[Qemu-devel] ping: [PATCH v12] block/raw-posix.c: Make physical devices usable in QEMU under Mac OS X host

[Programmingkid]

https://patchwork.ozlabs.org/patch/555945/

> Mac OS X can be picky when it comes to allowing the user
> to use physical devices in QEMU. Most mounted volumes
> appear to be off limits to QEMU. If an issue is detected,
> a message is displayed showing the user how to unmount a
> volume.
> 
> Signed-off-by: John Arbuckle <address@hidden>
> 
> ---
> Removed mediaType parameter from FindEjectableOpticalMedia().
> Added goto statements to hdev_open.
> Replaced snprintf() with g_strdup() in FindEjectableOpticalMedia().
> Added return statement to hdev_open for Linux compatibility.
> 
>  block/raw-posix.c |  163 
> ++++++++++++++++++++++++++++++++++++++++-------------
>  1 files changed, 124 insertions(+), 39 deletions(-)
> 
> diff --git a/block/raw-posix.c b/block/raw-posix.c
> index d9162fd..82e8e62 100644
> --- a/block/raw-posix.c
> +++ b/block/raw-posix.c
> @@ -43,6 +43,7 @@
>  #include <IOKit/storage/IOMedia.h>
>  #include <IOKit/storage/IOCDMedia.h>
>  //#include <IOKit/storage/IOCDTypes.h>
> +#include <IOKit/storage/IODVDMedia.h>
>  #include <CoreFoundation/CoreFoundation.h>
>  #endif
>  
> @@ -1975,33 +1976,46 @@ BlockDriver bdrv_file = {
>  /* host device */
>  
>  #if defined(__APPLE__) && defined(__MACH__)
> -static kern_return_t FindEjectableCDMedia( io_iterator_t *mediaIterator );
>  static kern_return_t GetBSDPath(io_iterator_t mediaIterator, char *bsdPath,
>                                  CFIndex maxPathSize, int flags);
> -kern_return_t FindEjectableCDMedia( io_iterator_t *mediaIterator )
> +static char *FindEjectableOpticalMedia(io_iterator_t *mediaIterator)
>  {
> -    kern_return_t       kernResult;
> +    kern_return_t kernResult = KERN_FAILURE;
>      mach_port_t     masterPort;
>      CFMutableDictionaryRef  classesToMatch;
> +    const char *matching_array[] = {kIODVDMediaClass, kIOCDMediaClass};
> +    char *mediaType = NULL;
>  
>      kernResult = IOMasterPort( MACH_PORT_NULL, &masterPort );
>      if ( KERN_SUCCESS != kernResult ) {
>          printf( "IOMasterPort returned %d\n", kernResult );
>      }
>  
> -    classesToMatch = IOServiceMatching( kIOCDMediaClass );
> -    if ( classesToMatch == NULL ) {
> -        printf( "IOServiceMatching returned a NULL dictionary.\n" );
> -    } else {
> -    CFDictionarySetValue( classesToMatch, CFSTR( kIOMediaEjectableKey ), 
> kCFBooleanTrue );
> -    }
> -    kernResult = IOServiceGetMatchingServices( masterPort, classesToMatch, 
> mediaIterator );
> -    if ( KERN_SUCCESS != kernResult )
> -    {
> -        printf( "IOServiceGetMatchingServices returned %d\n", kernResult );
> -    }
> +    int index;
> +    for (index = 0; index < ARRAY_SIZE(matching_array); index++) {
> +        classesToMatch = IOServiceMatching(matching_array[index]);
> +        if (classesToMatch == NULL) {
> +            error_report("IOServiceMatching returned NULL for %s",
> +                         matching_array[index]);
> +            continue;
> +        }
> +        CFDictionarySetValue(classesToMatch, CFSTR(kIOMediaEjectableKey),
> +                             kCFBooleanTrue);
> +        kernResult = IOServiceGetMatchingServices(masterPort, classesToMatch,
> +                                                  mediaIterator);
> +        if (kernResult != KERN_SUCCESS) {
> +            error_report("Note: IOServiceGetMatchingServices returned %d",
> +                         kernResult);
> +        }
>  
> -    return kernResult;
> +        /* If a match was found, leave the loop */
> +        if (*mediaIterator != 0) {
> +            DPRINTF("Matching using %s\n", matching_array[index]);
> +            mediaType = g_strdup(matching_array[index]);
> +            break;
> +        }
> +    }
> +    return mediaType;
>  }
>  
>  kern_return_t GetBSDPath(io_iterator_t mediaIterator, char *bsdPath,
> @@ -2033,7 +2047,35 @@ kern_return_t GetBSDPath(io_iterator_t mediaIterator, 
> char *bsdPath,
>      return kernResult;
>  }
>  
> -#endif
> +/* Sets up a real cdrom for use in QEMU */
> +static bool setup_cdrom(char *bsd_path, Error **errp)
> +{
> +    int index, num_of_test_partitions = 2, fd;
> +    char test_partition[MAXPATHLEN];
> +    bool partition_found = false;
> +
> +    /* look for a working partition */
> +    for (index = 0; index < num_of_test_partitions; index++) {
> +        snprintf(test_partition, sizeof(test_partition), "%ss%d", bsd_path,
> +                 index);
> +        fd = qemu_open(test_partition, O_RDONLY | O_BINARY | O_LARGEFILE);
> +        if (fd >= 0) {
> +            partition_found = true;
> +            qemu_close(fd);
> +            break;
> +        }
> +    }
> +
> +    /* if a working partition on the device was not found */
> +    if (partition_found == false) {
> +        error_setg(errp, "Failed to find a working partition on disc");
