| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * kvm nested virtualization support for s390x |
| * |
| * Copyright IBM Corp. 2016, 2018 |
| * |
| * Author(s): David Hildenbrand <dahi@linux.vnet.ibm.com> |
| */ |
| #include <linux/vmalloc.h> |
| #include <linux/kvm_host.h> |
| #include <linux/bug.h> |
| #include <linux/list.h> |
| #include <linux/bitmap.h> |
| #include <linux/sched/signal.h> |
| |
| #include <asm/gmap.h> |
| #include <asm/mmu_context.h> |
| #include <asm/sclp.h> |
| #include <asm/nmi.h> |
| #include <asm/dis.h> |
| #include <asm/fpu/api.h> |
| #include "kvm-s390.h" |
| #include "gaccess.h" |
| |
| struct vsie_page { |
| struct kvm_s390_sie_block scb_s; /* 0x0000 */ |
| /* |
| * the backup info for machine check. ensure it's at |
| * the same offset as that in struct sie_page! |
| */ |
| struct mcck_volatile_info mcck_info; /* 0x0200 */ |
| /* |
| * The pinned original scb. Be aware that other VCPUs can modify |
| * it while we read from it. Values that are used for conditions or |
| * are reused conditionally, should be accessed via READ_ONCE. |
| */ |
| struct kvm_s390_sie_block *scb_o; /* 0x0218 */ |
| /* the shadow gmap in use by the vsie_page */ |
| struct gmap *gmap; /* 0x0220 */ |
| /* address of the last reported fault to guest2 */ |
| unsigned long fault_addr; /* 0x0228 */ |
| /* calculated guest addresses of satellite control blocks */ |
| gpa_t sca_gpa; /* 0x0230 */ |
| gpa_t itdba_gpa; /* 0x0238 */ |
| gpa_t gvrd_gpa; /* 0x0240 */ |
| gpa_t riccbd_gpa; /* 0x0248 */ |
| gpa_t sdnx_gpa; /* 0x0250 */ |
| __u8 reserved[0x0700 - 0x0258]; /* 0x0258 */ |
| struct kvm_s390_crypto_cb crycb; /* 0x0700 */ |
| __u8 fac[S390_ARCH_FAC_LIST_SIZE_BYTE]; /* 0x0800 */ |
| }; |
| |
| /* trigger a validity icpt for the given scb */ |
| static int set_validity_icpt(struct kvm_s390_sie_block *scb, |
| __u16 reason_code) |
| { |
| scb->ipa = 0x1000; |
| scb->ipb = ((__u32) reason_code) << 16; |
| scb->icptcode = ICPT_VALIDITY; |
| return 1; |
| } |
| |
| /* mark the prefix as unmapped, this will block the VSIE */ |
| static void prefix_unmapped(struct vsie_page *vsie_page) |
| { |
| atomic_or(PROG_REQUEST, &vsie_page->scb_s.prog20); |
| } |
| |
| /* mark the prefix as unmapped and wait until the VSIE has been left */ |
| static void prefix_unmapped_sync(struct vsie_page *vsie_page) |
| { |
| prefix_unmapped(vsie_page); |
| if (vsie_page->scb_s.prog0c & PROG_IN_SIE) |
| atomic_or(CPUSTAT_STOP_INT, &vsie_page->scb_s.cpuflags); |
| while (vsie_page->scb_s.prog0c & PROG_IN_SIE) |
| cpu_relax(); |
| } |
| |
| /* mark the prefix as mapped, this will allow the VSIE to run */ |
| static void prefix_mapped(struct vsie_page *vsie_page) |
| { |
| atomic_andnot(PROG_REQUEST, &vsie_page->scb_s.prog20); |
| } |
| |
| /* test if the prefix is mapped into the gmap shadow */ |
| static int prefix_is_mapped(struct vsie_page *vsie_page) |
| { |
| return !(atomic_read(&vsie_page->scb_s.prog20) & PROG_REQUEST); |
| } |
| |
| /* copy the updated intervention request bits into the shadow scb */ |
| static void update_intervention_requests(struct vsie_page *vsie_page) |
| { |
| const int bits = CPUSTAT_STOP_INT | CPUSTAT_IO_INT | CPUSTAT_EXT_INT; |
| int cpuflags; |
| |
| cpuflags = atomic_read(&vsie_page->scb_o->cpuflags); |
| atomic_andnot(bits, &vsie_page->scb_s.cpuflags); |
| atomic_or(cpuflags & bits, &vsie_page->scb_s.cpuflags); |
| } |
| |
| /* shadow (filter and validate) the cpuflags */ |
| static int prepare_cpuflags(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; |
| int newflags, cpuflags = atomic_read(&scb_o->cpuflags); |
| |
| /* we don't allow ESA/390 guests */ |
| if (!(cpuflags & CPUSTAT_ZARCH)) |
| return set_validity_icpt(scb_s, 0x0001U); |
| |
| if (cpuflags & (CPUSTAT_RRF | CPUSTAT_MCDS)) |
| return set_validity_icpt(scb_s, 0x0001U); |
| else if (cpuflags & (CPUSTAT_SLSV | CPUSTAT_SLSR)) |
| return set_validity_icpt(scb_s, 0x0007U); |
| |
| /* intervention requests will be set later */ |
| newflags = CPUSTAT_ZARCH; |
| if (cpuflags & CPUSTAT_GED && test_kvm_facility(vcpu->kvm, 8)) |
| newflags |= CPUSTAT_GED; |
| if (cpuflags & CPUSTAT_GED2 && test_kvm_facility(vcpu->kvm, 78)) { |
| if (cpuflags & CPUSTAT_GED) |
| return set_validity_icpt(scb_s, 0x0001U); |
| newflags |= CPUSTAT_GED2; |
| } |
| if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_GPERE)) |
| newflags |= cpuflags & CPUSTAT_P; |
| if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_GSLS)) |
| newflags |= cpuflags & CPUSTAT_SM; |
| if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_IBS)) |
| newflags |= cpuflags & CPUSTAT_IBS; |
| if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_KSS)) |
| newflags |= cpuflags & CPUSTAT_KSS; |
| |
| atomic_set(&scb_s->cpuflags, newflags); |
| return 0; |
| } |
| /* Copy to APCB FORMAT1 from APCB FORMAT0 */ |
| static int setup_apcb10(struct kvm_vcpu *vcpu, struct kvm_s390_apcb1 *apcb_s, |
| unsigned long apcb_o, struct kvm_s390_apcb1 *apcb_h) |
| { |
| struct kvm_s390_apcb0 tmp; |
| |
| if (read_guest_real(vcpu, apcb_o, &tmp, sizeof(struct kvm_s390_apcb0))) |
| return -EFAULT; |
| |
| apcb_s->apm[0] = apcb_h->apm[0] & tmp.apm[0]; |
| apcb_s->aqm[0] = apcb_h->aqm[0] & tmp.aqm[0] & 0xffff000000000000UL; |
| apcb_s->adm[0] = apcb_h->adm[0] & tmp.adm[0] & 0xffff000000000000UL; |
| |
| return 0; |
