: Reset init failed %d\n", + rc); + return -EIO; + } } } while (retry);