p71924506
/
linux_old1
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

s390/mm: take ipte_lock during shadow faults 

Let's take the ipte_lock while working on guest 2 provided page table, just
like the other gaccess functions.

Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This commit is contained in:
David Hildenbrand 2016-01-27 17:24:03 +01:00 committed by Christian Borntraeger
parent 7a6741576b
commit f4debb4090
2 changed files with 12 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
arch/s390/kvm/gaccess.c
View File

@ -1073,6 +1073,7 @@ static int kvm_s390_shadow_tables(struct gmap *sg, unsigned long saddr,
/**
* kvm_s390_shadow_fault - handle fault on a shadow page table
* @vcpu: virtual cpu
* @sg: pointer to the shadow guest address space structure
* @saddr: faulting address in the shadow gmap
*
@ -1082,7 +1083,8 @@ 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 kvm_s390_shadow_fault(struct kvm_vcpu *vcpu, struct gmap *sg,
unsigned long saddr)
{
union vaddress vaddr;
union page_table_entry pte;
@ -1091,6 +1093,12 @@ int kvm_s390_shadow_fault(struct gmap *sg, unsigned long saddr)
int rc;
down_read(&sg->mm->mmap_sem);
/*
* We don't want any guest-2 tables to change - so the parent
* tables/pointers we read stay valid - unshadowing is however
* always possible - only guest_table_lock protects us.
*/
ipte_lock(vcpu);
rc = gmap_shadow_pgt_lookup(sg, saddr, &pgt, &dat_protection);
if (rc)
@ -1105,6 +1113,7 @@ int kvm_s390_shadow_fault(struct gmap *sg, unsigned long saddr)
rc = PGM_TRANSLATION_SPEC;
if (!rc)
rc = gmap_shadow_page(sg, saddr, __pte(pte.val));
ipte_unlock(vcpu);
up_read(&sg->mm->mmap_sem);
return rc;
}

3
arch/s390/kvm/gaccess.h
View File

@ -361,6 +361,7 @@ 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 kvm_s390_shadow_fault(struct kvm_vcpu *vcpu, struct gmap *shadow,
unsigned long saddr);
#endif /* __KVM_S390_GACCESS_H */