| |
| } |
| |
| /** |
| * setup_apcb00 - Copy to APCB FORMAT0 from APCB FORMAT0 |
| * @vcpu: pointer to the virtual CPU |
| * @apcb_s: pointer to start of apcb in the shadow crycb |
| * @apcb_o: pointer to start of original apcb in the guest2 |
| * @apcb_h: pointer to start of apcb in the guest1 |
| * |
| * Returns 0 and -EFAULT on error reading guest apcb |
| */ |
| static int setup_apcb00(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_apcb0))) |
| return -EFAULT; |
| |
| bitmap_and(apcb_s, apcb_s, apcb_h, sizeof(struct kvm_s390_apcb0)); |
| |
| 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); |
| case CRYCB_FORMAT1: |
| switch (fmt_h) { |
| case CRYCB_FORMAT2: |
| return setup_apcb10(vcpu, &crycb_s->apcb1, |
| (unsigned long) &crycb->apcb0, |
| &crycb_h->apcb1); |
| case CRYCB_FORMAT1: |
| return setup_apcb00(vcpu, |
| (unsigned long *) &crycb_s->apcb0, |
| (unsigned long) &crycb->apcb0, |
| (unsigned long *) &crycb_h->apcb0); |
| } |
| break; |
| case CRYCB_FORMAT0: |
| if ((crycb_o & PAGE_MASK) != ((crycb_o + 32) & PAGE_MASK)) |
| return -EACCES; |
| |
| switch (fmt_h) { |
| case CRYCB_FORMAT2: |
| return setup_apcb10(vcpu, &crycb_s->apcb1, |
| (unsigned long) &crycb->apcb0, |
| &crycb_h->apcb1); |
| case CRYCB_FORMAT1: |
| case CRYCB_FORMAT0: |
| return setup_apcb00(vcpu, |
| (unsigned long *) &crycb_s->apcb0, |
| (unsigned long) &crycb->apcb0, |
| (unsigned long *) &crycb_h->apcb0); |
| } |
| } |
| 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 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 |
| */ |
| 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; |
| unsigned long *b1, *b2; |
| u8 ecb3_flags; |
| u32 ecd_flags; |
| int apie_h; |
| int apie_s; |
| 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; |
| |
| apie_h = vcpu->arch.sie_block->eca & ECA_APIE; |
| apie_s = apie_h & scb_o->eca; |
| if (!apie_s && (!key_msk || (fmt_o == CRYCB_FORMAT0))) |
| return 0; |
| |
| 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_s) { |
| 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); |
| ecd_flags = scb_o->ecd & vcpu->arch.sie_block->ecd & ECD_ECC; |
| if (!ecb3_flags && !ecd_flags) |
| goto end; |
| |
| /* copy only the wrapping keys */ |
| if (read_guest_real(vcpu, crycb_addr + 72, |
| vsie_page->crycb.dea_wrapping_key_mask, 56)) |
| return set_validity_icpt(scb_s, 0x0035U); |
| |
| scb_s->ecb3 |= ecb3_flags; |
| scb_s->ecd |= ecd_flags; |
| |
| /* xor both blocks in one run */ |
| b1 = (unsigned long *) vsie_page->crycb.dea_wrapping_key_mask; |
| b2 = (unsigned long *) |
| 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, 0x0022U); |
| 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; |
| } |
| |
| /* shadow (round up/down) the ibc to avoid validity icpt */ |
| static void prepare_ibc(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; |
| /* READ_ONCE does not work on bitfields - use a temporary variable */ |
| const uint32_t __new_ibc = scb_o->ibc; |
| const uint32_t new_ibc = READ_ONCE(__new_ibc) & 0x0fffU; |
| __u64 min_ibc = (sclp.ibc >> 16) & 0x0fffU; |
| |
| scb_s->ibc = 0; |
| /* ibc installed in g2 and requested for g3 */ |
| if (vcpu->kvm->arch.model.ibc && new_ibc) { |
| scb_s->ibc = new_ibc; |
| /* takte care of the minimum ibc level of the machine */ |
| if (scb_s->ibc < min_ibc) |
| scb_s->ibc = min_ibc; |
| /* take care of the maximum ibc level set for the guest */ |
| if (scb_s->ibc > vcpu->kvm->arch.model.ibc) |
| scb_s->ibc = vcpu->kvm->arch.model.ibc; |
| } |
| } |
| |
| /* unshadow the scb, copying parameters back to the real scb */ |
| static void unshadow_scb(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; |
| |
| /* interception */ |
| scb_o->icptcode = scb_s->icptcode; |
| scb_o->icptstatus = scb_s->icptstatus; |
| scb_o->ipa = scb_s->ipa; |
| scb_o->ipb = scb_s->ipb; |
| scb_o->gbea = scb_s->gbea; |
| |
| /* timer */ |
| scb_o->cputm = scb_s->cputm; |
| scb_o->ckc = scb_s->ckc; |
| scb_o->todpr = scb_s->todpr; |
| |
| /* guest state */ |
| scb_o->gpsw = scb_s->gpsw; |
| scb_o->gg14 = scb_s->gg14; |
| scb_o->gg15 = scb_s->gg15; |
| memcpy(scb_o->gcr, scb_s->gcr, 128); |
| scb_o->pp = scb_s->pp; |
| |
| /* branch prediction */ |
| if (test_kvm_facility(vcpu->kvm, 82)) { |
| scb_o->fpf &= ~FPF_BPBC; |
| scb_o->fpf |= scb_s->fpf & FPF_BPBC; |
| } |
| |
| /* interrupt intercept */ |
| switch (scb_s->icptcode) { |
| case ICPT_PROGI: |
| case ICPT_INSTPROGI: |
| case ICPT_EXTINT: |
| memcpy((void *)((u64)scb_o + 0xc0), |
| (void *)((u64)scb_s + 0xc0), 0xf0 - 0xc0); |
| break; |
| } |
| |
| if (scb_s->ihcpu != 0xffffU) |
| scb_o->ihcpu = scb_s->ihcpu; |
| } |
| |
| /* |
| * Setup the shadow scb by copying and checking the relevant parts of the g2 |
| * provided scb. |
| * |
| * Returns: - 0 if the scb has been shadowed |
| * - > 0 if control has to be given to guest 2 |
| */ |
| static int shadow_scb(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; |
| /* READ_ONCE does not work on bitfields - use a temporary variable */ |
| const uint32_t __new_prefix = scb_o->prefix; |
| const uint32_t new_prefix = READ_ONCE(__new_prefix); |
| const bool wants_tx = READ_ONCE(scb_o->ecb) & ECB_TE; |
| bool had_tx = scb_s->ecb & ECB_TE; |
| unsigned long new_mso = 0; |
| int rc; |
| |
| /* make sure we don't have any leftovers when reusing the scb */ |
