path: root/drivers/net/xen-netback/netback.c (follow)
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2014-03-07xen-netback: Introduce TX grant mappingZoltan Kiss1-160/+272
This patch introduces grant mapping on netback TX path. It replaces grant copy operations, ditching grant copy coalescing along the way. Another solution for copy coalescing is introduced in "xen-netback: Handle guests with too many frags", older guests and Windows can broke before that patch applies. There is a callback (xenvif_zerocopy_callback) from core stack to release the slots back to the guests when kfree_skb or skb_orphan_frags called. It feeds a separate dealloc thread, as scheduling NAPI instance from there is inefficient, therefore we can't do dealloc from the instance. Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-07xen-netback: Handle foreign mapped pages on the guest RX pathZoltan Kiss1-5/+43
RX path need to know if the SKB fragments are stored on pages from another domain. Logically this patch should be after introducing the grant mapping itself, as it makes sense only after that. But to keep bisectability, I moved it here. It shouldn't change any functionality here. xenvif_zerocopy_callback and ubuf_to_vif are just stubs here, they will be introduced properly later on. Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-07xen-netback: Minor refactoring of netback codeZoltan Kiss1-19/+3
This patch contains a few bits of refactoring before introducing the grant mapping changes: - introducing xenvif_tx_pending_slots_available(), as this is used several times, and will be used more often - rename the thread to vifX.Y-guest-rx, to signify it does RX work from the guest point of view Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-07xen-netback: Use skb->cb for pending_idxZoltan Kiss1-17/+25
Storing the pending_idx at the first byte of the linear buffer never looked good, skb->cb is a more proper place for this. It also prevents the header to be directly grant copied there, and we don't have the pending_idx after we copied the header here, so it's time to change it. It also introduces helpers for the RX side Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-05xen-netback: Fix Rx stall due to race conditionZoltan Kiss1-10/+6
The recent patch to fix receive side flow control (11b57f90257c1d6a91cee720151b69e0c2020cf6: xen-netback: stop vif thread spinning if frontend is unresponsive) solved the spinning thread problem, however caused an another one. The receive side can stall, if: - [THREAD] xenvif_rx_action sets rx_queue_stopped to true - [INTERRUPT] interrupt happens, and sets rx_event to true - [THREAD] then xenvif_kthread sets rx_event to false - [THREAD] rx_work_todo doesn't return true anymore Also, if interrupt sent but there is still no room in the ring, it take quite a long time until xenvif_rx_action realize it. This patch ditch that two variable, and rework rx_work_todo. If the thread finds it can't fit more skb's into the ring, it saves the last slot estimation into rx_last_skb_slots, otherwise it's kept as 0. Then rx_work_todo will check if: - there is something to send to the ring (like before) - there is space for the topmost packet in the queue I think that's more natural and optimal thing to test than two bool which are set somewhere else. Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com> Reviewed-by: Paul Durrant <paul.durrant@citrix.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-14xen-netback: use new skb_checksum_setup functionPaul Durrant1-257/+3
Use skb_checksum_setup to set up partial checksum offsets rather then a private implementation. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-09xen-netback: stop vif thread spinning if frontend is unresponsivePaul Durrant1-5/+9
The recent patch to improve guest receive side flow control (ca2f09f2) had a slight flaw in the wait condition for the vif thread in that any remaining skbs in the guest receive side netback internal queue would prevent the thread from sleeping. An unresponsive frontend can lead to a permanently non-empty internal queue and thus the thread will spin. In this case the thread should really sleep until the frontend becomes responsive again. This patch adds an extra flag to the vif which is set if the shared ring is full and cleared when skbs are drained into the shared ring. Thus, if the thread runs, finds the shared ring full and can make no progress the flag remains set. If the flag remains set then the thread will sleep, regardless of a non-empty queue, until the next event from the frontend. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-06Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-5/+13
