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2013-02-01virtio: add a queue_index to VirtQueueJason Wang1-0/+8
Add a queue_index to VirtQueue and a helper to fetch it, this could be used by multiqueue supported device. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-02-01virtio: introduce virtio_del_queue()Jason Wang1-0/+9
Some device (such as virtio-net) needs the ability to destroy or re-order the virtqueues, this patch adds a helper to do this. Signed-off-by: Jason Wang <jasowang> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-01-21virtio-device: refactor virtio-device.KONRAD Frederic1-12/+58
Create the virtio-device which is abstract. All the virtio-device can extend this class. It also add some functions to virtio-bus. Signed-off-by: KONRAD Frederic <fred.konrad@greensocs.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-12-20virtio: make bindings typesafeMichael S. Tsirkin1-1/+1
Move bindings from opaque to DeviceState. This gives us better type safety with no performance cost. Add macros to make future QOM work easier. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2012-12-19misc: move include files to include/qemu/Paolo Bonzini1-2/+2
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-11-29virtio: limit avail bytes lookaheadMichael S. Tsirkin1-7/+8
Commit 0d8d7690850eb0cf2b2b60933cf47669a6b6f18f introduced a regression in virtio-net performance because it looks into the ring aggressively while we really only care about a single packet worth of buffers. Reported as bugzilla 1066055 in launchpad. To fix, add parameters limiting lookahead, and use in virtqueue_avail_bytes. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reported-by: Edivaldo de Araujo Pereira <edivaldoapereira@yahoo.com.br> Tested-by: Edivaldo de Araujo Pereira <edivaldoapereira@yahoo.com.br> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-10-23Rename target_phys_addr_t to hwaddrAvi Kivity1-38/+38
target_phys_addr_t is unwieldly, violates the C standard (_t suffixes are reserved) and its purpose doesn't match the name (most target_phys_addr_t addresses are not target specific). Replace it with a finger-friendly, standards conformant hwaddr. Outstanding patchsets can be fixed up with the command git rebase -i --exec 'find -name "*.[ch]" | xargs s/target_phys_addr_t/hwaddr/g' origin Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-09-28virtio: Introduce virtqueue_get_avail_bytes()Amit Shah1-7/+21
The current virtqueue_avail_bytes() is oddly named, and checks if a particular number of bytes are available in a vq. A better API is to fetch the number of bytes available in the vq, and let the caller do what's interesting with the numbers. Introduce virtqueue_get_avail_bytes(), which returns the number of bytes for buffers marked for both, in as well as out. virtqueue_avail_bytes() is made a wrapper over this new function. Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2012-09-28virtio: use unsigned int for counting bytes in vqAmit Shah1-1/+1
The virtqueue_avail_bytes() function counts bytes in an int. Use an unsigned int instead. Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2012-09-28virtio: don't mark unaccessed memory as dirtyMichael S. Tsirkin1-1/+1
offset of accessed buffer is calculated using iov_length, so it can exceed accessed len. If that happens math in len - offset wraps around, and size becomes wrong. As real value is 0, so this is harmless but unnecessary. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2012-08-06virtio: fix vhost handlingPaolo Bonzini1-2/+5
Commit b1f416aa8d870fab71030abc9401cfc77b948e8e breaks vhost_net because it always registers the virtio_pci_host_notifier_read() handler function on the ioeventfd, even when vhost_net.ko is using the ioeventfd. The result is both QEMU and vhost_net.ko polling on the same eventfd and the virtio_net.ko guest driver seeing inconsistent results: # ifconfig eth0 192.168.0.1 netmask 255.255.255.0 virtio_net virtio0: output:id 0 is not a head! To fix this, proceed the same as we do for irqfd: add a parameter to virtio_queue_set_host_notifier_fd_handler and in that case only set the notifier, not the handler. Cc: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Tested-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-07-12virtio: move common irqfd handling out of virtio-pciPaolo Bonzini1-0/+24
All transports can use the same event handler for the irqfd, though the exact mechanics of the assignment will be specific. Note that there are three states: handled by the kernel, handled in userspace, disabled. This also lets virtio use event_notifier_set_handler. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-07-12virtio: move common ioeventfd handling out of virtio-pciPaolo Bonzini1-0/+22
All transports can use the same event handler for the ioeventfd, though the exact setup (address/memory region) will be specific. This lets virtio use event_notifier_set_handler. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-25virtio: order index/descriptor readsMichael S. Tsirkin1-0/+5
virtio has the equivalent of: if (vq->last_avail_index != vring_avail_idx(vq)) { read descriptor head at vq->last_avail_index; } In theory, processor can reorder descriptor head read to happen speculatively before the index read. this would trigger the following race: host descriptor head read <- reads invalid head from ring guest writes valid descriptor head guest writes avail index host avail index read <- observes valid index as a result host will use an invalid head value. This was not observed in the field by me but after the experience with the previous two races I think it is prudent to address this theoretical race condition. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2012-04-25virtio: add missing mb() on enable notificationMichael S. Tsirkin1-0/+4
