* [PATCH] kvm: x86: move tracepoints outside extended quiescent state
@ 2015-12-10 17:38 Paolo Bonzini
2015-12-10 18:09 ` Borislav Petkov
0 siblings, 1 reply; 3+ messages in thread
From: Paolo Bonzini @ 2015-12-10 17:38 UTC (permalink / raw)
To: linux-kernel, kvm; +Cc: bp, stable
Invoking tracepoints within kvm_guest_enter/kvm_guest_exit causes a
lockdep splat.
Cc: stable@vger.kernel.org
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/kvm/svm.c | 4 ++--
arch/x86/kvm/vmx.c | 3 ++-
arch/x86/kvm/x86.c | 2 +-
3 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 83a1c643f9a5..899c40f826dd 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -3422,6 +3422,8 @@ static int handle_exit(struct kvm_vcpu *vcpu)
struct kvm_run *kvm_run = vcpu->run;
u32 exit_code = svm->vmcb->control.exit_code;
+ trace_kvm_exit(exit_code, vcpu, KVM_ISA_SVM);
+
if (!is_cr_intercept(svm, INTERCEPT_CR0_WRITE))
vcpu->arch.cr0 = svm->vmcb->save.cr0;
if (npt_enabled)
@@ -3892,8 +3894,6 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu)
vcpu->arch.regs[VCPU_REGS_RSP] = svm->vmcb->save.rsp;
vcpu->arch.regs[VCPU_REGS_RIP] = svm->vmcb->save.rip;
- trace_kvm_exit(svm->vmcb->control.exit_code, vcpu, KVM_ISA_SVM);
-
if (unlikely(svm->vmcb->control.exit_code == SVM_EXIT_NMI))
kvm_before_handle_nmi(&svm->vcpu);
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index af823a388c19..6b5605607849 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -8042,6 +8042,8 @@ static int vmx_handle_exit(struct kvm_vcpu *vcpu)
u32 exit_reason = vmx->exit_reason;
u32 vectoring_info = vmx->idt_vectoring_info;
+ trace_kvm_exit(exit_reason, vcpu, KVM_ISA_VMX);
+
/*
* Flush logged GPAs PML buffer, this will make dirty_bitmap more
* updated. Another good is, in kvm_vm_ioctl_get_dirty_log, before
@@ -8668,7 +8670,6 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
vmx->loaded_vmcs->launched = 1;
vmx->exit_reason = vmcs_read32(VM_EXIT_REASON);
- trace_kvm_exit(vmx->exit_reason, vcpu, KVM_ISA_VMX);
/*
* the KVM_REQ_EVENT optimization bit is only on for one entry, and if
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index eed32283d22c..2a8c035ec7fe 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6515,6 +6515,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
if (req_immediate_exit)
smp_send_reschedule(vcpu->cpu);
+ trace_kvm_entry(vcpu->vcpu_id);
__kvm_guest_enter();
if (unlikely(vcpu->arch.switch_db_regs)) {
@@ -6527,7 +6528,6 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
vcpu->arch.switch_db_regs &= ~KVM_DEBUGREG_RELOAD;
}
- trace_kvm_entry(vcpu->vcpu_id);
wait_lapic_expire(vcpu);
kvm_x86_ops->run(vcpu);
--
1.8.3.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] kvm: x86: move tracepoints outside extended quiescent state
2015-12-10 17:38 [PATCH] kvm: x86: move tracepoints outside extended quiescent state Paolo Bonzini
@ 2015-12-10 18:09 ` Borislav Petkov
2015-12-10 18:15 ` Paolo Bonzini
0 siblings, 1 reply; 3+ messages in thread
From: Borislav Petkov @ 2015-12-10 18:09 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: linux-kernel, kvm, stable
On Thu, Dec 10, 2015 at 06:38:57PM +0100, Paolo Bonzini wrote:
> Invoking tracepoints within kvm_guest_enter/kvm_guest_exit causes a
> lockdep splat.
