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path: root/hw/virtio-pci.c
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2012-06-03Merge remote-tracking branch 'qemu-kvm/uq/master' into stagingAnthony Liguori1-0/+126
* qemu-kvm/uq/master: virtio/vhost: Add support for KVM in-kernel MSI injection msix: Add msix_nr_vectors_allocated kvm: Enable use of kvm_irqchip_in_kernel in hwlib code kvm: Introduce kvm_irqchip_add/remove_irqfd kvm: Make kvm_irqchip_commit_routes an internal service kvm: Publicize kvm_irqchip_release_virq kvm: Introduce kvm_irqchip_add_msi_route kvm: Rename kvm_irqchip_add_route to kvm_irqchip_add_irq_route msix: Introduce vector notifiers msix: Invoke msix_handle_mask_update on msix_mask_all msix: Factor out msix_get_message kvm: update vmxcap for EPT A/D, INVPCID, RDRAND, VMFUNC kvm: Enable in-kernel irqchip support by default kvm: Add support for direct MSI injections kvm: Update kernel headers kvm: x86: Wire up MSI support for in-kernel irqchip pc: Enable MSI support at APIC level kvm: Introduce basic MSI support for in-kernel irqchips Introduce MSIMessage structure kvm: Refactor KVMState::max_gsi to gsi_count
2012-05-21virtio-blk: always enable VIRTIO_BLK_F_SCSIPaolo Bonzini1-0/+3
VIRTIO_BLK_F_SCSI is supposed to mean whether the host can *parse* SCSI requests, not *execute* them. You could run QEMU with scsi=on and a file-backed disk, and QEMU would fail all SCSI requests even though it advertises VIRTIO_BLK_F_SCSI. Because we need to do this to fix a migration compatibility problem related to how QEMU is invoked by management, we must do this unconditionally even on older machine types. This more or less assumes that no one ever invoked QEMU with scsi=off. Here is how testing goes: - old QEMU, scsi=on -> new QEMU, scsi=on - new QEMU, scsi=on -> old QEMU, scsi=on - old QEMU, scsi=off -> new QEMU, scsi=on - new QEMU, scsi=off -> old QEMU, scsi=on ok (new QEMU has VIRTIO_BLK_F_SCSI, adding host features is fine) - old QEMU, scsi=off -> new QEMU, scsi=off ok (new QEMU has VIRTIO_BLK_F_SCSI, adding host features is fine) - old QEMU, scsi=on -> new QEMU, scsi=off ok, bug fixed - new QEMU, scsi=on -> old QEMU, scsi=off doesn't work (same as: old QEMU, scsi=on -> old QEMU, scsi=off) - new QEMU, scsi=off -> old QEMU, scsi=off broken by the patch Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-05-21virtio-blk: define VirtIOBlkConfPaolo Bonzini1-4/+3
We will have to add another field to the virtio-blk configuration in the next patch. Avoid a proliferation of arguments to virtio_blk_init. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-05-21virtio-blk: blockdev_mark_auto_del is transport-independentPaolo Bonzini1-1/+0
Move it from virtio_blk_exit_pci to virtio_blk_exit. This is included here because the next patch removes proxy->block. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-05-21virtio/vhost: Add support for KVM in-kernel MSI injectionJan Kiszka1-0/+126
Make use of the new vector notifier to track changes of the MSI-X configuration of virtio PCI devices. On enabling events, we establish the required virtual IRQ to MSI-X message route and link the signaling eventfd file descriptor to this vIRQ line. That way, vhost-generated interrupts can be directly delivered to an in-kernel MSI-X consumer like the x86 APIC. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-05-19virtio-pci: add missing 'static'Blue Swirl1-1/+1
There are no outside references to virtio_portio. Add missing 'static' specifier. Reviewed-by: Stefan Weil <sw@weilnetz.de> Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2012-04-11virtio-pci: change virtio balloon PCI class codeDavid Gibson1-1/+7
Currently the virtio balloon device, when using the virtio-pci interface advertises itself with PCI class code MEMORY_RAM. This is wrong; the balloon is vaguely related to memory, but is nothing like a PCI memory device in the meaning of the class code, and this code is not required or suggested by the virtio PCI specification. Worse, this patch causes problems on the pseries machine, because the firmware, seeing this class code, advertises the device as memory in the device tree, and then a guest kernel bug causes it to see this "memory" before the real system memory, leading to a crash in early boot. This patch fixes the problem by removing the bogus PCI class code on the balloon device. The backwards compatibility PC machines get new compat properties so that they don't change. Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2012-02-22virtio-scsi: Add virtio-scsi stub deviceStefan Hajnoczi1-0/+56
