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* lguest and virtio: cleanup struct definitions to Linux style.Rusty Russell2009-07-30
| | | | | | | | | | I've been doing this for years, and akpm picked me up on it about 12 months ago. lguest partly serves as example code, so let's do it Right. Also, remove two unused fields in struct vblk_info in the example launcher. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@redhat.com>
* lguest: update commentryRusty Russell2009-07-30
| | | | | | | | | | Every so often, after code shuffles, I need to go through and unbitrot the Lguest Journey (see drivers/lguest/README). Since we now use RCU in a simple form in one place I took the opportunity to expand that explanation. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@redhat.com> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
* lguest: fix comment styleRusty Russell2009-07-30
| | | | | | | | | I don't really notice it (except to begrudge the extra vertical space), but Ingo does. And he pointed out that one excuse of lguest is as a teaching tool, it should set a good example. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@redhat.com>
* lguest: fix descriptor corruption in example launcherRusty Russell2009-07-30
| | | | | | | | | | | 1d589bb16b825b3a7b4edd34d997f1f1f953033d "Add serial number support for virtio_blk, V4a" extended 'struct virtio_blk_config' to 536 bytes. Lguest and S/390 both use an 8 bit value for the feature length, and this change broke them (if the code is naive). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: John Cooper <john.cooper@redhat.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com>
* lguest: add support for indirect ring entriesMark McLoughlin2009-06-12
| | | | | | | | | | | Support the VIRTIO_RING_F_INDIRECT_DESC feature. This is a simple matter of changing the descriptor walking code to operate on a struct vring_desc* and supplying it with an indirect table if detected. Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: suppress notifications in example LauncherRusty Russell2009-06-12
| | | | | | | | | | | | | | | | | | | | | | | The Guest only really needs to tell us about activity when we're going to listen to the eventfd: normally, we don't want to know. So if there are no available buffers, turn on notifications, re-check, then wait for the Guest to notify us via the eventfd, then turn notifications off again. There's enough else going on that the differences are in the noise. Before: Secs RxKicks TxKicks 1G TCP Guest->Host: 3.94 4686 32815 1M normal pings: 104 142862 1000010 1M 1k pings (-l 120): 57 142026 1000007 After: 1G TCP Guest->Host: 3.76 4691 32811 1M normal pings: 111 142859 997467 1M 1k pings (-l 120): 55 19648 501549 Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: try to batch interrupts on network receiveRusty Russell2009-06-12
| | | | | | | | | | | | | | | | | | | | | | | | | | Rather than triggering an interrupt every time, we only trigger an interrupt when there are no more incoming packets (or the recv queue is full). However, the overhead of doing the select to figure this out is measurable: 1M pings goes from 98 to 104 seconds, and 1G Guest->Host TCP goes from 3.69 to 3.94 seconds. It's close to the noise though. I tested various timeouts, including reducing it as the number of pending packets increased, timing a 1 gigabyte TCP send from Guest -> Host and Host -> Guest (GSO disabled, to increase packet rate). // time tcpblast -o -s 65536 -c 16k 192.168.2.1:9999 > /dev/null Timeout Guest->Host Pkts/irq Host->Guest Pkts/irq Before 11.3s 1.0 6.3s 1.0 0 11.7s 1.0 6.6s 23.5 1 17.1s 8.8 8.6s 26.0 1/pending 13.4s 1.9 6.6s 23.8 2/pending 13.6s 2.8 6.6s 24.1 5/pending 14.1s 5.0 6.6s 24.4 Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: avoid sending interrupts to Guest when no activity occurs.Rusty Russell2009-06-12
| | | | | | | | | | | | | | | | | | | | | | If we track how many buffers we've used, we can tell whether we really need to interrupt the Guest. This happens as a side effect of spurious notifications. Spurious notifications happen because it can take a while before the Host thread wakes up and sets the VRING_USED_F_NO_NOTIFY flag, and meanwhile the Guest can more notifications. A real fix would be to use wake counts, rather than a suppression flag, but the practical difference is generally in the noise: the interrupt is usually coalesced into a pending one anyway so we just save a system call which isn't clearly measurable. Secs Spurious IRQS 1G TCP Guest->Host: 3.93 58 1M normal pings: 100 72 1M 1k pings (-l 120): 57 492904 Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: implement deferred interrupts in example LauncherRusty Russell2009-06-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Rather than sending an interrupt on every buffer, we only send an interrupt when we're about to wait for the Guest to send us a new one. The console