This fixes an issue dual to the one fixed by patch 'virtio: add missing mb() on notification' and applies on top. In this case, to enable vq kick to exit to host, qemu writes out used flag then reads the avail index. if these are reordered we get a race: host avail index read: ring is empty guest avail index write guest flag read: exit disabled host used flag write: enable exit which results in a lost exit: host will never be notified about the avail index update. Again, happens in the field but only seems to trigger on some specific hardware. Insert an smp_mb barrier operation to ensure the correct ordering. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2012-04-25virtio: add missing mb() on notificationMichael S. Tsirkin1-0/+2
During normal operation, virtio first writes a used index and then checks whether it should interrupt the guest by reading guest avail index/flag values. Guest does the reverse: writes the index/flag, then checks the used ring. The ordering is important: if host avail flag read bypasses the used index write, we could in effect get this timing: host avail flag read guest enable interrupts: avail flag write guest check used ring: ring is empty host used index write which results in a lost interrupt: guest will never be notified about the used ring update. This actually can happen when using kvm with an io thread, such that the guest vcpu and qemu run on different host cpus, and this has actually been observed in the field (but only seems to trigger on very specific processor types) with userspace virtio: vhost has the necessary smp_mb() in place to prevent the regordering, so the same workload stalls forever waiting for an interrupt with vhost=off but works fine with vhost=on. Insert an smp_mb barrier operation in userspace virtio to ensure the correct ordering. Applying this patch fixed the race condition we have observed. Tested on x86_64. I checked the code generated by the new macro for i386 and ppc but didn't run virtio. Note: mb could in theory be implemented by __sync_synchronize, but this would make us hit old GCC bugs. Besides old GCC not implementing __sync_synchronize at all, there were bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36793 in this functionality as recently as in 4.3. As we need asm for rmb,wmb anyway, it's just as well to use it for mb. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2012-04-19virtio: add virtio_queue_get_idPaolo Bonzini1-0/+7
Serializing virtio-scsi requests needs a simple way to get from a VirtQueue to the number of the queue. The virtio_queue_get_id provides this. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-02-10virtio: Remove unneeded g_free() check in virtio_cleanup()Luiz Capitulino1-2/+1
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-01-21virtio: change memcpy to guest readsAlexander Graf1-6/+6
When accessing the device specific virtio config space, we memcpy the data into a variable in QEMU. At that point we're basically pulling host endianness into the game which is a really bad idea. So instead, let's use the target specific load/store helpers for memory pointers which fetch things in target endianness. The whole array is already populated in target endianness anyways (see virtio-blk). Signed-off-by: Alexander Graf <agraf@suse.de> Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
2011-11-28virtio: add and use virtio_set_featuresPaolo Bonzini1-6/+18
vdev->guest_features is not masking features that are not supported by the guest. Fix this by introducing a common wrapper to be used by all virtio bus implementations. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-09-23virtio: Use global memory barrier macrosDavid Gibson1-11/+3
The virtio code uses wmb() macros in several places, as required by the SMP-aware virtio protocol. However the wmb() macro is locally defined to be a compiler barrier only. This is probably sufficient on x86 due to its strong storage ordering model, but it certainly isn't on other platforms, such as ppc. In any case, qemu already has some globally defined memory barrier macros in qemu-barrier.h. This patch, therefore converts virtio.c to use those barrier macros. The macros in qemu-barrier.h are also wrong (or at least, safe for x86 only) but this way at least there's only one place to fix them. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-09-20Merge remote-tracking branch 'qmp/queue/qmp' into stagingAnthony Liguori1-2/+2
2011-09-17trace: add virtio_set_status() trace eventStefan Hajnoczi1-0/+10
The virtio device lifecycle can be observed by looking at the sequence of set status operations. This is especially important for catching the reset operation (status value 0), which resets the device and all virtqueues. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2011-09-15Drop the vm_running global variableLuiz Capitulino1-1/+1
Use runstate_is_running() instead, which is introduced by this commit. Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2011-09-15Replace the VMSTOP macros with a proper state typeLuiz Capitulino1-1/+1
