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2015-07-14block/curl: Don't lose original error when a connection fails.Richard W.M. Jones
Currently if qemu is connected to a curl source (eg. web server), and the web server fails / times out / dies, you always see a bogus EIO "Input/output error". For example, choose a large file located on any local webserver which you control: $ qemu-img convert -p http://example.com/large.iso /tmp/test Once it starts copying the file, stop the webserver and you will see qemu-img fail with: qemu-img: error while reading sector 61440: Input/output error This patch does two things: Firstly print the actual error from curl so it doesn't get lost. Secondly, change EIO to EPROTO. EPROTO is a POSIX.1 compatible errno which more accurately reflects that there was a protocol error, rather than some kind of hardware failure. After this patch is applied, the error changes to: $ qemu-img convert -p http://example.com/large.iso /tmp/test qemu-img: curl: transfer closed with 469989 bytes remaining to read qemu-img: error while reading sector 16384: Protocol error Signed-off-by: Richard W.M. Jones <rjones@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Jeff Cody <jcody@redhat.com>
2015-06-22qerror: Move #include out of qerror.hMarkus Armbruster
Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-11-03block/curl: Improve type safety of s->timeout.Richard W.M. Jones
qemu_opt_get_number returns a uint64_t, and curl_easy_setopt expects a long (not an int). There is no warning about the latter type error because curl_easy_setopt uses a varargs argument. Store the timeout (which is a positive number of seconds) as a uint64_t. Check that the number given by the user is reasonable. Zero is permissible (meaning no timeout is enforced by cURL). Cast it to long before calling curl_easy_setopt to fix the type error. Example error message after this change has been applied: $ ./qemu-img create -f qcow2 /tmp/test.qcow2 \ -b 'json: { "file.driver":"https", "file.url":"https://foo/bar", "file.timeout":-1 }' qemu-img: /tmp/test.qcow2: Could not open 'json: { "file.driver":"https", "file.url":"https://foo/bar", "file.timeout":-1 }': timeout parameter is too large or negative: Invalid argument Signed-off-by: Richard W.M. Jones <rjones@redhat.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com> Reviewed-by: Gonglei <arei.gonglei@huawei.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-10-20block: Rename BlockDriverCompletionFunc to BlockCompletionFuncMarkus Armbruster
I'll use it with block backends shortly, and the name is going to fit badly there. It's a block layer thing anyway, not just a block driver thing. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20block: Rename BlockDriverAIOCB* to BlockAIOCB*Markus Armbruster
I'll use BlockDriverAIOCB with block backends shortly, and the name is going to fit badly there. It's a block layer thing anyway, not just a block driver thing. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-09-22block: Rename qemu_aio_release -> qemu_aio_unrefFam Zheng
Suggested-by: Benoît Canet <benoit.canet@irqsave.net> Signed-off-by: Fam Zheng <famz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-09-22curl: Drop curl_aiocb_info.cancelFam Zheng
Signed-off-by: Fam Zheng <famz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-09-02curl: The macro that you have to uncomment to get debugging is DEBUG_CURL.Richard W.M. Jones
Signed-off-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2014-08-29curl: Don't deref NULL pointer in call to aio_poll.Richard W.M. Jones
In commit 63f0f45f2e89b60ff8245fec81328ddfde42a303 the following mechanical change was made: if (!state) { - qemu_aio_wait(); + aio_poll(state->s->aio_context, true); } The new code now checks if state is NULL and then dereferences it ('state->s') which is obviously incorrect. This commit replaces state->s->aio_context with bdrv_get_aio_context(bs), fixing this problem. The two other hunks are concerned with getting the BlockDriverState pointer bs to where it is needed. The original bug causes a segfault when using libguestfs to access a VMware vCenter Server and doing any kind of complex read-heavy operations. With this commit the segfault goes away. Signed-off-by: Richard W.M. Jones <rjones@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Benoît Canet <benoit.canet@nodalink.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-08-29curl: Allow a cookie or cookies to be sent with http/https requests.Richard W.M. Jones
In order to access VMware ESX efficiently, we need to send a session cookie. This patch is very simple and just allows you to send that session cookie. It punts on the question of how you get the session cookie in the first place, but in practice you can just run a `curl' command against the server and extract the cookie that way. To use it, add file.cookie to the curl URL. For example: $ qemu-img info 'json: { "file.driver":"https", "file.url":"https://vcenter/folder/Windows%202003/Windows%202003-flat.vmdk?dcPath=Datacenter&dsName=datastore1", "file.sslverify":"off", "file.cookie":"vmware_soap_session=\"52a01262-bf93-ccce-d379-8dabb3e55560\""}' image: [...] file format: raw virtual size: 8.0G (8589934592 bytes) disk size: unavailable Signed-off-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-08-29block.curl: adding 'timeout' optionDaniel Henrique Barboza
