diff options
author | Paolo Bonzini <pbonzini@redhat.com> | 2024-10-20 18:10:56 +0200 |
---|---|---|
committer | Paolo Bonzini <pbonzini@redhat.com> | 2024-10-20 18:10:56 +0200 |
commit | ddd5c5820116a04b5f95711518d3be922990b5ec (patch) | |
tree | e49db614cccc2db4ddb3973cbdb8973701e4d964 /arch | |
parent | RISCV: KVM: use raw_spinlock for critical section in imsic (diff) | |
parent | KVM: arm64: Don't eagerly teardown the vgic on init error (diff) | |
download | linux-ddd5c5820116a04b5f95711518d3be922990b5ec.tar.xz linux-ddd5c5820116a04b5f95711518d3be922990b5ec.zip |
Merge tag 'kvmarm-fixes-6.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 fixes for 6.12, take #2
- Fix the guest view of the ID registers, making the relevant fields
writable from userspace (affecting ID_AA64DFR0_EL1 and ID_AA64PFR1_EL1)
- Correcly expose S1PIE to guests, fixing a regression introduced
in 6.12-rc1 with the S1POE support
- Fix the recycling of stage-2 shadow MMUs by tracking the context
(are we allowed to block or not) as well as the recycling state
- Address a couple of issues with the vgic when userspace misconfigures
the emulation, resulting in various splats. Headaches courtesy
of our Syzkaller friends
Diffstat (limited to 'arch')
-rw-r--r-- | arch/arm64/include/asm/kvm_host.h | 7 | ||||
-rw-r--r-- | arch/arm64/include/asm/kvm_mmu.h | 3 | ||||
-rw-r--r-- | arch/arm64/include/asm/kvm_nested.h | 4 | ||||
-rw-r--r-- | arch/arm64/kvm/arm.c | 5 | ||||
-rw-r--r-- | arch/arm64/kvm/hypercalls.c | 12 | ||||
-rw-r--r-- | arch/arm64/kvm/mmu.c | 15 | ||||
-rw-r--r-- | arch/arm64/kvm/nested.c | 53 | ||||
-rw-r--r-- | arch/arm64/kvm/sys_regs.c | 75 | ||||
-rw-r--r-- | arch/arm64/kvm/vgic/vgic-init.c | 28 |
9 files changed, 170 insertions, 32 deletions
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 94cff508874b..bf64fed9820e 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -51,6 +51,7 @@ #define KVM_REQ_RELOAD_PMU KVM_ARCH_REQ(5) #define KVM_REQ_SUSPEND KVM_ARCH_REQ(6) #define KVM_REQ_RESYNC_PMU_EL0 KVM_ARCH_REQ(7) +#define KVM_REQ_NESTED_S2_UNMAP KVM_ARCH_REQ(8) #define KVM_DIRTY_LOG_MANUAL_CAPS (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE | \ KVM_DIRTY_LOG_INITIALLY_SET) @@ -212,6 +213,12 @@ struct kvm_s2_mmu { bool nested_stage2_enabled; /* + * true when this MMU needs to be unmapped before being used for a new + * purpose. + */ + bool pending_unmap; + + /* * 0: Nobody is currently using this, check vttbr for validity * >0: Somebody is actively using this. */ diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index cd4087fbda9a..66d93e320ec8 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -166,7 +166,8 @@ int create_hyp_exec_mappings(phys_addr_t phys_addr, size_t size, int create_hyp_stack(phys_addr_t phys_addr, unsigned long *haddr); void __init free_hyp_pgds(void); -void kvm_stage2_unmap_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size); +void kvm_stage2_unmap_range(struct kvm_s2_mmu *mmu, phys_addr_t start, + u64 size, bool may_block); void kvm_stage2_flush_range(struct kvm_s2_mmu *mmu, phys_addr_t addr, phys_addr_t end); void