| scb_s->icptcode = 0; |
| scb_s->eca = 0; |
| scb_s->ecb = 0; |
| scb_s->ecb2 = 0; |
| scb_s->ecb3 = 0; |
| scb_s->ecd = 0; |
| scb_s->fac = 0; |
| scb_s->fpf = 0; |
| |
| rc = prepare_cpuflags(vcpu, vsie_page); |
| if (rc) |
| goto out; |
| |
| /* timer */ |
| scb_s->cputm = scb_o->cputm; |
| scb_s->ckc = scb_o->ckc; |
| scb_s->todpr = scb_o->todpr; |
| scb_s->epoch = scb_o->epoch; |
| |
| /* guest state */ |
| scb_s->gpsw = scb_o->gpsw; |
| scb_s->gg14 = scb_o->gg14; |
| scb_s->gg15 = scb_o->gg15; |
| memcpy(scb_s->gcr, scb_o->gcr, 128); |
| scb_s->pp = scb_o->pp; |
| |
| /* interception / execution handling */ |
| scb_s->gbea = scb_o->gbea; |
| scb_s->lctl = scb_o->lctl; |
| scb_s->svcc = scb_o->svcc; |
| scb_s->ictl = scb_o->ictl; |
| /* |
| * SKEY handling functions can't deal with false setting of PTE invalid |
| * bits. Therefore we cannot provide interpretation and would later |
| * have to provide own emulation handlers. |
| */ |
| if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_KSS)) |
| scb_s->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE; |
| |
| scb_s->icpua = scb_o->icpua; |
| |
| if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_SM)) |
| new_mso = READ_ONCE(scb_o->mso) & 0xfffffffffff00000UL; |
| /* if the hva of the prefix changes, we have to remap the prefix */ |
| if (scb_s->mso != new_mso || scb_s->prefix != new_prefix) |
| prefix_unmapped(vsie_page); |
| /* SIE will do mso/msl validity and exception checks for us */ |
| scb_s->msl = scb_o->msl & 0xfffffffffff00000UL; |
| scb_s->mso = new_mso; |
| scb_s->prefix = new_prefix; |
| |
| /* We have to definetly flush the tlb if this scb never ran */ |
| if (scb_s->ihcpu != 0xffffU) |
| scb_s->ihcpu = scb_o->ihcpu; |
| |
| /* MVPG and Protection Exception Interpretation are always available */ |
| scb_s->eca |= scb_o->eca & (ECA_MVPGI | ECA_PROTEXCI); |
| /* Host-protection-interruption introduced with ESOP */ |
| if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_ESOP)) |
| scb_s->ecb |= scb_o->ecb & ECB_HOSTPROTINT; |
| /* |
| * CPU Topology |
| * This facility only uses the utility field of the SCA and none of |
| * the cpu entries that are problematic with the other interpretation |
| * facilities so we can pass it through |
| */ |
| if (test_kvm_facility(vcpu->kvm, 11)) |
| scb_s->ecb |= scb_o->ecb & ECB_PTF; |
| /* transactional execution */ |
| if (test_kvm_facility(vcpu->kvm, 73) && wants_tx) { |
| /* remap the prefix is tx is toggled on */ |
| if (!had_tx) |
| prefix_unmapped(vsie_page); |
| scb_s->ecb |= ECB_TE; |
| } |
| /* specification exception interpretation */ |
| scb_s->ecb |= scb_o->ecb & ECB_SPECI; |
| /* branch prediction */ |
| if (test_kvm_facility(vcpu->kvm, 82)) |
| scb_s->fpf |= scb_o->fpf & FPF_BPBC; |
| /* SIMD */ |
| if (test_kvm_facility(vcpu->kvm, 129)) { |
| scb_s->eca |= scb_o->eca & ECA_VX; |
| scb_s->ecd |= scb_o->ecd & ECD_HOSTREGMGMT; |
| } |
| /* Run-time-Instrumentation */ |
| if (test_kvm_facility(vcpu->kvm, 64)) |
| scb_s->ecb3 |= scb_o->ecb3 & ECB3_RI; |
| /* Instruction Execution Prevention */ |
| if (test_kvm_facility(vcpu->kvm, 130)) |
| scb_s->ecb2 |= scb_o->ecb2 & ECB2_IEP; |
| /* Guarded Storage */ |
| if (test_kvm_facility(vcpu->kvm, 133)) { |
| scb_s->ecb |= scb_o->ecb & ECB_GS; |
| scb_s->ecd |= scb_o->ecd & ECD_HOSTREGMGMT; |
| } |
| if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_SIIF)) |
| scb_s->eca |= scb_o->eca & ECA_SII; |
| if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_IB)) |
| scb_s->eca |= scb_o->eca & ECA_IB; |
| if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_CEI)) |
| scb_s->eca |= scb_o->eca & ECA_CEI; |
| /* Epoch Extension */ |
| if (test_kvm_facility(vcpu->kvm, 139)) { |
| scb_s->ecd |= scb_o->ecd & ECD_MEF; |
| scb_s->epdx = scb_o->epdx; |
| } |
| |
| /* etoken */ |
| if (test_kvm_facility(vcpu->kvm, 156)) |
| scb_s->ecd |= scb_o->ecd & ECD_ETOKENF; |
| |
| scb_s->hpid = HPID_VSIE; |
| scb_s->cpnc = scb_o->cpnc; |
| |
| prepare_ibc(vcpu, vsie_page); |
| rc = shadow_crycb(vcpu, vsie_page); |
| out: |
| if (rc) |
| unshadow_scb(vcpu, vsie_page); |
| return rc; |
| } |
| |
| void kvm_s390_vsie_gmap_notifier(struct gmap *gmap, unsigned long start, |
| unsigned long end) |
| { |
| struct kvm *kvm = gmap->private; |
| struct vsie_page *cur; |
| unsigned long prefix; |
| struct page *page; |
| int i; |
| |
| if (!gmap_is_shadow(gmap)) |
| return; |
| if (start >= 1UL << 31) |
| /* We are only interested in prefix pages */ |
| return; |
| |
| /* |
| * Only new shadow blocks are added to the list during runtime, |
| * therefore we can safely reference them all the time. |
| */ |
| for (i = 0; i < kvm->arch.vsie.page_count; i++) { |
| page = READ_ONCE(kvm->arch.vsie.pages[i]); |
| if (!page) |
| continue; |
| cur = page_to_virt(page); |
| if (READ_ONCE(cur->gmap) != gmap) |
| continue; |
| prefix = cur->scb_s.prefix << GUEST_PREFIX_SHIFT; |
| /* with mso/msl, the prefix lies at an offset */ |
| prefix += cur->scb_s.mso; |
| if (prefix <= end && start <= prefix + 2 * PAGE_SIZE - 1) |
| prefix_unmapped_sync(cur); |
| } |
| } |
| |
| /* |
| * Map the first prefix page and if tx is enabled also the second prefix page. |
| * |
| * The prefix will be protected, a gmap notifier will inform about unmaps. |
| * The shadow scb must not be executed until the prefix is remapped, this is |
