diff options
Diffstat (limited to 'arch/s390/kvm/vsie.c')
| -rw-r--r-- | arch/s390/kvm/vsie.c | 341 |
1 files changed, 215 insertions, 126 deletions
diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c index a687695d8f68..e5a23f1c9749 100644 --- a/arch/s390/kvm/vsie.c +++ b/arch/s390/kvm/vsie.c @@ -13,8 +13,8 @@ #include <linux/bitmap.h> #include <linux/sched/signal.h> #include <linux/io.h> +#include <linux/mman.h> -#include <asm/gmap.h> #include <asm/mmu_context.h> #include <asm/sclp.h> #include <asm/nmi.h> @@ -22,6 +22,11 @@ #include <asm/facility.h> #include "kvm-s390.h" #include "gaccess.h" +#include "gmap.h" + +enum vsie_page_flags { + VSIE_PAGE_IN_USE = 0, +}; struct vsie_page { struct kvm_s390_sie_block scb_s; /* 0x0000 */ @@ -36,8 +41,11 @@ struct vsie_page { * 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 */ + /* + * Flags: must be set/cleared atomically after the vsie page can be + * looked up by other CPUs. + */ + unsigned long flags; /* 0x0220 */ /* address of the last reported fault to guest2 */ unsigned long fault_addr; /* 0x0228 */ /* calculated guest addresses of satellite control blocks */ @@ -46,11 +54,21 @@ struct vsie_page { gpa_t gvrd_gpa; /* 0x0240 */ gpa_t riccbd_gpa; /* 0x0248 */ gpa_t sdnx_gpa; /* 0x0250 */ - __u8 reserved[0x0700 - 0x0258]; /* 0x0258 */ + /* + * guest address of the original SCB. Remains set for free vsie + * pages, so we can properly look them up in our addr_to_page + * radix tree. + */ + gpa_t scb_gpa; /* 0x0258 */ + /* the shadow gmap in use by the vsie_page */ + struct gmap_cache gmap_cache; /* 0x0260 */ + __u8 reserved[0x0700 - 0x0278]; /* 0x0278 */ struct kvm_s390_crypto_cb crycb; /* 0x0700 */ __u8 fac[S390_ARCH_FAC_LIST_SIZE_BYTE]; /* 0x0800 */ }; +static_assert(sizeof(struct vsie_page) == PAGE_SIZE); + /* trigger a validity icpt for the given scb */ static int set_validity_icpt(struct kvm_s390_sie_block *scb, __u16 reason_code) @@ -107,8 +125,8 @@ static int prepare_cpuflags(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 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)) + /* we don't allow ESA/390 guests unless explicitly enabled */ + if (!(cpuflags & CPUSTAT_ZARCH) && !vcpu->kvm->arch.allow_vsie_esamode) return set_validity_icpt(scb_s, 0x0001U); if (cpuflags & (CPUSTAT_RRF | CPUSTAT_MCDS)) @@ -117,7 +135,9 @@ static int prepare_cpuflags(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) return set_validity_icpt(scb_s, 0x0007U); /* intervention requests will be set later */ - newflags = CPUSTAT_ZARCH; + newflags = 0; + if (cpuflags & CPUSTAT_ZARCH) + 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)) { @@ -367,6 +387,17 @@ end: return 0; } +static void shadow_esa(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) +{ + struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; + + /* Ensure these bits are indeed turned off */ + scb_s->eca &= ~ECA_VX; + scb_s->ecb &= ~(ECB_GS | ECB_TE); + scb_s->ecb3 &= ~ECB3_RI; + scb_s->ecd &= ~ECD_HOSTREGMGMT; +} + /* shadow (round up/down) the ibc to avoid validity icpt */ static void prepare_ibc(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) { @@ -448,7 +479,7 @@ static int shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 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); + 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; @@ -496,6 +527,11 @@ static int shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) scb_s->icpua = scb_o->icpua; + if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_ZARCH)) + new_prefix &= GUEST_PREFIX_MASK_ESA; + else + new_prefix &= GUEST_PREFIX_MASK_ZARCH; + 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 */ @@ -570,6 +606,9 @@ static int shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) scb_s->hpid = HPID_VSIE; scb_s->cpnc = scb_o->cpnc; + if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_ZARCH)) + shadow_esa(vcpu, vsie_page); + prepare_ibc(vcpu, vsie_page); rc = shadow_crycb(vcpu, vsie_page); out: @@ -578,28 +617,17 @@ out: return rc; } -void kvm_s390_vsie_gmap_notifier(struct gmap *gmap, unsigned long start, - unsigned long end) +void kvm_s390_vsie_gmap_notifier(struct gmap *gmap, gpa_t start, gpa_t end) { - struct kvm *kvm = gmap->private; - struct vsie_page *cur; + struct vsie_page *cur, *next; unsigned long prefix; - struct page *page; - int i; - if (!gmap_is_shadow(gmap)) - return; + KVM_BUG_ON(!test_bit(GMAP_FLAG_SHADOW, &gmap->flags), gmap->kvm); /* * 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; + list_for_each_entry_safe(cur, next, &gmap->scb_users, gmap_cache.list) { prefix = cur->scb_s.prefix << GUEST_PREFIX_SHIFT; /* with mso/msl, the prefix lies at an offset */ prefix += cur->scb_s.mso; @@ -620,7 +648,7 @@ void kvm_s390_vsie_gmap_notifier(struct gmap *gmap, unsigned long start, * - -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) +static int map_prefix(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page, struct gmap *sg) { struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; u64 prefix = scb_s->prefix << GUEST_PREFIX_SHIFT; @@ -635,10 +663,9 @@ static int map_prefix(struct kvm_vcpu *vcpu, struct vsie_page *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); + rc = gaccess_shadow_fault(vcpu, sg, prefix, NULL, true); if (!rc && (scb_s->ecb & ECB_TE)) - rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, - prefix + PAGE_SIZE, NULL); + rc = gaccess_shadow_fault(vcpu, sg, prefix + PAGE_SIZE, NULL, true); /* * We don't have to mprotect, we will be called for all unshadows. * SIE will detect if protection applies and trigger a validity. @@ -750,7 +777,7 @@ static int pin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 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)) + ((gpa + offsetof(struct bsca_block, cpu[0]) - 1) & PAGE_MASK)) rc = set_validity_icpt(scb_s, 0x003bU); if (!rc) { rc = pin_guest_page(vcpu->kvm, gpa, &hpa); @@ -919,8 +946,9 @@ static int inject_fault(struct kvm_vcpu *vcpu, __u16 code, __u64 vaddr, * - > 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) +static int handle_fault(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page, struct gmap *sg) { + bool wr = kvm_s390_cur_gmap_fault_is_write(); int rc; if ((current->thread.gmap_int_code & PGM_INT_CODE_MASK) == PGM_PROTECTION) @@ -928,12 +956,10 @@ static int handle_fault(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) return inject_fault(vcpu, PGM_PROTECTION, current->thread.gmap_teid.addr * PAGE_SIZE, 1); - rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, - current->thread.gmap_teid.addr * PAGE_SIZE, NULL); + rc = gaccess_shadow_fault(vcpu, sg, current->thread.gmap_teid.addr * PAGE_SIZE, NULL, wr); if (rc > 0) { rc = inject_fault(vcpu, rc, - current->thread.gmap_teid.addr * PAGE_SIZE, - kvm_s390_cur_gmap_fault_is_write()); + current->thread.gmap_teid.addr * PAGE_SIZE, wr); if (rc >= 0) vsie_page->fault_addr = current->thread.gmap_teid.addr * PAGE_SIZE; } @@ -946,12 +972,10 @@ static int handle_fault(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) * * 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) +static void