The curl hardcoded timeout (5 seconds) sometimes is not long enough depending on the remote server configuration and network traffic. The user should be able to set how much long he is willing to wait for the connection. Adding a new option to set this timeout gives the user this flexibility. The previous default timeout of 5 seconds will be used if this option is not present. Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Daniel Henrique Barboza <danielhb@linux.vnet.ibm.com> Reviewed-by: Benoit Canet <benoit.canet@nodalink.com> Tested-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-08-15curl: Handle failure for potentially large allocationsKevin Wolf
Some code in the block layer makes potentially huge allocations. Failure is not completely unexpected there, so avoid aborting qemu and handle out-of-memory situations gracefully. This patch addresses the allocations in the curl block driver. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Benoit Canet <benoit@irqsave.net>
2014-06-16block: Drop superfluous conditionals around g_free()Markus Armbruster
Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-06-04curl: implement .bdrv_detach/attach_aio_context()Stefan Hajnoczi
The curl block driver uses fd handlers, timers, and BHs. The fd handlers and timers are managed on behalf of libcurl, which controls them using callback functions that the block driver implements. The simplest way to implement .bdrv_detach/attach_aio_context() is to clean up libcurl in the old event loop and initialize it again in the new event loop. We do not need to keep track of anything since there are no pending requests when the AioContext is changed. Also make sure to use aio_set_fd_handler() instead of qemu_aio_set_fd_handler() and aio_bh_new() instead of qemu_bh_new() so the current AioContext is passed in. Cc: Alexander Graf <agraf@suse.de> Cc: Fam Zheng <famz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com>
2014-05-19curl: Add sslverify optionMatthew Booth
This allows qemu to use images over https with a self-signed certificate. It defaults to verifying the certificate. Signed-off-by: Matthew Booth <mbooth@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-05-19curl: Remove broken parsing of options from urlMatthew Booth
The block layer now supports a generic json syntax for passing option parameters explicitly, making parsing of options from the url redundant. Signed-off-by: Matthew Booth <mbooth@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-05-19curl: Fix build when curl_multi_socket_action isn't availableMatthew Booth
Signed-off-by: Matthew Booth <mbooth@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-04-30curl: Fix hang reading from slow connectionsMatthew Booth
When receiving a new aio read request, we first look for an existing transaction whose range will cover the read request by the time it completes. However, we weren't checking that the existing transaction was still active. If it had timed out, we were adding the request to a transaction which would never complete and had already been cancelled, resulting in a hang. Signed-off-by: Matthew Booth <mbooth@redhat.com> Tested-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-04-30curl: Ensure all informationals are checked for completionMatthew Booth
According to the documentation, the correct way to ensure all informationals have been returned by curl_multi_info_read is to loop until it returns NULL. Signed-off-by: Matthew Booth <mbooth@redhat.com> Tested-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-04-30curl: Eliminate unnecessary use of curl_multi_socket_allMatthew Booth
curl_multi_socket_all is a deprecated catch-all which checks for activities on all open curl sockets. We have enough information from the event loop to check only the sockets with activity. This change removes use of curl_multi_socket_all in favour of curl_multi_socket_action called with the relevant handle. At the same time, it also ensures that the driver only checks for completion of read operations after reading from a socket, rather than both reading and writing. Signed-off-by: Matthew Booth <mbooth@redhat.com> Tested-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-04-30curl: Remove unnecessary explicit calls to internal event handlerMatthew Booth
Remove calls to curl_multi_do where the relevant handles are already registered to the event loop. Ensure that we kick off socket handling with CURL_SOCKET_TIMEOUT after adding a new handle. Signed-off-by: Matthew Booth <mbooth@redhat.com> Tested-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-04-30curl: Remove erroneous sleep waiting for curl completionMatthew Booth
The driver will not start more than a fixed number of curl sessions. If it needs more, it must wait for the completion of an existing one. The driver was sleeping, which will prevent the main loop from running, and therefore the event it's waiting on. It was also directly calling its internal handler rather than waiting on existing registered handlers to be called from the main loop. This change causes it simply to wait for a period of time whilst allowing the main loop to execute. Signed-off-by: Matthew Booth <mbooth@redhat.com> Tested-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-04-30curl: Fix return from curl_read_cb with invalid stateMatthew Booth