| * guaranteed by properly handling PROG_REQUEST. |
| * |
| * Returns: - 0 on if successfully mapped or already mapped |
| * - > 0 if control has to be given to guest 2 |
| * - -EAGAIN if the caller can retry immediately |
| * - -ENOMEM if out of memory |
| */ |
| static int map_prefix(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) |
| { |
| struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; |
| u64 prefix = scb_s->prefix << GUEST_PREFIX_SHIFT; |
| int rc; |
| |
| if (prefix_is_mapped(vsie_page)) |
| return 0; |
| |
| /* mark it as mapped so we can catch any concurrent unmappers */ |
| prefix_mapped(vsie_page); |
| |
| /* with mso/msl, the prefix lies at offset *mso* */ |
| prefix += scb_s->mso; |
| |
| rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, prefix, NULL); |
| if (!rc && (scb_s->ecb & ECB_TE)) |
| rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, |
| prefix + PAGE_SIZE, NULL); |
| /* |
| * We don't have to mprotect, we will be called for all unshadows. |
| * SIE will detect if protection applies and trigger a validity. |
| */ |
| if (rc) |
| prefix_unmapped(vsie_page); |
| if (rc > 0 || rc == -EFAULT) |
| rc = set_validity_icpt(scb_s, 0x0037U); |
| return rc; |
| } |
| |
| /* |
| * Pin the guest page given by gpa and set hpa to the pinned host address. |
| * Will always be pinned writable. |
| * |
| * Returns: - 0 on success |
| * - -EINVAL if the gpa is not valid guest storage |
| */ |
| static int pin_guest_page(struct kvm *kvm, gpa_t gpa, hpa_t *hpa) |
| { |
| struct page *page; |
| |
| page = gfn_to_page(kvm, gpa_to_gfn(gpa)); |
| if (is_error_page(page)) |
| return -EINVAL; |
| *hpa = (hpa_t) page_to_virt(page) + (gpa & ~PAGE_MASK); |
| return 0; |
| } |
| |
| /* Unpins a page previously pinned via pin_guest_page, marking it as dirty. */ |
| static void unpin_guest_page(struct kvm *kvm, gpa_t gpa, hpa_t hpa) |
| { |
| kvm_release_pfn_dirty(hpa >> PAGE_SHIFT); |
| /* mark the page always as dirty for migration */ |
| mark_page_dirty(kvm, gpa_to_gfn(gpa)); |
| } |
| |
| /* unpin all blocks previously pinned by pin_blocks(), marking them dirty */ |
| static void unpin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) |
| { |
| struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; |
| hpa_t hpa; |
| |
| hpa = (u64) scb_s->scaoh << 32 | scb_s->scaol; |
| if (hpa) { |
| unpin_guest_page(vcpu->kvm, vsie_page->sca_gpa, hpa); |
| vsie_page->sca_gpa = 0; |
| scb_s->scaol = 0; |
| scb_s->scaoh = 0; |
| } |
| |
| hpa = scb_s->itdba; |
| if (hpa) { |
| unpin_guest_page(vcpu->kvm, vsie_page->itdba_gpa, hpa); |
| vsie_page->itdba_gpa = 0; |
| scb_s->itdba = 0; |
| } |
| |
| hpa = scb_s->gvrd; |
| if (hpa) { |
| unpin_guest_page(vcpu->kvm, vsie_page->gvrd_gpa, hpa); |
| vsie_page->gvrd_gpa = 0; |
| scb_s->gvrd = 0; |
| } |
| |
| hpa = scb_s->riccbd; |
| if (hpa) { |
| unpin_guest_page(vcpu->kvm, vsie_page->riccbd_gpa, hpa); |
| vsie_page->riccbd_gpa = 0; |
| scb_s->riccbd = 0; |
| } |
| |
| hpa = scb_s->sdnxo; |
| if (hpa) { |
| unpin_guest_page(vcpu->kvm, vsie_page->sdnx_gpa, hpa); |
| vsie_page->sdnx_gpa = 0; |
| scb_s->sdnxo = 0; |
| } |
| } |
| |
| /* |
| * Instead of shadowing some blocks, we can simply forward them because the |
| * addresses in the scb are 64 bit long. |
| * |
| * This works as long as the data lies in one page. If blocks ever exceed one |
| * page, we have to fall back to shadowing. |
| * |
| * As we reuse the sca, the vcpu pointers contained in it are invalid. We must |
| * therefore not enable any facilities that access these pointers (e.g. SIGPIF). |
| * |
| * Returns: - 0 if all blocks were pinned. |
| * - > 0 if control has to be given to guest 2 |
| * - -ENOMEM if out of memory |
| */ |
| static int pin_blocks(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; |
| hpa_t hpa; |
| gpa_t gpa; |
| int rc = 0; |
| |
| gpa = READ_ONCE(scb_o->scaol) & ~0xfUL; |
| if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_64BSCAO)) |
| gpa |= (u64) READ_ONCE(scb_o->scaoh) << 32; |
| if (gpa) { |
| if (gpa < 2 * PAGE_SIZE) |
| rc = set_validity_icpt(scb_s, 0x0038U); |
| else if ((gpa & ~0x1fffUL) == kvm_s390_get_prefix(vcpu)) |
| rc = set_validity_icpt(scb_s, 0x0011U); |
| else if ((gpa & PAGE_MASK) != |
| ((gpa + sizeof(struct bsca_block) - 1) & PAGE_MASK)) |
| rc = set_validity_icpt(scb_s, 0x003bU); |
| if (!rc) { |
| rc = pin_guest_page(vcpu->kvm, gpa, &hpa); |
| if (rc) |
| rc = set_validity_icpt(scb_s, 0x0034U); |
| } |
| if (rc) |
| goto unpin; |
| vsie_page->sca_gpa = gpa; |
| scb_s->scaoh = (u32)((u64)hpa >> 32); |
| scb_s->scaol = (u32)(u64)hpa; |
| } |
| |
| gpa = READ_ONCE(scb_o->itdba) & ~0xffUL; |
| if (gpa && (scb_s->ecb & ECB_TE)) { |
| if (gpa < 2 * PAGE_SIZE) { |
| rc = set_validity_icpt(scb_s, 0x0080U); |
| goto unpin; |
| } |
| /* 256 bytes cannot cross page boundaries */ |
| rc = pin_guest_page(vcpu->kvm, gpa, &hpa); |
| if (rc) { |
| rc = set_validity_icpt(scb_s, 0x0080U); |
| goto unpin; |
| } |
| vsie_page->itdba_gpa = gpa; |
| scb_s->itdba = hpa; |
| } |
| |
| gpa = READ_ONCE(scb_o->gvrd) & ~0x1ffUL; |
| if (gpa && (scb_s->eca & ECA_VX) && !(scb_s->ecd & ECD_HOSTREGMGMT)) { |
| if (gpa < 2 * PAGE_SIZE) { |
| rc = set_validity_icpt(scb_s, 0x1310U); |
| goto unpin; |
| } |
| /* |
