Commit 90e07938 authored by Anthony Liguori's avatar Anthony Liguori
Browse files

Merge remote-tracking branch 'kwolf/for-anthony' into staging 



* kwolf/for-anthony:
  coroutine-sigaltstack.c: Use stack_t, not struct sigaltstack
  stream: fix ratelimit_set_speed
  atapi: make change media detection for guests easier
  Documentation: Update image format information
  Documentation: Update block cache mode information

Signed-off-by: default avatarAnthony Liguori <aliguori@us.ibm.com>
parents 3235f927 2ad2210a

coroutine-sigaltstack.c

+2 −2
Original line number Diff line number Diff line
@@ -171,8 +171,8 @@ static Coroutine *coroutine_new(void) 
    CoroutineThreadState *coTS;

    struct sigaction sa;

    struct sigaction osa;

    struct sigaltstack ss;

    struct sigaltstack oss;

    stack_t ss;

    stack_t oss;

    sigset_t sigs;

    sigset_t osigs;

    jmp_buf old_env;

hw/ide/atapi.c

+10 −5
Original line number Diff line number Diff line
@@ -1124,12 +1124,17 @@ void ide_atapi_cmd(IDEState *s) 
     * GET_EVENT_STATUS_NOTIFICATION to detect such tray open/close

     * states rely on this behavior.

     */

    if (!s->tray_open && bdrv_is_inserted(s->bs) && s->cdrom_changed) {

        ide_atapi_cmd_error(s, NOT_READY, ASC_MEDIUM_NOT_PRESENT);

    if (!(atapi_cmd_table[s->io_buffer[0]].flags & ALLOW_UA) &&

        !s->tray_open && bdrv_is_inserted(s->bs) && s->cdrom_changed) {



        if (s->cdrom_changed == 1) {

            ide_atapi_cmd_error(s, NOT_READY, ASC_MEDIUM_NOT_PRESENT);

            s->cdrom_changed = 2;

        } else {

            ide_atapi_cmd_error(s, UNIT_ATTENTION, ASC_MEDIUM_MAY_HAVE_CHANGED);

            s->cdrom_changed = 0;

        s->sense_key = UNIT_ATTENTION;

        s->asc = ASC_MEDIUM_MAY_HAVE_CHANGED;

        }



        return;

    }

hw/ide/core.c

+0 −6
Original line number Diff line number Diff line
@@ -2160,12 +2160,6 @@ static int ide_drive_post_load(void *opaque, int version_id) 
{

    IDEState *s = opaque;



    if (version_id < 3) {

        if (s->sense_key == UNIT_ATTENTION &&

            s->asc == ASC_MEDIUM_MAY_HAVE_CHANGED) {

            s->cdrom_changed = 1;

        }

    }

    if (s->identify_set) {

        bdrv_set_enable_write_cache(s->bs, !!(s->identify_data[85] & (1 << 5)));

    }

include/qemu/ratelimit.h

+1 −1
Original line number Diff line number Diff line
@@ -42,7 +42,7 @@ static inline void ratelimit_set_speed(RateLimit *limit, uint64_t speed, 
                                       uint64_t slice_ns)

{

    limit->slice_ns = slice_ns;

    limit->slice_quota = ((double)speed * 1000000000ULL) / slice_ns;

    limit->slice_quota = ((double)speed * slice_ns)/1000000000ULL;

}



#endif

qemu-doc.texi

+167 −0
Original line number Diff line number Diff line
@@ -416,6 +416,7 @@ snapshots. 
* vm_snapshots::              VM snapshots

* qemu_img_invocation::       qemu-img Invocation

* qemu_nbd_invocation::       qemu-nbd Invocation

* disk_images_formats::       Disk image file formats

* host_drives::               Using host drives

* disk_images_fat_images::    Virtual FAT disk images

* disk_images_nbd::           NBD access
@@ -507,6 +508,172 @@ state is not saved or restored properly (in particular USB). 


@include qemu-nbd.texi



@node disk_images_formats

@subsection Disk image file formats



QEMU supports many image file formats that can be used with VMs as well as with

any of the tools (like @code{qemu-img}). This includes the preferred formats

raw and qcow2 as well as formats that are supported for compatibility with

older QEMU versions or other hypervisors.



Depending on the image format, different options can be passed to

@code{qemu-img create} and @code{qemu-img convert} using the @code{-o} option.

This section describes each format and the options that are supported for it.