Conflicts: drivers/net/ethernet/qlogic/qlcnic/qlcnic_sriov_pf.c net/ipv6/ip6_tunnel.c net/ipv6/ip6_vti.c ipv6 tunnel statistic bug fixes conflicting with consolidation into generic sw per-cpu net stats. qlogic conflict between queue counting bug fix and the addition of multiple MAC address support. Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-29xen-netback: fix guest-receive-side array sizesPaul Durrant1-1/+1
The sizes chosen for the metadata and grant_copy_op arrays on the guest receive size are wrong; - The meta array is needlessly twice the ring size, when we only ever consume a single array element per RX ring slot - The grant_copy_op array is way too small. It's sized based on a bogus assumption: that at most two copy ops will be used per ring slot. This may have been true at some point in the past but it's clear from looking at start_new_rx_buffer() that a new ring slot is only consumed if a frag would overflow the current slot (plus some other conditions) so the actual limit is MAX_SKB_FRAGS grant_copy_ops per ring slot. This patch fixes those two sizing issues and, because grant_copy_ops grows so much, it pulls it out into a separate chunk of vmalloc()ed memory. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-19xen-netback: add gso_segs calculationPaul Durrant1-4/+15
netback already has code which parses IPv4 and v6 headers to set up checksum offsets and these are always applied to GSO packets being sent from frontends. It's therefore suboptimal that GSOs are being marked SKB_GSO_DODGY to defer the gso_segs calculation when netback already has all necessary information to hand to do the calculation. This patch adds that calculation. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Eric Dumazet <edumazet@google.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-19xen-netback: fix some error return codeWei Yongjun1-4/+12
'err' is overwrited to 0 after maybe_pull_tail() call, so the error code was not set if skb_partial_csum_set() call failed. Fix to return error -EPROTO from those error handling case instead of 0. Fixes: d52eb0d46f36 ('xen-netback: make sure skb linear area covers checksum field') Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-18Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-41/+40
Conflicts: drivers/net/ethernet/intel/i40e/i40e_main.c drivers/net/macvtap.c Both minor merge hassles, simple overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-17xen-netback: fix fragments error handling in checksum_setup_ip()Wei Yongjun1-0/+3
Fix to return -EPROTO error if fragments detected in checksum_setup_ip(). Fixes: 1431fb31ecba ('xen-netback: fix fragment detection in checksum setup') Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Reviewed-by: Paul Durrant <paul.durrant@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-12xen-netback: fix gso_prefix checkPaul Durrant1-1/+1
There is a mistake in checking the gso_prefix mask when passing large packets to a guest. The wrong shift is applied to the bit - the raw skb gso type is used rather then the translated one. This leads to large packets being handed to the guest without the GSO metadata. This patch fixes the check. The mistake manifested as errors whilst running Microsoft HCK large packet offload tests between a pair of Windows 8 VMs. I have verified this patch fixes those errors. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-12xen-netback: napi: don't prematurely request a tx eventPaul Durrant1-1/+1
This patch changes the RING_FINAL_CHECK_FOR_REQUESTS in xenvif_build_tx_gops to a check for RING_HAS_UNCONSUMED_REQUESTS as the former call has the side effect of advancing the ring event pointer and therefore inviting another interrupt from the frontend before the napi poll has actually finished, thereby defeating the point of napi. The event pointer is updated by RING_FINAL_CHECK_FOR_REQUESTS in xenvif_poll, the napi poll function, if the work done is less than the budget i.e. when actually transitioning back to interrupt mode. Reported-by: Malcolm Crossley <malcolm.crossley@citrix.com> Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-12xen-netback: napi: fix abuse of budgetPaul Durrant1-7/+7