kvm_stage2_wp_range(struct kvm_s2_mmu *mmu, phys_addr_t addr, phys_addr_t end); diff --git a/arch/arm64/include/asm/kvm_nested.h b/arch/arm64/include/asm/kvm_nested.h index e8bc6d67aba2..233e65522716 100644 --- a/arch/arm64/include/asm/kvm_nested.h +++ b/arch/arm64/include/asm/kvm_nested.h @@ -78,6 +78,8 @@ extern void kvm_s2_mmu_iterate_by_vmid(struct kvm *kvm, u16 vmid, extern void kvm_vcpu_load_hw_mmu(struct kvm_vcpu *vcpu); extern void kvm_vcpu_put_hw_mmu(struct kvm_vcpu *vcpu); +extern void check_nested_vcpu_requests(struct kvm_vcpu *vcpu); + struct kvm_s2_trans { phys_addr_t output; unsigned long block_size; @@ -124,7 +126,7 @@ extern int kvm_s2_handle_perm_fault(struct kvm_vcpu *vcpu, struct kvm_s2_trans *trans); extern int kvm_inject_s2_fault(struct kvm_vcpu *vcpu, u64 esr_el2); extern void kvm_nested_s2_wp(struct kvm *kvm); -extern void kvm_nested_s2_unmap(struct kvm *kvm); +extern void kvm_nested_s2_unmap(struct kvm *kvm, bool may_block); extern void kvm_nested_s2_flush(struct kvm *kvm); unsigned long compute_tlb_inval_range(struct kvm_s2_mmu *mmu, u64 val); diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index a0d01c46e408..48cafb65d6ac 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -997,6 +997,9 @@ static int kvm_vcpu_suspend(struct kvm_vcpu *vcpu) static int check_vcpu_requests(struct kvm_vcpu *vcpu) { if (kvm_request_pending(vcpu)) { + if (kvm_check_request(KVM_REQ_VM_DEAD, vcpu)) + return -EIO; + if (kvm_check_request(KVM_REQ_SLEEP, vcpu)) kvm_vcpu_sleep(vcpu); @@ -1031,6 +1034,8 @@ static int check_vcpu_requests(struct kvm_vcpu *vcpu) if (kvm_dirty_ring_check_request(vcpu)) return 0; + + check_nested_vcpu_requests(vcpu); } return 1; diff --git a/arch/arm64/kvm/hypercalls.c b/arch/arm64/kvm/hypercalls.c index 5763d979d8ca..ee6573befb81 100644 --- a/arch/arm64/kvm/hypercalls.c +++ b/arch/arm64/kvm/hypercalls.c @@ -317,7 +317,7 @@ int kvm_smccc_call_handler(struct kvm_vcpu *vcpu) * to the guest, and hide SSBS so that the * guest stays protected. */ - if (cpus_have_final_cap(ARM64_SSBS)) + if (kvm_has_feat(vcpu->kvm, ID_AA64PFR1_EL1, SSBS, IMP)) break; fallthrough; case SPECTRE_UNAFFECTED: @@ -428,7 +428,7 @@ int kvm_arm_copy_fw_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices) * Convert the workaround level into an easy-to-compare number, where higher * values mean better protection. */ -static int get_kernel_wa_level(u64 regid) +static int get_kernel_wa_level(struct kvm_vcpu *vcpu, u64 regid) { switch (regid) { case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1: @@ -449,7 +449,7 @@ static int get_kernel_wa_level(u64 regid) * don't have any FW mitigation if SSBS is there at * all times. */ - if (cpus_have_final_cap(ARM64_SSBS)) + if (kvm_has_feat(vcpu->kvm, ID_AA64PFR1_EL1, SSBS, IMP)) return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_AVAIL; fallthrough; case SPECTRE_UNAFFECTED: @@ -486,7 +486,7 @@ int kvm_arm_get_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1: case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2: case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3: - val = get_kernel_wa_level(reg->id) & KVM_REG_FEATURE_LEVEL_MASK; + val = get_kernel_wa_level(vcpu, reg->id) & KVM_REG_FEATURE_LEVEL_MASK; break; case KVM_REG_ARM_STD_BMAP: val = READ_ONCE(smccc_feat->std_bmap); @@ -588,7 +588,7 @@ int kvm_arm_set_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) if (val & ~KVM_REG_FEATURE_LEVEL_MASK) return -EINVAL; - if (get_kernel_wa_level(reg->id) < val) + if (get_kernel_wa_level(vcpu, reg->id) < val) return -EINVAL; return 0; @@ -624,7 +624,7 @@ int kvm_arm_set_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) * We can deal with NOT_AVAIL on NOT_REQUIRED, but not the * other way around. */ - if (get_kernel_wa_level(reg->id) < wa_level) + if (get_kernel_wa_level(vcpu, reg->id) < wa_level) return -EINVAL; return 0; diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index a509b63bd4dd..0f7658aefa1a 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -328,9 +328,10 @@ static void __unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 may_block)); } -void kvm_stage2_unmap_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size) +void kvm_stage2_unmap_range(struct kvm_s2_mmu *mmu, phys_addr_t start, + u64 size, bool may_block) { - __unmap_stage2_range(mmu, start, size, true); + __unmap_stage2_range(mmu, start, size, may_block); } void kvm_stage2_flush_range(struct kvm_s2_mmu *mmu, phys_addr_t addr, phys_addr_t end) @@ -1015,7 +1016,7 @@ static void stage2_unmap_memslot(struct kvm *kvm, if (!(vma->vm_flags & VM_PFNMAP)) { gpa_t gpa = addr + (vm_start - memslot->userspace_addr); - kvm_stage2_unmap_range(&kvm->arch.mmu, gpa, vm_end - vm_start); + kvm_stage2_unmap_range(&kvm->arch.mmu, gpa, vm_end - vm_start, true); } hva = vm_end; } while (hva < reg_end); @@ -1042,7 +1043,7 @@ void stage2_unmap_vm(struct kvm *kvm) kvm_for_each_memslot(memslot, bkt, slots) stage2_unmap_memslot(kvm, memslot); - kvm_nested_s2_unmap(kvm); + kvm_nested_s2_unmap(kvm, true); write_unlock(&kvm->mmu_lock); mmap_read_unlock(current->mm); @@ -1912,7 +1913,7 @@ bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) (range->end - range->start) << PAGE_SHIFT, range->may_block); - kvm_nested_s2_unmap(kvm); + kvm_nested_s2_unmap(kvm, range->may_block); return false; } @@ -2179,8 +2180,8 @@ void kvm_arch_flush_shadow_memslot(struct kvm *kvm, phys_addr_t size = slot->npages << PAGE_SHIFT; write_lock(&kvm->mmu_lock); - kvm_stage2_unmap_range(&kvm->arch.mmu, gpa, size); - kvm_nested_s2_unmap(kvm); + kvm_stage2_unmap_range(&kvm->arch.mmu, gpa, size, true); + kvm_nested_s2_unmap(kvm, true); write_unlock(&kvm->mmu_lock); } diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c index f9e30dd34c7a..c4b17d90fc49 100644 --- a/arch/arm64/kvm/nested.c +++ b/arch/arm64/kvm/nested.c @@ -632,9 +632,9 @@ static struct kvm_s2_mmu *get_s2_mmu_nested(struct kvm_vcpu *vcpu) /* Set the scene for the next search */ kvm->arch.nested_mmus_next = (i + 1) % kvm->arch.nested_mmus_size; - /* Clear the old state */ + /* Make sure we don't forget to do the laundry */ if (kvm_s2_mmu_valid(s2_mmu)) - kvm_stage2_unmap_range(s2_mmu, 0, kvm_phys_size(s2_mmu)); + s2_mmu->pending_unmap = true; /* * The virtual VMID (modulo CnP) will be used as a key when matching @@ -650,6 +650,16 @@ static struct kvm_s2_mmu *get_s2_mmu_nested(struct kvm_vcpu *vcpu) out: atomic_inc(&s2_mmu->refcnt); + + /* + * Set the vCPU request to perform an unmap, even if the pending unmap + * originates from another vCPU. This guarantees that the MMU has been + * completely unmapped before any vCPU actually uses it, and allows + * multiple vCPUs to lend a hand with completing the unmap. + */ + if (s2_mmu->pending_unmap) + kvm_make_request(KVM_REQ_NESTED_S2_UNMAP, vcpu); + return s2_mmu; } @@ -663,6 +673,13 @@ void kvm_init_nested_s2_mmu(struct kvm_s2_mmu *mmu) void kvm_vcpu_load_hw_mmu(struct kvm_vcpu *vcpu) { + /* + * The vCPU kept its reference on the MMU after the last put, keep + * rolling with it. + */ + if (vcpu->arch.hw_mmu) + return; + if (is_hyp_ctxt(vcpu)) { vcpu->arch.hw_mmu = &vcpu->kvm->arch.mmu; } else { @@ -674,10 +691,18 @@ void kvm_vcpu_load_hw_mmu(struct kvm_vcpu *vcpu) void kvm_vcpu_put_hw_mmu(struct kvm_vcpu *vcpu) { - if (kvm_is_nested_s2_mmu(vcpu->kvm, vcpu->arch.hw_mmu)) { + /* + * Keep a reference on the associated stage-2 MMU if the vCPU is + * scheduling out and not in WFI emulation, suggesting it is likely to + * reuse the MMU sometime soon. + */ + if (vcpu->scheduled_out && !vcpu_get_flag(vcpu, IN_WFI)) + return; + + if (kvm_is_nested_s2_mmu(vcpu->kvm, vcpu->arch.hw_mmu)) atomic_dec(&vcpu->arch.hw_mmu->refcnt); - vcpu->arch.hw_mmu = NULL; - } + + vcpu->arch.hw_mmu = NULL; } /* @@ -730,7 +755,7 @@ void kvm_nested_s2_wp(struct kvm *kvm) } } -void kvm_nested_s2_unmap(struct kvm *kvm) +void kvm_nested_s2_unmap(struct kvm *kvm, bool may_block) { int i; @@ -740,7 +765,7 @@ void kvm_nested_s2_unmap(struct kvm *kvm) struct kvm_s2_mmu *mmu = &kvm->arch.nested_mmus[i]; if (kvm_s2_mmu_valid(mmu)) - kvm_stage2_unmap_range(mmu, 0, kvm_phys_size(mmu)); + kvm_stage2_unmap_range(mmu, 0, kvm_phys_size(mmu), may_block); } } @@ -1184,3 +1209,17 @@ int kvm_init_nv_sysregs(struct kvm *kvm) return 0; } + +void check_nested_vcpu_requests(struct kvm_vcpu *vcpu) +{ + if (kvm_check_request(KVM_REQ_NESTED_S2_UNMAP, vcpu)) { + struct kvm_s2_mmu *mmu = vcpu->arch.hw_mmu; + + write_lock(&vcpu->kvm->mmu_lock); + if (mmu->pending_unmap) { + kvm_stage2_unmap_range(mmu, 0, kvm_phys_size(mmu), true); + mmu->pending_unmap = false; + } + write_unlock(&vcpu->kvm->mmu_lock); + } +} diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index dad88e31f953..375052d8cd22 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1527,6 +1527,14 @@ static u64 __kvm_read_sanitised_id_reg(const struct kvm_vcpu *vcpu, val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_MTE); val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_SME); + val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_RNDR_trap); + val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_NMI); + val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_MTE_frac); + val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_GCS); + val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_THE); + val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_MTEX); + val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_DF2); + val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_PFAR); break; case