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2016-10-10virtio: cleanup VMSTATE_VIRTIO_DEVICEHalil Pasic1-6/+0
Now all the usages of the old version of VMSTATE_VIRTIO_DEVICE are gone, so we can get rid of the conditionals, and the old macro. Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-10-10virtio: prepare change VMSTATE_VIRTIO_DEVICE macroHalil Pasic1-0/+21
In most cases the functions passed to VMSTATE_VIRTIO_DEVICE only call the virtio_load and virtio_save wrappers. Some include some pre- and post- massaging too. The massaging is better expressed as such in the VMStateDescription. Let us prepare for changing the semantic of the VMSTATE_VIRTIO_DEVICE macro so that it is more similar to the other VMSTATE_*_DEVICE macros in a sense that it is a field definition. The preprocessor conditionals are going to be removed as soon as every usage is converted to the new semantic. Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-10-10virtio: add virtio_detach_element()Stefan Hajnoczi1-2/+25
During device reset or similar situations a VirtQueueElement needs to be freed without pushing it onto the used ring or rewinding the virtqueue. Extract a new function to do this. Later patches add virtio_detach_element() calls to existing device so that scatter-gather lists are unmapped and vq->inuse goes back to zero during device reset. Currently some devices don't bother and simply call g_free(elem) which is not a clean way to throw away a VirtQueueElement. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Acked-by: Greg Kurz <groug@kaod.org> Reviewed-by: Ladi Prosek <lprosek@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-09-23virtio: handle virtqueue_get_head() errorsStefan Hajnoczi1-10/+17
Stop processing the vring if virtqueue_get_head() fetches an out-of-bounds head index. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2016-09-23virtio: handle virtqueue_num_heads() errorsStefan Hajnoczi1-3/+8
If the avail ring index is bogus virtqueue_num_heads() must return -EINVAL. The only caller is virtqueue_get_avail_bytes(). Return saying no bytes are available when virtqueue_num_heads() fails. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2016-09-23virtio: handle virtqueue_read_next_desc() errorsStefan Hajnoczi1-13/+32
Stop processing the vring if an avail ring index is invalid. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2016-09-23virtio: use unsigned int for virtqueue_get_avail_bytes() indexStefan Hajnoczi1-1/+1
The virtio code uses int, unsigned int, and uint16_t for virtqueue indices. The uint16_t is used for the low-level descriptor layout in virtio_ring.h while code that isn't concerned with descriptor layout can use unsigned int. Use of int is problematic because it can result in signed/unsigned comparison and incompatible int*/unsigned int* pointer types. Make the virtqueue_get_avail_bytes() 'i' variable unsigned int. This eliminates the need to introduce casts and modify code further in the patches that follow. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2016-09-23virtio: handle virtqueue_get_avail_bytes() errorsStefan Hajnoczi1-6/+11
If the vring is invalid, tell the caller no bytes are available and mark the device broken. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2016-09-23virtio: handle virtqueue_map_desc() errorsStefan Hajnoczi1-19/+55
Errors can occur during virtqueue_pop(), especially in virtqueue_map_desc(). In order to handle this we must unmap iov[] before returning NULL. The caller will consider the virtqueue empty and the virtio_error() call will have marked the device broken. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-09-23virtio: migrate vdev->broken flagStefan Hajnoczi1-0/+19
Send a subsection if the vdev->broken flag is set. This allows live migration of broken virtio devices. The subsection is only sent if vdev->broken has been set. In most cases the flag will be clear and no subsection will be sent. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2016-09-23virtio: stop virtqueue processing if device is brokenStefan Hajnoczi1-0/+39
QEMU prints an error message and exits when the device enters an invalid state. Terminating the process is heavy-handed. The guest may still be able to function even if there is a bug in a virtio guest driver. Moreover, exiting is a bug in nested virtualization where a nested guest could DoS other nested guests by killing a pass-through virtio device. I don't think this configuration is possible today but it is likely in the future. If the broken flag is set, do not process virtqueues or write back used descriptors. The broken flag can be cleared again by resetting the device. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2016-09-23virtio: fix stray tab characterStefan Hajnoczi1-1/+1
Fix a single occurrence of a tab character in a file that otherwise uses spaces for indentation. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2016-09-23virtio: add check for descriptor's mapped addressPrasad J Pandit1-0/+5