>
> Cc: stable@vger.kernel.org
> Reported-by: Borislav Petkov <bp@alien8.de>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
> arch/x86/kvm/svm.c | 4 ++--
> arch/x86/kvm/vmx.c | 3 ++-
> arch/x86/kvm/x86.c | 2 +-
> 3 files changed, 5 insertions(+), 4 deletions(-)
Looks like you missed some...
[ 144.296364] kvm: zapping shadow pages for mmio generation wraparound
[ 164.699053] kvm: zapping shadow pages for mmio generation wraparound
[ 312.115767] kvm: zapping shadow pages for mmio generation wraparound
[ 432.277585] kvm: zapping shadow pages for mmio generation wraparound
[ 434.547820] ===============================
[ 434.552020] [ INFO: suspicious RCU usage. ]
[ 434.556223] 4.4.0-rc4+ #1 Not tainted
[ 434.559886] -------------------------------
[ 434.564072] arch/x86/kvm/trace.h:971 suspicious rcu_dereference_check() usage!
[ 434.571303]
other info that might help us debug this:
[ 434.579324]
RCU used illegally from idle CPU!
rcu_scheduler_active = 1, debug_locks = 0
[ 434.590209] RCU used illegally from extended quiescent state!
[ 434.595971] 1 lock held by qemu-system-x86/2402:
[ 434.600596] #0: (&vcpu->mutex){+.+.+.}, at: [<ffffffffa020872c>] vcpu_load+0x1c/0x80 [kvm]
[ 434.609146]
stack backtrace:
[ 434.613526] CPU: 4 PID: 2402 Comm: qemu-system-x86 Not tainted 4.4.0-rc4+ #1
[ 434.620583] Hardware name: Dell Inc. Precision T3600/0PTTT9, BIOS A13 05/11/2014
[ 434.627987] 0000000000000001 ffff88042f79fcf0 ffffffff813c2cfc ffff880435aa0000
[ 434.635443] ffff88042f79fd20 ffffffff810c5157 ffff88042fd48000 0000000295a85563
[ 434.642886] 0000000295de483f 0000000000000000 ffff88042f79fd58 ffffffffa023ec6e
[ 434.650334] Call Trace:
[ 434.652804] [<ffffffff813c2cfc>] dump_stack+0x4e/0x82
[ 434.657950] [<ffffffff810c5157>] lockdep_rcu_suspicious+0xe7/0x120
[ 434.664239] [<ffffffffa023ec6e>] wait_lapic_expire+0xfe/0x1e0 [kvm]
[ 434.670606] [<ffffffffa022183e>] kvm_arch_vcpu_ioctl_run+0x76e/0x19c0 [kvm]
[ 434.677674] [<ffffffffa0221982>] ? kvm_arch_vcpu_ioctl_run+0x8b2/0x19c0 [kvm]
[ 434.684905] [<ffffffff81858acc>] ? mutex_lock_killable_nested+0x29c/0x4c0
[ 434.691792] [<ffffffffa0208b32>] kvm_vcpu_ioctl+0x342/0x700 [kvm]
[ 434.697984] [<ffffffff810c4a7d>] ? __lock_is_held+0x4d/0x70
[ 434.703655] [<ffffffff812351ae>] ? __fget+0xfe/0x200
[ 434.708719] [<ffffffff812291f1>] do_vfs_ioctl+0x301/0x550
[ 434.714208] [<ffffffff8123531a>] ? __fget_light+0x2a/0x90
[ 434.719700] [<ffffffff81229481>] SyS_ioctl+0x41/0x70
[ 434.724754] [<ffffffff8185cb36>] entry_SYSCALL_64_fastpath+0x16/0x7a
[ 437.411818] kvm [2400]: vcpu0 unhandled rdmsr: 0x606
[ 437.416898] kvm [2400]: vcpu0 unhandled rdmsr: 0x34
--
Regards/Gruss,
Boris.
