kpriv/linux-hardened
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

KVM: s390: Don't enable skeys by default

Browse source 
The first invocation of storage key operations on a given cpu will be intercepted.

On these intercepts we will enable storage keys for the guest and remove the
previously added intercepts.

Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This commit is contained in:
Dominik Dingel 2014-01-14 18:11:14 +01:00 committed by Christian Borntraeger
parent 934bc131ef
commit 693ffc0802
5 changed files with 33 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

3
arch/s390/include/asm/kvm_host.h
View file

@ -89,6 +89,9 @@ struct kvm_s390_sie_block {
__u16 lctl; /* 0x0044 */ __u16 lctl; /* 0x0044 */
__s16 icpua; /* 0x0046 */ __s16 icpua; /* 0x0046 */
#define ICTL_LPSW 0x00400000 #define ICTL_LPSW 0x00400000
#define ICTL_ISKE 0x00004000
#define ICTL_SSKE 0x00002000
#define ICTL_RRBE 0x00001000
__u32 ictl; /* 0x0048 */ __u32 ictl; /* 0x0048 */
__u32 eca; /* 0x004c */ __u32 eca; /* 0x004c */
__u8 icptcode; /* 0x0050 */ __u8 icptcode; /* 0x0050 */

2
arch/s390/include/asm/mmu_context.h
View file

@ -23,7 +23,7 @@ static inline int init_new_context(struct task_struct *tsk,
mm->context.asce_bits |= _ASCE_TYPE_REGION3; mm->context.asce_bits |= _ASCE_TYPE_REGION3;
#endif #endif
mm->context.has_pgste = 0; mm->context.has_pgste = 0;
mm->context.use_skey = 1; mm->context.use_skey = 0;
mm->context.asce_limit = STACK_TOP_MAX; mm->context.asce_limit = STACK_TOP_MAX;
crst_table_init((unsigned long *) mm->pgd, pgd_entry_type(mm)); crst_table_init((unsigned long *) mm->pgd, pgd_entry_type(mm));
return 0; return 0;

1
arch/s390/kvm/kvm-s390.c
View file

@ -465,6 +465,7 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
vcpu->arch.sie_block->ecb2 = 8; vcpu->arch.sie_block->ecb2 = 8;
vcpu->arch.sie_block->eca = 0xC1002001U; vcpu->arch.sie_block->eca = 0xC1002001U;
vcpu->arch.sie_block->fac = (int) (long) vfacilities; vcpu->arch.sie_block->fac = (int) (long) vfacilities;
vcpu->arch.sie_block->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE;
if (kvm_enabled_cmma()) { if (kvm_enabled_cmma()) {
cbrl = alloc_page(GFP_KERNEL | __GFP_ZERO); cbrl = alloc_page(GFP_KERNEL | __GFP_ZERO);
if (cbrl) { if (cbrl) {

14
arch/s390/kvm/priv.c
View file

@ -147,8 +147,21 @@ static int handle_store_cpu_address(struct kvm_vcpu *vcpu)
return 0; return 0;
} }
static void __skey_check_enable(struct kvm_vcpu *vcpu)
{
if (!(vcpu->arch.sie_block->ictl & (ICTL_ISKE | ICTL_SSKE | ICTL_RRBE)))
return;
s390_enable_skey();
trace_kvm_s390_skey_related_inst(vcpu);
vcpu->arch.sie_block->ictl &= ~(ICTL_ISKE | ICTL_SSKE | ICTL_RRBE);
}
static int handle_skey(struct kvm_vcpu *vcpu) static int handle_skey(struct kvm_vcpu *vcpu)
{ {
__skey_check_enable(vcpu);
vcpu->stat.instruction_storage_key++; vcpu->stat.instruction_storage_key++;
if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE) if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
@ -618,6 +631,7 @@ static int handle_pfmf(struct kvm_vcpu *vcpu)
} }
if (vcpu->run->s.regs.gprs[reg1] & PFMF_SK) { if (vcpu->run->s.regs.gprs[reg1] & PFMF_SK) {
__skey_check_enable(vcpu);
if (set_guest_storage_key(current->mm, useraddr, if (set_guest_storage_key(current->mm, useraddr,
vcpu->run->s.regs.gprs[reg1] & PFMF_KEY, vcpu->run->s.regs.gprs[reg1] & PFMF_KEY,
vcpu->run->s.regs.gprs[reg1] & PFMF_NQ)) vcpu->run->s.regs.gprs[reg1] & PFMF_NQ))

14
arch/s390/kvm/trace.h
View file

@ -30,6 +30,20 @@
TP_printk("%02d[%016lx-%016lx]: " p_str, __entry->id, \ TP_printk("%02d[%016lx-%016lx]: " p_str, __entry->id, \
__entry->pswmask, __entry->pswaddr, p_args) __entry->pswmask, __entry->pswaddr, p_args)
TRACE_EVENT(kvm_s390_skey_related_inst,
TP_PROTO(VCPU_PROTO_COMMON),
TP_ARGS(VCPU_ARGS_COMMON),
TP_STRUCT__entry(
VCPU_FIELD_COMMON
),
TP_fast_assign(
VCPU_ASSIGN_COMMON
),
VCPU_TP_PRINTK("%s", "first instruction related to skeys on vcpu")
);
TRACE_EVENT(kvm_s390_major_guest_pfault, TRACE_EVENT(kvm_s390_major_guest_pfault,
TP_PROTO(VCPU_PROTO_COMMON), TP_PROTO(VCPU_PROTO_COMMON),
TP_ARGS(VCPU_ARGS_COMMON), TP_ARGS(VCPU_ARGS_COMMON),