- 24 Feb, 2010 40 commits
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Amit Shah authored
With MULTIPORT support, the control queue is an integral part of the functioning of the device. If we can't get any buffers allocated, the host won't be able to relay important information and the device may not function as intended. Ensure 'probe' doesn't succeed until the control queue has at least one buffer allocated for its ivq. Signed-off-by:
Amit Shah <amit.shah@redhat.com> Signed-off-by:
Rusty Russell <rusty@rustcorp.com.au>
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Amit Shah authored
Add the ability to remove the virtio_console module. This aids debugging. Signed-off-by:
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Amit Shah authored
If unused data exists in in_vq, ensure we flush that first and then detach unused buffers, which will ensure all buffers from the in_vq are removed. Also ensure we free the buffers after detaching them. Signed-off-by:
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Amit Shah authored
Signed-off-by:
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Amit Shah authored
This is helpful in examining ports' state. Signed-off-by:
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Amit Shah authored
Remove port data; deregister from the hvc core if it's a console port. Signed-off-by:
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Amit Shah authored
If the 'nr_ports' variable in the config space is updated to a higher value, that means new ports have been hotplugged. Introduce a new workqueue to handle such updates and create new ports. Signed-off-by:
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Amit Shah authored
Remove any data that we might have in a port's inbuf when closing a port or when any data is received when a port is closed. Signed-off-by:
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Amit Shah authored
The host can set a name for ports so that they're easily discoverable instead of going by the /dev/vportNpn naming. This attribute will be placed in /sys/class/virtio-ports/vportNpn/name. udev scripts can then create symlinks to the port using the name. Signed-off-by:
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Amit Shah authored
Add a guest_connected field that ensures only one process can have a port open at a time. This also ensures we don't have a race when we later add support for dropping buffers when closing the char dev and buffer caching is turned off for the particular port. Signed-off-by:
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Amit Shah authored
Allow guest userspace applications to open, read from, write to, poll the ports via the char dev interface. When a port gets opened, a notification is sent to the host via a control message indicating a connection has been established. Similarly, on closing of the port, a notification is sent indicating disconnection. Signed-off-by:
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Amit Shah authored
The char device will be used as an interface by applications on the guest to communicate with apps on the host. The devices created are placed in /dev/vportNpn where N is the virtio-console device number and n is the port number for that device. One dynamic major device number is allocated for each device and minor numbers are allocated for the ports contained within that device. The file operation for the char devs will be added in the following commits. Signed-off-by:
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Amit Shah authored
When ports get advertised as char devices, the buffers will come from userspace. Equip the fill_readbuf function with the ability to write to userspace buffers. Signed-off-by:
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Amit Shah authored
This commit adds a new feature, MULTIPORT. If the host supports this feature as well, the config space has the number of ports defined for that device. New ports are spawned according to this information. The config space also has the maximum number of ports that can be spawned for a particular device. This is useful in initializing the appropriate number of virtqueues in advance, as ports might be hot-plugged in later. Using this feature, generic ports can be created which are not tied to hvc consoles. We also open up a private channel between the host and the guest via which some "control" messages are exchanged for the ports, like whether the port being spawned is a console port, resizing the console window, etc. Next commits will add support for hotplugging and presenting char devices in /dev/ for bi-directional guest-host communication. Signed-off-by:
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Amit Shah authored
Adding support for generic ports that will write to userspace will need some code changes. Consolidate the write routine into send_buf() and put_chars() now just calls into the new function. Signed-off-by:
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Amit Shah authored
In preparation for serving data to userspace (generic ports) as well as in-kernel users (hvc consoles), separate out the functionality common to both in a 'fill_readbuf()' function. Signed-off-by:
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Amit Shah authored
With support for multiple ports, each port will have its own input and output vqs. Prepare the probe function for this change. Signed-off-by:
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Amit Shah authored
Console ports could be hot-added. Also, with the new multiport support, a port is identified as a console port only if the host sends a control message. Move the console port init into a separate function so it can be invoked from other places. Signed-off-by:
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Amit Shah authored
Move out console-specific stuff into a separate struct from 'struct port' as we need to maintain two lists: one for all the ports (which includes consoles) and one only for consoles since the hvc callbacks only give us the vtermno. This makes console handling cleaner. Signed-off-by:
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Amit Shah authored
When multiple console support is added, ensure each port's size gets updated when a new one is opened via hvc. Signed-off-by:
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Amit Shah authored
Rather than assume a single port, add a 'struct ports_device' which stores data related to all the ports for that device. Currently, there's only one port and is hooked up with hvc, but that will change. Signed-off-by:
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Rusty Russell authored
Now we can use an allocation function to remove our global console variable. Signed-off-by:
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Amit Shah authored
Keep a list of all ports being used as a console, and provide a lock and a lookup function. The hvc callbacks only give us a vterm number, so we need to map this. Signed-off-by:
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Rusty Russell authored
Part of removing our "one console" assumptions, use vdev->priv to point to the port (currently == the global console). Signed-off-by:
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Amit Shah authored
This makes taking locks around the get_buf vq operation easier, as well as complements the add_inbuf() operation. Signed-off-by:
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Amit Shah authored
add_inbuf() assumed one port and one inbuf per port. Remove that assumption. Also move the function so that put_chars and get_chars are together. Signed-off-by:
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Amit Shah authored
Collect port buffer, used_len, offset fields into a single structure. Signed-off-by:
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Rusty Russell authored
We are heading towards a multiple-"port" system, so as part of weaning off globals we encapsulate the information into 'struct port'. Signed-off-by:
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Amit Shah authored
We support only one virtio_console device at a time. If multiple are found, error out if one is already initialized. Signed-off-by:
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Rusty Russell authored
This is nicer for modern R/O protection. And noone needs it non-const, so constify the callers as well. Signed-off-by:
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Rusty Russell authored
That way, we can make it const as is good kernel style. We use a separate indirection for the early console, rather than mugging ops.put_chars. We rename it hv_ops, too. Signed-off-by:
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Rusty Russell authored
Remove old lguest-style comments. [Amit: - wingify comments acc. to kernel style - indent comments ] Signed-off-by: -
Amit Shah authored
vq operations depend on vq->data[i] being NULL to figure out if the vq entry is in use (since the previous patch). We have to initialize them to NULL to ensure we don't work with junk data and trigger false BUG_ONs. Signed-off-by:
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Shirley Ma authored
There's currently no way for a virtio driver to ask for unused buffers, so it has to keep a list itself to reclaim them at shutdown. This is redundant, since virtio_ring stores that information. So add a new hook to do this. Signed-off-by:
Shirley Ma <xma@us.ibm.com> Signed-off-by:
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Christoph Hellwig authored
Allow reading various alignment values from the config page. This allows the guest to much better align I/O requests depending on the storage topology. Note that the formats for the config values appear a bit messed up, but we follow the formats used by ATA and SCSI so they are expected in the storage world. Signed-off-by:
Christoph Hellwig <hch@lst.de> Signed-off-by:
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Michael S. Tsirkin authored
virtio is communicating with a virtual "device" that actually runs on another host processor. Thus SMP barriers can be used to control memory access ordering. Where possible, we should use SMP barriers which are more lightweight than mandatory barriers, because mandatory barriers also control MMIO effects on accesses through relaxed memory I/O windows (which virtio does not use) (compare specifically smp_rmb and rmb on x86_64). We can't just use smp_mb and friends though, because we must force memory ordering even if guest is UP since host could be running on another CPU, but SMP barriers are defined to barrier() in that configuration. So, for UP fall back to mandatory barriers instead. Signed-off-by:
Michael S. Tsirkin <mst@redhat.com> Signed-off-by:
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Rusty Russell authored
With DEBUG defined, we add an ->in_use flag to detect if the caller invokes two virtio methods in parallel. The barriers attempt to ensure timely update of the ->in_use flag. But they're voodoo: if we need these barriers it implies that the calling code doesn't have sufficient synchronization to ensure the code paths aren't invoked at the same time anyway, and we want to detect it. Also, adding barriers changes timing, so turning on debug has more chance of hiding real problems. Thanks to MST for drawing my attention to this code... CC: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: -
Rusty Russell authored
Two years ago 5bbf89fc removed the horrible bzImage unpacking code. Now it's time to remove the unneeded zlib.h include, too. Signed-off-by:
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Rusty Russell authored
When running under qemu-kvm-0.11.0: BUG: unable to handle kernel paging request at 56e58955 ... Process vballoon (pid: 1297, ti=c7976000 task=c70a6ca0 task.ti=c7 ... Call Trace: [<c88253a3>] ? balloon+0x1b3/0x440 [virtio_balloon] [<c041c2d7>] ? schedule+0x327/0x9d0 [<c88251f0>] ? balloon+0x0/0x440 [virtio_balloon] [<c014a2d4>] ? kthread+0x74/0x80 [<c014a260>] ? kthread+0x0/0x80 [<c0103b36>] ? kernel_thread_helper+0x6/0x30 need_stats_update should be zero-initialized. Signed-off-by:
Adam Litke <agl@us.ibm.com>
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Adam Litke authored
This is a fix for my earlier patch: "virtio: Add memory statistics reporting to the balloon driver (V4)". I discovered that all_vm_events() can sleep and therefore stats collection cannot be done in interrupt context. One solution is to handle the interrupt by noting that stats need to be collected and waking the existing vballoon kthread which will complete the work via stats_handle_request(). Rusty, is this a saner way of doing business? There is one issue that I would like a broader opinion on. In stats_request, I update vb->need_stats_update and then wake up the kthread. The kthread uses vb->need_stats_update as a condition variable. Do I need a memory barrier between the update and wake_up to ensure that my kthread sees the correct value? My testing suggests that it is not needed but I would like some confirmation from the experts. Signed-off-by:
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