[PATCH v8 20/22] KVM: s390: Handling of Cypto control block in VSIE

Tony Krowiak
2018-08-08T14:44:30Z

From: Pierre Morel <pmorel@linux.ibm.com>

Shadowing the crypto control block now supports APCB shadowing.

AP instruction interpretation for guest 3 through ECA.28 is shadowed when
guest 2 ECA.28 is set.

CRYCB is shadowed for APCB and wrapping keys.

CRYCB format 0 is now supported for both guests 2 and 3.

Shadow CRYCB always uses the guest 2 CRYCB format and it
follows that:

* Guest 3 CRYCB format 0 is supported with guest 2 CRYCB format 0,1 or 2
* Guest 3 CRYCB format 1 is supported with guest 2 CRYCB format 1 or 2
* Guest 3 CRYCB format 2 is supported with guest 2 CRYCB format 2

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Tested-by: Michael Mueller <mimu@linux.ibm.com>
Tested-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
arch/s390/kvm/vsie.c | 224 ++++++++++++++++++++++++++++++++++++++++++++------
1 files changed, 200 insertions(+), 24 deletions(-)

diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c
index aa30b48..fc7986b 100644
--- a/arch/s390/kvm/vsie.c
+++ b/arch/s390/kvm/vsie.c
@@ -136,17 +136,8 @@ 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)
+/* Copy keys into shadow crycb, is only called if MSA3 is available. */
+static int copy_key_masks(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;
@@ -155,30 +146,17 @@ static int shadow_crycb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
unsigned long *b1, *b2;
u8 ecb3_flags;

- scb_s->crycbd = 0;
- if (!(crycbd_o & 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;
@@ -189,6 +167,204 @@ static int shadow_crycb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
return 0;
}

