vfio/type1: optimize vfio_pin_pages_remote()

When vfio_pin_pages_remote() is called with a range of addresses that
includes large folios, the function currently performs individual
statistics counting operations for each page. This can lead to significant
performance overheads, especially when dealing with large ranges of pages.
Batch processing of statistical counting operations can effectively enhance
performance.

In addition, the pages obtained through longterm GUP are neither invalid
nor reserved. Therefore, we can reduce the overhead associated with some
calls to function is_invalid_reserved_pfn().

The performance test results for completing the 16G VFIO IOMMU DMA mapping
are as follows.

Base(v6.16):
------- AVERAGE (MADV_HUGEPAGE) --------
VFIO MAP DMA in 0.049 s (328.5 GB/s)
------- AVERAGE (MAP_POPULATE) --------
VFIO MAP DMA in 0.268 s (59.6 GB/s)
------- AVERAGE (HUGETLBFS) --------
VFIO MAP DMA in 0.051 s (310.9 GB/s)

With this patch:
------- AVERAGE (MADV_HUGEPAGE) --------
VFIO MAP DMA in 0.025 s (629.8 GB/s)
------- AVERAGE (MAP_POPULATE) --------
VFIO MAP DMA in 0.253 s (63.1 GB/s)
------- AVERAGE (HUGETLBFS) --------
VFIO MAP DMA in 0.030 s (530.5 GB/s)

For large folio, we achieve an over 40% performance improvement.
For small folios, the performance test results indicate a
slight improvement.

Signed-off-by: Li Zhe <lizhe.67@bytedance.com>
Co-developed-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Tested-by: Eric Farman <farman@linux.ibm.com>
Link: https://lore.kernel.org/r/20250814064714.56485-3-lizhe.67@bytedance.com


Signed-off-by: Alex Williamson <alex.williamson@redhat.com>