Add a useless virtio SCSI HBA device: qemu -device virtio-scsi-pci Signed-off-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>
2012-02-15qom: Unify type registrationAndreas Färber1-2/+2
Replace device_init() with generalized type_init(). While at it, unify naming convention: type_init([$prefix_]register_types) Also, type_init() is a function, so add preceding blank line where necessary and don't put a semicolon after the closing brace. Signed-off-by: Andreas Färber <afaerber@suse.de> Cc: Anthony Liguori <anthony@codemonkey.ws> Cc: malc <av1474@comtv.ru> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-02-03qdev: remove baked in notion of aliases (v2)Anthony Liguori1-8/+0
Limit them to the device_add functionality. Device aliases were a hack based on the fact that virtio was modeled the wrong way. The mechanism for aliasing is very limited in that only one alias can exist for any device. We have to support it for the purposes of compatibility but we only need to support it in device_add so restrict it to that piece of code. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> --- v1 -> v2 - Use a table for aliases (Paolo)
2012-02-03qdev: register all types natively through QEMU Object ModelAnthony Liguori1-32/+44
This was done in a mostly automated fashion. I did it in three steps and then rebased it into a single step which avoids repeatedly touching every file in the tree. The first step was a sed-based addition of the parent type to the subclass registration functions. The second step was another sed-based removal of subclass registration functions while also adding virtual functions from the base class into a class_init function as appropriate. Finally, a python script was used to convert the DeviceInfo structures and qdev_register_subclass functions to TypeInfo structures, class_init functions, and type_register_static calls. We are almost fully converted to QOM after this commit. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-01-27pci: convert to QEMU Object ModelAnthony Liguori1-76/+112
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-01-27qdev: prepare source tree for code conversionAnthony Liguori1-88/+86
These are various small stylistic changes which help make things more consistent such that the automated conversion script can be simpler. It's not necessary to agree or disagree with these style changes because all of this code is going to be rewritten by the patch monkey script anyway. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-01-21virtio-pci: Fix endianness of virtio configBenjamin Herrenschmidt1-2/+26
The virtio config area in PIO space is a bit special. The initial header is little endian but the rest (device specific) is guest native endian. The PIO accessors for PCI on machines that don't have native IO ports assume that all PIO is little endian, which works fine for everything except the above. A complicated way to fix it would be to split the BAR into two memory regions with different endianess settings, but this isn't practical to do, besides, the PIO code doesn't honor region endianness anyway (I have a patch for that too but it isn't necessary at this stage). So I decided to go for the quick fix instead which consists of reverting the swap in virtio-pci in selected places, hoping that when we eventually do a "v2" of the virtio protocols, we sort that out once and for all using a fixed endian setting for everything. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Alexander Graf <agraf@suse.de> [agraf: keep virtio in libhw and determine endianness through a helper function in exec.c] Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
2012-01-13prepare for future GPLv2+ relicensingPaolo Bonzini1-0/+2
All files under GPLv2 will get GPLv2+ changes starting tomorrow. event_notifier.c and exec-obsolete.h were only ever touched by Red Hat employees and can be relicensed now. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-12-09virtio-pci: use pci macrosHui Kai Ran1-3/+4
Signed-off-by: Hui Kai Ran <hkran@linux.vnet.ibm.com> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-12-04hw/9pfs: Add qdev.reset callback for virtio-9p-pci deviceAneesh Kumar K.V1-1/+1
Add the device reset callback Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2011-11-28virtio: add and use virtio_set_featuresPaolo Bonzini1-7/+2
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>
2011-11-01Revert "virtio: Add PCI memory BAR in addition to PIO BAR"Anthony Liguori1-2/+0
This reverts commit 46d95bfec7f9429d5228078219413d7e33496d65.
