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ARM/arm64: KVM: fix use of WnR bit in kvm_is_write_fault()

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The ISS encoding for an exception from a Data Abort has a WnR
bit[6] that indicates whether the Data Abort was caused by a
read or a write instruction. While there are several fields
in the encoding that are only valid if the ISV bit[24] is set,
WnR is not one of them, so we can read it unconditionally.

Instead of fixing both implementations of kvm_is_write_fault()
in place, reimplement it just once using kvm_vcpu_dabt_iswrite(),
which already does the right thing with respect to the WnR bit.
Also fix up the callers to pass 'vcpu'

Acked-by: Laszlo Ersek <lersek@redhat.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
This commit is contained in:
Ard Biesheuvel 2014-09-09 11:27:09 +01:00 committed by Marc Zyngier
parent de56fb1923
commit a7d079cea2
3 changed files with 10 additions and 26 deletions
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11
arch/arm/include/asm/kvm_mmu.h
View File

@ -78,17 +78,6 @@ 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)
{
unsigned long hsr_ec = hsr >> HSR_EC_SHIFT;
if (hsr_ec == HSR_EC_IABT)
return false;
else if ((hsr & HSR_ISV) && !(hsr & HSR_WNR))
return false;
else
return true;
}
static inline void kvm_clean_pgd(pgd_t *pgd)
{
clean_dcache_area(pgd, PTRS_PER_S2_PGD * sizeof(pgd_t));

12
arch/arm/kvm/mmu.c
View File

@ -746,6 +746,14 @@ static bool transparent_hugepage_adjust(pfn_t *pfnp, phys_addr_t *ipap)
return false;
}
static bool kvm_is_write_fault(struct kvm_vcpu *vcpu)
{
if (kvm_vcpu_trap_is_iabt(vcpu))
return false;
return kvm_vcpu_dabt_iswrite(vcpu);
}
static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
struct kvm_memory_slot *memslot, unsigned long hva,
unsigned long fault_status)
@ -760,7 +768,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
pfn_t pfn;
pgprot_t mem_type = PAGE_S2;
write_fault = kvm_is_write_fault(kvm_vcpu_get_hsr(vcpu));
write_fault = kvm_is_write_fault(vcpu);
if (fault_status == FSC_PERM && !write_fault) {
kvm_err("Unexpected L2 read permission error\n");
return -EFAULT;
@ -886,7 +894,7 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run)
gfn = fault_ipa >> PAGE_SHIFT;
memslot = gfn_to_memslot(vcpu->kvm, gfn);
hva = gfn_to_hva_memslot_prot(memslot, gfn, &writable);
write_fault = kvm_is_write_fault(kvm_vcpu_get_hsr(vcpu));
write_fault = kvm_is_write_fault(vcpu);
if (kvm_is_error_hva(hva) || (write_fault && !writable)) {
if (is_iabt) {
/* Prefetch Abort on I/O address */

13
arch/arm64/include/asm/kvm_mmu.h
View File

@ -93,19 +93,6 @@ void kvm_clear_hyp_idmap(void);
#define kvm_set_pte(ptep, pte) set_pte(ptep, pte)
#define kvm_set_pmd(pmdp, pmd) set_pmd(pmdp, pmd)
static inline bool kvm_is_write_fault(unsigned long esr)
{
unsigned long esr_ec = esr >> ESR_EL2_EC_SHIFT;
if (esr_ec == ESR_EL2_EC_IABT)
return false;
if ((esr & ESR_EL2_ISV) && !(esr & ESR_EL2_WNR))
return false;
return true;
}
static inline void kvm_clean_pgd(pgd_t *pgd) {}
static inline void kvm_clean_pmd_entry(pmd_t *pmd) {}
static inline void kvm_clean_pte(pte_t *pte) {}