Today, when notifying a VM state change with vm_state_notify(), we pass a VMSTOP macro as the 'reason' argument. This is not ideal because the VMSTOP macros tell why qemu stopped and not exactly what the current VM state is. One example to demonstrate this problem is that vm_start() calls vm_state_notify() with reason=0, which turns out to be VMSTOP_USER. This commit fixes that by replacing the VMSTOP macros with a proper state type called RunState. Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2011-08-20Use glib memory allocation and free functionsAnthony Liguori1-6/+6
qemu_malloc/qemu_free no longer exist after this commit. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-07-27virtio: Plug memleak by freeing vdevAmit Shah1-0/+1
virtio_common_init() allocates RAM for the vdev struct (and any additional memory, depending on the size passed to the function). This memory wasn't being freed until now. Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2011-07-17virtio: fix indirect descriptor buffer overflowMichael S. Tsirkin1-0/+8
We were previously allowing arbitrarily-long indirect descriptors, which could lead to a buffer overflow in qemu-kvm process. CVE-2011-2212 Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2011-06-24Strip trailing '\n' from error_report()'s first argumentMarkus Armbruster1-2/+2
error_report() prepends location, and appends a newline. The message constructed from the arguments should not contain a newline. Fix the obvious offenders. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-06-12virtio: event index supportMichael S. Tsirkin1-9/+83
Add support for event_idx feature, and utilize it to reduce the number of interrupts and exits for the guest. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2011-06-12virtio: correctly initialize vm_runningJason Wang1-0/+1
Current vm_running was not explicitly initialized and its value was changed by vm state notifier, this may confuse the virtio device being hotplugged such as virtio-net with vhost backend as it may think the vm was not running. Solve this by initialize this value explicitly in virtio_common_init(). Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2011-06-12virtio: guard against negative vq notifiesStefan Hajnoczi1-3/+1
The virtio_queue_notify() function checks that the virtqueue number is less than the maximum number of virtqueues. A signed comparison is used but the virtqueue number could be negative if a buggy or malicious guest is run. This results in memory accesses outside of the virtqueue array. It is risky doing input validation in common code instead of at the guest<->host boundary. Note that virtio_queue_set_addr(), virtio_queue_get_addr(), virtio_queue_get_num(), and many other virtio functions do *not* validate the virtqueue number argument. Instead of fixing the comparison in virtio_queue_notify(), move the comparison to the virtio bindings (just like VIRTIO_PCI_QUEUE_SEL) where we have a uint32_t value and can avoid ever calling into common virtio code if the virtqueue number is invalid. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2011-04-15Remove unused sysemu.h include directivesBlue Swirl1-1/+0
Remove unused sysemu.h include directives to speed up build with the following patches. Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2011-01-10virtio-pci: Use ioeventfd for virtqueue notifyStefan Hajnoczi1-3/+11
Virtqueue notify is currently handled synchronously in userspace virtio. This prevents the vcpu from executing guest code while hardware emulation code handles the notify. On systems that support KVM, the ioeventfd mechanism can be used to make virtqueue notify a lightweight exit by deferring hardware emulation to the iothread and allowing the VM to continue execution. This model is similar to how vhost receives virtqueue notifies. The result of this change is improved performance for userspace virtio devices. Virtio-blk throughput increases especially for multithreaded scenarios and virtio-net transmit throughput increases substantially. Some virtio devices are known to have guest drivers which expect a notify to be processed synchronously and spin waiting for completion. For virtio-net, this also seems to interact with the guest stack in strange ways so that TCP throughput for small message sizes (~200bytes) is harmed. Only enable ioeventfd for virtio-blk for now. Care must be taken not to interfere with vhost-net, which uses host notifiers. If the set_host_notifier() API is used by a device virtio-pci will disable virtio-ioeventfd and let the device deal with host notifiers as it wishes. Finally, there used to be a limit of 6 KVM io bus devices inside the kernel. On such a kernel, don't use ioeventfd for virtqueue host notification since the limit is reached too easily. This ensures that existing vhost-net setups (which always use ioeventfd) have ioeventfds available so they can continue to work. After migration and on VM change state (running/paused) virtio-ioeventfd will enable/disable itself. * VIRTIO_CONFIG_S_DRIVER_OK -> enable virtio-ioeventfd * !VIRTIO_CONFIG_S_DRIVER_OK -> disable virtio-ioeventfd * virtio_pci_set_host_notifier() -> disable virtio-ioeventfd * vm_change_state(running=0) -> disable virtio-ioeventfd * vm_change_state(running=1) -> enable virtio-ioeventfd Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2011-01-10virtio: move vmstate change tracking to coreMichael S. Tsirkin1-0/+22