netback seems to be somewhat confused about the napi budget parameter. The parameter is supposed to limit the number of skbs processed in each poll, but netback has this confused with grant operations. This patch fixes that, properly limiting the work done in each poll. Note that this limit makes sure we do not process any more data from the shared ring than we intend to pass back from the poll. This is important to prevent tx_queue potentially growing without bound. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-11xen-netback: make sure skb linear area covers checksum fieldPaul Durrant1-32/+28
skb_partial_csum_set requires that the linear area of the skb covers the checksum field. The checksum setup code in netback was only doing that pullup in the case when the pseudo header checksum was being recalculated though. This patch makes that pullup unconditional. (I pullup the whole transport header just for simplicity; the requirement is only for the check field but in the case of UDP this is the last field in the header and in the case of TCP it's the last but one). The lack of pullup manifested as failures running Microsoft HCK network tests on a pair of Windows 8 VMs and it has been verified that this patch fixes the problem. Suggested-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-09xen-netback: improve guest-receive-side flow controlPaul Durrant1-146/+71
The way that flow control works without this patch is that, in start_xmit() the code uses xenvif_count_skb_slots() to predict how many slots xenvif_gop_skb() will consume and then adds this to a 'req_cons_peek' counter which it then uses to determine if the shared ring has that amount of space available by checking whether 'req_prod' has passed that value. If the ring doesn't have space the tx queue is stopped. xenvif_gop_skb() will then consume slots and update 'req_cons' and issue responses, updating 'rsp_prod' as it goes. The frontend will consume those responses and post new requests, by updating req_prod. So, req_prod chases req_cons which chases rsp_prod, and can never exceed that value. Thus if xenvif_count_skb_slots() ever returns a number of slots greater than xenvif_gop_skb() uses, req_cons_peek will get to a value that req_prod cannot possibly achieve (since it's limited by the 'real' req_cons) and, if this happens enough times, req_cons_peek gets more than a ring size ahead of req_cons and the tx queue then remains stopped forever waiting for an unachievable amount of space to become available in the ring. Having two routines trying to calculate the same value is always going to be fragile, so this patch does away with that. All we essentially need to do is make sure that we have 'enough stuff' on our internal queue without letting it build up uncontrollably. So start_xmit() makes a cheap optimistic check of how much space is needed for an skb and only turns the queue off if that is unachievable. net_rx_action() is the place where we could do with an accurate predicition but, since that has proven tricky to calculate, a cheap worse-case (but not too bad) estimate is all we really need since the only thing we *must* prevent is xenvif_gop_skb() consuming more slots than are available. Without this patch I can trivially stall netback permanently by just doing a large guest to guest file copy between two Windows Server 2008R2 VMs on a single host. Patch tested with frontends in: - Windows Server 2008R2 - CentOS 6.0 - Debian Squeeze - Debian Wheezy - SLES11 Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Annie Li <annie.li@oracle.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-05xen-netback: fix fragment detection in checksum setupPaul Durrant1-99/+137
The code to detect fragments in checksum_setup() was missing for IPv4 and too eager for IPv6. (It transpires that Windows seems to send IPv6 packets with a fragment header even if they are not a fragment - i.e. offset is zero, and M bit is not set). This patch also incorporates a fix to callers of maybe_pull_tail() where skb->network_header was being erroneously added to the length argument. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> cc: David Miller <davem@davemloft.net> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-11-28xen-netback: include definition of csum_ipv6_magicAndy Whitcroft1-0/+1
We are now using csum_ipv6_magic, include the appropriate header. Avoids the following error: drivers/net/xen-netback/netback.c:1313:4: error: implicit declaration of function 'csum_ipv6_magic' [-Werror=implicit-function-declaration] tcph->check = ~csum_ipv6_magic(&ipv6h->saddr, Signed-off-by: Andy Whitcroft <apw@canonical.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-11-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-5/+5
