Messages in this thread | | | Date | Fri, 21 Jun 2019 17:33:28 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [RFC PATCH v4 20/21] iommu/vt-d: hpet: Reserve an interrupt remampping table entry for watchdog |
| |
On Wed, 19 Jun 2019, Jacob Pan wrote: > On Tue, 18 Jun 2019 01:08:06 +0200 (CEST) > Thomas Gleixner <tglx@linutronix.de> wrote: > > > > Unless this problem is not solved and I doubt it can be solved after > > talking to IOMMU people and studying manuals, > > I agree. modify irte might be done with cmpxchg_double() but the queued > invalidation interface for IRTE cache flush is shared with DMA and > requires holding a spinlock for enque descriptors, QI tail update etc. > > Also, reserving & manipulating IRTE slot for hpet via backdoor might not > be needed if the HPET PCI BDF (found in ACPI) can be utilized. But it > might need more work to add a fake PCI device for HPET.
What would PCI/BDF solve?
Thanks,
tglx
| |