diff options
| -rw-r--r-- | arch/s390/include/asm/kvm_host.h | 15 | ||||
| -rw-r--r-- | arch/s390/include/uapi/asm/kvm.h | 1 | ||||
| -rw-r--r-- | arch/s390/kvm/Makefile | 2 | ||||
| -rw-r--r-- | arch/s390/kvm/kvm-s390.c | 15 | ||||
| -rw-r--r-- | arch/s390/kvm/kvm-s390.h | 7 | ||||
| -rw-r--r-- | arch/s390/kvm/priv.c | 1 | ||||
| -rw-r--r-- | arch/s390/kvm/vsie.c | 755 |
7 files changed, 794 insertions, 2 deletions
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h index 96bef30e2e33..255609c86901 100644 --- a/arch/s390/include/asm/kvm_host.h +++ b/arch/s390/include/asm/kvm_host.h @@ -145,7 +145,7 @@ struct kvm_s390_sie_block { __u64 cputm; /* 0x0028 */ __u64 ckc; /* 0x0030 */ __u64 epoch; /* 0x0038 */ - __u8 reserved40[4]; /* 0x0040 */ + __u32 svcc; /* 0x0040 */ #define LCTL_CR0 0x8000 #define LCTL_CR6 0x0200 #define LCTL_CR9 0x0040 @@ -167,6 +167,9 @@ struct kvm_s390_sie_block { #define ICPT_INST 0x04 #define ICPT_PROGI 0x08 #define ICPT_INSTPROGI 0x0C +#define ICPT_EXTINT 0x14 +#define ICPT_VALIDITY 0x20 +#define ICPT_STOP 0x28 #define ICPT_OPEREXC 0x2C #define ICPT_PARTEXEC 0x38 #define ICPT_IOINST 0x40 @@ -281,6 +284,7 @@ struct kvm_vcpu_stat { u32 instruction_stsi; u32 instruction_stfl; u32 instruction_tprot; + u32 instruction_sie; u32 instruction_essa; u32 instruction_sthyi; u32 instruction_sigp_sense; @@ -637,6 +641,14 @@ struct sie_page2 { u8 reserved900[0x1000 - 0x900]; /* 0x0900 */ } __packed; +struct kvm_s390_vsie { + struct mutex mutex; + struct radix_tree_root addr_to_page; + int page_count; + int next; + struct page *pages[KVM_MAX_VCPUS]; +}; + struct kvm_arch{ void *sca; int use_esca; @@ -661,6 +673,7 @@ struct kvm_arch{ struct sie_page2 *sie_page2; struct kvm_s390_cpu_model model; struct kvm_s390_crypto crypto; + struct kvm_s390_vsie vsie; u64 epoch; /* subset of available cpu features enabled by user space */ DECLARE_BITMAP(cpu_feat, KVM_S390_VM_CPU_FEAT_NR_BITS); diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h index f0818d70d73d..62423b1931c0 100644 --- a/arch/s390/include/uapi/asm/kvm.h +++ b/arch/s390/include/uapi/asm/kvm.h @@ -98,6 +98,7 @@ struct kvm_s390_vm_cpu_machine { #define KVM_S390_VM_CPU_FEAT_NR_BITS 1024 #define KVM_S390_VM_CPU_FEAT_ESOP 0 +#define KVM_S390_VM_CPU_FEAT_SIEF2 1 struct kvm_s390_vm_cpu_feat { __u64 feat[16]; }; diff --git a/arch/s390/kvm/Makefile b/arch/s390/kvm/Makefile index 82e73e2b953d..09a9e6dfc09f 100644 --- a/arch/s390/kvm/Makefile +++ b/arch/s390/kvm/Makefile @@ -12,6 +12,6 @@ common-objs = $(KVM)/kvm_main.o $(KVM)/eventfd.o $(KVM)/async_pf.o $(KVM)/irqch ccflags-y := -Ivirt/kvm -Iarch/s390/kvm kvm-objs := $(common-objs) kvm-s390.o intercept.o interrupt.o priv.o sigp.o -kvm-objs += diag.o gaccess.o guestdbg.o sthyi.o +kvm-objs += diag.o gaccess.o guestdbg.o sthyi.o vsie.o obj-$(CONFIG_KVM) += kvm.o diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index a890f7d20711..3fb124226e97 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -99,6 +99,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { { "instruction_stfl", VCPU_STAT(instruction_stfl) }, { "instruction_tprot", VCPU_STAT(instruction_tprot) }, { "instruction_sthyi", VCPU_STAT(instruction_sthyi) }, + { "instruction_sie", VCPU_STAT(instruction_sie) }, { "instruction_sigp_sense", VCPU_STAT(instruction_sigp_sense) }, { "instruction_sigp_sense_running", VCPU_STAT(instruction_sigp_sense_running) }, { "instruction_sigp_external_call", VCPU_STAT(instruction_sigp_external_call) }, @@ -142,6 +143,7 @@ static DECLARE_BITMAP(kvm_s390_available_cpu_feat, KVM_S390_VM_CPU_FEAT_NR_BITS) static struct kvm_s390_vm_cpu_subfunc kvm_s390_available_subfunc; static struct gmap_notifier gmap_notifier; +static struct gmap_notifier vsie_gmap_notifier; debug_info_t *kvm_s390_dbf; /* Section: not file related */ @@ -187,6 +189,8 @@ int kvm_arch_hardware_setup(void) { gmap_notifier.notifier_call = kvm_gmap_notifier; gmap_register_pte_notifier(&gmap_notifier); + vsie_gmap_notifier.notifier_call = kvm_s390_vsie_gmap_notifier; + gmap_register_pte_notifier(&vsie_gmap_notifier); atomic_notifier_chain_register(&s390_epoch_delta_notifier, &kvm_clock_notifier); return 