SYS_ID_AA64PFR2_EL1: /* We only expose FPMR */ @@ -1550,7 +1558,8 @@ static u64 __kvm_read_sanitised_id_reg(const struct kvm_vcpu *vcpu, val &= ~ID_AA64MMFR2_EL1_CCIDX_MASK; break; case SYS_ID_AA64MMFR3_EL1: - val &= ID_AA64MMFR3_EL1_TCRX | ID_AA64MMFR3_EL1_S1POE; + val &= ID_AA64MMFR3_EL1_TCRX | ID_AA64MMFR3_EL1_S1POE | + ID_AA64MMFR3_EL1_S1PIE; break; case SYS_ID_MMFR4_EL1: val &= ~ARM64_FEATURE_MASK(ID_MMFR4_EL1_CCIDX); @@ -2376,7 +2385,19 @@ static const struct sys_reg_desc sys_reg_descs[] = { ID_AA64PFR0_EL1_RAS | ID_AA64PFR0_EL1_AdvSIMD | ID_AA64PFR0_EL1_FP), }, - ID_SANITISED(ID_AA64PFR1_EL1), + ID_WRITABLE(ID_AA64PFR1_EL1, ~(ID_AA64PFR1_EL1_PFAR | + ID_AA64PFR1_EL1_DF2 | + ID_AA64PFR1_EL1_MTEX | + ID_AA64PFR1_EL1_THE | + ID_AA64PFR1_EL1_GCS | + ID_AA64PFR1_EL1_MTE_frac | + ID_AA64PFR1_EL1_NMI | + ID_AA64PFR1_EL1_RNDR_trap | + ID_AA64PFR1_EL1_SME | + ID_AA64PFR1_EL1_RES0 | + ID_AA64PFR1_EL1_MPAM_frac | + ID_AA64PFR1_EL1_RAS_frac | + ID_AA64PFR1_EL1_MTE)), ID_WRITABLE(ID_AA64PFR2_EL1, ID_AA64PFR2_EL1_FPMR), ID_UNALLOCATED(4,3), ID_WRITABLE(ID_AA64ZFR0_EL1, ~ID_AA64ZFR0_EL1_RES0), @@ -2390,7 +2411,21 @@ static const struct sys_reg_desc sys_reg_descs[] = { .get_user = get_id_reg, .set_user = set_id_aa64dfr0_el1, .reset = read_sanitised_id_aa64dfr0_el1, - .val = ID_AA64DFR0_EL1_PMUVer_MASK | + /* + * Prior to FEAT_Debugv8.9, the architecture defines context-aware + * breakpoints (CTX_CMPs) as the highest numbered breakpoints (BRPs). + * KVM does not trap + emulate the breakpoint registers, and as such + * cannot support a layout that misaligns with the underlying hardware. + * While it may be possible to describe a subset that aligns with + * hardware, just prevent changes to BRPs and CTX_CMPs altogether for + * simplicity. + * + * See DDI0487K.a, section D2.8.3 Breakpoint types and linking + * of breakpoints for more details. + */ + .val = ID_AA64DFR0_EL1_DoubleLock_MASK | + ID_AA64DFR0_EL1_WRPs_MASK | + ID_AA64DFR0_EL1_PMUVer_MASK | ID_AA64DFR0_EL1_DebugVer_MASK, }, ID_SANITISED(ID_AA64DFR1_EL1), ID_UNALLOCATED(5,2), @@ -2433,6 +2468,7 @@ static const struct sys_reg_desc sys_reg_descs[] = { ID_AA64MMFR2_EL1_NV | ID_AA64MMFR2_EL1_CCIDX)), ID_WRITABLE(ID_AA64MMFR3_EL1, (ID_AA64MMFR3_EL1_TCRX | + ID_AA64MMFR3_EL1_S1PIE | ID_AA64MMFR3_EL1_S1POE)), ID_SANITISED(ID_AA64MMFR4_EL1), ID_UNALLOCATED(7,5), @@ -2903,7 +2939,7 @@ static bool handle_alle1is(struct kvm_vcpu *vcpu, struct sys_reg_params *p, * Drop all shadow S2s, resulting in S1/S2 TLBIs for each of the * corresponding VMIDs. */ - kvm_nested_s2_unmap(vcpu->kvm); + kvm_nested_s2_unmap(vcpu->kvm, true); write_unlock(&vcpu->kvm->mmu_lock); @@ -2955,7 +2991,30 @@ union tlbi_info { static void s2_mmu_unmap_range(struct kvm_s2_mmu *mmu, const union tlbi_info *info) { - kvm_stage2_unmap_range(mmu, info->range.start, info->range.size); + /* + * The unmap operation is allowed