+/* Copy masks into apcb when g2 and g3 use format 1 */
+static int copy_apcb1(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
+{
+ struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
+ struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
+ const uint32_t crycbd_o = READ_ONCE(scb_o->crycbd);
+ const u32 crycb_o = crycbd_o & 0x7ffffff8U;
+ struct kvm_s390_crypto_cb *crycb_h = &vcpu->kvm->arch.sie_page2->crycb;
+ struct kvm_s390_crypto_cb *crycb_s = &vsie_page->crycb;
+ unsigned long *apcb_s = (unsigned long *) &crycb_s->apcb1;
+ unsigned long *apcb_h = (unsigned long *) &crycb_h->apcb1;
+ int i;
+ u32 src;
+
+ src = crycb_o + offsetof(struct kvm_s390_crypto_cb, apcb1);
+ if (read_guest_real(vcpu, src, apcb_s, sizeof(struct kvm_s390_apcb1)))
+ return set_validity_icpt(scb_s, 0x0035U);
+
+ for (i = 0; i < sizeof(struct kvm_s390_apcb1); i += sizeof(*apcb_s))
+ *apcb_s &= *apcb_h;
+
+ return 0;
+}
+
+/*
+ * Copy masks into apcb when g2 use format 1 and g3 use format 0
+ * In this case the shadow APCB uses format 1
+ */
+static int copy_apcb01(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
+{
+ struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
+ struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
+ const uint32_t crycbd_o = READ_ONCE(scb_o->crycbd);
+ const u32 crycb_o = crycbd_o & 0x7ffffff8U;
+ struct kvm_s390_apcb1 *apcb_h = &vcpu->kvm->arch.sie_page2->crycb.apcb1;
+ struct kvm_s390_apcb1 *apcb_s = &vsie_page->crycb.apcb1;
+ u32 src;
+
+ memset(apcb_s, 0, sizeof(*apcb_s));
+
+ src = crycb_o + offsetof(struct kvm_s390_crypto_cb, apcb0.apm[0]);
+ if (read_guest_real(vcpu, src, &apcb_s->apm[0], sizeof(__u64)))
+ return set_validity_icpt(scb_s, 0x0035U);
+
+ src = crycb_o + offsetof(struct kvm_s390_crypto_cb, apcb0.aqm[0]);
+ if (read_guest_real(vcpu, src, &apcb_s->aqm[0], sizeof(__u64)))
+ return set_validity_icpt(scb_s, 0x0035U);
+
+ src = crycb_o + offsetof(struct kvm_s390_crypto_cb, apcb0.adm[0]);
+ if (read_guest_real(vcpu, src, &apcb_s->adm[0], sizeof(__u64)))
+ return set_validity_icpt(scb_s, 0x0035U);
+
+ apcb_s->apm[0] &= apcb_h->apm[0];
+ apcb_s->aqm[0] &= apcb_h->aqm[0];
+ apcb_s->adm[0] &= apcb_h->adm[0];
+
+ return 0;
+}
+
+/* Copy masks into apcb when g2 and g3 use format 0 */
+static int copy_apcb0(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
+{
+ struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
+ struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
+ const uint32_t crycbd_o = READ_ONCE(scb_o->crycbd);
+ const u32 crycb_o = crycbd_o & 0x7ffffff8U;
+ struct kvm_s390_apcb0 *apcb_h = &vcpu->kvm->arch.sie_page2->crycb.apcb0;
+ struct kvm_s390_apcb0 *apcb_s = &vsie_page->crycb.apcb0;
+ u32 src;
+
+ src = crycb_o + offsetof(struct kvm_s390_crypto_cb, apcb0.apm[0]);
+ if (read_guest_real(vcpu, src, &apcb_s->apm[0], sizeof(__u64)))
+ return set_validity_icpt(scb_s, 0x0035U);
+
+ src = crycb_o + offsetof(struct kvm_s390_crypto_cb, apcb0.aqm[0]);
+ if (read_guest_real(vcpu, src, &apcb_s->aqm[0], sizeof(__u64)))
+ return set_validity_icpt(scb_s, 0x0035U);
+
+ src = crycb_o + offsetof(struct kvm_s390_crypto_cb, apcb0.adm[0]);
+ if (read_guest_real(vcpu, src, &apcb_s->adm[0], sizeof(__u64)))
+ return set_validity_icpt(scb_s, 0x0035U);
+
+ apcb_s->apm[0] &= apcb_h->apm[0];
+ apcb_s->aqm[0] &= apcb_h->aqm[0];
+ apcb_s->adm[0] &= apcb_h->adm[0];
+
+ return 0;
+}
+
+/* Shadowing APCB depends on G2 and G3 CRYCB format */
+static int copy_apcb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page,
+ int g2_fmt, int g3_fmt)
+{
+ struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
+ int ret = 0;
+
+ switch (g2_fmt) {
+ case CRYCB_FORMAT0:
+ switch (g3_fmt) {
+ case CRYCB_FORMAT0:
+ ret = copy_apcb0(vcpu, vsie_page);
+ break;
+ default:
+ return set_validity_icpt(scb_s, 0x0020U);
+ }
+ break;
+ case CRYCB_FORMAT1:
+ switch (g3_fmt) {
+ case CRYCB_FORMAT1:
+ case CRYCB_FORMAT0: /* Fall through to copy APCB */
+ ret = copy_apcb0(vcpu, vsie_page);
+ break;
+ default:
+ return set_validity_icpt(scb_s, 0x0020U);
+ }
+ break;
+ case CRYCB_FORMAT2:
+ switch (g3_fmt) {
+ case CRYCB_FORMAT0:
+ case CRYCB_FORMAT1:
+ ret = copy_apcb01(vcpu, vsie_page);
+ break;
+ case CRYCB_FORMAT2:
+ ret = copy_apcb1(vcpu, vsie_page);
+ break;
+ }
+ break;
+ default:
+ /*
+ * Guest 2 format is valid or we can not get to here.
+ */
+ break;
+ }
+
+ return ret;
+}
+
+/*
+ * Create a shadow copy of the crycb block.
+ * - Setup key wrapping, if requested for guest 3 and enabled for guest 2.
+ * - Shadow APCB if requested by guest 3 and enabled for guest 2 through
+ * ECA_APIE.
+ *
+ * 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
+ * - < 0 if something went wrong on copy
+ */
+#define ECA_APIE 0x00000008
+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;
+ const uint32_t crycbd_o = READ_ONCE(scb_o->crycbd);
+ const u32 crycb_addr = crycbd_o & 0x7ffffff8U;
+ int g2_fmt = vcpu->arch.sie_block->crycbd & CRYCB_FORMAT_MASK;
+ int g3_fmt = crycbd_o & CRYCB_FORMAT_MASK;
+ int g2_apie, g2_msa3, g3_apie, g3_msa3;
+ int size, ret;
+
+ /* crycb should not cross a page boundary */
+ size = (g3_fmt == CRYCB_FORMAT2) ? 0x100 : 0x80;
+ if ((crycb_addr & PAGE_MASK) != ((crycb_addr + size) & PAGE_MASK))
+ return set_validity_icpt(scb_s, 0x003CU);
+
+ g2_apie = vcpu->arch.sie_block->eca & ECA_APIE;
+ g3_apie = scb_o->eca & g2_apie;
+
+ g2_msa3 = test_kvm_facility(vcpu->kvm, 76);
+ g3_msa3 = (g3_fmt != CRYCB_FORMAT0) & g2_msa3;
+
+ scb_s->crycbd = 0;
+ /* If no AP instructions and no keys we just set crycbd to 0 */
+ if (!(g3_apie || g3_msa3))
+ return 0;
+
+ if (!crycb_addr)
+ return set_validity_icpt(scb_s, 0x0039U);
+
+ if (g3_apie) {
+ ret = copy_apcb(vcpu, vsie_page, g2_fmt, g3_fmt);
+ if (ret)
+ goto out;
+ scb_s->eca |= g3_apie;
+ }
+
+ if (g3_msa3)
+ ret = copy_key_masks(vcpu, vsie_page);
+
+ if (!ret)
+ scb_s->crycbd = ((__u32)(__u64) &vsie_page->crycb) | g2_fmt;
+
+out:
+ return ret;
+}
+
/* shadow (round up/down) the ibc to avoid validity icpt */
static void prepare_ibc(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
{
--
1.7.1