Hi, > From: Lu Baolu [mailto:baolu...@linux.intel.com] > Sent: Friday, November 9, 2018 9:40 AM > Subject: Re: [PATCH v4 04/12] iommu/vt-d: Add 256-bit invalidation descriptor > support > > Hi, > > On 11/8/18 3:20 PM, Liu, Yi L wrote: > > Hi, > > > >> From: Lu Baolu [mailto:baolu...@linux.intel.com] > >> Sent: Thursday, November 8, 2018 2:14 PM > >> > >> Hi, > >> > >> On 11/8/18 1:45 PM, Liu, Yi L wrote: > >>>> From: Lu Baolu [mailto:baolu...@linux.intel.com] > >>>> Sent: Thursday, November 8, 2018 1:25 PM > >>>> Subject: Re: [PATCH v4 04/12] iommu/vt-d: Add 256-bit invalidation > >>>> descriptor support > >>>> > >>>> Hi, > >>>> > >>>> On 11/8/18 11:49 AM, Liu, Yi L wrote: > >>>>> Hi, > >>>>> > >>>>>> From: Lu Baolu [mailto:baolu...@linux.intel.com] > >>>>>> Sent: Thursday, November 8, 2018 10:17 AM > >>>>>> Subject: Re: [PATCH v4 04/12] iommu/vt-d: Add 256-bit > >>>>>> invalidation descriptor support > >>>>>> > >>>>>> Hi Yi, > >>>>>> > >>>>>> On 11/7/18 2:07 PM, Liu, Yi L wrote: > >>>>>>> Hi Baolu, > >>>>>>> > >>>>>>>> From: Lu Baolu [mailto:baolu...@linux.intel.com] > >>>>>>>> Sent: Monday, November 5, 2018 1:32 PM > >>>>>>> [...] > >>>>>>> > >>>>>>>> --- > >>>>>>>> drivers/iommu/dmar.c | 83 > >>>>>>>> +++++++++++++++++++---------- > >>>>>>>> drivers/iommu/intel-svm.c | 76 > >>>>>>>> ++++++++++++++++---------- > >>>>>>>> drivers/iommu/intel_irq_remapping.c | 6 ++- > >>>>>>>> include/linux/intel-iommu.h | 9 +++- > >>>>>>>> 4 files changed, 115 insertions(+), 59 deletions(-) > >>>>>>>> > >>>>>>>> diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c index > >>>>>>>> d9c748b6f9e4..ec10427b98ac 100644 > >>>>>>>> --- a/drivers/iommu/dmar.c > >>>>>>>> +++ b/drivers/iommu/dmar.c > >>>>>>>> @@ -1160,6 +1160,7 @@ static int qi_check_fault(struct > >>>>>>>> intel_iommu *iommu, int > >>>>>>>> index) > >>>>>>>> int head, tail; > >>>>>>>> struct q_inval *qi = iommu->qi; > >>>>>>>> int wait_index = (index + 1) % QI_LENGTH; > >>>>>>>> + int shift = qi_shift(iommu); > >>>>>>>> > >>>>>>>> if (qi->desc_status[wait_index] == QI_ABORT) > >>>>>>>> return -EAGAIN; > >>>>>>>> @@ -1173,13 +1174,15 @@ static int qi_check_fault(struct > >>>>>>>> intel_iommu *iommu, int index) > >>>>>>>> */ > >>>>>>>> if (fault & DMA_FSTS_IQE) { > >>>>>>>> head = readl(iommu->reg + DMAR_IQH_REG); > >>>>>>>> - if ((head >> DMAR_IQ_SHIFT) == index) { > >>>>>>>> + if ((head >> shift) == index) { > >>>>>>>> + struct qi_desc *desc = qi->desc + head; > >>>>>>>> + > >>>>>>>> pr_err("VT-d detected invalid > >>>>>>>> descriptor: " > >>>>>>>> "low=%llx, high=%llx\n", > >>>>>>>> - (unsigned long long)qi->desc[index].low, > >>>>>>>> - (unsigned long > >>>>>>>> long)qi->desc[index].high); > >>>>>>>> - memcpy(&qi->desc[index], &qi->desc[wait_index], > >>>>>>>> - sizeof(struct qi_desc)); > >>>>>>>> + (unsigned long long)desc->qw0, > >>>>>>>> + (unsigned long long)desc->qw1); > >>>>>>> Still missing qw2 and qw3. May make the print differ based on if > >>>>>>> smts is > >> configed. > >>>>>> qw2 and qw3 are reserved from software point of view. We don't > >>>>>> need to print it for information. > >>>>> But for Scalable mode, it should be valid? > >>>> No. It's reserved for software. > >>> No, I don’t think so. PRQ response would also be queued to hardware > >>> by QI. For such QI descriptors, the high bits are not reserved. > >>> > >> > >> Do you mean the private data fields of a page request descriptor or a > >> page group response descriptor? Those fields contains software > >> defined private data (might a kernel pointer?). We should avoid > >> leaking such information in the generic kernel message for security > >> consideration. > >> Or anything I missed? > > > > yes, I'm not sure what kind of data it may be in the private data > > field. From software point of view, it may be helpful to show the full > > content of the QI descriptor for error triage. Personally, I'm fine if you > > keep it on > this point. > > > > Okay, thanks. > > I think I need to put some comments there so that people could understand my > consideration.
yeah, that would be helpful. :-) Regards, Yi Liu _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