Move tracking vmstate change from virtio-net to virtio.c as it is going to be used by virito-blk and virtio-pci for the ioeventfd support. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2010-11-24virtio: fix up VQ checksMichael S. Tsirkin1-11/+16
When migration triggers before a VQ is initialized, base pa is 0 and last_used_index must be 0 too: we don't have a ring to compare to. Reported-by: Juan Quintela <quintela@redhat.com> Tested-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2010-11-24virtio: Convert fprintf() to error_report()Stefan Hajnoczi1-17/+18
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> (cherry picked from commit cd92f4cc22fbe12a7bf60c9430731f768dc1537c)
2010-10-27virtio: sanity-check available indexMichael S. Tsirkin1-0/+11
Checking available index upon load instead of only when vm is running makes is easier to debug failures. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2010-10-07virtio: invoke set_status callback on resetMichael S. Tsirkin1-0/+2
As status is set to 0 on reset, invoke the relevant callback. This makes for a cleaner code in devices as they don't need to duplicate the code in their reset routine, as well as excercises this path a little more. In particular this makes it possible to unify vhost-net handling code with the following patch. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2010-09-09trace: Trace virtqueue operationsStefan Hajnoczi1-0/+8
This patch adds trace events for virtqueue operations including adding/removing buffers, notifying the guest, and receiving a notify from the guest. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2010-08-30virtio: Factor virtqueue_map_sg outKevin Wolf1-14/+24
Separate the mapping of requests to host memory from the descriptor iteration. The next patch will make use of it in a different context. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-05-12virtio: invoke set_features on loadMichael S. Tsirkin1-0/+2
After migration, vhost was not getting features acked because set_features callback was never invoked. The fix is just to invoke that callback. Reported-by: David L Stevens <dlstevens@us.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Tested-by: David L Stevens <dlstevens@us.ibm.com>
2010-04-01win32: Fix compiler errors from u_int64_tStefan Weil1-1/+1
u_int64_t raises compiler error messages: CC libhw32/virtio.o /qemu/ar7/hw/virtio.c: In function ‘virtio_queue_get_avail_size’: /qemu/ar7/hw/virtio.c:776: error: ‘u_int64_t’ undeclared (first use in this function) /qemu/ar7/hw/virtio.c:776: error: (Each undeclared identifier is reported only once /qemu/ar7/hw/virtio.c:776: error: for each function it appears in.) Replacing u_int64_t by uint64_t helps. Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Stefan Weil <weil@mail.berlios.de> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-04-01virtio: notifier support + APIs for queue fieldsMichael S. Tsirkin1-1/+79
vhost needs physical addresses for ring and other queue fields, so add APIs for these. In particular, add binding API to set host/guest notifiers. Will be used by vhost. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-01-20virtio: Remove duplicate macro definition for max. virtqueues, bump up the maxAmit Shah1-2/+0
VIRTIO_PCI_QUEUE_MAX is redefined in hw/virtio.c. Let's just keep it in hw/virtio.h. Also, bump up the value of the maximum allowed virtqueues to 64. This is in preparation to allow multiple ports per virtio-console device. Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-01-11virtio: add features as qdev propertiesMichael S. Tsirkin1-1/+1
Add feature bits as properties to virtio. This makes it possible to e.g. define machine without indirect buffer support, which is required for 0.10 compatibility, or without hardware checksum support, which is required for 0.11 compatibility. Since default values for optional features are now set by qdev, get_features callback has been modified: it sets non-optional bits, and clears bits not supported by host. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Gerd Hoffmann <kraxel@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-01-11virtio: rename features -> guest_featuresMichael S. Tsirkin1-4/+4
Rename features->guest_features. This is what they are, avoid confusion with host features which we also need to keep around. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-12-12virtio: verify features on loadMichael S. Tsirkin1-1/+10
migrating between hosts which have different features might break silently, if the migration destination does not support some features supported by source. Prevent this from happening by comparing acked feature bits with the mask supported by the device. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-30qemu/virtio: make wmb compiler barrier + commentsMichael S. Tsirkin1-1/+4
wmb must be at least a compiler barrier, even without SMP. Further, we likely need some rmb()/mb() as well: I have not audited the code but lguest has mb(), add a comment for now. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-01Revert "Get rid of _t suffix"Anthony Liguori1-28/+28
In the very least, a change like this requires discussion on the list. The naming convention is goofy and it causes a massive merge problem. Something like this _must_ be presented on the list first so people can provide input and cope with it. This reverts commit 99a0949b720a0936da2052cb9a46db04ffc6db29. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
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