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| author | Kim Phillips <kim.phillips@linaro.org> | 2014-06-26 01:45:51 +0100 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2015-04-30 11:15:07 +0200 |
| commit | 714b16417725d1adc0b8d2010c5cbb4c8df5e371 (patch) | |
| tree | 05d15a0b49d32e7cae5b1444cb9739aba412ff4a /arch/arm | |
| parent | ae4760d4e450dff0a8880d91d7b546a818c619a7 (diff) | |
| download | lwn-714b16417725d1adc0b8d2010c5cbb4c8df5e371.tar.gz lwn-714b16417725d1adc0b8d2010c5cbb4c8df5e371.zip | |
ARM: KVM: user_mem_abort: support stage 2 MMIO page mapping
commit b88657674d39fc2127d62d0de9ca142e166443c8 upstream.
A userspace process can map device MMIO memory via VFIO or /dev/mem,
e.g., for platform device passthrough support in QEMU.
During early development, we found the PAGE_S2 memory type being used
for MMIO mappings. This patch corrects that by using the more strongly
ordered memory type for device MMIO mappings: PAGE_S2_DEVICE.
Signed-off-by: Kim Phillips <kim.phillips@linaro.org>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/kvm/mmu.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c index 9f83bc755018..484084b6a585 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -647,6 +647,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, unsigned long mmu_seq; unsigned long hva = gfn_to_hva(vcpu->kvm, gfn); struct kvm_mmu_memory_cache *memcache = &vcpu->arch.mmu_page_cache; + pgprot_t mem_type = PAGE_S2; write_fault = kvm_is_write_fault(kvm_vcpu_get_hsr(vcpu)); if (fault_status == FSC_PERM && !write_fault) { @@ -675,7 +676,10 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, if (is_error_pfn(pfn)) return -EFAULT; - new_pte = pfn_pte(pfn, PAGE_S2); + if (kvm_is_mmio_pfn(pfn)) + mem_type = PAGE_S2_DEVICE; + + new_pte = pfn_pte(pfn, mem_type); coherent_cache_guest_page(vcpu, hva, PAGE_SIZE); spin_lock(&vcpu->kvm->mmu_lock); @@ -685,7 +689,8 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, kvm_set_s2pte_writable(&new_pte); kvm_set_pfn_dirty(pfn); } - stage2_set_pte(vcpu->kvm, memcache, fault_ipa, &new_pte, false); + stage2_set_pte(vcpu->kvm, memcache, fault_ipa, &new_pte, + mem_type == PAGE_S2_DEVICE); out_unlock: spin_unlock(&vcpu->kvm->mmu_lock); |