Re: [Qemu-devel] [PATCH v6 08/18] intel_iommu: fix trace for addr translation

[Jason Wang <jasowang@redhat.com>]

On 2017年02月07日 14:25, Peter Xu wrote:
> On Tue, Feb 07, 2017 at 01:40:39PM +0800, Jason Wang wrote:
>>
>> On 2017年02月03日 16:22, Peter Xu wrote:
>>> Another patch to convert the DPRINTF() stuffs. This patch focuses on the
>>> address translation path and caching.
>>>
>>> Signed-off-by: Peter Xu<peterx@redhat.com>
>>> ---
>>>   hw/i386/intel_iommu.c | 84 ++++++++++++++++++++-------------------------------
>>>   hw/i386/trace-events  |  7 +++++
>>>   2 files changed, 39 insertions(+), 52 deletions(-)
>> Similar to previous patch, this in fact a conversion not a fix.
> I'll fix the subject.
>
>>> diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
>>> index d7b9a01..c672621 100644
>>> --- a/hw/i386/intel_iommu.c
>>> +++ b/hw/i386/intel_iommu.c
>>> @@ -260,11 +260,9 @@ static void vtd_update_iotlb(IntelIOMMUState *s, uint16_t source_id,
>>>       uint64_t *key = g_malloc(sizeof(*key));
>>>       uint64_t gfn = vtd_get_iotlb_gfn(addr, level);
>>> -    VTD_DPRINTF(CACHE, "update iotlb sid 0x%"PRIx16 " iova 0x%"PRIx64
>>> -                " slpte 0x%"PRIx64 " did 0x%"PRIx16, source_id, addr, slpte,
>>> -                domain_id);
>>> +    trace_vtd_iotlb_page_update(source_id, addr, slpte, domain_id);
>>>       if (g_hash_table_size(s->iotlb) >= VTD_IOTLB_MAX_SIZE) {
>>> -        VTD_DPRINTF(CACHE, "iotlb exceeds size limit, forced to reset");
>>> +        trace_vtd_iotlb_reset("iotlb exceeds size limit");
>>>           vtd_reset_iotlb(s);
>>>       }
>>> @@ -505,8 +503,7 @@ static int vtd_get_root_entry(IntelIOMMUState *s, uint8_t index,
>>>       addr = s->root + index * sizeof(*re);
>>>       if (dma_memory_read(&address_space_memory, addr, re, sizeof(*re))) {
>>> -        VTD_DPRINTF(GENERAL, "error: fail to access root-entry at 0x%"PRIx64
>>> -                    " + %"PRIu8, s->root, index);
>>> +        trace_vtd_err("Fail to access root-entry");
>> Looks like some information were removed which may be valuable for
>> debugging, any reason for do this?
> I was trying to avoid introducing unnecessary traces, and I did a
> judgement on which one is important.
>
> I'll keep all the fields printed and add new traces for each of them
> if you really want it.

If it does not cause too much trouble, let's keep those informations.

Thanks

>
> Thanks,
>
> -- peterx
>