| * 512 bytes vector registers cannot cross page boundaries |
| * if this block gets bigger, we have to shadow it. |
| */ |
| rc = pin_guest_page(vcpu->kvm, gpa, &hpa); |
| if (rc) { |
| rc = set_validity_icpt(scb_s, 0x1310U); |
| goto unpin; |
| } |
| vsie_page->gvrd_gpa = gpa; |
| scb_s->gvrd = hpa; |
| } |
| |
| gpa = READ_ONCE(scb_o->riccbd) & ~0x3fUL; |
| if (gpa && (scb_s->ecb3 & ECB3_RI)) { |
| if (gpa < 2 * PAGE_SIZE) { |
| rc = set_validity_icpt(scb_s, 0x0043U); |
| goto unpin; |
| } |
| /* 64 bytes cannot cross page boundaries */ |
| rc = pin_guest_page(vcpu->kvm, gpa, &hpa); |
| if (rc) { |
| rc = set_validity_icpt(scb_s, 0x0043U); |
| goto unpin; |
| } |
| /* Validity 0x0044 will be checked by SIE */ |
| vsie_page->riccbd_gpa = gpa; |
| scb_s->riccbd = hpa; |
| } |
| if (((scb_s->ecb & ECB_GS) && !(scb_s->ecd & ECD_HOSTREGMGMT)) || |
| (scb_s->ecd & ECD_ETOKENF)) { |
| unsigned long sdnxc; |
| |
| gpa = READ_ONCE(scb_o->sdnxo) & ~0xfUL; |
| sdnxc = READ_ONCE(scb_o->sdnxo) & 0xfUL; |
| if (!gpa || gpa < 2 * PAGE_SIZE) { |
| rc = set_validity_icpt(scb_s, 0x10b0U); |
| goto unpin; |
| } |
| if (sdnxc < 6 || sdnxc > 12) { |
| rc = set_validity_icpt(scb_s, 0x10b1U); |
| goto unpin; |
| } |
| if (gpa & ((1 << sdnxc) - 1)) { |
| rc = set_validity_icpt(scb_s, 0x10b2U); |
| goto unpin; |
| } |
| /* Due to alignment rules (checked above) this cannot |
| * cross page boundaries |
| */ |
| rc = pin_guest_page(vcpu->kvm, gpa, &hpa); |
| if (rc) { |
| rc = set_validity_icpt(scb_s, 0x10b0U); |
| goto unpin; |
| } |
| vsie_page->sdnx_gpa = gpa; |
| scb_s->sdnxo = hpa | sdnxc; |
| } |
| return 0; |
| unpin: |
| unpin_blocks(vcpu, vsie_page); |
| return rc; |
| } |
| |
| /* unpin the scb provided by guest 2, marking it as dirty */ |
| static void unpin_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page, |
| gpa_t gpa) |
| { |
| hpa_t hpa = (hpa_t) vsie_page->scb_o; |
| |
| if (hpa) |
| unpin_guest_page(vcpu->kvm, gpa, hpa); |
| vsie_page->scb_o = NULL; |
| } |
| |
| /* |
| * Pin the scb at gpa provided by guest 2 at vsie_page->scb_o. |
| * |
| * Returns: - 0 if the scb was pinned. |
| * - > 0 if control has to be given to guest 2 |
| */ |
| static int pin_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page, |
| gpa_t gpa) |
| { |
| hpa_t hpa; |
| int rc; |
| |
| rc = pin_guest_page(vcpu->kvm, gpa, &hpa); |
| if (rc) { |
| rc = kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING); |
| WARN_ON_ONCE(rc); |
| return 1; |
| } |
| vsie_page->scb_o = (struct kvm_s390_sie_block *) hpa; |
| return 0; |
| } |
| |
| /* |
| * Inject a fault into guest 2. |
| * |
| * Returns: - > 0 if control has to be given to guest 2 |
| * < 0 if an error occurred during injection. |
| */ |
| static int inject_fault(struct kvm_vcpu *vcpu, __u16 code, __u64 vaddr, |
| bool write_flag) |
| { |
| struct kvm_s390_pgm_info pgm = { |
| .code = code, |
| .trans_exc_code = |
| /* 0-51: virtual address */ |
| (vaddr & 0xfffffffffffff000UL) | |
| /* 52-53: store / fetch */ |
| (((unsigned int) !write_flag) + 1) << 10, |
| /* 62-63: asce id (alway primary == 0) */ |
| .exc_access_id = 0, /* always primary */ |
| .op_access_id = 0, /* not MVPG */ |
| }; |
| int rc; |
| |
| if (code == PGM_PROTECTION) |
| pgm.trans_exc_code |= 0x4UL; |
| |
| rc = kvm_s390_inject_prog_irq(vcpu, &pgm); |
| return rc ? rc : 1; |
| } |
| |
| /* |
| * Handle a fault during vsie execution on a gmap shadow. |
| * |
| * Returns: - 0 if the fault was resolved |
| * - > 0 if control has to be given to guest 2 |
| * - < 0 if an error occurred |
| */ |
| static int handle_fault(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) |
| { |
| int rc; |
| |
| if (current->thread.gmap_int_code == PGM_PROTECTION) |
| /* we can directly forward all protection exceptions */ |
| return inject_fault(vcpu, PGM_PROTECTION, |
| current->thread.gmap_addr, 1); |
| |
| rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, |
| current->thread.gmap_addr, NULL); |
| if (rc > 0) { |
| rc = inject_fault(vcpu, rc, |
| current->thread.gmap_addr, |
| current->thread.gmap_write_flag); |
| if (rc >= 0) |
| vsie_page->fault_addr = current->thread.gmap_addr; |
| } |
| return rc; |
| } |
| |
| /* |
| * Retry the previous fault that required guest 2 intervention. This avoids |
| * one superfluous SIE re-entry and direct exit. |
| * |
| * Will ignore any errors. The next SIE fault will do proper fault handling. |
| */ |
| static void handle_last_fault(struct kvm_vcpu *vcpu, |
| struct vsie_page *vsie_page) |
| { |
| if (vsie_page->fault_addr) |
| kvm_s390_shadow_fault(vcpu, vsie_page->gmap, |
| vsie_page->fault_addr, NULL); |
| vsie_page->fault_addr = 0; |
| } |
| |
| static inline void clear_vsie_icpt(struct vsie_page *vsie_page) |
| { |
| vsie_page->scb_s.icptcode = 0; |
| } |
| |
| /* rewind the psw and clear the vsie icpt, so we can retry execution */ |
| static void retry_vsie_icpt(struct vsie_page *vsie_page) |
| { |
| struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; |
| int ilen = insn_length(scb_s->ipa >> 8); |
| |
| /* take care of EXECUTE instructions */ |
| if (scb_s->icptstatus & 1) { |
| ilen = (scb_s->icptstatus >> 4) & 0x6; |
| if (!ilen) |
| ilen = 4; |
| } |
| scb_s->gpsw.addr = __rewind_psw(scb_s->gpsw, ilen); |
| clear_vsie_icpt(vsie_page); |
| } |
| |
| /* |
| * Try to shadow + enable the guest 2 provided facility list. |
