github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-07-30 19:21:28 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

KVM: arm64: Extract VMA size resolution in user_mem_abort()

Browse Source 
As part of an effort to refactor user_mem_abort() into smaller, more
focused helper functions, extract the logic responsible for determining
the VMA shift and page size into a new static helper,
kvm_s2_resolve_vma_size().

Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Signed-off-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
This commit is contained in:
Fuad Tabba 2026-03-06 14:02:20 +00:00 committed by Marc Zyngier
parent f338e77383
commit 66fcf49200
1 changed files with 73 additions and 57 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

130
arch/arm64/kvm/mmu.c
View File

@ -1639,6 +1639,77 @@ static int gmem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
return ret != -EAGAIN ? ret : 0;
}
static short kvm_s2_resolve_vma_size(struct vm_area_struct *vma,
unsigned long hva,
struct kvm_memory_slot *memslot,
struct kvm_s2_trans *nested,
bool *force_pte, phys_addr_t *ipa)
{
short vma_shift;
long vma_pagesize;
if (*force_pte)
vma_shift = PAGE_SHIFT;
else
vma_shift = get_vma_page_shift(vma, hva);
switch (vma_shift) {
#ifndef __PAGETABLE_PMD_FOLDED
case PUD_SHIFT:
if (fault_supports_stage2_huge_mapping(memslot, hva, PUD_SIZE))
break;
fallthrough;
#endif
case CONT_PMD_SHIFT:
vma_shift = PMD_SHIFT;
fallthrough;
case PMD_SHIFT:
if (fault_supports_stage2_huge_mapping(memslot, hva, PMD_SIZE))
break;
fallthrough;
case CONT_PTE_SHIFT:
vma_shift = PAGE_SHIFT;
*force_pte = true;
fallthrough;
case PAGE_SHIFT:
break;
default:
WARN_ONCE(1, "Unknown vma_shift %d", vma_shift);
}
vma_pagesize = 1UL << vma_shift;
if (nested) {
unsigned long max_map_size;
max_map_size = *force_pte ? PAGE_SIZE : PUD_SIZE;
*ipa = kvm_s2_trans_output(nested);
/*
* If we're about to create a shadow stage 2 entry, then we
* can only create a block mapping if the guest stage 2 page
* table uses at least as big a mapping.
*/
max_map_size = min(kvm_s2_trans_size(nested), max_map_size);
/*
* Be careful that if the mapping size falls between
* two host sizes, take the smallest of the two.
*/
if (max_map_size >= PMD_SIZE && max_map_size < PUD_SIZE)
max_map_size = PMD_SIZE;
else if (max_map_size >= PAGE_SIZE && max_map_size < PMD_SIZE)
max_map_size = PAGE_SIZE;
*force_pte = (max_map_size == PAGE_SIZE);
vma_pagesize = min_t(long, vma_pagesize, max_map_size);
vma_shift = __ffs(vma_pagesize);
}
return vma_shift;
}
static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
struct kvm_s2_trans *nested,
struct kvm_memory_slot *memslot, unsigned long hva,
@ -1695,65 +1766,10 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
return -EFAULT;
}
if (force_pte)
vma_shift = PAGE_SHIFT;
else
vma_shift = get_vma_page_shift(vma, hva);
switch (vma_shift) {
#ifndef __PAGETABLE_PMD_FOLDED
case PUD_SHIFT:
if (fault_supports_stage2_huge_mapping(memslot, hva, PUD_SIZE))
break;
fallthrough;
#endif
case CONT_PMD_SHIFT:
vma_shift = PMD_SHIFT;
fallthrough;
case PMD_SHIFT:
if (fault_supports_stage2_huge_mapping(memslot, hva, PMD_SIZE))
break;
fallthrough;
case CONT_PTE_SHIFT:
vma_shift = PAGE_SHIFT;
force_pte = true;
fallthrough;
case PAGE_SHIFT:
break;
default:
WARN_ONCE(1, "Unknown vma_shift %d", vma_shift);
}
vma_shift = kvm_s2_resolve_vma_size(vma, hva, memslot, nested,
&force_pte, &ipa);
vma_pagesize = 1UL << vma_shift;
if (nested) {
unsigned long max_map_size;
max_map_size = force_pte ? PAGE_SIZE : PUD_SIZE;
ipa = kvm_s2_trans_output(nested);
/*
* If we're about to create a shadow stage 2 entry, then we
* can only create a block mapping if the guest stage 2 page
* table uses at least as big a mapping.
*/
max_map_size = min(kvm_s2_trans_size(nested), max_map_size);
/*
* Be careful that if the mapping size falls between
* two host sizes, take the smallest of the two.
*/
if (max_map_size >= PMD_SIZE && max_map_size < PUD_SIZE)
max_map_size = PMD_SIZE;
else if (max_map_size >= PAGE_SIZE && max_map_size < PMD_SIZE)
max_map_size = PAGE_SIZE;
force_pte = (max_map_size == PAGE_SIZE);
vma_pagesize = min_t(long, vma_pagesize, max_map_size);
vma_shift = __ffs(vma_pagesize);
}
/*
* Both the canonical IPA and fault IPA must be aligned to the
* mapping size to ensure we find the right PFN and lay down the