2011-11-01virtio: Add PCI memory BAR in addition to PIO BARDavid Gibson1-0/+2
Currently, virtio devices are usually presented to the guest as an emulated PCI device, virtio_pci. Although the actual IO operations are done through system memory, the configuration of the virtio device is done through the one PCI IO space BAR that virtio_pci presents. But PCI IO space (aka PIO) is deprecated for modern PCI devices, and on some systems with many PCI domains accessing PIO space can be problematic. For example on the existing PowerVM implementation of the PAPR spec, PCI PIO access is not supported at all. We're hoping that our KVM implementation will support PCI PIO (once we support PCI at all), but it will probably have some irritating limitations. This patch, therefore, extends the virtio_pci device to have a PCI memory space (MMIO) BAR as well as the IO BAR. The MMIO BAR contains exactly the same registers, in exactly the same layout as the existing PIO BAR. Because the PIO BAR is still present, existing guest drivers should still work fine. With this change in place, future guest drivers can check for an MMIO BAR and use that if present (falling back to PIO when possible to support older qemu versions). Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-10-12hw/9pfs: Use ioeventfd for 9pAneesh Kumar K.V1-5/+0
With ioeventfd: [root@qemu-img-64 storage]# dd if=/dev/zero of=/storage/testx bs=8k count=131072 oflag=direct 131072+0 records in 131072+0 records out 1073741824 bytes (1.1 GB) copied, 26.767 s, 40.1 MB/s Without: [root@qemu-img-64 storage]# dd if=/dev/zero of=/storage/testx bs=8k count=131072 oflag=direct 131072+0 records in 131072+0 records out 1073741824 bytes (1.1 GB) copied, 65.3361 s, 16.4 MB/s Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2011-08-08pci: rename pci_register_bar_region() to pci_register_bar()Avi Kivity1-5/+4
Reviewed-by: Richard Henderson <rth@twiddle.net> Reviewed-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-08-08msix: convert to memory APIAvi Kivity1-6/+10
The msix table is defined as a subregion, to allow for a BAR that mixes device specific regions with the msix table. Reviewed-by: Richard Henderson <rth@twiddle.net> Reviewed-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-08-08virtio-pci: convert to memory APIAvi Kivity1-44/+26
except msix. [jan: fix build] [aliguori: fix build] Reviewed-by: Richard Henderson <rth@twiddle.net> Reviewed-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-08-04Merge remote-tracking branch 'mst/for_anthony' into stagingAnthony Liguori1-9/+9
2011-08-04virtio-balloon: Add exit handler, fix memleaksAmit Shah1-1/+10
Add an exit handler that will free up RAM after a virtio-balloon device is unplugged. Signed-off-by: Amit Shah <amit.shah@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com>
2011-08-04virtio-balloon: Check if balloon registration failedAmit Shah1-0/+3
Multiple balloon registrations are not allowed; check if the registration with the qemu balloon api succeeded. If not, fail the device init. Signed-off-by: Amit Shah <amit.shah@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com>
2011-07-27virtio-pci: use generic logic for command accessMichael S. Tsirkin1-9/+9
In practice, guests don't generate config requests that cross a word boundary, so the logic to detect command word access is correct because PCI_COMMAND is 0x4. But depending on this is tricky, further, it will break with guests that do try to generate a misaligned access as we pass it to devices without splitting. Better to use the generic range_covers_byte for this. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2011-07-05virtio-blk: Turn drive serial into a qdev propertyMarkus Armbruster1-1/+3
It needs to be a qdev property, because it belongs to the drive's guest part. Precedence: commit a0fef654 and 6ced55a5. Bonus: info qtree now shows the serial number. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-06-15Merge remote-tracking branch 'origin/master' into pciMichael S. Tsirkin1-58/+2
Conflicts: hw/virtio-pci.c
2011-06-12virtio: guard against negative vq notifiesStefan Hajnoczi1-1/+3
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>
2011-06-12virtio-pci.c: convert to PCIDEviceInfo to initialize idsIsaku Yamahata1-38/+31
use PCIDeviceInfo to initialize ids. Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2011-06-01virtio-9p: Move 9p device registration into virtio-9p.cAneesh Kumar K.V1-55/+2
This patch move the 9p device registration into its own file Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Venkateswararao Jujjuri (JV) <jvrao@linux.vnet.ibm.com>
2011-04-18PXE: Use consistent naming for PXE ROMsAlex Williamson1-1/+1
And add missing ROMs to tarbin build target. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2011-04-04virtio: use generic name when possibleAlexander Graf1-0/+3
We have two different virtio buses: pci and s390. The abstraction path taken in qemu is to have generic aliases for each device type in the architecture specific qdev devices. So let's make use of these aliases whenever we can and define them whenever we can. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-03-28virtio-pci: fix bus master work around on loadMichael S. Tsirkin1-7/+6
Commit c81131db15dd1844d0db1d51f3cd7a105cfd2cf3 detects old guests by comparing virtio and PCI status. It attempts to do this on load, as well, but load_config callback in a binding is invoked too early and so the virtio status isn't set yet. We could add yet another callback to the binding, to invoke after load, but it seems easier to reuse the existing vmstate callback. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Cc: Alexander Graf <agraf@suse.de>
2011-03-21virtio-serial: Enable ioeventfdAmit Shah1-0/+3
Enable ioeventfd for virtio-serial devices by default. Commit 25db9ebe15125deb32958c6df74996f745edf1f9 lists the benefits of using ioeventfd. Copying a file from guest to host over a virtio-serial channel didn't show much difference in time or io_exit rate. Signed-off-by: Amit Shah <amit.shah@redhat.com>