| * Retry instruction execution if enabled for and provided by guest 2. |
| * |
| * Returns: - 0 if handled (retry or guest 2 icpt) |
| * - > 0 if control has to be given to guest 2 |
| */ |
| static int handle_stfle(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) |
| { |
| struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; |
| __u32 fac = READ_ONCE(vsie_page->scb_o->fac) & 0x7ffffff8U; |
| |
| if (fac && test_kvm_facility(vcpu->kvm, 7)) { |
| retry_vsie_icpt(vsie_page); |
| if (read_guest_real(vcpu, fac, &vsie_page->fac, |
| sizeof(vsie_page->fac))) |
| return set_validity_icpt(scb_s, 0x1090U); |
| scb_s->fac = (__u32)(__u64) &vsie_page->fac; |
| } |
| return 0; |
| } |
| |
| /* |
| * Get a register for a nested guest. |
| * @vcpu the vcpu of the guest |
| * @vsie_page the vsie_page for the nested guest |
| * @reg the register number, the upper 4 bits are ignored. |
| * returns: the value of the register. |
| */ |
| static u64 vsie_get_register(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page, u8 reg) |
| { |
| /* no need to validate the parameter and/or perform error handling */ |
| reg &= 0xf; |
| switch (reg) { |
| case 15: |
| return vsie_page->scb_s.gg15; |
| case 14: |
| return vsie_page->scb_s.gg14; |
| default: |
| return vcpu->run->s.regs.gprs[reg]; |
| } |
| } |
| |
| static int vsie_handle_mvpg(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) |
| { |
| struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; |
| unsigned long pei_dest, pei_src, src, dest, mask, prefix; |
| u64 *pei_block = &vsie_page->scb_o->mcic; |
| int edat, rc_dest, rc_src; |
| union ctlreg0 cr0; |
| |
| cr0.val = vcpu->arch.sie_block->gcr[0]; |
| edat = cr0.edat && test_kvm_facility(vcpu->kvm, 8); |
| mask = _kvm_s390_logical_to_effective(&scb_s->gpsw, PAGE_MASK); |
| prefix = scb_s->prefix << GUEST_PREFIX_SHIFT; |
| |
| dest = vsie_get_register(vcpu, vsie_page, scb_s->ipb >> 20) & mask; |
| dest = _kvm_s390_real_to_abs(prefix, dest) + scb_s->mso; |
| src = vsie_get_register(vcpu, vsie_page, scb_s->ipb >> 16) & mask; |
| src = _kvm_s390_real_to_abs(prefix, src) + scb_s->mso; |
| |
| rc_dest = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, dest, &pei_dest); |
| rc_src = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, src, &pei_src); |
| /* |
| * Either everything went well, or something non-critical went wrong |
| * e.g. because of a race. In either case, simply retry. |
| */ |
| if (rc_dest == -EAGAIN || rc_src == -EAGAIN || (!rc_dest && !rc_src)) { |
| retry_vsie_icpt(vsie_page); |
| return -EAGAIN; |
| } |
| /* Something more serious went wrong, propagate the error */ |
| if (rc_dest < 0) |
| return rc_dest; |
| if (rc_src < 0) |
| return rc_src; |
| |
| /* The only possible suppressing exception: just deliver it */ |
| if (rc_dest == PGM_TRANSLATION_SPEC || rc_src == PGM_TRANSLATION_SPEC) { |
| clear_vsie_icpt(vsie_page); |
| rc_dest = kvm_s390_inject_program_int(vcpu, PGM_TRANSLATION_SPEC); |
| WARN_ON_ONCE(rc_dest); |
| return 1; |
| } |
| |
| /* |
| * Forward the PEI intercept to the guest if it was a page fault, or |
| * also for segment and region table faults if EDAT applies. |
| */ |
| if (edat) { |
| rc_dest = rc_dest == PGM_ASCE_TYPE ? rc_dest : 0; |
| rc_src = rc_src == PGM_ASCE_TYPE ? rc_src : 0; |
| } else { |
| rc_dest = rc_dest != PGM_PAGE_TRANSLATION ? rc_dest : 0; |
| rc_src = rc_src != PGM_PAGE_TRANSLATION ? rc_src : 0; |
| } |
| if (!rc_dest && !rc_src) { |
| pei_block[0] = pei_dest; |
| pei_block[1] = pei_src; |
| return 1; |
| } |
| |
| retry_vsie_icpt(vsie_page); |
| |
| /* |
| * The host has edat, and the guest does not, or it was an ASCE type |
| * exception. The host needs to inject the appropriate DAT interrupts |
| * into the guest. |
| */ |
| if (rc_dest) |
| return inject_fault(vcpu, rc_dest, dest, 1); |
| return inject_fault(vcpu, rc_src, src, 0); |
| } |
| |
| /* |
| * Run the vsie on a shadow scb and a shadow gmap, without any further |
| * sanity checks, handling SIE faults. |
| * |
| * Returns: - 0 everything went fine |
| * - > 0 if control has to be given to guest 2 |
| * - < 0 if an error occurred |
| */ |
| static int do_vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) |
| __releases(vcpu->kvm->srcu) |
| __acquires(vcpu->kvm->srcu) |
| { |
| struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; |
| struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; |
| int guest_bp_isolation; |
| int rc = 0; |
| |
| handle_last_fault(vcpu, vsie_page); |
| |
| kvm_vcpu_srcu_read_unlock(vcpu); |
| |
| /* save current guest state of bp isolation override */ |
| guest_bp_isolation = test_thread_flag(TIF_ISOLATE_BP_GUEST); |
| |
| /* |
| * The guest is running with BPBC, so we have to force it on for our |
| * nested guest. This is done by enabling BPBC globally, so the BPBC |
| * control in the SCB (which the nested guest can modify) is simply |
| * ignored. |
| */ |
| if (test_kvm_facility(vcpu->kvm, 82) && |
| vcpu->arch.sie_block->fpf & FPF_BPBC) |
| set_thread_flag(TIF_ISOLATE_BP_GUEST); |
| |
| local_irq_disable(); |
| guest_enter_irqoff(); |
| local_irq_enable(); |
| |
| /* |
| * Simulate a SIE entry of the VCPU (see sie64a), so VCPU blocking |
| * and VCPU requests also hinder the vSIE from running and lead |
