slackcoder/qemu - QEMU is a generic and open source machine & userspace emulator and virtualizer

Age	Commit message (Collapse)	Author
2019-03-22	trace-events: Shorten file names in comments	Markus Armbruster
	We spell out sub/dir/ in sub/dir/trace-events' comments pointing to source files. That's because when trace-events got split up, the comments were moved verbatim. Delete the sub/dir/ part from these comments. Gets rid of several misspellings. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-id: 20190314180929.27722-3-armbru@redhat.com Message-Id: <20190314180929.27722-3-armbru@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-03-22	trace-events: Consistently point to docs/devel/tracing.txt	Markus Armbruster
	Almost all trace-events point to docs/devel/tracing.txt in a comment right at the beginning. Touch up the ones that don't. [Updated with Markus' new commit description wording. --Stefan] Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-id: 20190314180929.27722-2-armbru@redhat.com Message-Id: <20190314180929.27722-2-armbru@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2018-12-14	file-posix: Switch to .bdrv_co_ioctl	Kevin Wolf
	No real reason to keep using the callback based mechanism here when the rest of the file-posix driver is coroutine based. Changing it brings ioctls more in line with how other request types work. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-09-22	scsi, file-posix: add support for persistent reservation management	Paolo Bonzini
	It is a common requirement for virtual machine to send persistent reservations, but this currently requires either running QEMU with CAP_SYS_RAWIO, or using out-of-tree patches that let an unprivileged QEMU bypass Linux's filter on SG_IO commands. As an alternative mechanism, the next patches will introduce a privileged helper to run persistent reservation commands without expanding QEMU's attack surface unnecessarily. The helper is invoked through a "pr-manager" QOM object, to which file-posix.c passes SG_IO requests for PERSISTENT RESERVE OUT and PERSISTENT RESERVE IN commands. For example: $ qemu-system-x86_64 -device virtio-scsi \ -object pr-manager-helper,id=helper0,path=/var/run/qemu-pr-helper.sock -drive if=none,id=hd,driver=raw,file.filename=/dev/sdb,file.pr-manager=helper0 -device scsi-block,drive=hd or: $ qemu-system-x86_64 -device virtio-scsi \ -object pr-manager-helper,id=helper0,path=/var/run/qemu-pr-helper.sock -blockdev node-name=hd,driver=raw,file.driver=host_device,file.filename=/dev/sdb,file.pr-manager=helper0 -device scsi-block,drive=hd Multiple pr-manager implementations are conceivable and possible, though only one is implemented right now. For example, a pr-manager could: - talk directly to the multipath daemon from a privileged QEMU (i.e. QEMU links to libmpathpersist); this makes reservation work properly with multipath, but still requires CAP_SYS_RAWIO - use the Linux IOC_PR_* ioctls (they require CAP_SYS_ADMIN though) - more interestingly, implement reservations directly in QEMU through file system locks or a shared database (e.g. sqlite) Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>