KVM: s390: vsie: Allow CRYCB FORMAT-2

When the guest and the host both use CRYCB FORMAT-2,
we copy the guest's FORMAT-1 APCB to a FORMAT-1
shadow APCB.

This patch also cleans up the shadow_crycb() function.

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Message-Id: <20180925231641.4954-19-akrowiak@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This commit is contained in:
Pierre Morel 2018-09-25 19:16:33 -04:00 committed by Christian Borntraeger
parent 3af84def9c
commit 56019f9aca

View File

@ -136,14 +136,81 @@ static int prepare_cpuflags(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
return 0;
}
/*
/**
* setup_apcb11 - Copy the FORMAT1 APCB from the guest to the shadow CRYCB
* @vcpu: pointer to the virtual CPU
* @apcb_s: pointer to start of apcb in the shadow crycb
* @apcb_o: pointer to start of original guest apcb
* @apcb_h: pointer to start of apcb in the host
*
* Returns 0 and -EFAULT on error reading guest apcb
*/
static int setup_apcb11(struct kvm_vcpu *vcpu, unsigned long *apcb_s,
unsigned long apcb_o,
unsigned long *apcb_h)
{
if (read_guest_real(vcpu, apcb_o, apcb_s,
sizeof(struct kvm_s390_apcb1)))
return -EFAULT;
bitmap_and(apcb_s, apcb_s, apcb_h, sizeof(struct kvm_s390_apcb1));
return 0;
}
/**
* setup_apcb - Create a shadow copy of the apcb.
* @vcpu: pointer to the virtual CPU
* @crycb_s: pointer to shadow crycb
* @crycb_o: pointer to original guest crycb
* @crycb_h: pointer to the host crycb
* @fmt_o: format of the original guest crycb.
* @fmt_h: format of the host crycb.
*
* Checks the compatibility between the guest and host crycb and calls the
* appropriate copy function.
*
* Return 0 or an error number if the guest and host crycb are incompatible.
*/
static int setup_apcb(struct kvm_vcpu *vcpu, struct kvm_s390_crypto_cb *crycb_s,
const u32 crycb_o,
struct kvm_s390_crypto_cb *crycb_h,
int fmt_o, int fmt_h)
{
struct kvm_s390_crypto_cb *crycb;
crycb = (struct kvm_s390_crypto_cb *) (unsigned long)crycb_o;
switch (fmt_o) {
case CRYCB_FORMAT2:
if ((crycb_o & PAGE_MASK) != ((crycb_o + 256) & PAGE_MASK))
return -EACCES;
if (fmt_h != CRYCB_FORMAT2)
return -EINVAL;
return setup_apcb11(vcpu, (unsigned long *)&crycb_s->apcb1,
(unsigned long) &crycb->apcb1,
(unsigned long *)&crycb_h->apcb1);
}
return -EINVAL;
}
/**
* shadow_crycb - Create a shadow copy of the crycb block
* @vcpu: a pointer to the virtual CPU
* @vsie_page: a pointer to internal date used for the vSIE
*
* Create a shadow copy of the crycb block and setup key wrapping, if
* requested for guest 3 and enabled for guest 2.
*
* We accept format-1 or format-2, but we treat it as a format-1 (no AP in g2),
* and we convert it into format-2 in the shadow CRYCB.
* We accept format-1 or format-2, but we convert format-1 into format-2
* in the shadow CRYCB.
* Using format-2 enables the firmware to choose the right format when
* scheduling the SIE.
* There is nothing to do for format-0.
*
* This function centralize the issuing of set_validity_icpt() for all
* the subfunctions working on the crycb.
*
* Returns: - 0 if shadowed or nothing to do
* - > 0 if control has to be given to guest 2
*/
@ -155,24 +222,42 @@ static int shadow_crycb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
const u32 crycb_addr = crycbd_o & 0x7ffffff8U;
unsigned long *b1, *b2;
u8 ecb3_flags;
int apie_h;
int key_msk = test_kvm_facility(vcpu->kvm, 76);
int fmt_o = crycbd_o & CRYCB_FORMAT_MASK;
int fmt_h = vcpu->arch.sie_block->crycbd & CRYCB_FORMAT_MASK;
int ret = 0;
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))
apie_h = vcpu->arch.sie_block->eca & ECA_APIE;
if (!apie_h && !key_msk)
return 0;
if ((crycb_addr & PAGE_MASK) != ((crycb_addr + 128) & PAGE_MASK))
return set_validity_icpt(scb_s, 0x003CU);
else if (!crycb_addr)
if (!crycb_addr)
return set_validity_icpt(scb_s, 0x0039U);
if (fmt_o == CRYCB_FORMAT1)
if ((crycb_addr & PAGE_MASK) !=
((crycb_addr + 128) & PAGE_MASK))
return set_validity_icpt(scb_s, 0x003CU);
if (apie_h && (scb_o->eca & ECA_APIE)) {
ret = setup_apcb(vcpu, &vsie_page->crycb, crycb_addr,
vcpu->kvm->arch.crypto.crycb,
fmt_o, fmt_h);
if (ret)
goto end;
scb_s->eca |= scb_o->eca & ECA_APIE;
}
/* 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;
goto end;
/* copy only the wrapping keys */
if (read_guest_real(vcpu, crycb_addr + 72,
@ -180,7 +265,6 @@ static int shadow_crycb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
return set_validity_icpt(scb_s, 0x0035U);
scb_s->ecb3 |= ecb3_flags;
scb_s->crycbd = ((__u32)(__u64) &vsie_page->crycb) | CRYCB_FORMAT2;
/* xor both blocks in one run */
b1 = (unsigned long *) vsie_page->crycb.dea_wrapping_key_mask;
@ -188,6 +272,16 @@ static int shadow_crycb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
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);
end:
switch (ret) {
case -EINVAL:
return set_validity_icpt(scb_s, 0x0020U);
case -EFAULT:
return set_validity_icpt(scb_s, 0x0035U);
case -EACCES:
return set_validity_icpt(scb_s, 0x003CU);
}
scb_s->crycbd = ((__u32)(__u64) &vsie_page->crycb) | CRYCB_FORMAT2;
return 0;
}