| * to an immediate exit. kvm_s390_vsie_kick() has to be used to |
| * also kick the vSIE. |
| */ |
| vcpu->arch.sie_block->prog0c |= PROG_IN_SIE; |
| barrier(); |
| if (test_cpu_flag(CIF_FPU)) |
| load_fpu_regs(); |
| if (!kvm_s390_vcpu_sie_inhibited(vcpu)) |
| rc = sie64a(scb_s, vcpu->run->s.regs.gprs); |
| barrier(); |
| vcpu->arch.sie_block->prog0c &= ~PROG_IN_SIE; |
| |
| local_irq_disable(); |
| guest_exit_irqoff(); |
| local_irq_enable(); |
| |
| /* restore guest state for bp isolation override */ |
| if (!guest_bp_isolation) |
| clear_thread_flag(TIF_ISOLATE_BP_GUEST); |
| |
| kvm_vcpu_srcu_read_lock(vcpu); |
| |
| if (rc == -EINTR) { |
| VCPU_EVENT(vcpu, 3, "%s", "machine check"); |
| kvm_s390_reinject_machine_check(vcpu, &vsie_page->mcck_info); |
| return 0; |
| } |
| |
| if (rc > 0) |
| rc = 0; /* we could still have an icpt */ |
| else if (rc == -EFAULT) |
| return handle_fault(vcpu, vsie_page); |
| |
| switch (scb_s->icptcode) { |
| case ICPT_INST: |
| if (scb_s->ipa == 0xb2b0) |
| rc = handle_stfle(vcpu, vsie_page); |
| break; |
| case ICPT_STOP: |
| /* stop not requested by g2 - must have been a kick */ |
| if (!(atomic_read(&scb_o->cpuflags) & CPUSTAT_STOP_INT)) |
| clear_vsie_icpt(vsie_page); |
| break; |
| case ICPT_VALIDITY: |
| if ((scb_s->ipa & 0xf000) != 0xf000) |
| scb_s->ipa += 0x1000; |
| break; |
| case ICPT_PARTEXEC: |
| if (scb_s->ipa == 0xb254) |
| rc = vsie_handle_mvpg(vcpu, vsie_page); |
| break; |
| } |
| return rc; |
| } |
| |
| static void release_gmap_shadow(struct vsie_page *vsie_page) |
| { |
| if (vsie_page->gmap) |
| gmap_put(vsie_page->gmap); |
| WRITE_ONCE(vsie_page->gmap, NULL); |
| prefix_unmapped(vsie_page); |
| } |
| |
| static int acquire_gmap_shadow(struct kvm_vcpu *vcpu, |
| struct vsie_page *vsie_page) |
| { |
| unsigned long asce; |
| union ctlreg0 cr0; |
| struct gmap *gmap; |
| int edat; |
| |
| asce = vcpu->arch.sie_block->gcr[1]; |
| cr0.val = vcpu->arch.sie_block->gcr[0]; |
| edat = cr0.edat && test_kvm_facility(vcpu->kvm, 8); |
| edat += edat && test_kvm_facility(vcpu->kvm, 78); |
| |
| /* |
| * ASCE or EDAT could have changed since last icpt, or the gmap |
| * we're holding has been unshadowed. If the gmap is still valid, |
| * we can safely reuse it. |
| */ |
| if (vsie_page->gmap && gmap_shadow_valid(vsie_page->gmap, asce, edat)) |
| return 0; |
| |
| /* release the old shadow - if any, and mark the prefix as unmapped */ |
| release_gmap_shadow(vsie_page); |
| gmap = gmap_shadow(vcpu->arch.gmap, asce, edat); |
| if (IS_ERR(gmap)) |
| return PTR_ERR(gmap); |
| gmap->private = vcpu->kvm; |
| WRITE_ONCE(vsie_page->gmap, gmap); |
| return 0; |
| } |
| |
| /* |
| * Register the shadow scb at the VCPU, e.g. for kicking out of vsie. |
| */ |
| static void register_shadow_scb(struct kvm_vcpu *vcpu, |
| struct vsie_page *vsie_page) |
| { |
| struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; |
| |
| WRITE_ONCE(vcpu->arch.vsie_block, &vsie_page->scb_s); |
| /* |
| * External calls have to lead to a kick of the vcpu and |
| * therefore the vsie -> Simulate Wait state. |
| */ |
| kvm_s390_set_cpuflags(vcpu, CPUSTAT_WAIT); |
| /* |
| * We have to adjust the g3 epoch by the g2 epoch. The epoch will |
| * automatically be adjusted on tod clock changes via kvm_sync_clock. |
| */ |
| preempt_disable(); |
| scb_s->epoch += vcpu->kvm->arch.epoch; |
| |
| if (scb_s->ecd & ECD_MEF) { |
| scb_s->epdx += vcpu->kvm->arch.epdx; |
| if (scb_s->epoch < vcpu->kvm->arch.epoch) |
| scb_s->epdx += 1; |
| } |
| |
| preempt_enable(); |
| } |
| |
| /* |
| * Unregister a shadow scb from a VCPU. |
| */ |
| static void unregister_shadow_scb(struct kvm_vcpu *vcpu) |
| { |
| kvm_s390_clear_cpuflags(vcpu, CPUSTAT_WAIT); |
| WRITE_ONCE(vcpu->arch.vsie_block, NULL); |
| } |
| |
| /* |
| * Run the vsie on a shadowed scb, managing the gmap shadow, handling |
| * prefix pages and faults. |
| * |
| * Returns: - 0 if no errors occurred |
| * - > 0 if control has to be given to guest 2 |
| * - -ENOMEM if out of memory |
| */ |
| static int vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) |
| { |
| struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; |
| int rc = 0; |
| |
| while (1) { |
| rc = acquire_gmap_shadow(vcpu, vsie_page); |
| if (!rc) |
| rc = map_prefix(vcpu, vsie_page); |
| if (!rc) { |
| gmap_enable(vsie_page->gmap); |
| update_intervention_requests(vsie_page); |
| rc = do_vsie_run(vcpu, vsie_page); |
| gmap_enable(vcpu->arch.gmap); |
| } |
| atomic_andnot(PROG_BLOCK_SIE, &scb_s->prog20); |
| |
| if (rc == -EAGAIN) |
| rc = 0; |
| if (rc || scb_s->icptcode || signal_pending(current) || |
| kvm_s390_vcpu_has_irq(vcpu, 0) || |
| kvm_s390_vcpu_sie_inhibited(vcpu)) |
| break; |
| cond_resched(); |
| } |
| |
| if (rc == -EFAULT) { |
| /* |
| * Addressing exceptions are always presentes as intercepts. |
| * As addressing exceptions are suppressing and our guest 3 PSW |
| * points at the responsible instruction, we have to |
| * forward the PSW and set the ilc. If we can't read guest 3 |
| * instruction, we can use an arbitrary ilc. Let's always use |
| * ilen = 4 for now, so we can avoid reading in guest 3 virtual |
| * memory. (we could also fake the shadow so the hardware |
| * handles it). |
| */ |
| scb_s->icptcode = ICPT_PROGI; |
| scb_s->iprcc = PGM_ADDRESSING; |
| scb_s->pgmilc = 4; |
