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qemu/scsi/Makefile.objs

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scsi: move non-emulation specific code to scsi/ util/scsi.c includes some SCSI code that is shared by block/iscsi.c and hw/scsi, but the introduction of the persistent reservation helper will add many more instances of this. There is also include/block/scsi.h, which actually is not part of the core block layer. The persistent reservation manager will also need a home. A scsi/ directory provides one for both the aforementioned shared code and the PR manager code. Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-22 08:08:27 +03:00
block-obj-y += utils.o
scsi, file-posix: add support for persistent reservation management 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>
2017-08-21 19:58:56 +03:00
scsi: add persistent reservation manager using qemu-pr-helper This adds a concrete subclass of pr-manager that talks to qemu-pr-helper. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-21 19:58:56 +03:00
block-obj-$(CONFIG_LINUX) += pr-manager.o pr-manager-helper.o
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