input and network input still send interrupts manually, but the block device, network and console output queues can simply rely on this logic to send interrupts to the Guest at the right time. The patch is cluttered by moving trigger_irq() higher in the code. In practice, two factors make this optimization less interesting: (1) we often only get one input at a time, even for networking, (2) triggering an interrupt rapidly tends to get coalesced anyway. Before: Secs RxIRQS TxIRQs 1G TCP Guest->Host: 3.72 32784 32771 1M normal pings: 99 1000004 995541 100,000 1k pings (-l 120): 5 49510 49058 After: 1G TCP Guest->Host: 3.69 32809 32769 1M normal pings: 99 1000004 996196 100,000 1k pings (-l 120): 5 52435 52361 (Note the interrupt count on 100k pings goes *up*: see next patch). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: have example Launcher service all devices in separate threadsRusty Russell2009-06-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently lguest has three threads: the main Launcher thread, a Waker thread, and a thread for the block device (because synchronous block was simply too painful to bear). The Waker selects() on all the input file descriptors (eg. stdin, net devices, pipe to the block thread) and when one becomes readable it calls into the kernel to kick the Launcher thread out into userspace, which repeats the poll, services the device(s), and then tells the kernel to release the Waker before re-entering the kernel to run the Guest. Also, to make a slightly-decent network transmit routine, the Launcher would suppress further network interrupts while it set a timer: that signal handler would write to a pipe, which would rouse the Waker which would prod the Launcher out of the kernel to check the network device again. Now we can convert all our virtqueues to separate threads: each one has a separate eventfd for when the Guest pokes the device, and can trigger interrupts in the Guest directly. The linecount shows how much this simplifies, but to really bring it home, here's an strace analysis of single Guest->Host ping before: * Guest sends packet, notifies xmit vq, return control to Launcher * Launcher clears notification flag on xmit ring * Launcher writes packet to TUN device writev(4, [{"\0\0\0\0\0\0\0\0\0\0", 10}, {"\366\r\224`\2058\272m\224vf\274\10\0E\0\0T\0\0@\0@\1\265"..., 98}], 2) = 108 * Launcher sets up interrupt for Guest (xmit ring is empty) write(10, "\2\0\0\0\3\0\0\0", 8) = 0 * Launcher sets up timer for interrupt mitigation setitimer(ITIMER_REAL, {it_interval={0, 0}, it_value={0, 505}}, NULL) = 0 * Launcher re-runs guest pread64(10, 0xbfa5f4d4, 4, 0) ... * Waker notices reply packet in tun device (it was in select) select(12, [0 3 4 6 11], NULL, NULL, NULL) = 1 (in [4]) * Waker kicks Launcher out of guest: pwrite64(10, "\3\0\0\0\1\0\0\0", 8, 0) = 0 * Launcher returns from running guest: ... = -1 EAGAIN (Resource temporarily unavailable) * Launcher looks at input fds: select(7, [0 3 4 6], NULL, NULL, {0, 0}) = 1 (in [4], left {0, 0}) * Launcher reads pong from tun device: readv(4, [{"\0\0\0\0\0\0\0\0\0\0", 10}, {"\272m\224vf\274\366\r\224`\2058\10\0E\0\0T\364\26\0\0@"..., 1518}], 2) = 108 * Launcher injects guest notification: write(10, "\2\0\0\0\2\0\0\0", 8) = 0 * Launcher rechecks fds: select(7, [0 3 4 6], NULL, NULL, {0, 0}) = 0 (Timeout) * Launcher clears Waker: pwrite64(10, "\3\0\0\0\0\0\0\0", 8, 0) = 0 * Launcher reruns Guest: pread64(10, 0xbfa5f4d4, 4, 0) = ? ERESTARTSYS (To be restarted) * Signal comes in, uses pipe to wake up Launcher: --- SIGALRM (Alarm clock) @ 0 (0) --- write(8, "\0", 1) = 1 sigreturn() = ? (mask now []) * Waker sees write on pipe: select(12, [0 3 4 6 11], NULL, NULL, NULL) = 1 (in [6]) * Waker kicks Launcher out of Guest: pwrite64(10, "\3\0\0\0\1\0\0\0", 8, 0) = 0 * Launcher exits from kernel: pread64(10, 0xbfa5f4d4, 4, 0) = -1 EAGAIN (Resource temporarily unavailable) * Launcher looks to see what fd woke it: select(7, [0 3 4 6], NULL, NULL, {0, 0}) = 1 (in [6], left {0, 0}) * Launcher reads timeout fd, sets notification flag on xmit ring read(6, "\0", 32) = 1 * Launcher rechecks fds: select(7, [0 3 4 6], NULL, NULL, {0, 0}) = 0 (Timeout) * Launcher clears Waker: pwrite64(10, "\3\0\0\0\0\0\0\0", 8, 0) = 0 * Launcher resumes Guest: pread64(10, "\0p\0\4", 4, 0) .... strace analysis of single Guest->Host ping after: * Guest sends packet, notifies xmit vq, creates event on eventfd. * Network xmit thread wakes from read on eventfd: read(7, "\1\0\0\0\0\0\0\0", 8) = 8 * Network xmit thread writes packet to TUN device writev(4, [{"\0\0\0\0\0\0\0\0\0\0", 10}, {"J\217\232FI\37j\27\375\276\0\304\10\0E\0\0T\0\0@\0@\1\265"..., 98}], 2) = 108 * Network recv thread wakes up from read on tunfd: readv(4, [{"\0\0\0\0\0\0\0\0\0\0", 10}, {"j\27\375\276\0\304J\217\232FI\37\10\0E\0\0TiO\0\0@\1\214"..., 1518}], 2) = 108 * Network recv thread sets up interrupt for the Guest write(6, "\2\0\0\0\2\0\0\0", 8) = 0 * Network recv thread goes back to reading tunfd 13:39:42.460285 readv(4, <unfinished ...> * Network xmit thread sets up interrupt for Guest (xmit ring is empty) write(6, "\2\0\0\0\3\0\0\0", 8) = 0 * Network xmit thread goes back to reading from eventfd read(7, <unfinished ...> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: PAE supportMatias Zabaljauregui2009-06-12
