From 693ffc0802db41911ada95a3e77546f0ed1e7d00 Mon Sep 17 00:00:00 2001 From: Dominik Dingel Date: Tue, 14 Jan 2014 18:11:14 +0100 Subject: [PATCH] KVM: s390: Don't enable skeys by default 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 Acked-by: Martin Schwidefsky Signed-off-by: Christian Borntraeger --- arch/s390/include/asm/kvm_host.h | 3 +++ arch/s390/include/asm/mmu_context.h | 2 +- arch/s390/kvm/kvm-s390.c | 1 + arch/s390/kvm/priv.c | 14 ++++++++++++++ arch/s390/kvm/trace.h | 14 ++++++++++++++ 5 files changed, 33 insertions(+), 1 deletion(-) diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h index 154b60089be9..a993b6f3429f 100644 --- a/arch/s390/include/asm/kvm_host.h +++ b/arch/s390/include/asm/kvm_host.h @@ -89,6 +89,9 @@ struct kvm_s390_sie_block { __u16 lctl; /* 0x0044 */ __s16 icpua; /* 0x0046 */ #define ICTL_LPSW 0x00400000 +#define ICTL_ISKE 0x00004000 +#define ICTL_SSKE 0x00002000 +#define ICTL_RRBE 0x00001000 __u32 ictl; /* 0x0048 */ __u32 eca; /* 0x004c */ __u8 icptcode; /* 0x0050 */ diff --git a/arch/s390/include/asm/mmu_context.h b/arch/s390/include/asm/mmu_context.h index 05925ead0748..d42fb1b728d8 100644 --- a/arch/s390/include/asm/mmu_context.h +++ b/arch/s390/include/asm/mmu_context.h @@ -23,7 +23,7 @@ static inline int init_new_context(struct task_struct *tsk, mm->context.asce_bits |= _ASCE_TYPE_REGION3; #endif mm->context.has_pgste = 0; - mm->context.use_skey = 1; + mm->context.use_skey = 0; mm->context.asce_limit = STACK_TOP_MAX; crst_table_init((unsigned long *) mm->pgd, pgd_entry_type(mm)); return 0; diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index b3ecb8f5b6ce..b767ec97368a 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -465,6 +465,7 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu) vcpu->arch.sie_block->ecb2 = 8; vcpu->arch.sie_block->eca = 0xC1002001U; vcpu->arch.sie_block->fac = (int) (long) vfacilities; + vcpu->arch.sie_block->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE; if (kvm_enabled_cmma()) { cbrl = alloc_page(GFP_KERNEL | __GFP_ZERO); if (cbrl) { diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c index 476e9e218f43..8a63e992936b 100644 --- a/arch/s390/kvm/priv.c +++ b/arch/s390/kvm/priv.c @@ -147,8 +147,21 @@ static int handle_store_cpu_address(struct kvm_vcpu *vcpu) 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) { + __skey_check_enable(vcpu); + vcpu->stat.instruction_storage_key++; 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) { + __skey_check_enable(vcpu); if (set_guest_storage_key(current->mm, useraddr, vcpu->run->s.regs.gprs[reg1] & PFMF_KEY, vcpu->run->s.regs.gprs[reg1] & PFMF_NQ)) diff --git a/arch/s390/kvm/trace.h b/arch/s390/kvm/trace.h index e8e7213d4cc5..a4bf7d78a0db 100644 --- a/arch/s390/kvm/trace.h +++ b/arch/s390/kvm/trace.h @@ -30,6 +30,20 @@ TP_printk("%02d[%016lx-%016lx]: " p_str, __entry->id, \ __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, TP_PROTO(VCPU_PROTO_COMMON), TP_ARGS(VCPU_ARGS_COMMON), -- 2.30.2