A curl write callback is supposed to return the number of bytes it handled. curl_read_cb would have erroneously reported it had handled all bytes in the event that the internal curl state was invalid. Signed-off-by: Matthew Booth <mbooth@redhat.com> Tested-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-04-30curl: Remove unnecessary use of gotoMatthew Booth
This isn't any of the usually acceptable uses of goto. Signed-off-by: Matthew Booth <mbooth@redhat.com> Tested-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-04-30curl: Fix long lineMatthew Booth
Signed-off-by: Matthew Booth <mbooth@redhat.com> Tested-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-04-22curl: Replaced old error handling with error reporting API.Maria Kustova
Signed-off-by: Maria Kustova <maria.k@catit.be> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-04-01curl: check data size before memcpy to local buffer. (CVE-2014-0144)Fam Zheng
curl_read_cb is callback function for libcurl when data arrives. The data size passed in here is not guaranteed to be within the range of request we submitted, so we may overflow the guest IO buffer. Check the real size we have before memcpy to buffer to avoid overflow. Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-02-21curl: correctly propagate errorsPaolo Bonzini
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-02-17Use error_is_set() only when necessaryMarkus Armbruster
error_is_set(&var) is the same as var != NULL, but it takes whole-program analysis to figure that out. Unnecessarily hard for optimizers, static checkers, and human readers. Dumb it down to obvious. Gets rid of several dozen Coverity false positives. Note that the obvious form is already used in many places. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Andreas Färber <afaerber@suse.de> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-01-24block/curl: Implement the libcurl timer callback interfacePeter Maydell
libcurl versions 7.16.0 and later have a timer callback interface which must be implemented in order for libcurl to make forward progress (it will sometimes rely on being called back on the timeout if there are no file descriptors registered). Implement the callback, and use a QEMU AIO timer to ensure we prod libcurl again when it asks us to. Based on Peter's original patch plus my fix to add curl_multi_timeout_do. Should compile just fine even on older versions of libcurl. I also tried copy-on-read and streaming: $ ./qemu-img create -f qcow2 -o \ backing_file=http://download.fedoraproject.org/pub/fedora/linux/releases/20/Live/x86_64/Fedora-Live-Desktop-x86_64-20-1.iso \ foo.qcow2 1G $ x86_64-softmmu/qemu-system-x86_64 \ -drive if=none,file=foo.qcow2,copy-on-read=on,id=cd \ -device ide-cd,drive=cd --enable-kvm -m 1024 Direct http usage is probably too slow, but with copy-on-read ultimately the image does boot! After some time, streaming gets canceled by an EIO, which needs further investigation. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-01-06qemu-option: Remove qemu_opts_create_nofailPeter Crosthwaite
This is a boiler-plate _nofail variant of qemu_opts_create. Remove and use error_abort in call sites. null/0 arguments needs to be added for the id and fail_if_exists fields in affected callsites due to argument inconsistency between the normal and no_fail variants. Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2013-09-12bdrv: Use "Error" for opening imagesMax Reitz
Add an Error ** parameter to BlockDriver.bdrv_open and BlockDriver.bdrv_file_open to allow more specific error messages. Signed-off-by: Max Reitz <mreitz@redhat.com>
2013-09-01curl: qemu_bh_new() can never return NULLStefan Hajnoczi
Drop error code path which cannot be taken since qemu_bh_new() does not return NULL. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2013-08-19aio: drop io_flush argumentStefan Hajnoczi
The .io_flush() handler no longer exists and has no users. Drop the io_flush argument to aio_set_fd_handler() and related functions. The AioFlushEventNotifierHandler and AioFlushHandler typedefs are no longer used and are dropped too. Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-08-19block/curl: drop curl_aio_flush()Stefan Hajnoczi
.io_flush() is no longer called so drop curl_aio_flush(). The acb[] array that the function checks is still used in other parts of block/curl.c. Therefore we cannot remove acb[], it is needed. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-07-05curl: refuse to open URL from HTTP server without range supportFam Zheng
