From: Avi Kivity <avi@redhat.com>
To: stable@vger.kernel.org
Cc: Marcelo Tosatti <mtosatti@redhat.com>, kvm@vger.kernel.org
Subject: [PATCH 06/11] KVM: Ensure all vcpus are consistent with in-kernel irqchip settings
Date: Wed, 9 May 2012 16:10:42 +0300 [thread overview]
Message-ID: <1336569047-23576-7-git-send-email-avi@redhat.com> (raw)
In-Reply-To: <1336569047-23576-1-git-send-email-avi@redhat.com>
If some vcpus are created before KVM_CREATE_IRQCHIP, then
irqchip_in_kernel() and vcpu->arch.apic will be inconsistent, leading
to potential NULL pointer dereferences.
Fix by:
- ensuring that no vcpus are installed when KVM_CREATE_IRQCHIP is called
- ensuring that a vcpu has an apic if it is installed after KVM_CREATE_IRQCHIP
This is somewhat long winded because vcpu->arch.apic is created without
kvm->lock held.
Based on earlier patch by Michael Ellerman.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Avi Kivity <avi@redhat.com>
(cherry picked from commit 3e515705a1f46beb1c942bb8043c16f8ac7b1e9e)
---
arch/ia64/kvm/kvm-ia64.c | 5 +++++
arch/x86/kvm/x86.c | 8 ++++++++
include/linux/kvm_host.h | 7 +++++++
virt/kvm/kvm_main.c | 4 ++++
4 files changed, 24 insertions(+)
diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
index 4050520..8c25855 100644
--- a/arch/ia64/kvm/kvm-ia64.c
+++ b/arch/ia64/kvm/kvm-ia64.c
@@ -1169,6 +1169,11 @@ static enum hrtimer_restart hlt_timer_fn(struct hrtimer *data)
#define PALE_RESET_ENTRY 0x80000000ffffffb0UL
+bool kvm_vcpu_compatible(struct kvm_vcpu *vcpu)
+{
+ return irqchip_in_kernel(vcpu->kcm) == (vcpu->arch.apic != NULL);
+}
+
int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
{
struct kvm_vcpu *v;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 410b6b0..8d1c6c6 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3131,6 +3131,9 @@ long kvm_arch_vm_ioctl(struct file *filp,
r = -EEXIST;
if (kvm->arch.vpic)
goto create_irqchip_unlock;
+ r = -EINVAL;
+ if (atomic_read(&kvm->online_vcpus))
+ goto create_irqchip_unlock;
r = -ENOMEM;
vpic = kvm_create_pic(kvm);
if (vpic) {
@@ -5956,6 +5959,11 @@ void kvm_arch_check_processor_compat(void *rtn)
kvm_x86_ops->check_processor_compatibility(rtn);
}
+bool kvm_vcpu_compatible(struct kvm_vcpu *vcpu)
+{
+ return irqchip_in_kernel(vcpu->kvm) == (vcpu->arch.apic != NULL);
+}
+
int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
{
struct page *page;
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index bc21720..4c4e83d 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -775,6 +775,13 @@ static inline bool kvm_vcpu_is_bsp(struct kvm_vcpu *vcpu)
{
return vcpu->kvm->bsp_vcpu_id == vcpu->vcpu_id;
}
+
+bool kvm_vcpu_compatible(struct kvm_vcpu *vcpu);
+
+#else
+
+static inline bool kvm_vcpu_compatible(struct kvm_vcpu *vcpu) { return true; }
+
#endif
#ifdef __KVM_HAVE_DEVICE_ASSIGNMENT
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 4c68c1e..7858228 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1720,6 +1720,10 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
goto vcpu_destroy;
mutex_lock(&kvm->lock);
+ if (!kvm_vcpu_compatible(vcpu)) {
+ r = -EINVAL;
+ goto unlock_vcpu_destroy;
+ }
if (atomic_read(&kvm->online_vcpus) == KVM_MAX_VCPUS) {
r = -EINVAL;
goto unlock_vcpu_destroy;
--
1.7.10.1
next prev parent reply other threads:[~2012-05-09 13:11 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-09 13:10 [PATCH 00/11] KVM fixes for 3.3.5 Avi Kivity
2012-05-09 13:10 ` [PATCH 01/11] KVM: s390: do store status after handling STOP_ON_STOP bit Avi Kivity
2012-05-09 13:10 ` [PATCH 02/11] KVM: s390: Sanitize fpc registers for KVM_SET_FPU Avi Kivity
2012-05-09 13:10 ` [PATCH 03/11] KVM: Fix write protection race during dirty logging Avi Kivity
2012-05-09 13:10 ` [PATCH 04/11] KVM: mmu_notifier: Flush TLBs before releasing mmu_lock Avi Kivity
2012-05-09 13:10 ` [PATCH 05/11] KVM: x86 emulator: correctly mask pmc index bits in RDPMC instruction emulation Avi Kivity
2012-05-09 13:10 ` Avi Kivity [this message]
2012-05-09 13:10 ` [PATCH 07/11] KVM: VMX: Fix delayed load of shared MSRs Avi Kivity
2012-05-09 13:10 ` [PATCH 08/11] KVM: nVMX: Fix erroneous exception bitmap check Avi Kivity
2012-05-09 13:10 ` [PATCH 09/11] KVM: VMX: vmx_set_cr0 expects kvm->srcu locked Avi Kivity
2012-05-09 13:10 ` [PATCH 10/11] KVM: VMX: Fix kvm_set_shared_msr() called in preemptible context Avi Kivity
2012-05-09 13:10 ` [PATCH 11/11] KVM: lock slots_lock around device assignment Avi Kivity
2012-05-10 16:28 ` [PATCH 00/11] KVM fixes for 3.3.5 Greg KH
2012-05-12 0:35 ` Ben Hutchings
2012-05-13 9:23 ` Avi Kivity
2012-05-13 10:19 ` Ben Hutchings
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