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ANDROID: KVM: arm64: Drop FOLL_FORCE when pinning guest memory pages

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Passing FOLL_FORCE when pinning guest memory pages was intended to allow
the VMM to map guest memory as PROT_NONE without prohibiting access from
the guest. As it turns out, crosvm doesn't implement this, and since
the host kernel will inject a signal into the VMM on a bad access
irrespective of the stage-1 permissions, we can drop the FOLL_FORCE flag
altogether.

Bug: 226564150
Signed-off-by: Will Deacon <willdeacon@google.com>
Change-Id: If21091b6adf3dbe4155c5c840753c912d283b159
This commit is contained in:
Will Deacon
2022-03-25 11:31:35 +00:00
parent 94bf7ff642
commit 3f5ffbd827
1 changed files with 1 additions and 4 deletions
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5
arch/arm64/kvm/mmu.c
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@@ -1163,10 +1163,7 @@ static int pkvm_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
unsigned long hva)
{
struct mm_struct *mm = current->mm;
unsigned int flags = FOLL_FORCE |
FOLL_HWPOISON |
FOLL_LONGTERM |
FOLL_WRITE;
unsigned int flags = FOLL_HWPOISON | FOLL_LONGTERM | FOLL_WRITE;
struct kvm_pinned_page *ppage;
struct kvm *kvm = vcpu->kvm;
struct page *page;