virtio back end uses set of buffers to facilitate I/O operations. If its size is too large, 'cpu_physical_memory_map' could return a null address. This would result in a null dereference while un-mapping descriptors. Add check to avoid it. Reported-by: Qinghao Tang <luodalongde@gmail.com> Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com>
2016-09-09virtio: add virtqueue_rewind()Stefan Hajnoczi1-0/+22
virtqueue_discard() requires a VirtQueueElement but virtio-balloon does not migrate its in-use element. Introduce a new function that is similar to virtqueue_discard() but doesn't require a VirtQueueElement. This will allow virtio-balloon to access element again after migration with the usual proviso that the guest may have modified the vring since last time. Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Roman Kagan <rkagan@virtuozzo.com> Cc: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Ladi Prosek <lprosek@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-09-09virtio: zero vq->inuse in virtio_reset()Stefan Hajnoczi1-0/+1
vq->inuse must be zeroed upon device reset like most other virtqueue fields. In theory, virtio_reset() just needs assert(vq->inuse == 0) since devices must clean up in-flight requests during reset (requests cannot not be leaked!). In practice, it is difficult to achieve vq->inuse == 0 across reset because balloon, blk, 9p, etc implement various different strategies for cleaning up requests. Most devices call g_free(elem) directly without telling virtio.c that the VirtQueueElement is cleaned up. Therefore vq->inuse is not decremented during reset. This patch zeroes vq->inuse and trusts that devices are not leaking VirtQueueElements across reset. I will send a follow-up series that refactors request life-cycle across all devices and converts vq->inuse = 0 into assert(vq->inuse == 0) but this more invasive approach is not appropriate for stable trees. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Cc: qemu-stable <qemu-stable@nongnu.org> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Ladi Prosek <lprosek@redhat.com>
2016-08-23virtio: decrement vq->inuse in virtqueue_discard()Stefan Hajnoczi1-0/+1
virtqueue_discard() moves vq->last_avail_idx back so the element can be popped again. It's necessary to decrement vq->inuse to avoid "leaking" the element count. Cc: qemu-stable@nongnu.org Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-08-23virtio: recalculate vq->inuse after migrationStefan Hajnoczi1-0/+15
The vq->inuse field is not migrated. Many devices don't hold VirtQueueElements across migration so it doesn't matter that vq->inuse starts at 0 on the destination QEMU. At least virtio-serial, virtio-blk, and virtio-balloon migrate while holding VirtQueueElements. For these devices we need to recalculate vq->inuse upon load so the value is correct. Cc: qemu-stable@nongnu.org Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-07-29Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into stagingPeter Maydell1-0/+5
pc, pci, virtio: cleanups, fixes a bunch of bugfixes and a couple of cleanups making these easier and/or making debugging easier Signed-off-by: Michael S. Tsirkin <mst@redhat.com> # gpg: Signature made Fri 29 Jul 2016 04:11:01 BST # gpg: using RSA key 0x281F0DB8D28D5469 # gpg: Good signature from "Michael S. Tsirkin <mst@kernel.org>" # gpg: aka "Michael S. Tsirkin <mst@redhat.com>" # Primary key fingerprint: 0270 606B 6F3C DF3D 0B17 0970 C350 3912 AFBE 8E67 # Subkey fingerprint: 5D09 FD08 71C8 F85B 94CA 8A0D 281F 0DB8 D28D 5469 * remotes/mst/tags/for_upstream: (41 commits) mptsas: Fix a migration compatible issue vhost: do not update last avail idx on get_vring_base() failure vhost: add vhost_net_set_backend() vhost-user: add error report in vhost_user_write() tests: fix vhost-user-test leak tests: plug some leaks in virtio-net-test vhost-user: wait until backend init is completed char: add and use tcp_chr_wait_connected char: add chr_wait_connected callback vhost: add assert() to check runtime behaviour vhost-net: vhost_migration_done is vhost-user specific Revert "vhost-net: do not crash if backend is not present" vhost-user: add get_vhost_net() assertions vhost-user: keep vhost_net after a disconnection vhost-user: check vhost_user_{read,write}() return value vhost-user: check qemu_chr_fe_set_msgfds() return value vhost-user: call set_msgfds unconditionally qemu-char: fix qemu_chr_fe_set_msgfds() crash when disconnected vhost: use error_report() instead of fprintf(stderr,...) vhost: add missing VHOST_OPS_DEBUG ... Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-07-29virtio: check vring descriptor buffer lengthPrasad J Pandit1-0/+5
virtio back end uses set of buffers to facilitate I/O operations. An infinite loop unfolds in virtqueue_pop() if a buffer was of zero size. Add check to avoid it. Reported-by: Li Qiang <liqiang6-s@360.cn> Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-27virtio: error out if guest exceeds virtqueue sizeStefan Hajnoczi1-0/+5
