github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-11-07 06:17:02 +01:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

KVM: arm64: Use kvm_s2_fault_vma_info in pkvm_mem_abort()

Browse Source 
To paraphrase Marc in commit 08f97454b7 ("KVM: arm64: Fix protected
mode handling of pages larger than 4kB"), pkvm_pgtable_stage2_map()
assumes the address passed as a parameter is aligned to the size of the
intended mapping, while HPFAR_EL2 gives the IPA minus the bottom 12
bits, regardless of the system page size configuration.

To fix this alignment, bring support for kvm_s2_fault_vma_info in
pkvm_mem_abort() and use its members where possible. They do contain the
page-alignment we need to fix the fault on system with pages larger than
4K.

Also, add a check at the start of pkvm_pgtable_stage2_map(), it does not
support !PAGE_ALIGNED arguments.

Fixes: ea03466e80 ("KVM: arm64: Handle aborts from protected VMs")
Cc: stable@vger.kernel.org
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Reviewed-by: Fuad Tabba <fuad.tabba@linux.dev>
Tested-by: Fuad Tabba <fuad.tabba@linux.dev>
Link: https://patch.msgid.link/20260928095454.3255918-5-vdonnefort@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
This commit is contained in:
Vincent Donnefort 2026-09-28 10:54:53 +01:00 committed by Marc Zyngier
parent 80b0b86dc5
commit 0cdcc10392
2 changed files with 21 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
arch/arm64/kvm/mmu.c
View File

@ -1374,9 +1374,11 @@ static bool fault_supports_stage2_huge_mapping(const struct kvm_s2_fault_desc *s
if (map_size == PAGE_SIZE)
return true;
/* pKVM only supports PMD_SIZE huge-mappings */
if (is_protected_kvm_enabled() && map_size != PMD_SIZE)
return false;
/* pKVM only supports PMD_SIZE huge-mappings for non-protected VMs */
if (is_protected_kvm_enabled()) {
if (vcpu_is_protected(s2fd->vcpu) || map_size != PMD_SIZE)
return false;
}
size = memslot->npages * PAGE_SIZE;
@ -1621,6 +1623,9 @@ struct kvm_s2_fault_vma_info {
bool map_non_cacheable;
};
static int kvm_s2_fault_get_vma_info(const struct kvm_s2_fault_desc *s2fd,
struct kvm_s2_fault_vma_info *s2vi);
static gfn_t get_canonical_gfn(const struct kvm_s2_fault_desc *s2fd,
const struct kvm_s2_fault_vma_info *s2vi);
@ -1710,12 +1715,12 @@ static int gmem_abort(const struct kvm_s2_fault_desc *s2fd)
static int pkvm_mem_abort(const struct kvm_s2_fault_desc *s2fd)
{
unsigned int flags = FOLL_HWPOISON | FOLL_LONGTERM | FOLL_WRITE;
struct kvm_s2_fault_vma_info s2vi = {};
struct kvm_vcpu *vcpu = s2fd->vcpu;
struct kvm_pgtable *pgt = vcpu->arch.hw_mmu->pgt;
struct mm_struct *mm = current->mm;
struct kvm *kvm = vcpu->kvm;
void *hyp_memcache;
struct page *page;
int ret;
hyp_memcache = get_mmu_memcache(vcpu);
@ -1723,12 +1728,16 @@ static int pkvm_mem_abort(const struct kvm_s2_fault_desc *s2fd)
if (ret)
return -ENOMEM;
ret = kvm_s2_fault_get_vma_info(s2fd, &s2vi);
if (ret)
return ret;
ret = account_locked_vm(mm, 1, true);
if (ret)
return ret;
mmap_read_lock(mm);
ret = pin_user_pages(s2fd->hva, 1, flags, &page);
ret = pin_user_pages(s2fd->hva, 1, flags, &s2vi.page);
mmap_read_unlock(mm);
if (ret == -EHWPOISON) {
@ -1738,7 +1747,7 @@ static int pkvm_mem_abort(const struct kvm_s2_fault_desc *s2fd)
} else if (ret != 1) {
ret = -EFAULT;
goto dec_account;
} else if (!folio_test_swapbacked(page_folio(page))) {
} else if (!folio_test_swapbacked(page_folio(s2vi.page))) {
/*
* We really can't deal with page-cache pages returned by GUP
* because (a) we may trigger writeback of a page for which we
@ -1758,8 +1767,8 @@ static int pkvm_mem_abort(const struct kvm_s2_fault_desc *s2fd)
}
write_lock(&kvm->mmu_lock);
ret = pkvm_pgtable_stage2_map(pgt, s2fd->fault_ipa, PAGE_SIZE,
page_to_phys(page), KVM_PGTABLE_PROT_RWX,
ret = pkvm_pgtable_stage2_map(pgt, gfn_to_gpa(s2vi.gfn), PAGE_SIZE,
page_to_phys(s2vi.page), KVM_PGTABLE_PROT_RWX,
hyp_memcache, 0);
write_unlock(&kvm->mmu_lock);
if (ret) {
@ -1770,7 +1779,7 @@ static int pkvm_mem_abort(const struct kvm_s2_fault_desc *s2fd)
return 0;
unpin:
unpin_user_pages(&page, 1);
unpin_user_page(s2vi.page);
dec_account:
account_locked_vm(mm, 1, false);
return ret;

3
arch/arm64/kvm/pkvm.c
View File

@ -414,6 +414,9 @@ int pkvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size,
u64 end = addr + size;
int ret;
if (WARN_ON_ONCE(!PAGE_ALIGNED(addr | size)))
return -EINVAL;
lockdep_assert_held_write(&kvm->mmu_lock);
mapping = pkvm_mapping_iter_first(&pgt->pkvm_mappings, addr, end - 1);