On Fri, Apr 25, 2025 at 10:58:10PM -0700, Nicolin Chen wrote: > +- IOMMUFD_OBJ_VCMDQ, representing a hardware queue as a subset of a vIOMMU's > + virtualization feature for a VM to directly execute guest-issued commands > to > + invalidate HW cache entries holding the mappings or translations of a > guest- > + owned stage-1 page table. Along with this queue object, iommufd provides > the > + user space an mmap interface for VMM to mmap a physical MMIO region from > the > + host physical address space to a guest physical address space, to > exclusively > + control the allocated vCMDQ HW. Thus, when allocating a vCMDQ, the VMM must > + request a pair of VMA info (vm_pgoff/size) for a later mmap call. The > length > + argument of an mmap call could be smaller than the given size for a > paritial > + mmap, but the given vm_pgoff (as the addr argument of the mmap call) should "... partial mmap, ..." > + never be offsetted, which also implies that the mmap will always start from > + the beginning of the physical MMIO region. > + Thanks.
-- An old man doll... just what I always wanted! - Clara
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