CURL driver requests partial data from server on guest IO req. For HTTP and HTTPS, it uses "Range: ***" in requests, and this will not work if server not accepting range. This patch does this check when open. * Removed curl_size_cb, which is not used: On one hand it's registered to libcurl as CURLOPT_WRITEFUNCTION, instead of CURLOPT_HEADERFUNCTION, which will get called with *data*, not *header*. On the other hand the s->len is assigned unconditionally later. In this gone function, the sscanf for "Content-Length: %zd", on (void *)ptr, which is not guaranteed to be zero-terminated, is potentially a security bug. So this patch fixes it as a side-effect. The bug is reported as: https://bugs.launchpad.net/qemu/+bug/1188943 (Note the bug is marked "private" so you might not be able to see it) * Introduced curl_header_cb, which is used to parse header and mark the server as accepting range if "Accept-Ranges: bytes" line is seen from response header. If protocol is HTTP or HTTPS, but server response has no not this support, refuse to open this URL. Note that python builtin module SimpleHTTPServer is an example of not supporting range, if you need to test this driver, get a better server or use internet URLs. Signed-off-by: Fam Zheng <famz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-06-17curl: Don't set curl options on the handle just before it's going to be deleted.Richard W.M. Jones
(Found by Kamil Dudka) Signed-off-by: Richard W.M. Jones <rjones@redhat.com> Cc: Michael Tokarev <mjt@tls.msk.ru> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-06-17block/curl.c: Refuse to open the handle for writes.Richard W.M. Jones
Signed-off-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-06-11curl: Whitespace only changes.Richard W.M. Jones
Trivial patch to remove odd whitespace. Signed-off-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2013-04-22block: Remove filename parameter from .bdrv_file_open()Kevin Wolf
It is unused now in all block drivers. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2013-04-22curl: Use bdrv_open options instead of filenameKevin Wolf
As a bonus, going through the QemuOpts QEMU_OPT_SIZE parser for the readahead option gives us proper error reporting that the previous use of atoi() lacked. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2013-03-22block: Add options QDict to bdrv_file_open() prototypesKevin Wolf
The new parameter is unused yet. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2013-02-13block/curl: only restrict protocols with libcurl>=7.19.4Stefan Hajnoczi
The curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, ...) interface was introduced in libcurl 7.19.4. Therefore we cannot protect against CVE-2013-0249 when linking against an older libcurl. This fixes the build failure introduced by fb6d1bbd246c7a57ef53d3847ef225cd1349d602. Reported-by: Andreas Färber <afaerber@suse.de> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Tested-by: Andreas Färber <andreas.faeber@web.de> Message-id: 1360743934-8337-1-git-send-email-stefanha@redhat.com Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-02-08block/curl: disable extra protocols to prevent CVE-2013-0249Stefan Hajnoczi
There is a buffer overflow in libcurl POP3/SMTP/IMAP. The workaround is simple: disable extra protocols so that they cannot be exploited. Full details here: http://curl.haxx.se/docs/adv_20130206.html QEMU only cares about HTTP, HTTPS, FTP, FTPS, and TFTP. I have tested that this fix prevents the exploit on my host with libcurl-7.27.0-5.fc18. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-12-19block: move include files to include/block/Paolo Bonzini
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-11-14aio: rename AIOPool to AIOCBInfoStefan Hajnoczi
Now that AIOPool no longer keeps a freelist, it isn't really a "pool" anymore. Rename it to AIOCBInfo and make it const since it no longer needs to be modified. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-12block/curl: Fix wrong free statementStefan Weil
Report from smatch: block/curl.c:546 curl_close(21) info: redundant null check on s->url calling free() The check was redundant, and free was also wrong because the memory was allocated using g_strdup. Signed-off-by: Stefan Weil <sw@weilnetz.de> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-06-11allow qemu_iovec_from_buffer() to specify offset from which to start copyingMichael Tokarev
Similar to qemu_iovec_memset(QEMUIOVector *qiov, size_t offset, int c, size_t bytes); the new prototype is: qemu_iovec_from_buf(QEMUIOVector *qiov, size_t offset, const void *buf, size_t bytes); The processing starts at offset bytes within qiov. This way, we may copy a bounce buffer directly to a middle of qiov. This is exactly the same function as iov_from_buf() from iov.c, so use the existing implementation and rename it to qemu_iovec_from_buf() to be shorter and to match the utility function. As with utility implementation, we now assert that the offset is inside actual iovec. Nothing changed for current callers, because `offset' parameter is new. While at it, stop using "bounce-qiov" in block/qcow2.c and copy decrypted data directly from cluster_data instead of recreating a temp qiov for doing that. Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2012-04-19aio: remove process_queue callback and qemu_aio_process_queuePaolo Bonzini
Both unused after the previous patch. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-03block/curl: Replace usleep by g_usleepStefan Weil
The function usleep is not available for all supported platforms: at least some versions of MinGW don't support it. usleep was also declared obsolete by POSIX.1-2001. The function g_usleep is part of glib2.0, so it is available for all supported platforms. Using nanosleep would also be possible but needs more code. Signed-off-by: Stefan Weil <sw@weilnetz.de> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>