Conflicts: drivers/net/ethernet/emulex/benet/be.h drivers/net/netconsole.c net/bridge/br_private.h Three mostly trivial conflicts. The net/bridge/br_private.h conflict was a function signature (argument addition) change overlapping with the extern removals from Joe Perches. In drivers/net/netconsole.c we had one change adjusting a printk message whilst another changed "printk(KERN_INFO" into "pr_info(". Lastly, the emulex change was a new inline function addition overlapping with Joe Perches's extern removals. Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-29xen-netback: use jiffies_64 value to calculate credit timeoutWei Liu1-5/+5
time_after_eq() only works if the delta is < MAX_ULONG/2. For a 32bit Dom0, if netfront sends packets at a very low rate, the time between subsequent calls to tx_credit_exceeded() may exceed MAX_ULONG/2 and the test for timer_after_eq() will be incorrect. Credit will not be replenished and the guest may become unable to send packets (e.g., if prior to the long gap, all credit was exhausted). Use jiffies_64 variant to mitigate this problem for 32bit Dom0. Suggested-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Wei Liu <wei.liu2@citrix.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: Jason Luan <jianhai.luan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-17xen-netback: enable IPv6 TCP GSO to the guestPaul Durrant1-10/+38
This patch adds code to handle SKB_GSO_TCPV6 skbs and construct appropriate extra or prefix segments to pass the large packet to the frontend. New xenstore flags, feature-gso-tcpv6 and feature-gso-tcpv6-prefix, are sampled to determine if the frontend is capable of handling such packets. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-17xen-netback: handle IPv6 TCP GSO packets from the guestPaul Durrant1-3/+8
This patch adds a xenstore feature flag, festure-gso-tcpv6, to advertise that netback can handle IPv6 TCP GSO packets. It creates SKB_GSO_TCPV6 skbs if the frontend passes an extra segment with the new type XEN_NETIF_GSO_TYPE_TCPV6 added to netif.h. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-17xen-netback: add support for IPv6 checksum offload from guestPaul Durrant1-39/+196
For performance of VM to VM traffic on a single host it is better to avoid calculation of TCP/UDP checksum in the sending frontend. To allow this this patch adds the code necessary to set up partial checksum for IPv6 packets and xenstore flag feature-ipv6-csum-offload to advertise that fact to frontends. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-08Revert "xen-netback: improve ring effeciency for guest RX"Wei Liu1-61/+83
This reverts commit 4f0581d25827d5e864bcf07b05d73d0d12a20a5c. The named changeset is causing problem. Let's aim to make this part less fragile before trying to improve things. Signed-off-by: Wei Liu <wei.liu2@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: Annie Li <annie.li@oracle.com> Cc: Matt Wilson <msw@amazon.com> Cc: Xi Xiong <xixiong@amazon.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Paul Durrant <paul.durrant@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-30xen-netback: improve ring effeciency for guest RXWei Liu1-83/+61
There was a bug that netback routines netbk/xenvif_skb_count_slots and netbk/xenvif_gop_frag_copy disagreed with each other, which caused netback to push wrong number of responses to netfront, which caused netfront to eventually crash. The bug was fixed in 6e43fc04a ("xen-netback: count number required slots for an skb more carefully"). Commit 6e43fc04a focused on backport-ability. The drawback with the existing packing scheme is that the ring is not used effeciently, as stated in 6e43fc04a. skb->data like: | 1111|222222222222|3333 | is arranged as: |1111 |222222222222|3333 | If we can do this: |111122222222|22223333 | That would save one ring slot, which improves ring effeciency. This patch effectively reverts 6e43fc04a. That patch made count_slots agree with gop_frag_copy, while this patch goes the other way around -- make gop_frag_copy agree with count_slots. The end result is that they still agree with each other, and the ring is now arranged like: |111122222222|22223333 | The patch that improves packing was first posted by Xi Xong and Matt Wilson. I only rebase it on top of net-next and rewrite commit message, so I retain all their SoBs. For more infomation about the original bug please refer to email listed below and commit message of 6e43fc04a. Original patch: http://lists.xen.org/archives/html/xen-devel/2013-07/msg00760.html Signed-off-by: Xi Xiong <xixiong@amazon.com> Reviewed-by: Matt Wilson <msw@amazon.com> [ msw: minor code cleanups, rewrote commit message, adjusted code to count RX slots instead of meta structures ] Signed-off-by: Matt Wilson <msw@amazon.com> Cc: Annie Li <annie.li@oracle.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: Ian Campbell <Ian.Campbell@citrix.com> [ liuw: rebased on top of net-next tree, rewrote commit message, coding style cleanup. ] Signed-off-by: Wei Liu <wei.liu2@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> Acked-by: Ian Campbell <Ian.Campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-12xen-netback: count number required slots for an skb more carefullyDavid Vrabel1-30/+64
