From: David Hildenbrand <dahi@xxxxxxxxxxxxxxxxxx>
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 <borntraeger@xxxxxxxxxx>
Signed-off-by: David Hildenbrand <dahi@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
---
arch/s390/kvm/vsie.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 55 insertions(+), 1 deletion(-)
diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c
index cd4bbfa..6b26b0b 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);
--
2.5.5
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