0; @@ -195,6 +199,7 @@ int kvm_arch_hardware_setup(void) void kvm_arch_hardware_unsetup(void) { gmap_unregister_pte_notifier(&gmap_notifier); + gmap_unregister_pte_notifier(&vsie_gmap_notifier); atomic_notifier_chain_unregister(&s390_epoch_delta_notifier, &kvm_clock_notifier); } @@ -252,6 +257,14 @@ static void kvm_s390_cpu_feat_init(void) if (MACHINE_HAS_ESOP) allow_cpu_feat(KVM_S390_VM_CPU_FEAT_ESOP); + /* + * We need SIE support, ESOP (PROT_READ protection for gmap_shadow), + * 64bit SCAO (SCA passthrough) and IDTE (for gmap_shadow unshadowing). + */ + if (!sclp.has_sief2 || !MACHINE_HAS_ESOP || !sclp.has_64bscao || + !test_facility(3)) + return; + allow_cpu_feat(KVM_S390_VM_CPU_FEAT_SIEF2); } int kvm_arch_init(void *opaque) @@ -1406,6 +1419,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) kvm->arch.epoch = 0; spin_lock_init(&kvm->arch.start_stop_lock); + kvm_s390_vsie_init(kvm); KVM_EVENT(3, "vm 0x%pK created by pid %u", kvm, current->pid); return 0; @@ -1463,6 +1477,7 @@ void kvm_arch_destroy_vm(struct kvm *kvm) gmap_remove(kvm->arch.gmap); kvm_s390_destroy_adapters(kvm); kvm_s390_clear_float_irqs(kvm); + kvm_s390_vsie_destroy(kvm); KVM_EVENT(3, "vm 0x%pK destroyed", kvm); } diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h index 52aa47e112d8..b137fbaac91c 100644 --- a/arch/s390/kvm/kvm-s390.h +++ b/arch/s390/kvm/kvm-s390.h @@ -252,6 +252,13 @@ int kvm_s390_handle_stctl(struct kvm_vcpu *vcpu); int kvm_s390_handle_lctl(struct kvm_vcpu *vcpu); int kvm_s390_handle_eb(struct kvm_vcpu *vcpu); +/* implemented in vsie.c */ +int kvm_s390_handle_vsie(struct kvm_vcpu *vcpu); +void kvm_s390_vsie_gmap_notifier(struct gmap *gmap, unsigned long start, + unsigned long end); +void kvm_s390_vsie_init(struct kvm *kvm); +void kvm_s390_vsie_destroy(struct kvm *kvm); + /* implemented in sigp.c */ int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu); int kvm_s390_handle_sigp_pei(struct kvm_vcpu *vcpu); diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c index 3db3be139992..c77ad2dc334f 100644 --- a/arch/s390/kvm/priv.c +++ b/arch/s390/kvm/priv.c @@ -719,6 +719,7 @@ static const intercept_handler_t b2_handlers[256] = { [0x10] = handle_set_prefix, [0x11] = handle_store_prefix, [0x12] = handle_store_cpu_address, + [0x14] = kvm_s390_handle_vsie, [0x21] = handle_ipte_interlock, [0x29] = handle_iske, [0x2a] = handle_rrbe, diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c new file mode 100644 index 000000000000..747d4f900155 --- /dev/null +++ b/arch/s390/kvm/vsie.c @@ -0,0 +1,755 @@ +/* + * kvm nested virtualization support for s390x + * + * Copyright IBM Corp. 2016 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License (version 2 only) + * as published by the Free Software Foundation. + * + * 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 <asm/gmap.h> +#include <asm/mmu_context.h> +#include <asm/sclp.h> +#include <asm/nmi.h> +#include "kvm-s390.h" +#include "gaccess.h" + +struct vsie_page { + struct kvm_s390_sie_block scb_s; /* 0x0000 */ + /* the pinned originial scb */ + struct kvm_s390_sie_block *scb_o; /* 0x0200 */ + /* the shadow gmap in use by the vsie_page */ + struct gmap *gmap; /* 0x0208 */ + __u8 reserved[0x1000 - 0x0210]; /* 0x0210 */ +} __packed; + +/* 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); +} + + +/* 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; + + atomic_set(&scb_s->cpuflags, newflags); + return 0; +} + +/* 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; + + /* 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; + case ICPT_PARTEXEC: + /* MVPG only */ + memcpy((void *)((u64)scb_o + 0xc0), + (void *)((u64)scb_s + 0xc0), 0xd0 - 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; + 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; + + 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. + */ + scb_s->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE; + scb_s->icpua = scb_o->icpua; + + /* SIE will do mso/msl validity and exception checks for us */ + scb_s->msl = scb_o->msl & 0xfffffffffff00000UL; + scb_s->mso = scb_o->mso & 0xfffffffffff00000UL; + scb_s->prefix = scb_o->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 & 0x01002000U; + +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 + PAGE_SIZE - 1) + prefix_unmapped_sync(cur); + } +} + +/* + * Map the first 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; + + /* 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); + /* + * 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 + * - -ENOMEM if out of memory + */ +static int pin_guest_page(struct kvm *kvm, gpa_t gpa, hpa_t *hpa) +{ + struct page *page; + hva_t hva; + int rc; + + hva = gfn_to_hva(kvm, gpa_to_gfn(gpa)); + if (kvm_is_error_hva(hva)) + return -EINVAL; + rc = get_user_pages_fast(hva, 1, 1, &page); + if (rc < 0) + return rc; + else if (rc != 1) + return -ENOMEM; + *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) +{ + struct page *page; + + page = virt_to_page(hpa); + set_page_dirty_lock(page); + put_page(page); + /* 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_o = vsie_page->scb_o; + struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; + hpa_t hpa; + gpa_t gpa; + + hpa = (u64) scb_s->scaoh << 32 | scb_s->scaol; + if (hpa) { + gpa = scb_o->scaol & ~0xfUL; + unpin_guest_page(vcpu->kvm, gpa, hpa); + scb_s->scaol = 0; + scb_s->scaoh = 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 = scb_o->scaol & ~0xfUL; + if (gpa) { + if (!(gpa & ~0x1fffUL)) + 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 == -EINVAL) + rc = set_validity_icpt(scb_s, 0x0034U); + } + if (rc) + goto unpin; + scb_s->scaoh = (u32)((u64)hpa >> 32); + scb_s->scaol = (u32)(u64)hpa; + } + 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 + * - -ENOMEM if out of memory + */ +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 == -EINVAL) { + rc = kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING); + if (!rc) + rc = 1; + } + if (!rc) + vsie_page->scb_o = (struct kvm_s390_sie_block *) hpa; + return rc; +} + +/* + * 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); + if (rc > 0) { + rc = inject_fault(vcpu, rc, + current->thread.gmap_addr, + current->thread.gmap_write_flag); + } + return rc; +} + +static inline void clear_vsie_icpt(struct vsie_page *vsie_page) +{ + vsie_page->scb_s.icptcode = 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) +{ + struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; + struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; + int rc; + + if (need_resched()) + schedule(); + if (test_cpu_flag(CIF_MCCK_PENDING)) + s390_handle_mcck(); + + srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx); + local_irq_disable(); + kvm_guest_enter(); + local_irq_enable(); + + rc = sie64a(scb_s, vcpu->run->s.regs.gprs); + + local_irq_disable(); + kvm_guest_exit(); + local_irq_enable(); + vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu); + + 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_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; + } + 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); +} + +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); + + 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; +} + +/* + * 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); + } + release_gmap_shadow(vsie_page); + + if (rc == -EAGAIN) + rc = 0; + if (rc || scb_s->icptcode || signal_pending(current) || + kvm_s390_vcpu_has_irq(vcpu, 0)) + break; + }; + + 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); + } + 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 | __GFP_ZERO); + 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)); + 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) != 4096); + 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)) + 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; + rc = vsie_run(vcpu, vsie_page); + 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); +} + +/* Destroy the vsie data structures. To be called when a vm is destroyed. */ +void kvm_s390_vsie_destroy(struct kvm *kvm) +{ + 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; + /* 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); +} |