| scb_s->gpsw.addr = __rewind_psw(scb_s->gpsw, 4); |
| rc = 1; |
| } |
| return rc; |
| } |
| |
| /* |
| * Get or create a vsie page for a scb address. |
| * |
| * Returns: - address of a vsie page (cached or new one) |
| * - NULL if the same scb address is already used by another VCPU |
| * - ERR_PTR(-ENOMEM) if out of memory |
| */ |
| static struct vsie_page *get_vsie_page(struct kvm *kvm, unsigned long addr) |
| { |
| struct vsie_page *vsie_page; |
| struct page *page; |
| int nr_vcpus; |
| |
| rcu_read_lock(); |
| page = radix_tree_lookup(&kvm->arch.vsie.addr_to_page, addr >> 9); |
| rcu_read_unlock(); |
| if (page) { |
| if (page_ref_inc_return(page) == 2) |
| return page_to_virt(page); |
| page_ref_dec(page); |
| } |
| |
| /* |
| * We want at least #online_vcpus shadows, so every VCPU can execute |
| * the VSIE in parallel. |
| */ |
| nr_vcpus = atomic_read(&kvm->online_vcpus); |
| |
| mutex_lock(&kvm->arch.vsie.mutex); |
| if (kvm->arch.vsie.page_count < nr_vcpus) { |
| page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO | GFP_DMA); |
| if (!page) { |
| mutex_unlock(&kvm->arch.vsie.mutex); |
| return ERR_PTR(-ENOMEM); |
| } |
| page_ref_inc(page); |
| kvm->arch.vsie.pages[kvm->arch.vsie.page_count] = page; |
| kvm->arch.vsie.page_count++; |
| } else { |
| /* reuse an existing entry that belongs to nobody */ |
| while (true) { |
| page = kvm->arch.vsie.pages[kvm->arch.vsie.next]; |
| if (page_ref_inc_return(page) == 2) |
| break; |
| page_ref_dec(page); |
| kvm->arch.vsie.next++; |
| kvm->arch.vsie.next %= nr_vcpus; |
| } |
| radix_tree_delete(&kvm->arch.vsie.addr_to_page, page->index >> 9); |
| } |
| page->index = addr; |
| /* double use of the same address */ |
| if (radix_tree_insert(&kvm->arch.vsie.addr_to_page, addr >> 9, page)) { |
| page_ref_dec(page); |
| mutex_unlock(&kvm->arch.vsie.mutex); |
| return NULL; |
| } |
| mutex_unlock(&kvm->arch.vsie.mutex); |
| |
| vsie_page = page_to_virt(page); |
| memset(&vsie_page->scb_s, 0, sizeof(struct kvm_s390_sie_block)); |
| release_gmap_shadow(vsie_page); |
| vsie_page->fault_addr = 0; |
| vsie_page->scb_s.ihcpu = 0xffffU; |
| return vsie_page; |
| } |
| |
| /* put a vsie page acquired via get_vsie_page */ |
| static void put_vsie_page(struct kvm *kvm, struct vsie_page *vsie_page) |
| { |
| struct page *page = pfn_to_page(__pa(vsie_page) >> PAGE_SHIFT); |
| |
| page_ref_dec(page); |
| } |
| |
| int kvm_s390_handle_vsie(struct kvm_vcpu *vcpu) |
| { |
| struct vsie_page *vsie_page; |
| unsigned long scb_addr; |
| int rc; |
| |
| vcpu->stat.instruction_sie++; |
| if (!test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_SIEF2)) |
| return -EOPNOTSUPP; |
| if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE) |
| return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP); |
| |
| BUILD_BUG_ON(sizeof(struct vsie_page) != PAGE_SIZE); |
| scb_addr = kvm_s390_get_base_disp_s(vcpu, NULL); |
| |
| /* 512 byte alignment */ |
| if (unlikely(scb_addr & 0x1ffUL)) |
| return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); |
| |
| if (signal_pending(current) || kvm_s390_vcpu_has_irq(vcpu, 0) || |
| kvm_s390_vcpu_sie_inhibited(vcpu)) |
| return 0; |
| |
| vsie_page = get_vsie_page(vcpu->kvm, scb_addr); |
| if (IS_ERR(vsie_page)) |
| return PTR_ERR(vsie_page); |
| else if (!vsie_page) |
| /* double use of sie control block - simply do nothing */ |
| return 0; |
| |
| rc = pin_scb(vcpu, vsie_page, scb_addr); |
| if (rc) |
| goto out_put; |
| rc = shadow_scb(vcpu, vsie_page); |
| if (rc) |
| goto out_unpin_scb; |
| rc = pin_blocks(vcpu, vsie_page); |
| if (rc) |
| goto out_unshadow; |
| register_shadow_scb(vcpu, vsie_page); |
| rc = vsie_run(vcpu, vsie_page); |
| unregister_shadow_scb(vcpu); |
| unpin_blocks(vcpu, vsie_page); |
| out_unshadow: |
| unshadow_scb(vcpu, vsie_page); |
| out_unpin_scb: |
| unpin_scb(vcpu, vsie_page, scb_addr); |
| out_put: |
| put_vsie_page(vcpu->kvm, vsie_page); |
| |
| return rc < 0 ? rc : 0; |
| } |
| |
| /* Init the vsie data structures. To be called when a vm is initialized. */ |
| void kvm_s390_vsie_init(struct kvm *kvm) |
| { |
| mutex_init(&kvm->arch.vsie.mutex); |
| INIT_RADIX_TREE(&kvm->arch.vsie.addr_to_page, GFP_KERNEL_ACCOUNT); |
| } |
| |
| /* Destroy the vsie data structures. To be called when a vm is destroyed. */ |
| void kvm_s390_vsie_destroy(struct kvm *kvm) |
| { |
| struct vsie_page *vsie_page; |
| struct page *page; |
| int i; |
| |
| mutex_lock(&kvm->arch.vsie.mutex); |
| for (i = 0; i < kvm->arch.vsie.page_count; i++) { |
| page = kvm->arch.vsie.pages[i]; |
| kvm->arch.vsie.pages[i] = NULL; |
| vsie_page = page_to_virt(page); |
| release_gmap_shadow(vsie_page); |
| /* free the radix tree entry */ |
| radix_tree_delete(&kvm->arch.vsie.addr_to_page, page->index >> 9); |
| __free_page(page); |
| } |
| kvm->arch.vsie.page_count = 0; |
| mutex_unlock(&kvm->arch.vsie.mutex); |
| } |
| |
| void kvm_s390_vsie_kick(struct kvm_vcpu *vcpu) |
| { |
| struct kvm_s390_sie_block *scb = READ_ONCE(vcpu->arch.vsie_block); |
| |
| /* |
| * Even if the VCPU lets go of the shadow sie block reference, it is |
| * still valid in the cache. So we can safely kick it. |
| */ |
| if (scb) { |
| atomic_or(PROG_BLOCK_SIE, &scb->prog20); |
| if (scb->prog0c & PROG_IN_SIE) |
| atomic_or(CPUSTAT_STOP_INT, &scb->cpuflags); |
| } |
| } |