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KVM: MMU: return page fault error code from permission_fault 

This will help in the implementation of PKRU, where the PK bit of the page
fault error code cannot be computed in advance (unlike I/D, R/W and U/S).

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
hifive-unleashed-5.1
Paolo Bonzini 2016-03-08 10:08:16 +01:00
parent e9ad4ec837
commit f13577e8aa
2 changed files with 12 additions and 8 deletions
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15
arch/x86/kvm/mmu.h
View File

@ -141,11 +141,15 @@ static inline bool is_write_protection(struct kvm_vcpu *vcpu)
}
/*
* Will a fault with a given page-fault error code (pfec) cause a permission
* fault with the given access (in ACC_* format)?
* Check if a given access (described through the I/D, W/R and U/S bits of a
* page fault error code pfec) causes a permission fault with the given PTE
* access rights (in ACC_* format).
*
* Return zero if the access does not fault; return the page fault error code
* if the access faults.
*/
static inline bool permission_fault(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
unsigned pte_access, unsigned pfec)
static inline u8 permission_fault(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
unsigned pte_access, unsigned pfec)
{
int cpl = kvm_x86_ops->get_cpl(vcpu);
unsigned long rflags = kvm_x86_ops->get_rflags(vcpu);
@ -169,7 +173,8 @@ static inline bool permission_fault(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
WARN_ON(pfec & PFERR_RSVD_MASK);
return (mmu->permissions[index] >> pte_access) & 1;
pfec |= PFERR_PRESENT_MASK;
return -((mmu->permissions[index] >> pte_access) & 1) & pfec;
}
void kvm_mmu_invalidate_zap_all_pages(struct kvm *kvm);

5
arch/x86/kvm/paging_tmpl.h
View File

@ -359,10 +359,9 @@ retry_walk:
walker->ptes[walker->level - 1] = pte;
} while (!is_last_gpte(mmu, walker->level, pte));
if (unlikely(permission_fault(vcpu, mmu, pte_access, access))) {
errcode |= PFERR_PRESENT_MASK;
errcode = permission_fault(vcpu, mmu, pte_access, access);
if (unlikely(errcode))
goto error;
}
gfn = gpte_to_gfn_lvl(pte, walker->level);
gfn += (addr & PT_LVL_OFFSET_MASK(walker->level)) >> PAGE_SHIFT;