From: Santosh Shukla <[email protected]>

VFIO allows a device driver to resolve a fault by mapping a MMIO
range. This can be subsequently result in user_mem_abort() to
try and compute a huge mapping based on the MMIO pfn, which is
a sure recipe for things to go wrong.

Instead, force a PTE mapping when the pfn faulted in has a device
mapping.

Fixes: 6d674e28f642 ("KVM: arm/arm64: Properly handle faulting of device 
mappings")
Suggested-by: Marc Zyngier <[email protected]>
Signed-off-by: Santosh Shukla <[email protected]>
[maz: rewritten commit message]
Signed-off-by: Marc Zyngier <[email protected]>
Reviewed-by: Gavin Shan <[email protected]>
Cc: [email protected]
Link: 
https://lore.kernel.org/r/[email protected]
---
 arch/arm64/kvm/mmu.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index e431d2d8e368..c7c6df6309d5 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -851,6 +851,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, 
phys_addr_t fault_ipa,
 
        if (kvm_is_device_pfn(pfn)) {
                device = true;
+               force_pte = true;
        } else if (logging_active && !write_fault) {
                /*
                 * Only actually map the page as writable if this was a write
-- 
2.28.0

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