> +    } else {
> +        DPRINTF("Using %s as optical disc\n", test_partition);
> +        pstrcpy(bsd_path, MAXPATHLEN, test_partition);
> +    }
> +    return partition_found;
> +}
> +#endif /* defined(__APPLE__) && defined(__MACH__) */
>  
>  static int hdev_probe_device(const char *filename)
>  {
> @@ -2115,6 +2157,16 @@ static bool hdev_is_sg(BlockDriverState *bs)
>      return false;
>  }
>  
> +/* Prints directions on mounting and unmounting a device */
> +static void print_unmounting_directions(const char *file_name)
> +{
> +    error_report("If device %s is mounted on the desktop, unmount"
> +                 " it first before using it in QEMU", file_name);
> +    error_report("Command to unmount device: diskutil unmountDisk %s",
> +                 file_name);
> +    error_report("Command to mount device: diskutil mountDisk %s", 
> file_name);
> +}
> +
>  static int hdev_open(BlockDriverState *bs, QDict *options, int flags,
>                       Error **errp)
>  {
> @@ -2125,32 +2177,55 @@ static int hdev_open(BlockDriverState *bs, QDict 
> *options, int flags,
>  #if defined(__APPLE__) && defined(__MACH__)
>      const char *filename = qdict_get_str(options, "filename");
>  
> -    if (strstart(filename, "/dev/cdrom", NULL)) {
> -        kern_return_t kernResult;
> -        io_iterator_t mediaIterator;
> -        char bsdPath[ MAXPATHLEN ];
> -        int fd;
> -
> -        kernResult = FindEjectableCDMedia( &mediaIterator );
> -        kernResult = GetBSDPath(mediaIterator, bsdPath, sizeof(bsdPath),
> -                                flags);
> -        if ( bsdPath[ 0 ] != '\0' ) {
> -            strcat(bsdPath,"s0");
> -            /* some CDs don't have a partition 0 */
> -            fd = qemu_open(bsdPath, O_RDONLY | O_BINARY | O_LARGEFILE);
> -            if (fd < 0) {
> -                bsdPath[strlen(bsdPath)-1] = '1';
> -            } else {
> -                qemu_close(fd);
> -            }
> -            filename = bsdPath;
> -            qdict_put(options, "filename", qstring_from_str(filename));
> +    /* If using a real cdrom */
> +    if (strcmp(filename, "/dev/cdrom") == 0) {
> +        char bsd_path[MAXPATHLEN];
> +        char *mediaType = NULL;
> +        kern_return_t ret_val;
> +        io_iterator_t mediaIterator = 0;
> +
> +        mediaType = FindEjectableOpticalMedia(&mediaIterator);
> +        if (mediaType == NULL) {
> +            error_setg(errp, "Please make sure your CD/DVD is in the optical"
> +                       " drive");
> +            goto hdev_open_Mac_error;
> +        }
> +
> +        ret_val = GetBSDPath(mediaIterator, bsd_path, sizeof(bsd_path), 
> flags);
> +        if (ret_val != KERN_SUCCESS) {
> +            error_setg(errp, "Could not get BSD path for optical drive");
> +            goto hdev_open_Mac_error;
> +        }
> +
> +        /* If a real optical drive was not found */
> +        if (bsd_path[0] == '\0') {
> +            error_setg(errp, "Failed to obtain bsd path for optical drive");
> +            goto hdev_open_Mac_error;
> +        }
> +
> +        /* If using a cdrom disc and finding a partition on the disc failed 
> */
> +        if (strncmp(mediaType, "IOCDMedia", 9) == 0 &&
> +                                         setup_cdrom(bsd_path, errp) == 
> false) {
> +            print_unmounting_directions(bsd_path);
> +            goto hdev_open_Mac_error;
>          }
>  
> -        if ( mediaIterator )
> -            IOObjectRelease( mediaIterator );
> +        g_free(mediaType);
> +        filename = bsd_path;
> +        qdict_put(options, "filename", qstring_from_str(filename));
> +        goto continue_as_normal; /* skip over error handling code */
> +
> +        /* If an error occurred above */
> +        hdev_open_Mac_error:
> +        if (mediaIterator) {
> +            IOObjectRelease(mediaIterator);
> +        }
> +        g_free(mediaType);
> +        return -1;
> +
> +        continue_as_normal: ;
>      }
> -#endif
> +#endif /* defined(__APPLE__) && defined(__MACH__) */
>  
>      s->type = FTYPE_FILE;
>  
> @@ -2159,8 +2234,18 @@ static int hdev_open(BlockDriverState *bs, QDict 
> *options, int flags,
>          if (local_err) {
>              error_propagate(errp, local_err);
>          }
> +        #if !defined(__APPLE__) && !defined(__MACH__)
>          return ret;
> +        #endif /* !defined(__APPLE__) && !defined(__MACH__) */
> +    }
> +
> +#if defined(__APPLE__) && defined(__MACH__)
> +    /* if a physical device experienced an error while being opened */
> +    if (strncmp(filename, "/dev/", 5) == 0 && ret != 0) {
> +        print_unmounting_directions(filename);
> +        return -1;
>      }
> +#endif /* defined(__APPLE__) && defined(__MACH__) */
>  
>      /* Since this does ioctl the device must be already opened */
>      bs->sg = hdev_is_sg(bs);
> -- 
> 1.7.5.4
> 
>