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Commit 7a674157 authored by David Hildenbrand's avatar David Hildenbrand Committed by Christian Borntraeger
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s390/mm: protection exceptions are corrrectly shadowed 



As gmap shadows contains correct protection permissions, protection
exceptons can directly be forwarded to guest 3. If we would encounter
a protection exception while faulting, the next guest 3 run will
automatically handle that for us.

Keep the dat_protection logic in place, as it will be helpful later.

Acked-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: default avatarDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
parent e52f8b61

arch/s390/kvm/gaccess.c

+1 −5
Original line number Diff line number Diff line
@@ -1075,7 +1075,6 @@ static int kvm_s390_shadow_tables(struct gmap *sg, unsigned long saddr, 
 * kvm_s390_shadow_fault - handle fault on a shadow page table

 * @sg: pointer to the shadow guest address space structure

 * @saddr: faulting address in the shadow gmap

 * @write: =1 map r/w, =0 map r/o

 *

 * Returns: - 0 if the shadow fault was successfully resolved

 *	    - > 0 (pgm exception code) on exceptions while faulting
@@ -1083,7 +1082,7 @@ static int kvm_s390_shadow_tables(struct gmap *sg, unsigned long saddr, 
 *	    - -EFAULT when accessing invalid guest addresses

 *	    - -ENOMEM if out of memory

 */

int kvm_s390_shadow_fault(struct gmap *sg, unsigned long saddr, int write)

int kvm_s390_shadow_fault(struct gmap *sg, unsigned long saddr)

{

	union vaddress vaddr;

	union page_table_entry pte;
@@ -1104,9 +1103,6 @@ int kvm_s390_shadow_fault(struct gmap *sg, unsigned long saddr, int write) 
		rc = PGM_PAGE_TRANSLATION;

	if (!rc && (pte.z || pte.co))

		rc = PGM_TRANSLATION_SPEC;

	dat_protection |= pte.p;

	if (!rc && write && dat_protection)

		rc = PGM_PROTECTION;

	if (!rc)

		rc = gmap_shadow_page(sg, saddr, __pte(pte.val));

	up_read(&sg->mm->mmap_sem);

arch/s390/kvm/gaccess.h

+1 −1
Original line number Diff line number Diff line
@@ -361,6 +361,6 @@ void ipte_unlock(struct kvm_vcpu *vcpu); 
int ipte_lock_held(struct kvm_vcpu *vcpu);

int kvm_s390_check_low_addr_prot_real(struct kvm_vcpu *vcpu, unsigned long gra);



int kvm_s390_shadow_fault(struct gmap *shadow, unsigned long saddr, int write);

int kvm_s390_shadow_fault(struct gmap *shadow, unsigned long saddr);



#endif /* __KVM_S390_GACCESS_H */