A broken or malicious guest can submit more requests than the virtqueue size permits, causing unbounded memory allocation in QEMU. The guest can submit requests without bothering to wait for completion and is therefore not bound by virtqueue size. This requires reusing vring descriptors in more than one request, which is not allowed by the VIRTIO 1.0 specification. In "3.2.1 Supplying Buffers to The Device", the VIRTIO 1.0 specification says: 1. The driver places the buffer into free descriptor(s) in the descriptor table, chaining as necessary and Note that the above code does not take precautions against the available ring buffer wrapping around: this is not possible since the ring buffer is the same size as the descriptor table, so step (1) will prevent such a condition. This implies that placing more buffers into the virtqueue than the descriptor table size is not allowed. QEMU is missing the check to prevent this case. Processing a request allocates a VirtQueueElement leading to unbounded memory allocation controlled by the guest. Exit with an error if the guest provides more requests than the virtqueue size permits. This bounds memory allocation and makes the buggy guest visible to the user. This patch fixes CVE-2016-5403 and was reported by Zhenhao Hong from 360 Marvel Team, China. Reported-by: Zhenhao Hong <hongzhenhao@360.cn> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-21virtio: Migration helper function and macroDr. David Alan Gilbert1-0/+6
To make conversion of virtio devices to VMState simple at first add a helper function for the simple virtio_save case and a helper macro that defines the VMState structure. These will probably go away or change as more of the virtio code gets converted. Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-07-21virtio: Introduce virtio_add_queue_aioFam Zheng1-4/+34
Using this function instead of virtio_add_queue marks the vq as aio based. This differentiation will be useful in later patches. Distinguish between virtqueue processing in the iohandler context and main loop AioContext. iohandler context is isolated from AioContexts and therefore does not run during aio_poll(). Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-21virtio: Add typedef for handle_outputFam Zheng1-5/+4
The function pointer signature has been repeated a few times, using a typedef may make coding easier. Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-04virtio: set low features early on loadMichael S. Tsirkin1-0/+10
virtio migrates the low 32 feature bits twice, the first copy is there for compatibility but ever since 019a3edbb25f1571e876f8af1ce4c55412939e5d: ("virtio: make features 64bit wide") it's ignored on load. This is wrong since virtio_net_load tests self announcement and guest offloads before the second copy including high feature bits is loaded. This means that self announcement, control vq and guest offloads are all broken after migration. Fix it up by loading low feature bits: somewhat ugly since high and low bits become out of sync temporarily, but seems unavoidable for compatibility. The right thing to do for new features is probably to test the host features, anyway. Fixes: 019a3edbb25f1571e876f8af1ce4c55412939e5d ("virtio: make features 64bit wide") Cc: qemu-stable@nongnu.org Reported-by: Robin Geuze <robing@transip.nl> Tested-by: Robin Geuze <robing@transip.nl> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-06-07virtio: drop duplicate virtio_queue_get_id() functionStefan Hajnoczi1-7/+0
The virtio_queue_get_id() function is the lesser used duplicate of virtio_get_queue_index(). Use the latter instead. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 1463767461-17922-1-git-send-email-stefanha@redhat.com
2016-04-22virtio: Mark host notifiers as externalFam Zheng1-2/+2
The effect of this change is the block layer drained section can work, for example when mirror job is being completed. Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-04-22event-notifier: Add "is_external" parameterFam Zheng1-4/+4
All callers pass "false" keeping the old semantics. The windows implementation doesn't distinguish the flag yet. On posix, it is passed down to the underlying aio context. Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-04-07virtio: merge virtio_queue_aio_set_host_notifier_handler with ↵Paolo Bonzini1-12/+5
virtio_queue_set_aio Eliminating the reentrancy is actually a nice thing that we can do with the API that Michael proposed, so let's make it first class. This also hides the complex assign/set_handler conventions from callers of virtio_queue_aio_set_host_notifier_handler, which in fact was always called with assign=true. Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-04-07virtio: add aio handlerMichael S. Tsirkin1-4/+32
In addition to handling IO in vcpu thread and in io thread, blk dataplane introduces yet another mode: handling it by AioContext. Currently, this reuses the same handler as previous modes, which triggers races as these were not designed to be reentrant. Add instead a separate handler just for aio; this will make it possible to disable regular handlers when dataplane is active. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-04-07virtio: make virtio_queue_notify_vq staticPaolo Bonzini1-1/+1