handle_last_fault(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page, struct gmap *sg) { if (vsie_page->fault_addr) - kvm_s390_shadow_fault(vcpu, vsie_page->gmap, - vsie_page->fault_addr, NULL); + gaccess_shadow_fault(vcpu, sg, vsie_page->fault_addr, NULL, true); vsie_page->fault_addr = 0; } @@ -1033,11 +1057,12 @@ static u64 vsie_get_register(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page, } } -static int vsie_handle_mvpg(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) +static int vsie_handle_mvpg(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page, struct gmap *sg) { struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; - unsigned long pei_dest, pei_src, src, dest, mask, prefix; + unsigned long src, dest, mask, prefix; u64 *pei_block = &vsie_page->scb_o->mcic; + union mvpg_pei pei_dest, pei_src; int edat, rc_dest, rc_src; union ctlreg0 cr0; @@ -1051,8 +1076,8 @@ static int vsie_handle_mvpg(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 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); + rc_dest = gaccess_shadow_fault(vcpu, sg, dest, &pei_dest, true); + rc_src = gaccess_shadow_fault(vcpu, sg, src, &pei_src, false); /* * Either everything went well, or something non-critical went wrong * e.g. because of a race. In either case, simply retry. @@ -1087,8 +1112,8 @@ static int vsie_handle_mvpg(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 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; + pei_block[0] = pei_dest.val; + pei_block[1] = pei_src.val; return 1; } @@ -1112,16 +1137,17 @@ static int vsie_handle_mvpg(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) * - > 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) +static int do_vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page, struct gmap *sg) __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; + unsigned long sie_return = SIE64_RETURN_NORMAL; int guest_bp_isolation; int rc = 0; - handle_last_fault(vcpu, vsie_page); + handle_last_fault(vcpu, vsie_page, sg); kvm_vcpu_srcu_read_unlock(vcpu); @@ -1138,10 +1164,6 @@ static int do_vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 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 @@ -1151,31 +1173,44 @@ static int do_vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) vcpu->arch.sie_block->prog0c |= PROG_IN_SIE; current->thread.gmap_int_code = 0; barrier(); - if (!kvm_s390_vcpu_sie_inhibited(vcpu)) - rc = sie64a(scb_s, vcpu->run->s.regs.gprs, vsie_page->gmap->asce); + if (!kvm_s390_vcpu_sie_inhibited(vcpu)) { +xfer_to_guest_mode_check: + local_irq_disable(); + xfer_to_guest_mode_prepare(); + if (xfer_to_guest_mode_work_pending()) { + local_irq_enable(); + rc = kvm_xfer_to_guest_mode_handle_work(vcpu); + if (rc) + goto skip_sie; + goto xfer_to_guest_mode_check; + } + guest_timing_enter_irqoff(); + sie_return = kvm_s390_enter_exit_sie(scb_s, vcpu->run->s.regs.gprs, sg->asce.val); + guest_timing_exit_irqoff(); + local_irq_enable(); + } + +skip_sie: 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"); + if (sie_return == SIE64_RETURN_MCCK) { kvm_s390_reinject_machine_check(vcpu, &vsie_page->mcck_info); return 0; } + WARN_ON_ONCE(sie_return != SIE64_RETURN_NORMAL); + if (rc > 0) rc = 0; /* we could still have an icpt */ else if (current->thread.gmap_int_code) - return handle_fault(vcpu, vsie_page); + return handle_fault(vcpu, vsie_page, sg); switch (scb_s->icptcode) { case ICPT_INST: @@ -1193,7 +1228,7 @@ static int do_vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) break; case ICPT_PARTEXEC: if (scb_s->ipa == 0xb254) - rc = vsie_handle_mvpg(vcpu, vsie_page); + rc = vsie_handle_mvpg(vcpu, vsie_page, sg); break; } return rc; @@ -1201,43 +1236,67 @@ static int do_vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 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); + struct gmap *gmap = vsie_page->gmap_cache.gmap; + + lockdep_assert_held(&gmap->kvm->arch.gmap->children_lock); + + list_del(&vsie_page->gmap_cache.list); + vsie_page->gmap_cache.gmap = NULL; prefix_unmapped(vsie_page); + + if (list_empty(&gmap->scb_users)) { + gmap_remove_child(gmap); + gmap_put(gmap); + } } -static int acquire_gmap_shadow(struct kvm_vcpu *vcpu, - struct vsie_page *vsie_page) +static struct gmap *acquire_gmap_shadow(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) { - unsigned long asce; union ctlreg0 cr0; struct gmap *gmap; + union asce asce; int edat; - asce = vcpu->arch.sie_block->gcr[1]; + asce.val = 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)) { - vcpu->kvm->stat.gmap_shadow_reuse++; - return 0; + scoped_guard(spinlock, &vcpu->kvm->arch.gmap->children_lock) { + gmap = vsie_page->gmap_cache.gmap; + if (gmap) { + /* + * 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 (gmap_is_shadow_valid(gmap, asce, edat)) { + vcpu->kvm->stat.gmap_shadow_reuse++; + gmap_get(gmap); + return gmap; + } + /* release the old shadow and mark the prefix as unmapped */ + release_gmap_shadow(vsie_page); + } } - - /* 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); +again: + gmap = gmap_create_shadow(vcpu->arch.mc, vcpu->kvm->arch.gmap, asce, edat); if (IS_ERR(gmap)) - return PTR_ERR(gmap); - vcpu->kvm->stat.gmap_shadow_create++; - WRITE_ONCE(vsie_page->gmap, gmap); - return 0; + return gmap; + scoped_guard(spinlock, &vcpu->kvm->arch.gmap->children_lock) { + /* unlikely race condition, remove the previous shadow */ + if (vsie_page->gmap_cache.gmap) + release_gmap_shadow(vsie_page); + if (!gmap->parent) { + gmap_put(gmap); + goto again; + } + vcpu->kvm->stat.gmap_shadow_create++; + list_add(&vsie_page->gmap_cache.list, &gmap->scb_users); + vsie_page->gmap_cache.gmap = gmap; + prefix_unmapped(vsie_page); + } + return gmap; } /* @@ -1290,15 +1349,20 @@ static void unregister_shadow_scb(struct kvm_vcpu *vcpu) static int vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) { struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; + struct gmap *sg = NULL; int rc = 0; while (1) { - rc = acquire_gmap_shadow(vcpu, vsie_page); + sg = acquire_gmap_shadow(vcpu, vsie_page); + if (IS_ERR(sg)) { + rc = PTR_ERR(sg); + sg = NULL; + } if (!rc) - rc = map_prefix(vcpu, vsie_page); + rc = map_prefix(vcpu, vsie_page, sg); if (!rc) { update_intervention_requests(vsie_page); - rc = do_vsie_run(vcpu, vsie_page); + rc = do_vsie_run(vcpu, vsie_page, sg); } atomic_andnot(PROG_BLOCK_SIE, &scb_s->prog20); @@ -1316,14 +1380,17 @@ static int vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) * but rewind the PSW to re-enter SIE once that's completed * instead of passing a "no action" intercept to the guest. */ - if (signal_pending(current) || - kvm_s390_vcpu_has_irq(vcpu, 0) || + if (kvm_s390_vcpu_has_irq(vcpu, 0) || kvm_s390_vcpu_sie_inhibited(vcpu)) { kvm_s390_rewind_psw(vcpu, 4); break; } + if (sg) + sg = gmap_put(sg); cond_resched(); } + if (sg) + sg = gmap_put(sg); if (rc == -EFAULT) { /* @@ -1345,6 +1412,20 @@ static int vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) return rc; } +/* Try getting a given vsie page, returning "true" on success. */ +static inline bool try_get_vsie_page(struct vsie_page *vsie_page) +{ + if (test_bit(VSIE_PAGE_IN_USE, &vsie_page->flags)) + return