to drop the MMU lock and block, which + * means that @mmu could be used for a different context than the one + * currently being invalidated. + * + * This behavior is still safe, as: + * + * 1) The vCPU(s) that recycled the MMU are responsible for invalidating + * the entire MMU before reusing it, which still honors the intent + * of a TLBI. + * + * 2) Until the guest TLBI instruction is 'retired' (i.e. increment PC + * and ERET to the guest), other vCPUs are allowed to use stale + * translations. + * + * 3) Accidentally unmapping an unrelated MMU context is nonfatal, and + * at worst may cause more aborts for shadow stage-2 fills. + * + * Dropping the MMU lock also implies that shadow stage-2 fills could + * happen behind the back of the TLBI. This is still safe, though, as + * the L1 needs to put its stage-2 in a consistent state before doing + * the TLBI. + */ + kvm_stage2_unmap_range(mmu, info->range.start, info->range.size, true); } static bool handle_vmalls12e1is(struct kvm_vcpu *vcpu, struct sys_reg_params *p, @@ -3050,7 +3109,11 @@ static void s2_mmu_unmap_ipa(struct kvm_s2_mmu *mmu, max_size = compute_tlb_inval_range(mmu, info->ipa.addr); base_addr &= ~(max_size - 1); - kvm_stage2_unmap_range(mmu, base_addr, max_size); + /* + * See comment in s2_mmu_unmap_range() for why this is allowed to + * reschedule. + */ + kvm_stage2_unmap_range(mmu, base_addr, max_size, true); } static bool handle_ipas2e1is(struct kvm_vcpu *vcpu, struct sys_reg_params *p, diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c index e7c53e8af3d1..d88fdeaf6144 100644 --- a/arch/arm64/kvm/vgic/vgic-init.c +++ b/arch/arm64/kvm/vgic/vgic-init.c @@ -417,8 +417,28 @@ static void __kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu) kfree(vgic_cpu->private_irqs); vgic_cpu->private_irqs = NULL; - if (vcpu->kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3) + if (vcpu->kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3) { + /* + * If this vCPU is being destroyed because of a failed creation + * then unregister the redistributor to avoid leaving behind a + * dangling pointer to the vCPU struct. + * + * vCPUs that have been successfully created (i.e. added to + * kvm->vcpu_array) get unregistered in kvm_vgic_destroy(), as + * this function gets called while holding kvm->arch.config_lock + * in the VM teardown path and would otherwise introduce a lock + * inversion w.r.t. kvm->srcu. + * + * vCPUs that failed creation are torn down outside of the + * kvm->arch.config_lock and do not get unregistered in + * kvm_vgic_destroy(), meaning it is both safe and necessary to + * do so here. + */ + if (kvm_get_vcpu_by_id(vcpu->kvm, vcpu->vcpu_id) != vcpu) + vgic_unregister_redist_iodev(vcpu); + vgic_cpu->rd_iodev.base_addr = VGIC_ADDR_UNDEF; + } } void kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu) @@ -536,10 +556,10 @@ int kvm_vgic_map_resources(struct kvm *kvm) out: mutex_unlock(&kvm->arch.config_lock); out_slots: - mutex_unlock(&kvm->slots_lock); - if (ret) - kvm_vgic_destroy(kvm); + kvm_vm_dead(kvm); + + mutex_unlock(&kvm->slots_lock); return ret; } |