From bbeaa58b32ab627b68748543b3dcb98b9a28d570 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Thu, 26 Nov 2015 13:11:42 +0100 Subject: KVM: s390: vsie: support aes dea wrapping keys As soon as message-security-assist extension 3 is enabled for guest 2, we have to allow key wrapping for guest 3. Acked-by: Christian Borntraeger Signed-off-by: David Hildenbrand Signed-off-by: Christian Borntraeger --- arch/s390/kvm/vsie.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 55 insertions(+), 1 deletion(-) (limited to 'arch/s390/kvm/vsie.c') diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c index cd4bbfa72881..6b26b0be63c1 100644 --- a/arch/s390/kvm/vsie.c +++ b/arch/s390/kvm/vsie.c @@ -28,7 +28,8 @@ struct vsie_page { struct kvm_s390_sie_block *scb_o; /* 0x0200 */ /* the shadow gmap in use by the vsie_page */ struct gmap *gmap; /* 0x0208 */ - __u8 reserved[0x0800 - 0x0210]; /* 0x0210 */ + __u8 reserved[0x0700 - 0x0210]; /* 0x0210 */ + struct kvm_s390_crypto_cb crycb; /* 0x0700 */ __u8 fac[S390_ARCH_FAC_LIST_SIZE_BYTE]; /* 0x0800 */ } __packed; @@ -111,6 +112,58 @@ static int prepare_cpuflags(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) return 0; } +/* + * Create a shadow copy of the crycb block and setup key wrapping, if + * requested for guest 3 and enabled for guest 2. + * + * We only accept format-1 (no AP in g2), but convert it into format-2 + * There is nothing to do for format-0. + * + * Returns: - 0 if shadowed or nothing to do + * - > 0 if control has to be given to guest 2 + */ +static int shadow_crycb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) +{ + struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; + struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; + u32 crycb_addr = scb_o->crycbd & 0x7ffffff8U; + unsigned long *b1, *b2; + u8 ecb3_flags; + + scb_s->crycbd = 0; + if (!(scb_o->crycbd & vcpu->arch.sie_block->crycbd & CRYCB_FORMAT1)) + return 0; + /* format-1 is supported with message-security-assist extension 3 */ + if (!test_kvm_facility(vcpu->kvm, 76)) + return 0; + /* we may only allow it if enabled for guest 2 */ + ecb3_flags = scb_o->ecb3 & vcpu->arch.sie_block->ecb3 & + (ECB3_AES | ECB3_DEA); + if (!ecb3_flags) + return 0; + + if ((crycb_addr & PAGE_MASK) != ((crycb_addr + 128) & PAGE_MASK)) + return set_validity_icpt(scb_s, 0x003CU); + else if (!crycb_addr) + return set_validity_icpt(scb_s, 0x0039U); + + /* copy only the wrapping keys */ + if (read_guest_real(vcpu, crycb_addr + 72, &vsie_page->crycb, 56)) + return set_validity_icpt(scb_s, 0x0035U); + + scb_s->ecb3 |= ecb3_flags; + scb_s->crycbd = ((__u32)(__u64) &vsie_page->crycb) | CRYCB_FORMAT1 | + CRYCB_FORMAT2; + + /* xor both blocks in one run */ + b1 = (unsigned long *) vsie_page->crycb.dea_wrapping_key_mask; + b2 = (unsigned long *) + vcpu->kvm->arch.crypto.crycb->dea_wrapping_key_mask; + /* as 56%8 == 0, bitmap_xor won't overwrite any data */ + bitmap_xor(b1, b1, b2, BITS_PER_BYTE * 56); + return 0; +} + /* shadow (round up/down) the ibc to avoid validity icpt */ static void prepare_ibc(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) { @@ -248,6 +301,7 @@ static int shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) scb_s->ecb |= scb_o->ecb & 0x02U; prepare_ibc(vcpu, vsie_page); + rc = shadow_crycb(vcpu, vsie_page); out: if (rc) unshadow_scb(vcpu, vsie_page); -- cgit