Messages in this thread | | | Subject | Re: [PATCH v9 07/22] KVM: s390: refactor crypto initialization | From | Tony Krowiak <> | Date | Mon, 20 Aug 2018 16:33:47 -0400 |
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On 08/20/2018 12:41 PM, David Hildenbrand wrote: > On 13.08.2018 23:48, Tony Krowiak wrote: >> From: Tony Krowiak <akrowiak@linux.ibm.com> >> >> This patch refactors the code that initializes and sets up the >> crypto configuration for a guest. The following changes are >> implemented via this patch: >> >> 1. Prior to the introduction of AP device virtualization, it >> was not necessary to provide guest access to the CRYCB >> unless the MSA extension 3 (MSAX3) facility was installed >> on the host system. With the introduction of AP device >> virtualization, the CRYCB must be made accessible to the >> guest if the AP instructions are installed on the host >> and are to be provided to the guest. >> >> 2. Introduces a flag indicating AP instructions executed on >> the guest shall be interpreted by the firmware. It is >> initialized to indicate AP instructions are to be >> to be interpreted and is used to set the SIE bit for >> each vcpu during vcpu setup. >> >> Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com> >> Reviewed-by: Halil Pasic <pasic@linux.ibm.com> >> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> >> Acked-by: Janosch Frank <frankja@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/include/asm/kvm_host.h | 2 + >> arch/s390/include/uapi/asm/kvm.h | 1 + >> arch/s390/kvm/kvm-s390.c | 81 +++++++++++++++++++------------------- >> 3 files changed, 44 insertions(+), 40 deletions(-) >> >> diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h >> index af39561..4a739d4 100644 >> --- a/arch/s390/include/asm/kvm_host.h >> +++ b/arch/s390/include/asm/kvm_host.h >> @@ -187,6 +187,7 @@ struct kvm_s390_sie_block { >> #define ECA_AIV 0x00200000 >> #define ECA_VX 0x00020000 >> #define ECA_PROTEXCI 0x00002000 >> +#define ECA_APIE 0x00000008 >> #define ECA_SII 0x00000001 >> __u32 eca; /* 0x004c */ >> #define ICPT_INST 0x04 >> @@ -256,6 +257,7 @@ struct kvm_s390_sie_block { >> __u8 reservede4[4]; /* 0x00e4 */ >> __u64 tecmc; /* 0x00e8 */ >> __u8 reservedf0[12]; /* 0x00f0 */ >> +#define CRYCB_FORMAT_MASK 0x00000003 >> #define CRYCB_FORMAT1 0x00000001 >> #define CRYCB_FORMAT2 0x00000003 >> __u32 crycbd; /* 0x00fc */ >> diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h >> index 4cdaa55..a580dec 100644 >> --- a/arch/s390/include/uapi/asm/kvm.h >> +++ b/arch/s390/include/uapi/asm/kvm.h >> @@ -130,6 +130,7 @@ struct kvm_s390_vm_cpu_machine { >> #define KVM_S390_VM_CPU_FEAT_PFMFI 11 >> #define KVM_S390_VM_CPU_FEAT_SIGPIF 12 >> #define KVM_S390_VM_CPU_FEAT_KSS 13 >> +#define KVM_S390_VM_CPU_FEAT_AP 14 >> struct kvm_s390_vm_cpu_feat { >> __u64 feat[16]; >> }; >> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c >> index 19f4f44..f7de123 100644 >> --- a/arch/s390/kvm/kvm-s390.c >> +++ b/arch/s390/kvm/kvm-s390.c >> @@ -40,6 +40,7 @@ >> #include <asm/sclp.h> >> #include <asm/cpacf.h> >> #include <asm/timex.h> >> +#include <asm/ap.h> >> #include "kvm-s390.h" >> #include "gaccess.h" >> >> @@ -1881,49 +1882,37 @@ long kvm_arch_vm_ioctl(struct file *filp, >> return r; >> } >> >> -static int kvm_s390_query_ap_config(u8 *config) >> -{ >> - u32 fcn_code = 0x04000000UL; >> - u32 cc = 0; >> - >> - memset(config, 0, 128); >> - asm volatile( >> - "lgr 0,%1\n" >> - "lgr 2,%2\n" >> - ".long 0xb2af0000\n" /* PQAP(QCI) */ >> - "0: ipm %0\n" >> - "srl %0,28\n" >> - "1:\n" >> - EX_TABLE(0b, 1b) >> - : "+r" (cc) >> - : "r" (fcn_code), "r" (config) >> - : "cc", "0", "2", "memory" >> - ); >> - >> - return cc; >> -} >> - >> static int kvm_s390_apxa_installed(void) >> { >> - u8 config[128]; >> - int cc; >> + struct ap_config_info