| | | | | | | | This version requires that host and guest have the same PAE status. NX cap is not offered to the guest, yet. Signed-off-by: Matias Zabaljauregui <zabaljauregui@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: fix writev returning short on console outputRusty Russell2009-06-12
| | | | | | | I've never seen it here, but I can't find anywhere that says writev will write everything. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: clean up length-used value in example launcherRusty Russell2009-06-12
| | | | | | | | | | | The "len" field in the used ring for virtio indicates the number of bytes *written* to the buffer. This means the guest doesn't have to zero the buffers in advance as it always knows the used length. Erroneously, the console and network example code puts the length *read* into that field. The guest ignores it, but it's wrong. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: clean up example launcher compile flags.Rusty Russell2009-06-12
| | | | | | | | | | | | 18 months ago 5bbf89fc260830f3f58b331d946a16b39ad1ca2d changed to loading bzImages directly, and no longer manually ungzipping them, so we no longer need libz. Also, -m32 is useful for those on 64-bit platforms (and harmless on 32-bit). Reported-by: Ron Minnich <rminnich@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: remove invalid interrupt forcing logic.Rusty Russell2009-06-12
| | | | | | | | | | | | | | | | | | 20887611523e749d99cc7d64ff6c97d27529fbae (lguest: notify on empty) introduced lguest support for the VIRTIO_F_NOTIFY_ON_EMPTY flag, but in fact it turned on interrupts all the time. Because we always process one buffer at a time, the inflight count is always 0 when call trigger_irq and so we always ignore VRING_AVAIL_F_NO_INTERRUPT from the Guest. It should be looking to see if there are more buffers in the Guest's queue: if it's empty, then we force an interrupt. This makes little difference, since we usually have an empty queue; but that's the subject of another patch. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: get more serious about wmb() in example Launcher codeRusty Russell2009-06-12
| | | | | | | | | | Since the Launcher process runs the Guest, it doesn't have to be very serious about its barriers: the Guest isn't running while we are (Guest is UP). Before we change to use threads to service devices, we need to fix this. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: cleanup passing of /dev/lguest fd around example launcher.Rusty Russell2009-06-12
| | | | | | | We hand the /dev/lguest fd everywhere; it's far neater to just make it a global (it already is, in fact, hidden in the waker_fds struct). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: be paranoid about guest playing with device descriptors.Rusty Russell2009-06-12
| | | | | | | | | | | We can't trust the values in the device descriptor table once the guest has booted, so keep local copies. They could set them to strange values then cause us to segv (they're 8 bit values, so they can't make our pointers go too wild). This becomes more important with the following patches which read them. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: document 32-bit and PAE requirementsRusty Russell2009-04-19
| | | | | | | | | | Robert noted that we don't actually document that lguest is 32-bit only, nor that PAE must be off (CONFIG_PAE is now prompted for if HIGHMEM is set to "off). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: lguest@ozlabs.org Cc: "Robert P. J. Day" <rpjday@crashcourse.ca>
* lguest: tell git to ignore Documentation/lguest/lguestMatt Kraai2009-04-19
| | | | | | | This is the example lguest launcher binary. Signed-off-by: Matt Kraai <kraai@ftbfs.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: barrier me harderRusty Russell2009-03-30
| | | | | | | | | | Impact: barrier correctness in example launcher I doubt either lguest user will complain about performance. Reported-by: Christoph Hellwig <hch@infradead.org> Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: disable the FORTIFY for lguest.Tim 'mithro' Ansell2009-01-29
| | | | | | | | Makes all the warnings go away when compiling lguest on Ubuntu on Intrepid or greater. Signed-off-by: Timothy R Ansell <mithro@mithis.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: move the initial guest page table creation code to the hostMatias Zabaljauregui2008-12-29
