[RFC 02/19] KVM: s390: refactor crypto initialization

Tony Krowiak
2017-10-13T17:38:47Z

This patch introduces the following changes to crypto initialization.

* For key management operations support, the crypto control block
(CRYCB) referenced by the KVM guest's SIE state description is
formatted only if the Message-Security-Assist (MSA) extension 3
facility is installed (STFLE.76 is set). Virtualization of AP
facilities, however; requires that a CRYCB of the appropriate
format be made available to SIE regardless of the value of STFLE.76.

* The Execution Controls A (ECA) field bit 28 in the SIE block needs
to be set to enable interpretive execution mode of adjunct processor (AP)
instructions.

Signed-off-by: Tony Krowiak <akrowiak@linux.vnet.ibm.com>
---
arch/s390/include/asm/kvm_host.h | 1 +
arch/s390/kvm/kvm-s390.c | 17 +++++++++++++----
2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 50a6b25..5683f18 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -188,6 +188,7 @@ struct kvm_s390_sie_block {
#define ECA_MVPGI 0x01000000
#define ECA_VX 0x00020000
#define ECA_PROTEXCI 0x00002000
+#define ECA_AP 0x00000008
#define ECA_SII 0x00000001
__u32 eca; /* 0x004c */
#define ICPT_INST 0x04
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 40d0a1a..e57fc9b 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -1819,7 +1819,9 @@ static void kvm_s390_set_crycb_format(struct kvm *kvm)
{
kvm->arch.crypto.crycbd = (__u32)(unsigned long) kvm->arch.crypto.crycb;

- if (kvm_s390_apxa_installed())
+ if (!test_kvm_facility(kvm, 76))
+ kvm->arch.crypto.crycbd &= ~(CRYCB_FORMAT2); /* format 0 */
+ else if (kvm_s390_apxa_installed())
kvm->arch.crypto.crycbd |= CRYCB_FORMAT2;
else
kvm->arch.crypto.crycbd |= CRYCB_FORMAT1;
@@ -1836,12 +1838,12 @@ static u64 kvm_s390_get_initial_cpuid(void)

static void kvm_s390_crypto_init(struct kvm *kvm)
{
- if (!test_kvm_facility(kvm, 76))
- return;
-
kvm->arch.crypto.crycb = &kvm->arch.sie_page2->crycb;
kvm_s390_set_crycb_format(kvm);

+ if (!test_kvm_facility(kvm, 76))
+ return;
+
/* Enable AES/DEA protected key functions by default */
kvm->arch.crypto.aes_kw = 1;
kvm->arch.crypto.dea_kw = 1;
@@ -2366,8 +2368,15 @@ void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
vcpu->arch.enabled_gmap = vcpu->arch.gmap;
}

+static void kvm_s390_vcpu_set_crypto_exec_mode(struct kvm_vcpu *vcpu)
+{
+ vcpu->arch.sie_block->eca |= ECA_AP;
+}
+
static void kvm_s390_vcpu_crypto_setup(struct kvm_vcpu *vcpu)
{
+ kvm_s390_vcpu_set_crypto_exec_mode(vcpu);
+
if (!test_kvm_facility(vcpu->kvm, 76))
return;

--
1.7.1