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  1. 01 10月, 2015 1 次提交
  3. 25 9月, 2015 2 次提交
    • L
      pcnet: remove muldiv64() · c6acbe86
      由 Laurent Vivier 提交于 
      Originally, timers were ticks based, and it made sense to
add ticks to current time to know when to trigger an alarm.

But since commit:

74475455 change all other clock references to use nanosecond resolution accessors

All timers use nanoseconds and we need to convert ticks to nanoseconds, by
doing something like:

    y = muldiv64(x, get_ticks_per_sec(), PCI_FREQUENCY)

where x is the number of device ticks and y the number of system ticks.

y is used as nanoseconds in timer functions,
it works because 1 tick is 1 nanosecond.
(get_ticks_per_sec() is 10^9)

But as PCI frequency is 33 MHz, we can also do:

    y = x * 30; /* 33 MHz PCI period is 30 ns */

Which is much more simple.

This implies a 33.333333 MHz PCI frequency,
but this is correct.
Signed-off-by: NLaurent Vivier <lvivier@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
      c6acbe86
    • L
      rtl8139: remove muldiv64() · 37b9ab92
      由 Laurent Vivier 提交于 
      Originally, timers were ticks based, and it made sense to
add ticks to current time to know when to trigger an alarm.

But since commit:

74475455 change all other clock references to use nanosecond resolution accessors

All timers use nanoseconds and we need to convert ticks to nanoseconds, by
doing something like:

    y = muldiv64(x, get_ticks_per_sec(), PCI_FREQUENCY)

where x is the number of device ticks and y the number of system ticks.

y is used as nanoseconds in timer functions,
it works because 1 tick is 1 nanosecond.
(get_ticks_per_sec() is 10^9)

But as PCI frequency is 33 MHz, we can also do:

    y = x * 30; /* 33 MHz PCI period is 30 ns */

Which is much more simple.

This implies a 33.333333 MHz PCI frequency,
but this is correct.
Signed-off-by: NLaurent Vivier <lvivier@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
      37b9ab92
  5. 24 9月, 2015 6 次提交
  7. 18 9月, 2015 1 次提交
    • M
      Fix bad error handling after memory_region_init_ram() · f8ed85ac
      由 Markus Armbruster 提交于 
      Symptom:

    $ qemu-system-x86_64 -m 10000000
    Unexpected error in ram_block_add() at /work/armbru/qemu/exec.c:1456:
    upstream-qemu: cannot set up guest memory 'pc.ram': Cannot allocate memory
    Aborted (core dumped)

Root cause: commit ef701d7b screwed up handling of out-of-memory
conditions.  Before the commit, we report the error and exit(1), in
one place, ram_block_add().  The commit lifts the error handling up
the call chain some, to three places.  Fine.  Except it uses
&error_abort in these places, changing the behavior from exit(1) to
abort(), and thus undoing the work of commit 39228250 "exec: Don't
abort when we can't allocate guest memory".

The three places are:

* memory_region_init_ram()

  Commit 49946538 (right after commit ef701d7b) lifted the error
  handling further, through memory_region_init_ram(), multiplying the
  incorrect use of &error_abort.  Later on, imitation of existing
  (bad) code may have created more.

* memory_region_init_ram_ptr()

  The &error_abort is still there.

* memory_region_init_rom_device()

  Doesn't need fixing, because commit 33e0eb52 (soon after commit
  ef701d7b) lifted the error handling further, and in the process
  changed it from &error_abort to passing it up the call chain.
  Correct, because the callers are realize() methods.

Fix the error handling after memory_region_init_ram() with a
Coccinelle semantic patch:

    @r@
    expression mr, owner, name, size, err;
    position p;
    @@
            memory_region_init_ram(mr, owner, name, size,
    (
    -                              &error_abort
    +                              &error_fatal
    |
                                   err@p
    )
                                  );
    @script:python@
        p << r.p;
    @@
    print "%s:%s:%s" % (p[0].file, p[0].line, p[0].column)

When the last argument is &error_abort, it gets replaced by
&error_fatal.  This is the fix.

If the last argument is anything else, its position is reported.  This
lets us check the fix is complete.  Four positions get reported:

* ram_backend_memory_alloc()

  Error is passed up the call chain, ultimately through
  user_creatable_complete().  As far as I can tell, it's callers all
  handle the error sanely.

* fsl_imx25_realize(), fsl_imx31_realize(), dp8393x_realize()

  DeviceClass.realize() methods, errors handled sanely further up the
  call chain.

We're good.  Test case again behaves:

    $ qemu-system-x86_64 -m 10000000
    qemu-system-x86_64: cannot set up guest memory 'pc.ram': Cannot allocate memory
    [Exit 1 ]

The next commits will repair the rest of commit ef701d7b's damage.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Message-Id: <1441983105-26376-3-git-send-email-armbru@redhat.com>
Reviewed-by: NPeter Crosthwaite <crosthwaite.peter@gmail.com>
      f8ed85ac
  9. 17 9月, 2015 3 次提交
  11. 15 9月, 2015 3 次提交
  13. 11 9月, 2015 5 次提交
  15. 10 9月, 2015 1 次提交
  17. 09 9月, 2015 1 次提交
  19. 07 9月, 2015 1 次提交
  21. 02 9月, 2015 7 次提交
  23. 13 8月, 2015 1 次提交
  25. 04 8月, 2015 1 次提交
  27. 03 8月, 2015 7 次提交