@table @option

@item raw



Raw disk image format. This format has the advantage of

being simple and easily exportable to all other emulators. If your

file system supports @emph{holes} (for example in ext2 or ext3 on

Linux or NTFS on Windows), then only the written sectors will reserve

space. Use @code{qemu-img info} to know the real size used by the

image or @code{ls -ls} on Unix/Linux.



@item qcow2

QEMU image format, the most versatile format. Use it to have smaller

images (useful if your filesystem does not supports holes, for example

on Windows), optional AES encryption, zlib based compression and

support of multiple VM snapshots.



Supported options:

@table @code

@item compat

Determines the qcow2 version to use. @code{compat=0.10} uses the traditional

image format that can be read by any QEMU since 0.10 (this is the default).

@code{compat=1.1} enables image format extensions that only QEMU 1.1 and

newer understand. Amongst others, this includes zero clusters, which allow

efficient copy-on-read for sparse images.



@item backing_file

File name of a base image (see @option{create} subcommand)

@item backing_fmt

Image format of the base image

@item encryption

If this option is set to @code{on}, the image is encrypted.



Encryption uses the AES format which is very secure (128 bit keys). Use

a long password (16 characters) to get maximum protection.



@item cluster_size

Changes the qcow2 cluster size (must be between 512 and 2M). Smaller cluster

sizes can improve the image file size whereas larger cluster sizes generally

provide better performance.



@item preallocation

Preallocation mode (allowed values: off, metadata). An image with preallocated

metadata is initially larger but can improve performance when the image needs

to grow.



@item lazy_refcounts

If this option is set to @code{on}, reference count updates are postponed with

the goal of avoiding metadata I/O and improving performance. This is

particularly interesting with @option{cache=writethrough} which doesn't batch

metadata updates. The tradeoff is that after a host crash, the reference count

tables must be rebuilt, i.e. on the next open an (automatic) @code{qemu-img

check -r all} is required, which may take some time.



This option can only be enabled if @code{compat=1.1} is specified.



@end table



@item qed

Old QEMU image format with support for backing files and compact image files

(when your filesystem or transport medium does not support holes).



When converting QED images to qcow2, you might want to consider using the

@code{lazy_refcounts=on} option to get a more QED-like behaviour.



Supported options:

@table @code

@item backing_file

File name of a base image (see @option{create} subcommand).

@item backing_fmt

Image file format of backing file (optional).  Useful if the format cannot be

autodetected because it has no header, like some vhd/vpc files.

@item cluster_size

Changes the cluster size (must be power-of-2 between 4K and 64K). Smaller

cluster sizes can improve the image file size whereas larger cluster sizes

generally provide better performance.

@item table_size

Changes the number of clusters per L1/L2 table (must be power-of-2 between 1

and 16).  There is normally no need to change this value but this option can be

used for performance benchmarking.

@end table



@item qcow

Old QEMU image format with support for backing files, compact image files,

encryption and compression.



Supported options:

@table @code

@item backing_file

File name of a base image (see @option{create} subcommand)

@item encryption

If this option is set to @code{on}, the image is encrypted.

@end table



@item cow

User Mode Linux Copy On Write image format. It is supported only for

compatibility with previous versions.

Supported options:

@table @code

@item backing_file

File name of a base image (see @option{create} subcommand)

@end table



@item vdi

VirtualBox 1.1 compatible image format.

Supported options:

@table @code

@item static

If this option is set to @code{on}, the image is created with metadata

preallocation.

@end table



@item vmdk

VMware 3 and 4 compatible image format.



Supported options:

@table @code

@item backing_file

File name of a base image (see @option{create} subcommand).

@item compat6

Create a VMDK version 6 image (instead of version 4)

@item subformat

Specifies which VMDK subformat to use. Valid options are

@code{monolithicSparse} (default),

@code{monolithicFlat},

@code{twoGbMaxExtentSparse},

@code{twoGbMaxExtentFlat} and

@code{streamOptimized}.

@end table



@item vpc

VirtualPC compatible image format (VHD).

Supported options:

@table @code

@item subformat

Specifies which VHD subformat to use. Valid options are

@code{dynamic} (default) and @code{fixed}.

@end table

@end table



@subsubsection Read-only formats

More disk image file formats are supported in a read-only mode.

@table @option

@item bochs

Bochs images of @code{growing} type.

@item cloop

Linux Compressed Loop image, useful only to reuse directly compressed

CD-ROM images present for example in the Knoppix CD-ROMs.

@item dmg

Apple disk image.

@item parallels

Parallels disk image format.

@end table





@node host_drives

@subsection Using host drives