When a VM is providing an iSCSI target and the LUN is used by the backend domain, the generated skbs for direct I/O writes to the disk have large, multi-page skb->data but no frags. With some lengths and starting offsets, xen_netbk_count_skb_slots() would be one short because the simple calculation of DIV_ROUND_UP(skb_headlen(), PAGE_SIZE) was not accounting for the decisions made by start_new_rx_buffer() which does not guarantee responses are fully packed. For example, a skb with length < 2 pages but which spans 3 pages would be counted as requiring 2 slots but would actually use 3 slots. skb->data: | 1111|222222222222|3333 | Fully packed, this would need 2 slots: |111122222222|22223333 | But because the 2nd page wholy fits into a slot it is not split across slots and goes into a slot of its own: |1111 |222222222222|3333 | Miscounting the number of slots means netback may push more responses than the number of available requests. This will cause the frontend to get very confused and report "Too many frags/slots". The frontend never recovers and will eventually BUG. Fix this by counting the number of required slots more carefully. In xen_netbk_count_skb_slots(), more closely follow the algorithm used by xen_netbk_gop_skb() by introducing xen_netbk_count_frag_slots() which is the dry-run equivalent of netbk_gop_frag_copy(). Signed-off-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-29xen-netback: rename functionsWei Liu1-111/+112
As we move to 1:1 model and melt xen_netbk and xenvif together, it would be better to use single prefix for all functions in xen-netback. Signed-off-by: Wei Liu <wei.liu2@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-29xen-netback: switch to NAPI + kthread 1:1 modelWei Liu1-430/+177
This patch implements 1:1 model netback. NAPI and kthread are utilized to do the weight-lifting job: - NAPI is used for guest side TX (host side RX) - kthread is used for guest side RX (host side TX) Xenvif and xen_netbk are made into one structure to reduce code size. This model provides better scheduling fairness among vifs. It is also prerequisite for implementing multiqueue for Xen netback. Signed-off-by: Wei Liu <wei.liu2@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-29xen-netback: remove page tracking facilityWei Liu1-75/+2
The data flow from DomU to DomU on the same host in current copying scheme with tracking facility: copy DomU --------> Dom0 DomU | ^ |____________________________| copy The page in Dom0 is a page with valid MFN. So we can always copy from page Dom0, thus removing the need for a tracking facility. copy copy DomU --------> Dom0 -------> DomU Simple iperf test shows no performance regression (obviously we copy twice either way): W/ tracking: ~5.3Gb/s W/o tracking: ~5.4Gb/s Signed-off-by: Wei Liu <wei.liu2@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Acked-by: Matt Wilson <msw@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-07-01xen: Use more current logging stylesJoe Perches1-4/+3
Instead of mixing printk and pr_<level> forms, just use pr_<level> Miscellaneous changes around these conversions: Add a missing newline to avoid message interleaving, coalesce formats, reflow modified lines to 80 columns. Signed-off-by: Joe Perches <joe@perches.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-24xen-netback: double free on unloadDan Carpenter1-2/+2
There is a typo here, "i" vs "j", so we would crash on module_exit(). Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-19Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-3/+5