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-03-22hw: explicitly include qemu-common.h and cpu.hPaolo Bonzini1-1/+2
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22include/qemu/osdep.h: Don't include qapi/error.hMarkus Armbruster1-0/+1
Commit 57cb38b included qapi/error.h into qemu/osdep.h to get the Error typedef. Since then, we've moved to include qemu/osdep.h everywhere. Its file comment explains: "To avoid getting into possible circular include dependencies, this file should not include any other QEMU headers, with the exceptions of config-host.h, compiler.h, os-posix.h and os-win32.h, all of which are doing a similar job to this file and are under similar constraints." qapi/error.h doesn't do a similar job, and it doesn't adhere to similar constraints: it includes qapi-types.h. That's in excess of 100KiB of crap most .c files don't actually need. Add the typedef to qemu/typedefs.h, and include that instead of qapi/error.h. Include qapi/error.h in .c files that need it and don't get it now. Include qapi-types.h in qom/object.h for uint16List. Update scripts/clean-includes accordingly. Update it further to match reality: replace config.h by config-target.h, add sysemu/os-posix.h, sysemu/os-win32.h. Update the list of includes in the qemu/osdep.h comment quoted above similarly. This reduces the number of objects depending on qapi/error.h from "all of them" to less than a third. Unfortunately, the number depending on qapi-types.h shrinks only a little. More work is needed for that one. Signed-off-by: Markus Armbruster <armbru@redhat.com> [Fix compilation without the spice devel packages. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-25virtio: export vring_notify as virtio_should_notifyPaolo Bonzini1-2/+2
Virtio dataplane needs to trigger the irq manually through the guest notifier. Export virtio_should_notify so that it can be used around event_notifier_set. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: Fam Zheng <famz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-02-25virtio: add AioContext-specific function for host notifiersPaolo Bonzini1-0/+16
This is used to register ioeventfd with a dataplane thread. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-02-18vhost-user interrupt management fixesVictor Kaplansky1-0/+1
Since guest_mask_notifier can not be used in vhost-user mode due to buffering implied by unix control socket, force use_mask_notifier on virtio devices of vhost-user interfaces, and send correct callfd to the guest at vhost start. Using guest_notifier_mask function in vhost-user case may break interrupt mask paradigm, because mask/unmask is not really done when returning from guest_notifier_mask call, instead message is posted in a unix socket, and processed later. Add an option boolean flag 'use_mask_notifier' to disable the use of guest_notifier_mask in virtio pci. Signed-off-by: Didier Pallard <didier.pallard@6wind.com> Signed-off-by: Victor Kaplansky <victork@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-02-06virtio: combine write of an entry into used ringVincenzo Maffione1-13/+12
Fill in an element of the used ring with a single combined access to the guest physical memory, rather than using two separated accesses. This reduces the overhead due to expensive address translation. Signed-off-by: Vincenzo Maffione <v.maffione@gmail.com> Message-Id: <e4a89a767a4a92cbb6bcc551e151487eb36e1722.1450218353.git.v.maffione@gmail.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-02-06virtio: read avail_idx from VQ only when necessaryVincenzo Maffione1-4/+22
The virtqueue_pop() implementation needs to check if the avail ring contains some pending buffers. To perform this check, it is not always necessary to fetch the avail_idx in the VQ memory, which is expensive. This patch introduces a shadow variable tracking avail_idx and modifies virtio_queue_empty() to access avail_idx in physical memory only when necessary. Signed-off-by: Vincenzo Maffione <v.maffione@gmail.com> Message-Id: <b617d6459902773d9f4ab843bfaca764f5af8eda.1450218353.git.v.maffione@gmail.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-02-06virtio: cache used_idx in a VirtQueue fieldVincenzo Maffione1-3/+9
Accessing used_idx in the VQ requires an expensive access to guest physical memory. Before this patch, 3 accesses are normally done for each pop/push/notify call. However, since the used_idx is only written by us, we can track it in our internal data structure. Signed-off-by: Vincenzo Maffione <v.maffione@gmail.com> Message-Id: <3d062ec54e9a7bf9fb325c1fd693564951f2b319.1450218353.git.v.maffione@gmail.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-02-06virtio: combine the read of a descriptorPaolo Bonzini1-51/+35
Compared to vring, virtio has a performance penalty of 10%. Fix it by combining all the reads for a descriptor in a single address_space_read call. This also simplifies the code nicely. Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-02-06virtio: slim down allocation of VirtQueueElementsPaolo Bonzini1-31/+51
