From babbf1760970f141eb4021288ce0fb7196bc1a23 Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Fri, 6 Feb 2015 10:59:16 -0700 Subject: [PATCH] vfio/type1: Chunk contiguous reserved/invalid page mappings We currently map invalid and reserved pages, such as often occur from mapping MMIO regions of a VM through the IOMMU, using single pages. There's really no reason we can't instead follow the methodology we use for normal pages and find the largest possible physically contiguous chunk for mapping. The only difference is that we don't do locked memory accounting for these since they're not back by RAM. In most applications this will be a very minor improvement, but when graphics and GPGPU devices are in play, MMIO BARs become non-trivial. Signed-off-by: Alex Williamson --- drivers/vfio/vfio_iommu_type1.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index e6e7f155bdd9..35c90089478e 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -265,6 +265,7 @@ static long vfio_pin_pages(unsigned long vaddr, long npage, unsigned long limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; bool lock_cap = capable(CAP_IPC_LOCK); long ret, i; + bool rsvd; if (!current->mm) return -ENODEV; @@ -273,10 +274,9 @@ static long vfio_pin_pages(unsigned long vaddr, long npage, if (ret) return ret; - if (is_invalid_reserved_pfn(*pfn_base)) - return 1; + rsvd = is_invalid_reserved_pfn(*pfn_base); - if (!lock_cap && current->mm->locked_vm + 1 > limit) { + if (!rsvd && !lock_cap && current->mm->locked_vm + 1 > limit) { put_pfn(*pfn_base, prot); pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n", __func__, limit << PAGE_SHIFT); @@ -284,7 +284,8 @@ static long vfio_pin_pages(unsigned long vaddr, long npage, } if (unlikely(disable_hugepages)) { - vfio_lock_acct(1); + if (!rsvd) + vfio_lock_acct(1); return 1; } @@ -296,12 +297,14 @@ static long vfio_pin_pages(unsigned long vaddr, long npage, if (ret) break; - if (pfn != *pfn_base + i || is_invalid_reserved_pfn(pfn)) { + if (pfn != *pfn_base + i || + rsvd != is_invalid_reserved_pfn(pfn)) { put_pfn(pfn, prot); break; } - if (!lock_cap && current->mm->locked_vm + i + 1 > limit) { + if (!rsvd && !lock_cap && + current->mm->locked_vm + i + 1 > limit) { put_pfn(pfn, prot); pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n", __func__, limit << PAGE_SHIFT); @@ -309,7 +312,8 @@ static long vfio_pin_pages(unsigned long vaddr, long npage, } } - vfio_lock_acct(i); + if (!rsvd) + vfio_lock_acct(i); return i; } -- 2.20.1