2011-03-21virtio-serial: Use a struct to pass config information from proxyAmit Shah1-6/+6
Instead of using a single variable to pass to the virtio_serial_init function, use a struct so that expanding the number of variables to be passed on later is easier. Signed-off-by: Amit Shah <amit.shah@redhat.com>
2011-02-01vhost: force vhost off for non-MSI guestsmst@redhat.com1-0/+7
When MSI is off, each interrupt needs to be bounced through the io thread when it's set/cleared, so vhost-net causes more context switches and higher CPU utilization than userspace virtio which handles networking in the same thread. We'll need to fix this by adding level irq support in kvm irqfd, for now disable vhost-net in these configurations. Added a vhostforce flag to force vhost-net back on. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-01-11ioeventfd: error handling cleanupMichael S. Tsirkin1-11/+17
- Don't return status from start/stop functions where it's ignored - report errors to make debugging easier - assert on unexpected failures - don't disable notifiers on error so that we'll retry when guest driver restarts Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-01-10virtio-pci: Use ioeventfd for virtqueue notifyStefan Hajnoczi1-22/+172
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-pci: Rename bugs field to flagsStefan Hajnoczi1-8/+7
The VirtIOPCIProxy bugs field is currently used to enable workarounds for older guests. Rename it to flags so that other per-device behavior can be tracked. A later patch uses the flags field to remember whether ioeventfd should be used for virtqueue host notification. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2010-12-11Introduce fw_name field to DeviceInfo structure.Gleb Natapov1-0/+1
Add "fw_name" to DeviceInfo to use in device path building. In contrast to "name" "fw_name" should refer to functionality device provides instead of particular device model like "name" does. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2010-11-21virtio-pci: Convert fprintf() to error_report()Stefan Hajnoczi1-2/+2
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-11-21virtfs: enable MSI-XGerd Hoffmann1-1/+4
This patch enables MSI-X for virtfs-9p-pci. It also adds a compat property to pc-0.13 which turns it of there to stay compatible to 0.13-stable. Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-10-07virtio: change set guest notifier to per-deviceMichael S. Tsirkin1-1/+28
When using irqfd with vhost-net to inject interrupts, a single evenfd might inject multiple interrupts. Implementing this is much easier with a single per-device callback to set guest notifiers. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2010-09-07virtio-net: Introduce a new bottom half packet TXAlex Williamson1-0/+1
Based on a patch from Mark McLoughlin, this patch introduces a new bottom half packet transmitter that avoids the latency imposed by the tx_timer approach. Rather than scheduling a timer when a TX packet comes in, schedule a bottom half to be run from the iothread. The bottom half handler first attempts to flush the queue with notification disabled (this is where we could race with a guest without txburst). If we flush a full burst, reschedule immediately. If we send short of a full burst, try to re-enable notification. To avoid a race with TXs that may have occurred, we must then flush again. If we find some packets to send, the guest it probably active, so we can reschedule again. tx_timer and tx_bh are mutually exclusive, so we can re-use the tx_waiting flag to indicate one or the other needs to be setup. This allows us to seamlessly migrate between timer and bh TX handling. The bottom half handler becomes the new default and we add a new tx= option to virtio-net-pci. Usage: -device virtio-net-pci,tx=timer # select timer mitigation vs "bh" Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2010-09-07virtio-net: Limit number of packets sent per TX flushAlex Williamson1-0/+2
If virtio_net_flush_tx() is called with notification disabled, we can race with the guest, processing packets at the same rate as they get produced. The trouble is that this means we have no guaranteed exit condition from the function and can spend minutes in there. Currently flush_tx is only called with notification on, which seems to limit us to one pass through the queue per call. An upcoming patch changes this. Also add an option to set this value on the command line as different workloads may wish to use different values. We can't necessarily support any random value, so this is a developer option: x-txburst= Usage: -device virtio-net-pci,x-txburst=64 # 64 packets per tx flush One pass through the queue (256) seems to be a good default value for this, balancing latency with throughput. We use a signed int for x-txburst because 2^31 packets in a burst would take many, many minutes to process and it allows us to easily return a negative value value from virtio_net_flush_tx() to indicate a back-off or error condition. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2010-09-07virtio-net: Make tx_timer timeout configurableAlex Williamson1-1/+4
Add an option to make the TX mitigation timer adjustable as a device option. The 150us hard coded default used currently is reasonable, but may not be suitable for all workloads, this gives us a way to adjust it using a single binary. We can't support any random option though, so use the "x-" prefix to indicate this is a developer option. Usage: -device virtio-net-pci,x-txtimer=500000,... # .5ms timeout Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2010-08-24Rearrange block headersBlue Swirl1-0/+1
Changing block.h or blockdev.h resulted in recompiling most objects. Move DriveInfo typedef and BlockInterfaceType enum definitions to qemu-common.h and rearrange blockdev.h use to decrease churn. Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
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