Conflicts: drivers/net/wireless/ath/ath9k/Kconfig drivers/net/xen-netback/netback.c net/batman-adv/bat_iv_ogm.c net/wireless/nl80211.c The ath9k Kconfig conflict was a change of a Kconfig option name right next to the deletion of another option. The xen-netback conflict was overlapping changes involving the handling of the notify list in xen_netbk_rx_action(). Batman conflict resolution provided by Antonio Quartulli, basically keep everything in both conflict hunks. The nl80211 conflict is a little more involved. In 'net' we added a dynamic memory allocation to nl80211_dump_wiphy() to fix a race that Linus reported. Meanwhile in 'net-next' the handlers were converted to use pre and post doit handlers which use a flag to determine whether to hold the RTNL mutex around the operation. However, the dump handlers to not use this logic. Instead they have to explicitly do the locking. There were apparent bugs in the conversion of nl80211_dump_wiphy() in that we were not dropping the RTNL mutex in all the return paths, and it seems we very much should be doing so. So I fixed that whilst handling the overlapping changes. To simplify the initial returns, I take the RTNL mutex after we try to allocate 'tb'. Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-13xen-netback: don't de-reference vif pointer after having called xenvif_put()Jan Beulich1-5/+6
When putting vif-s on the rx notify list, calling xenvif_put() must be deferred until after the removal from the list and the issuing of the notification, as both operations dereference the pointer. Changing this got me to notice that the "irq" variable was effectively unused (and was of too narrow type anyway). Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-23xen-netback: split event channels support for Xen backend driverWei Liu1-4/+10
Netback and netfront only use one event channel to do TX / RX notification, which may cause unnecessary wake-up of processing routines. This patch adds a new feature called feature-split-event-channels to netback, enabling it to handle TX and RX events separately. Netback will use tx_irq to notify guest for TX completion, rx_irq for RX notification. If frontend doesn't support this feature, tx_irq equals to rx_irq. Signed-off-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-17xen-netback: enable user to unload netback moduleWei Liu1-0/+20
This patch enables user to unload netback module, which is useful when user wants to upgrade to a newer netback module without rebooting the host. Netfront cannot handle netback removal event. As we cannot fix all possible frontends we add module get / put along with vif get / put to avoid mis-unloading of netback. To unload netback module, user needs to shutdown all VMs or migrate them to another host or unplug all vifs before hand. Signed-off-by: Wei Liu <wei.liu2@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com>¬ Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-17xen-netback: remove dead codeWei Liu1-4/+0
The array mmap_pages is never touched in the initialization function. This is remnant of mapping mechanism, which does not exist upstream. In current upstream code this array only tracks usage of pages inside netback. Those pages are allocated when contructing a SKB and passed directly to network subsystem. Signed-off-by: Wei Liu <wei.liu2@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-02xen-netback: better names for thresholdsWei Liu1-20/+29
This patch only changes some names to avoid confusion. In this patch we have: MAX_SKB_SLOTS_DEFAULT -> FATAL_SKB_SLOTS_DEFAULT max_skb_slots -> fatal_skb_slots #define XEN_NETBK_LEGACY_SLOTS_MAX XEN_NETIF_NR_SLOTS_MIN The fatal_skb_slots is the threshold to determine whether a packet is malicious. XEN_NETBK_LEGACY_SLOTS_MAX is the maximum slots a valid packet can have at this point. It is defined to be XEN_NETIF_NR_SLOTS_MIN because that's guaranteed to be supported by all backends. Suggested-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-02xen-netback: avoid allocating variable size array on stackWei Liu1-2/+14
Tune xen_netbk_count_requests to not touch working array beyond limit, so that we can make working array size constant. Suggested-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-02xen-netback: remove redundent parameter in netbk_count_requestsWei Liu1-4/+2
Tracking down from the caller, first_idx is always equal to vif->tx.req_cons. Remove it to avoid confusion. Suggested-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Wei Liu <wei.liu2@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-22xen-netback: don't disconnect frontend when seeing oversize packetWei Liu1-6/+16
