diff options
Diffstat (limited to 'qemu-options.hx')
| -rw-r--r-- | qemu-options.hx | 35 |
1 files changed, 27 insertions, 8 deletions
diff --git a/qemu-options.hx b/qemu-options.hx index 463f520c57..6be621c232 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -186,6 +186,7 @@ DEF("accel", HAS_ARG, QEMU_OPTION_accel, " split-wx=on|off (enable TCG split w^x mapping)\n" " tb-size=n (TCG translation block cache size)\n" " dirty-ring-size=n (KVM dirty ring GFN count, default 0)\n" + " eager-split-size=n (KVM Eager Page Split chunk size, default 0, disabled. ARM only)\n" " notify-vmexit=run|internal-error|disable,notify-window=n (enable notify VM exit and set notify window, x86 only)\n" " thread=single|multi (enable multi-threaded TCG)\n", QEMU_ARCH_ALL) SRST @@ -244,6 +245,20 @@ SRST is disabled (dirty-ring-size=0). When enabled, KVM will instead record dirty pages in a bitmap. + ``eager-split-size=n`` + KVM implements dirty page logging at the PAGE_SIZE granularity and + enabling dirty-logging on a huge-page requires breaking it into + PAGE_SIZE pages in the first place. KVM on ARM does this splitting + lazily by default. There are performance benefits in doing huge-page + split eagerly, especially in situations where TLBI costs associated + with break-before-make sequences are considerable and also if guest + workloads are read intensive. The size here specifies how many pages + to break at a time and needs to be a valid block size which is + 1GB/2MB/4KB, 32MB/16KB and 512MB/64KB for 4KB/16KB/64KB PAGE_SIZE + respectively. Be wary of specifying a higher size as it will have an + impact on the memory. By default, this feature is disabled + (eager-split-size=0). + ``notify-vmexit=run|internal-error|disable,notify-window=n`` Enables or disables notify VM exit support on x86 host and specify the corresponding notify window to trigger the VM exit if enabled. @@ -1209,10 +1224,10 @@ SRST ERST DEF("hda", HAS_ARG, QEMU_OPTION_hda, - "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL) + "-hda/-hdb file use 'file' as hard disk 0/1 image\n", QEMU_ARCH_ALL) DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL) DEF("hdc", HAS_ARG, QEMU_OPTION_hdc, - "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL) + "-hdc/-hdd file use 'file' as hard disk 2/3 image\n", QEMU_ARCH_ALL) DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL) SRST ``-hda file`` @@ -1222,18 +1237,22 @@ SRST ``-hdc file`` \ ``-hdd file`` - Use file as hard disk 0, 1, 2 or 3 image (see the :ref:`disk images` - chapter in the System Emulation Users Guide). + Use file as hard disk 0, 1, 2 or 3 image on the default bus of the + emulated machine (this is for example the IDE bus on most x86 machines, + but it can also be SCSI, virtio or something else on other target + architectures). See also the :ref:`disk images` chapter in the System + Emulation Users Guide. ERST DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom, - "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n", + "-cdrom file use 'file' as CD-ROM image\n", QEMU_ARCH_ALL) SRST ``-cdrom file`` - Use file as CD-ROM image (you cannot use ``-hdc`` and ``-cdrom`` at - the same time). You can use the host CD-ROM by using ``/dev/cdrom`` - as filename. + Use file as CD-ROM image on the default bus of the emulated machine + (which is IDE1 master on x86, so you cannot use ``-hdc`` and ``-cdrom`` + at the same time there). On systems that support it, you can use the + host CD-ROM by using ``/dev/cdrom`` as filename. ERST DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev, |