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KVM: arm64: Force PTE mapping on fault resulting in a device mapping 

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: 6d674e28f6 ("KVM: arm/arm64: Properly handle faulting of device mappings")
Suggested-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Santosh Shukla <sashukla@nvidia.com>
[maz: rewritten commit message]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/1603711447-11998-2-git-send-email-sashukla@nvidia.com
zero-sugar-mainline-defconfig
Santosh Shukla 2020-10-26 16:54:07 +05:30 committed by Marc Zyngier
parent 2f40c46021
commit 91a2c34b7d
1 changed files with 1 additions and 0 deletions
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arch/arm64/kvm/mmu.c
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@ -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