| | | | | | | | This patch moves the initial guest page table creation code to the host, so the launcher keeps working with PAE enabled configs. Signed-off-by: Matias Zabaljauregui <zabaljauregui@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: use LGUEST_VRING_ALIGN instead of relying on pagesizeRusty Russell2008-12-29
| | | | | | | | This doesn't really matter, since lguest is i386 only at the moment, but we could actually choose a different value. (lguest doesn't have a guarenteed ABI). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: fix example launcher compile after moved asm-x86 dir.Rusty Russell2008-10-30
| | | | Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* doc/x86: fix doc subdirsUwe Hermann2008-10-28
| | | | | | | | | | The Documentation/i386 and Documentation/x86_64 directories and their contents have been moved into Documentation/x86. Fix references to those files accordingly. Signed-off-by: Uwe Hermann <uwe@hermann-uwe.de> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* lguest: update commentryRusty Russell2008-08-25
| | | | Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: don't set MAC address for guest unless specifiedRusty Russell2008-08-12
| | | | | | | | | | | This shows up when trying to bridge: tap0: received packet with own address as source address As Max Krasnyansky points out, there's no reason to give the guest the same mac address as the TUN device. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Max Krasnyansky <maxk@qualcomm.com>
* lguest: turn Waker into a thread, not a processRusty Russell2008-07-28
| | | | | | | | | | | | | | lguest uses a Waker process to break it out of the kernel (ie. actually running the guest) when file descriptor needs attention. Changing this from a process to a thread somewhat simplifies things: it can directly access the fd_set of things to watch. More importantly, it means that the Waker can see Guest memory correctly, so /dev/vring file descriptors will work as anticipated (the alternative is to actually mmap MAP_SHARED, but you can't do that with /dev/zero). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: Enlarge virtio ringsRusty Russell2008-07-28
| | | | | | | | | | With big packets, 128 entries is a little small. Guest -> Host 1GB TCP: Before: 8.43625 seconds xmit 95640 recv 198266 timeout 49771 usec 1252 After: 8.01099 seconds xmit 49200 recv 102263 timeout 26014 usec 2118 Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: Use GSO/IFF_VNET_HDR extensions on tun/tapRusty Russell2008-07-28
| | | | | | | | | | | | Guest -> Host 1GB TCP: Before 20.1974 seconds xmit 214510 recv 5 timeout 214491 usec 278 After 8.43625 seconds xmit 95640 recv 198266 timeout 49771 usec 1252 Host -> Guest 1GB TCP: Before: Seconds 9.98854 xmit 172166 recv 5344 timeout 172157 usec 251 After: Seconds 5.72803 xmit 244322 recv 9919 timeout 244302 usec 156 Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: Remove 'network: no dma buffer!' warningRusty Russell2008-07-28
| | | | | | | This warning can happen a lot under load, and it should be warnx not warn anwyay. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: Adaptive timeoutRusty Russell2008-07-28
| | | | | | | | | | | | Since the correct timeout value varies, use a heuristic which adjusts the timeout depending on how many packets we've seen. This gives slightly worse results, but doesn't need tweaking when GSO is introduced. 500 usec 19.1887 xmit 561141 recv 1 timeout 559657 Dynamic (278) 20.1974 xmit 214510 recv 5 timeout 214491 usec 278 Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: Tell Guest net not to notify us on every packet xmitRusty Russell2008-07-28
| | | | | | | | | | | | | | | | | | | | | | | | | virtio_ring has the ability to suppress notifications. This prevents a guest exit for every packet, but we need to set a timer on packet receipt to re-check if there were any remaining packets. Here are the times for 1G TCP Guest->Host with different timeout settings (it matters because the TCP window doesn't grow big enough to fill the entire buffer): Timeout value Seconds Xmit/Recv/Timeout None (before) 25.3784 xmit 7750233 recv 1 2500 usec 62.5119 xmit 207020 recv 2 timeout 207020 1000 usec 34.5379 xmit 207003 recv 2 timeout 207003 750 usec 29.2305 xmit 207002 recv 1 timeout 207002 500 usec 19.1887 xmit 561141 recv 1 timeout 559657 250 usec 20.0465 xmit 214128 recv 2 timeout 214110 100 usec 19.2583 xmit 561621 recv 1 timeout 560153 (Note that these values are sensitive to the GSO patches which come later, and probably other traffic-related variables, so take with a large grain of salt). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: net block unneeded receive queue update notificationsRusty Russell2008-07-28
| | | | | | | | | | Number of exits transmitting 10GB Guest->Host before: network xmit 7858610 recv 118136 After: network xmit 7750233 recv 1 Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: wrap last_avail accesses.Rusty Russell2008-07-28
