diff options
| -rw-r--r-- | Documentation/virtual/kvm/locking.txt | 8 | ||||
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/hyperv.c | 24 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 1 |
4 files changed, 23 insertions, 11 deletions
diff --git a/Documentation/virtual/kvm/locking.txt b/Documentation/virtual/kvm/locking.txt index e5dd9f4d6100..fd013bf4115b 100644 --- a/Documentation/virtual/kvm/locking.txt +++ b/Documentation/virtual/kvm/locking.txt @@ -13,8 +13,12 @@ The acquisition orders for mutexes are as follows: - kvm->slots_lock is taken outside kvm->irq_lock, though acquiring them together is quite rare. -For spinlocks, kvm_lock is taken outside kvm->mmu_lock. Everything -else is a leaf: no other lock is taken inside the critical sections. +On x86, vcpu->mutex is taken outside kvm->arch.hyperv.hv_lock. + +For spinlocks, kvm_lock is taken outside kvm->mmu_lock. + +Everything else is a leaf: no other lock is taken inside the critical +sections. 2: Exception ------------ diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 7892530cbacf..2e25038dbd93 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -704,6 +704,7 @@ struct kvm_apic_map { /* Hyper-V emulation context */ struct kvm_hv { + struct mutex hv_lock; u64 hv_guest_os_id; u64 hv_hypercall; u64 hv_tsc_page; diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index 99cde5220e07..1572c35b4f1a 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -852,6 +852,10 @@ void kvm_hv_setup_tsc_page(struct kvm *kvm, if (!(hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE)) return; + mutex_lock(&kvm->arch.hyperv.hv_lock); + if (!(hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE)) + goto out_unlock; + gfn = hv->hv_tsc_page >> HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT; /* * Because the TSC parameters only vary when there is a @@ -859,7 +863,7 @@ void kvm_hv_setup_tsc_page(struct kvm *kvm, */ if (unlikely(kvm_read_guest(kvm, gfn_to_gpa(gfn), &tsc_seq, sizeof(tsc_seq)))) - return; + goto out_unlock; /* * While we're computing and writing the parameters, force the @@ -868,15 +872,15 @@ void kvm_hv_setup_tsc_page(struct kvm *kvm, hv->tsc_ref.tsc_sequence = 0; if (kvm_write_guest(kvm, gfn_to_gpa(gfn), &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence))) - return; + goto out_unlock; if (!compute_tsc_page_parameters(hv_clock, &hv->tsc_ref)) - return; + goto out_unlock; /* Ensure sequence is zero before writing the rest of the struct. */ smp_wmb(); if (kvm_write_guest(kvm, gfn_to_gpa(gfn), &hv->tsc_ref, sizeof(hv->tsc_ref))) - return; + goto out_unlock; /* * Now switch to the TSC page mechanism by writing the sequence. @@ -891,6 +895,8 @@ void kvm_hv_setup_tsc_page(struct kvm *kvm, hv->tsc_ref.tsc_sequence = tsc_seq; kvm_write_guest(kvm, gfn_to_gpa(gfn), &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence)); +out_unlock: + mutex_unlock(&kvm->arch.hyperv.hv_lock); } static int kvm_hv_set_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data, @@ -1142,9 +1148,9 @@ int kvm_hv_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host) if (kvm_hv_msr_partition_wide(msr)) { int r; - mutex_lock(&vcpu->kvm->lock); + mutex_lock(&vcpu->kvm->arch.hyperv.hv_lock); r = kvm_hv_set_msr_pw(vcpu, msr, data, host); - mutex_unlock(&vcpu->kvm->lock); + mutex_unlock(&vcpu->kvm->arch.hyperv.hv_lock); return r; } else return kvm_hv_set_msr(vcpu, msr, data, host); @@ -1155,9 +1161,9 @@ int kvm_hv_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata) if (kvm_hv_msr_partition_wide(msr)) { int r; - mutex_lock(&vcpu->kvm->lock); + mutex_lock(&vcpu->kvm->arch.hyperv.hv_lock); r = kvm_hv_get_msr_pw(vcpu, msr, pdata); - mutex_unlock(&vcpu->kvm->lock); + mutex_unlock(&vcpu->kvm->arch.hyperv.hv_lock); return r; } else return kvm_hv_get_msr(vcpu, msr, pdata); @@ -1165,7 +1171,7 @@ int kvm_hv_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata) bool kvm_hv_hypercall_enabled(struct kvm *kvm) { - return kvm->arch.hyperv.hv_hypercall & HV_X64_MSR_HYPERCALL_ENABLE; + return READ_ONCE(kvm->arch.hyperv.hv_hypercall) & HV_X64_MSR_HYPERCALL_ENABLE; } static void kvm_hv_hypercall_set_result(struct kvm_vcpu *vcpu, u64 result) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 1f0d2383f5ee..49da1064ef50 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -7881,6 +7881,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) raw_spin_lock_init(&kvm->arch.tsc_write_lock); mutex_init(&kvm->arch.apic_map_lock); + mutex_init(&kvm->arch.hyperv.hv_lock); spin_lock_init(&kvm->arch.pvclock_gtod_sync_lock); kvm->arch.kvmclock_offset = -ktime_get_boot_ns(); |