false; + return !test_and_set_bit(VSIE_PAGE_IN_USE, &vsie_page->flags); +} + +/* Put a vsie page acquired through get_vsie_page / try_get_vsie_page. */ +static void put_vsie_page(struct vsie_page *vsie_page) +{ + clear_bit(VSIE_PAGE_IN_USE, &vsie_page->flags); +} + /* * Get or create a vsie page for a scb address. * @@ -1355,16 +1436,21 @@ static int vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 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); + vsie_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); + if (vsie_page) { + if (try_get_vsie_page(vsie_page)) { + if (vsie_page->scb_gpa == addr) + return vsie_page; + /* + * We raced with someone reusing + putting this vsie + * page before we grabbed it. + */ + put_vsie_page(vsie_page); + } } /* @@ -1375,51 +1461,51 @@ static struct vsie_page *get_vsie_page(struct kvm *kvm, unsigned long addr) 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) { + vsie_page = (void *)__get_free_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO | GFP_DMA); + if (!vsie_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; + __set_bit(VSIE_PAGE_IN_USE, &vsie_page->flags); + kvm->arch.vsie.pages[kvm->arch.vsie.page_count] = vsie_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) + vsie_page = kvm->arch.vsie.pages[kvm->arch.vsie.next]; + if (try_get_vsie_page(vsie_page)) 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); + if (vsie_page->scb_gpa != ULONG_MAX) + radix_tree_delete(&kvm->arch.vsie.addr_to_page, + vsie_page->scb_gpa >> 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); + /* Mark it as invalid until it resides in the tree. */ + vsie_page->scb_gpa = ULONG_MAX; + + /* Double use of the same address or allocation failure. */ + if (radix_tree_insert(&kvm->arch.vsie.addr_to_page, addr >> 9, vsie_page)) { + put_vsie_page(vsie_page); mutex_unlock(&kvm->arch.vsie.mutex); return NULL; } + vsie_page->scb_gpa = addr; 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); + if (vsie_page->gmap_cache.gmap) { + scoped_guard(spinlock, &kvm->arch.gmap->children_lock) + if (vsie_page->gmap_cache.gmap) + release_gmap_shadow(vsie_page); + } + prefix_unmapped(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; @@ -1439,18 +1525,19 @@ int kvm_s390_handle_vsie(struct kvm_vcpu *vcpu) 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)) { + if (kvm_s390_vcpu_has_irq(vcpu, 0) || kvm_s390_vcpu_sie_inhibited(vcpu)) { kvm_s390_rewind_psw(vcpu, 4); return 0; } vsie_page = get_vsie_page(vcpu->kvm, scb_addr); - if (IS_ERR(vsie_page)) + if (IS_ERR(vsie_page)) { return PTR_ERR(vsie_page); - else if (!vsie_page) + } else if (!vsie_page) { /* double use of sie control block - simply do nothing */ + kvm_s390_rewind_psw(vcpu, 4); return 0; + } rc = pin_scb(vcpu, vsie_page, scb_addr); if (rc) @@ -1470,7 +1557,7 @@ out_unshadow: out_unpin_scb: unpin_scb(vcpu, vsie_page, scb_addr); out_put: - put_vsie_page(vcpu->kvm, vsie_page); + put_vsie_page(vsie_page); return rc < 0 ? rc : 0; } @@ -1486,18 +1573,20 @@ void kvm_s390_vsie_init(struct kvm *kvm) 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]; + vsie_page = kvm->arch.vsie.pages[i]; + scoped_guard(spinlock, &kvm->arch.gmap->children_lock) + if (vsie_page->gmap_cache.gmap) + release_gmap_shadow(vsie_page); 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); + if (vsie_page->scb_gpa != ULONG_MAX) + radix_tree_delete(&kvm->arch.vsie.addr_to_page, + vsie_page->scb_gpa >> 9); + free_page((unsigned long)vsie_page); } kvm->arch.vsie.page_count = 0; mutex_unlock(&kvm->arch.vsie.mutex); |