| | | | | | | | To simplify the transition to when we publish indices in the ring (and make shuffling my patch queue easier), wrap them in a lg_last_avail() macro. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: virtio-rng supportRusty Russell2008-07-28
| | | | | | | | This is a simple patch to add support for the virtio "hardware random generator" to lguest. It gets about 1.2 MB/sec reading from /dev/hwrng in the guest. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: Support assigning a MAC addressMark McLoughlin2008-07-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | If you've got a nice DHCP configuration which maps MAC addresses to specific IP addresses, then you're going to want to start your guest with one of those MAC addresses. Also, in Fedora, we have persistent network interface naming based on the MAC address, so with randomly assigned addresses you're soon going to hit eth13. Who knows what will happen then! Allow assigning a MAC address to the network interface with e.g. --tunnet=bridge:eth0:00:FF:95:6B:DA:3D or: --tunnet=192.168.121.1:00:FF:95:6B:DA:3D which is pretty unintelligable, but ... (includes Rusty's minor rework) Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: Don't leak /dev/zero fdMark McLoughlin2008-07-28
| | | | | Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: fix verbose printing of device features.Rusty Russell2008-07-28
| | | | | | %02x is more appropriate for bytes than %08x. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: notify on emptyRusty Russell2008-05-30
| | | | | | | | This is the lguest implementation of the VIRTIO_F_NOTIFY_ON_EMPTY feature. It is currently only published for network devices, but it is turned on for everyone. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: make Launcher see device status updatesRusty Russell2008-05-02
| | | | | | | This brings us closer to Real Life, where we'd examine the device features once it's set the DRIVER_OK status bit. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: de-structify virtio_block status byteRusty Russell2008-05-02
| | | | | | | | | Ron Minnich points out that a struct containing a char is not always sizeof(char); simplest to remove the structure to avoid confusion. Cc: "ron minnich" <rminnich@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: comment documentation update.Rusty Russell2008-03-27
| | | | | | | | | Took some cycles to re-read the Lguest Journey end-to-end, fix some rot and tighten some phrases. Only comments change. No new jokes, but a couple of recycled old jokes. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: Don't need comment terminator before disk section.Rusty Russell2008-03-27
| | | | Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: lguest.txt documentation fixPaul Bolle2008-03-27
| | | | | | | | Mention the config options for the Virtio drivers and move the Virtualization menu to the toplevel. Signed-off-by: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: Add puppies which where previously missing.Tim Ansell2008-03-27
| | | | | | | lguest doesn't have features, it has puppies! Signed-off-by: Timothy R Ansell <mithro@mithis.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lguest: Do not append space to guests kernel command linePaul Bolle2008-03-10
| | | | | | | | | | | | | | The lguest launcher appends a space to the kernel command line (if kernel arguments are specified on its command line). This space is unneeded. More importantly, this appended space will make Red Hat's nash script interpreter (used in a Fedora style initramfs) add an empty argument to init's command line. This empty argument will make kernel arguments like "init=/bin/bash" fail (because the shell will try to execute a script with an empty name). This could be considered a bug in nash, but is easily fixed in the lguest launcher too. Signed-off-by: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: reset functionRusty Russell2008-02-04
| | | | | | | | | | | | | | | | | | | | | A reset function solves three problems: 1) It allows us to renegotiate features, eg. if we want to upgrade a guest driver without rebooting the guest. 2) It gives us a clean way of shutting down virtqueues: after a reset, we know that the buffers won't be used by the host, and 3) It helps the guest recover from messed-up drivers. So we remove the ->shutdown hook, and the only way we now remove feature bits is via reset. We leave it to the driver to do the reset before it deletes queues: the balloon driver, for example, needs to chat to the host in its remove function. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: clarify NO_NOTIFY flag usageRusty Russell2008-02-04
| | | | | | | | | The other side (host) can set the NO_NOTIFY flag as an optimization, to say "no need to kick me when you add things". Make it clear that this is advisory only; especially that we should always notify when the ring is full. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-18 21:46:15 -0500