info; >> >> - if (test_facility(12)) { >> - cc = kvm_s390_query_ap_config(config); >> - >> - if (cc) >> - pr_err("PQAP(QCI) failed with cc=%d", cc); >> - else >> - return config[0] & 0x40; >> + if (ap_instructions_available()) { >> + if (ap_qci(&info) == 0) >> + return info.apxa; >> } >> >> return 0; >> } >> >> +/* >> + * The format of the crypto control block (CRYCB) is specified in the 3 low >> + * order bits of the CRYCB designation (CRYCBD) field as follows: >> + * Format 0: Neither the message security assist extension 3 (MSAX3) nor the >> + * AP extended addressing (APXA) facility are installed. >> + * Format 1: The APXA facility is not installed but the MSAX3 facility is. >> + * Format 2: Both the APXA and MSAX3 facilities are installed >> + */ >> static void kvm_s390_set_crycb_format(struct kvm *kvm) >> { >> kvm->arch.crypto.crycbd = (__u32)(unsigned long) kvm->arch.crypto.crycb; >> >> + /* Clear the CRYCB format bits - i.e., set format 0 by default */ >> + kvm->arch.crypto.crycbd &= ~(CRYCB_FORMAT_MASK); >> + >> + /* Check whether MSAX3 is installed */ >> + if (!test_kvm_facility(kvm, 76)) >> + return; >> + >> if (kvm_s390_apxa_installed()) >> kvm->arch.crypto.crycbd |= CRYCB_FORMAT2; >> else >> @@ -1941,12 +1930,12 @@ 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; >> @@ -2474,17 +2463,29 @@ void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu) >> >> static void kvm_s390_vcpu_crypto_setup(struct kvm_vcpu *vcpu) >> { >> - if (!test_kvm_facility(vcpu->kvm, 76)) >> + /* >> + * If neither the AP instructions nor the MSAX3 facility are installed >> + * on the host, then there is no need for a CRYCB in SIE because they >> + * will not be installed on the guest either. >> + */ >> + if (!test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_AP) && >> + !test_facility(76)) > I think this can just stay "test_kvm_facility(vcpu->kvm, 76)", and the > comment should be changed to > > "If neither the AP instructions nor the MSAX3 facility are configured > for the guest, there is nothing to set up." > > Or am I missing something important here?
No, you're not missing anything, it can be test_kvm_facility() and I'm more than happy to change the comment.
> > After the CPU has been created, both feature can no longer change. The > only thing that might change is kvm->arch.crypto.aes_kw/dea_kw but only > with test_kvm_facility(vcpu->kvm, 76). > >> return; >> >> + vcpu->arch.sie_block->crycbd = vcpu->kvm->arch.crypto.crycbd; >> vcpu->arch.sie_block->ecb3 &= ~(ECB3_AES | ECB3_DEA); >> >> - if (vcpu->kvm->arch.crypto.aes_kw) >> - vcpu->arch.sie_block->ecb3 |= ECB3_AES; >> - if (vcpu->kvm->arch.crypto.dea_kw) >> - vcpu->arch.sie_block->ecb3 |= ECB3_DEA; >> + vcpu->arch.sie_block->eca &= ~ECA_APIE; > As this feature can never flip, clearing the flag is not necessary.
Okay.
> >> + if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_AP)) >> + vcpu->arch.sie_block->eca |= ECA_APIE; >> >> - vcpu->arch.sie_block->crycbd = vcpu->kvm->arch.crypto.crycbd; >> + /* If MSAX3 is installed on the guest, set up protected key support */ >> + if (test_kvm_facility(vcpu->kvm, 76)) { >> + if (vcpu->kvm->arch.crypto.aes_kw) >> + vcpu->arch.sie_block->ecb3 |= ECB3_AES; >> + if (vcpu->kvm->arch.crypto.dea_kw) >> + vcpu->arch.sie_block->ecb3 |= ECB3_DEA; >> + } > As the feature can never change, and aes_kw/dea_kw are only set to 1 in > case we have test_kvm_facility(vcpu->kvm, 76), this change is not needed. > > I think this function can be pretty much left alone. Just add the > KVM_S390_VM_CPU_FEAT_AP handling.
I disagree, what about the case where the KVM_S390_VM_CPU_FEAT_AP is configured for the guest but the MSAX3 facility (76) is not?
> >> } >> >> void kvm_s390_vcpu_unsetup_cmma(struct kvm_vcpu *vcpu) >> >
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