On 05.11.14 23:00, Samuel Mendoza-Jonas wrote:
> On 05/11/14 19:05, Alexander Graf wrote:
>>
>>
>> On 05.11.14 07:17, Samuel Mendoza-Jonas wrote:
>>> If a TCG guest reboots during a running migration HTAB entries are not
>>> marked dirty, and the destination boots with an invalid HTAB.
>>>
>>> When a reboot occurs reset the state of HTAB migration, and explicitly
>>> inform the destination of invalid entries.
>>>
>>> Signed-off-by: Samuel Mendoza-Jonas <sam...@au1.ibm.com>
>>> ---
>>> hw/ppc/spapr.c | 59
>>> +++++++++++++++++++++++++++++++++++---------------
>>> include/hw/ppc/spapr.h | 1 +
>>> 2 files changed, 42 insertions(+), 18 deletions(-)
>>>
>>> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
>>> index 1610c28..9f419e8 100644
>>> --- a/hw/ppc/spapr.c
>>> +++ b/hw/ppc/spapr.c
>>> @@ -829,26 +829,30 @@ static void spapr_reset_htab(sPAPREnvironment *spapr)
>>>
>>> shift = kvmppc_reset_htab(spapr->htab_shift);
>>>
>>> + pthread_mutex_lock(&spapr->htab_mutex);
>>> if (shift > 0) {
>>> /* Kernel handles htab, we don't need to allocate one */
>>> spapr->htab_shift = shift;
>>> kvmppc_kern_htab = true;
>>>
>>> /* Tell readers to update their file descriptor */
>>> - pthread_mutex_lock(&spapr->htab_mutex);
>>> if (spapr->htab_fd > 0) {
>>> spapr->htab_fd_stale = true;
>>> }
>>> - pthread_mutex_unlock(&spapr->htab_mutex);
>>> } else {
>>> if (!spapr->htab) {
>>> /* Allocate an htab if we don't yet have one */
>>> spapr->htab = qemu_memalign(HTAB_SIZE(spapr),
>>> HTAB_SIZE(spapr));
>>> + } else {
>>> + spapr->htab_mig_full = true;
>>> + spapr->htab_first_pass = true;
>>> + spapr->htab_save_index = 0;
>>
>> You could just set the dirty bitmap to "all dirty" here, no? Then you
>> don't need all the changes belong I presume?
>
> Yes, then you just need to reset htab_save_index to zero. The idea of this
> approach
> was to avoid walking the HTAB twice (once to dirty and once to read it). But
> it is
> a lot of changes for a fairly small benefit. If setting it dirty is preferred
> I'll
> test and send that version. Thanks!
Yes, please. I would prefer to keep this code as simple as I can ;). And
the less corner cases we need to watch out for, the easier it becomes.
Alex