Some frontend drivers are sending packets > 64 KiB in length. This length overflows the length field in the first slot making the following slots have an invalid length. Turn this error back into a non-fatal error by dropping the packet. To avoid having the following slots having fatal errors, consume all slots in the packet. This does not reopen the security hole in XSA-39 as if the packet as an invalid number of slots it will still hit fatal error case. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Wei Liu <wei.liu2@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-22xen-netback: coalesce slots in TX path and fix regressionsWei Liu1-51/+224
This patch tries to coalesce tx requests when constructing grant copy structures. It enables netback to deal with situation when frontend's MAX_SKB_FRAGS is larger than backend's MAX_SKB_FRAGS. With the help of coalescing, this patch tries to address two regressions avoid reopening the security hole in XSA-39. Regression 1. The reduction of the number of supported ring entries (slots) per packet (from 18 to 17). This regression has been around for some time but remains unnoticed until XSA-39 security fix. This is fixed by coalescing slots. Regression 2. The XSA-39 security fix turning "too many frags" errors from just dropping the packet to a fatal error and disabling the VIF. This is fixed by coalescing slots (handling 18 slots when backend's MAX_SKB_FRAGS is 17) which rules out false positive (using 18 slots is legit) and dropping packets using 19 to `max_skb_slots` slots. To avoid reopening security hole in XSA-39, frontend sending packet using more than max_skb_slots is considered malicious. The behavior of netback for packet is thus: 1-18 slots: valid 19-max_skb_slots slots: drop and respond with an error max_skb_slots+ slots: fatal error max_skb_slots is configurable by admin, default value is 20. Also change variable name from "frags" to "slots" in netbk_count_requests. Please note that RX path still has dependency on MAX_SKB_FRAGS. This will be fixed with separate patch. Signed-off-by: Wei Liu <wei.liu2@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-12xen-netback: switch to use skb_partial_csum_set()Jason Wang1-14/+8
Switch to use skb_partial_csum_set() to simplify the codes. Cc: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-10xen-netback: fix sparse warningstephen hemminger1-1/+1
Fix warning about 0 used as NULL. Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-27net: switch to use skb_probe_transport_header()Jason Wang1-9/+1
Switch to use the new help skb_probe_transport_header() to do the l4 header probing for untrusted sources. For packets with partial csum, the header should already been set by skb_partial_csum_set(). Cc: Eric Dumazet <edumazet@google.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-26netback: set transport header before passing it to kernelJason Wang1-0/+12
Currently, for the packets receives from netback, before doing header check, kernel just reset the transport header in netif_receive_skb() which pretends non l4 header. This is suboptimal for precise packet length estimation (introduced in 1def9238: net_sched: more precise pkt_len computation) which needs correct l4 header for gso packets. The patch just reuse the header probed by netback for partial checksum packets and tries to use skb_flow_dissect() for other cases, if both fail, just pretend no l4 header. Cc: Eric Dumazet <edumazet@google.com> Cc: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-25xen-netback: remove skb in xen_netbk_alloc_pageWei Liu1-3/+2
This variable is never used. Signed-off-by: Wei Liu <wei.liu2@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-19Revert "xen: netback: remove redundant xenvif_put"David S. Miller1-0/+1
This reverts commit d37204566a61d5116d385ae909db8e14a734b30f. This change is incorrect, as per Jan Beulich: ==================== But this is wrong from all we can tell, we discussed this before (Wei pointed to the discussion in an earlier reply). The core of it is that the put here parallels the one in netbk_tx_err(), and the one in xenvif_carrier_off() matches the get from xenvif_connect() (which normally would be done on the path coming through xenvif_disconnect()). ==================== And a previous discussion of this issue is at: http://marc.info/?l=xen-devel&m=136084174026977&w=2 Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-19xen: netback: remove redundant xenvif_putAndrew Jones1-1/+0
netbk_fatal_tx_err() calls xenvif_carrier_off(), which does a xenvif_put(). As callers of netbk_fatal_tx_err should only have one reference to the vif at this time, then the xenvif_put in netbk_fatal_tx_err is one too many. Signed-off-by: Andrew Jones <drjones@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>