Permission fault can be more than just a write fault. Execution
fault can also occur if the page is flagged with the XN bit.
kvm_decode_fault() returns a value that indicates the fault type
(read, write, exec).
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
---
arch/arm/include/asm/kvm_mmu.h | 14 ++++++++++----
arch/arm/kvm/mmu.c | 10 ++++++----
2 files changed, 16 insertions(+), 8 deletions(-)
diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h
index 970f3b5..257e2bc 100644
--- a/arch/arm/include/asm/kvm_mmu.h
+++ b/arch/arm/include/asm/kvm_mmu.h
@@ -58,15 +58,21 @@ static inline void kvm_set_pte(pte_t *pte, pte_t new_pte)
flush_pmd_entry(pte);
}
-static inline bool kvm_is_write_fault(unsigned long hsr)
+enum kvm_fault_type {
+ KVM_READ_FAULT,
+ KVM_WRITE_FAULT,
+ KVM_EXEC_FAULT,
+};
+
+static inline enum kvm_fault_type kvm_decode_fault(unsigned long hsr)
{
unsigned long hsr_ec = hsr >> HSR_EC_SHIFT;
if (hsr_ec == HSR_EC_IABT)
- return false;
+ return KVM_EXEC_FAULT;
else if ((hsr & HSR_ISV) && !(hsr & HSR_WNR))
- return false;
+ return KVM_READ_FAULT;
else
- return true;
+ return KVM_WRITE_FAULT;
}
static inline void kvm_clean_pgd(pgd_t *pgd)
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index 633b546..58a45d1 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -510,12 +510,13 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
pte_t new_pte, *ptep;
pfn_t pfn;
int ret;
- bool write_fault, writable;
+ bool writable;
+ enum kvm_fault_type fault_type;
unsigned long mmu_seq;
struct kvm_mmu_memory_cache *memcache = &vcpu->arch.mmu_page_cache;
- write_fault = kvm_is_write_fault(kvm_vcpu_get_hsr(vcpu));
- if (fault_status == FSC_PERM && !write_fault) {
+ fault_type = kvm_decode_fault(kvm_vcpu_get_hsr(vcpu));
+ if (fault_status == FSC_PERM && fault_type == KVM_READ_FAULT) {
kvm_err("Unexpected L2 read permission error\n");
return -EFAULT;
}
@@ -537,7 +538,8 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
*/
smp_rmb();
- pfn = gfn_to_pfn_prot(vcpu->kvm, gfn, write_fault, &writable);
+ pfn = gfn_to_pfn_prot(vcpu->kvm, gfn,
+ fault_type == KVM_WRITE_FAULT, &writable);
if (is_error_pfn(pfn))
return -EFAULT;
--
1.8.1.2
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