Build the addresses and s/g lists on the stack, and then copy them to a VirtQueueElement that is just as big as required to contain this particular s/g list. The cost of the copy is minimal compared to that of a large malloc. When virtqueue_map is used on the destination side of migration or on loadvm, the iovecs have already been split at memory region boundary, so we can just reuse the out_num/in_num we find in the file. Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-02-06virtio: introduce virtqueue_alloc_elementPaolo Bonzini1-11/+99
Allocate the arrays for in_addr/out_addr/in_sg/out_sg outside the VirtQueueElement. For now, virtqueue_pop and vring_pop keep allocating a very large VirtQueueElement. Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-02-06virtio: introduce qemu_get/put_virtqueue_elementPaolo Bonzini1-0/+13
Move allocation to virtio functions also when loading/saving a VirtQueueElement. This will also let the load/save functions keep backwards compatibility when the VirtQueueElement layout is changed. Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-02-06virtio: move allocation to virtqueue_pop/vring_popPaolo Bonzini1-4/+8
The return code of virtqueue_pop/vring_pop is unused except to check for errors or 0. We can thus easily move allocation inside the functions and just return a pointer to the VirtQueueElement. The advantage is that we will be able to allocate only the space that is needed for the actual size of the s/g list instead of the full VIRTQUEUE_MAX_SIZE items. Currently VirtQueueElement takes about 48K of memory, and this kind of allocation puts a lot of stress on malloc. By cutting the size by two or three orders of magnitude, malloc can use much more efficient algorithms. The patch is pretty large, but changes to each device are testable more or less independently. Splitting it would mostly add churn. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2016-02-04Fix virtio migrationDr. David Alan Gilbert1-4/+4
I misunderstood the vmstate macro definition when I reworked the virtio .get/.put. The VMSTATE_STRUCT_VARRAY_KNOWN, was described as being for "a variable length array (i.e. _type *_field) but we know the length". However it actually specified operation for arrays embedded in the struct (i.e. _type _field[]) since it lacked the VMS_POINTER flag. This caused offset calculation to be completely off, examining and potentially sending random data instead of the VirtQueue content. Replace the otherwise unused VMSTATE_STRUCT_VARRAY_KNOWN with a VMSTATE_STRUCT_VARRAY_POINTER_KNOWN that includes the VMS_POINTER flag (so now actually doing what it advertises) and use it in the virtio migration code. Fixes and description as per Sascha's suggestions/debug. Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reported-by: Sascha Silbe <silbe@linux.vnet.ibm.com> Tested-By: Sascha Silbe <silbe@linux.vnet.ibm.com> Reviewed-By: Sascha Silbe <silbe@linux.vnet.ibm.com> Fixes: 50e5ae4dc3e4f21e874512f9e87b93b5472d26e0 Fixes: 2cf0148674430b6693c60d42b7eef721bfa9509f Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Tested-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2016-01-29virtio: Clean up includesPeter Maydell1-1/+1
Clean up includes so that osdep.h is included first and headers which it implies are not included manually. This commit was created with scripts/clean-includes. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 1453832250-766-15-git-send-email-peter.maydell@linaro.org
2016-01-09virtio: fix error message for number of queuesCornelia Huck1-1/+1
There's no such thing as "PCI queues" in the virtio core. Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-01-09migration/virtio: Remove simple .get/.put useDr. David Alan Gilbert1-68/+19
The 'virtqueue_state' and 'ringsize' can be saved using VMSTATE macros rather than hand coded .get/.put Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Amit Shah <amit.shah@redhat.com>
2015-11-12virtio-pci: fix 1.0 virtqueue migrationJason Wang1-0/+58
We don't migrate the followings fields for virtio-pci: uint32_t dfselect; uint32_t gfselect; uint32_t guest_features[2]; struct { uint16_t num; bool enabled; uint32_t desc[2]; uint32_t avail[2]; uint32_t used[2]; } vqs[VIRTIO_QUEUE_MAX]; This will confuse driver if migrating during initialization. Solves this issue by: - introduce transport specific callbacks to load and store extra virtqueue states. - add a new subsection for virtio to migrate transport specific modern device state. - implement pci specific callbacks. - add a new property for virtio-pci for whether or not to migrate extra state. - compat the migration for 2.4 and elder machine types Cc: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2015-10-29virtio: drop virtqueue_map_sgMichael S. Tsirkin1-7/+0
Deprecated in favor of virtqueue_map. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Igor Mammedov <imammedo@redhat.com>
2015-10-29virtio: switch to virtio_mapMichael S. Tsirkin1-2/+1
Drop use of the deprecated virtio_map_sg in virtio core. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Igor Mammedov <imammedo@redhat.com>
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