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Commit 56019f9a authored by Pierre Morel's avatar Pierre Morel Committed by Christian Borntraeger
Browse files

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: default avatarPierre Morel <pmorel@linux.ibm.com>
Signed-off-by: default avatarTony Krowiak <akrowiak@linux.ibm.com>
Message-Id: <20180925231641.4954-19-akrowiak@linux.vnet.ibm.com>
Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
parent 3af84def

arch/s390/kvm/vsie.c

+104 −10
Original line number Diff line number Diff line
@@ -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;

}