xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

KVM: MMU: try to fix up page faults before giving up

Browse Source 
The vGPU folks would like to trap the first access to a BAR by setting
vm_ops on the VMAs produced by mmap-ing a VFIO device.  The fault handler
then can use remap_pfn_range to place some non-reserved pages in the VMA.

This kind of VM_PFNMAP mapping is not handled by KVM, but follow_pfn
and fixup_user_fault together help supporting it.  The patch also supports
VM_MIXEDMAP vmas where the pfns are not reserved and thus subject to
reference counting.

Cc: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Tested-by: Neo Jia <cjia@nvidia.com>
Reported-by: Kirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini
2016-06-07 17:51:18 +02:00
parent 92176a8ede
commit add6a0cd1c
2 changed files with 43 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

1
mm/gup.c
View File

@@ -720,6 +720,7 @@ retry:
}
return 0;
}
EXPORT_SYMBOL_GPL(fixup_user_fault);
static __always_inline long __get_user_pages_locked(struct task_struct *tsk,
struct mm_struct *mm,