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Commit 92176a8e authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

KVM: MMU: prepare to support mapping of VM_IO and VM_PFNMAP frames 



Handle VM_IO like VM_PFNMAP, as is common in the rest of Linux; extract
the formula to convert hva->pfn into a new function, which will soon
gain more capabilities.

Cc: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 196f20ca

virt/kvm/kvm_main.c

+15 −5
Original line number Diff line number Diff line
@@ -1442,6 +1442,16 @@ static bool vma_is_valid(struct vm_area_struct *vma, bool write_fault) 
	return true;

}



static int hva_to_pfn_remapped(struct vm_area_struct *vma,

			       unsigned long addr, bool *async,

			       bool write_fault, kvm_pfn_t *p_pfn)

{

	*p_pfn = ((addr - vma->vm_start) >> PAGE_SHIFT) +

		vma->vm_pgoff;

	BUG_ON(!kvm_is_reserved_pfn(*p_pfn));

	return 0;

}



/*

 * Pin guest page in memory and return its pfn.

 * @addr: host virtual address which maps memory to the guest
@@ -1461,7 +1471,7 @@ static kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async, 
{

	struct vm_area_struct *vma;

	kvm_pfn_t pfn = 0;

	int npages;

	int npages, r;



	/* we can do it either atomically or asynchronously, not both */

	BUG_ON(atomic && async);
@@ -1487,10 +1497,10 @@ static kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async, 


	if (vma == NULL)

		pfn = KVM_PFN_ERR_FAULT;

	else if ((vma->vm_flags & VM_PFNMAP)) {

		pfn = ((addr - vma->vm_start) >> PAGE_SHIFT) +

			vma->vm_pgoff;

		BUG_ON(!kvm_is_reserved_pfn(pfn));

	else if (vma->vm_flags & (VM_IO | VM_PFNMAP)) {

		r = hva_to_pfn_remapped(vma, addr, async, write_fault, &pfn);

		if (r < 0)

			pfn = KVM_PFN_ERR_FAULT;

	} else {

		if (async && vma_is_valid(vma, write_fault))

			*async = true;