ECO tip #101: Trim your mails when you reply.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] kvm: x86: move tracepoints outside extended quiescent state
2015-12-10 18:09 ` Borislav Petkov
@ 2015-12-10 18:15 ` Paolo Bonzini
0 siblings, 0 replies; 3+ messages in thread
From: Paolo Bonzini @ 2015-12-10 18:15 UTC (permalink / raw)
To: Borislav Petkov; +Cc: linux-kernel, kvm, stable
On 10/12/2015 19:09, Borislav Petkov wrote:
> On Thu, Dec 10, 2015 at 06:38:57PM +0100, Paolo Bonzini wrote:
>> Invoking tracepoints within kvm_guest_enter/kvm_guest_exit causes a
>> lockdep splat.
>>
>> Cc: stable@vger.kernel.org
>> Reported-by: Borislav Petkov <bp@alien8.de>
>> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
>> ---
>> arch/x86/kvm/svm.c | 4 ++--
>> arch/x86/kvm/vmx.c | 3 ++-
>> arch/x86/kvm/x86.c | 2 +-
>> 3 files changed, 5 insertions(+), 4 deletions(-)
>
> Looks like you missed some...
Yeah, wait_lapic_expire also have to be moved before __kvm_guest_enter.
Paolo
> [ 144.296364] kvm: zapping shadow pages for mmio generation wraparound
> [ 164.699053] kvm: zapping shadow pages for mmio generation wraparound
> [ 312.115767] kvm: zapping shadow pages for mmio generation wraparound
> [ 432.277585] kvm: zapping shadow pages for mmio generation wraparound
>
> [ 434.547820] ===============================
> [ 434.552020] [ INFO: suspicious RCU usage. ]
> [ 434.556223] 4.4.0-rc4+ #1 Not tainted
> [ 434.559886] -------------------------------
> [ 434.564072] arch/x86/kvm/trace.h:971 suspicious rcu_dereference_check() usage!
> [ 434.571303]
> other info that might help us debug this:
>
> [ 434.579324]
> RCU used illegally from idle CPU!
> rcu_scheduler_active = 1, debug_locks = 0
> [ 434.590209] RCU used illegally from extended quiescent state!
> [ 434.595971] 1 lock held by qemu-system-x86/2402:
> [ 434.600596] #0: (&vcpu->mutex){+.+.+.}, at: [<ffffffffa020872c>] vcpu_load+0x1c/0x80 [kvm]
> [ 434.609146]
> stack backtrace:
> [ 434.613526] CPU: 4 PID: 2402 Comm: qemu-system-x86 Not tainted 4.4.0-rc4+ #1
> [ 434.620583] Hardware name: Dell Inc. Precision T3600/0PTTT9, BIOS A13 05/11/2014
> [ 434.627987] 0000000000000001 ffff88042f79fcf0 ffffffff813c2cfc ffff880435aa0000
> [ 434.635443] ffff88042f79fd20 ffffffff810c5157 ffff88042fd48000 0000000295a85563
> [ 434.642886] 0000000295de483f 0000000000000000 ffff88042f79fd58 ffffffffa023ec6e
> [ 434.650334] Call Trace:
> [ 434.652804] [<ffffffff813c2cfc>] dump_stack+0x4e/0x82
> [ 434.657950] [<ffffffff810c5157>] lockdep_rcu_suspicious+0xe7/0x120
> [ 434.664239] [<ffffffffa023ec6e>] wait_lapic_expire+0xfe/0x1e0 [kvm]
> [ 434.670606] [<ffffffffa022183e>] kvm_arch_vcpu_ioctl_run+0x76e/0x19c0 [kvm]
> [ 434.677674] [<ffffffffa0221982>] ? kvm_arch_vcpu_ioctl_run+0x8b2/0x19c0 [kvm]
> [ 434.684905] [<ffffffff81858acc>] ? mutex_lock_killable_nested+0x29c/0x4c0
> [ 434.691792] [<ffffffffa0208b32>] kvm_vcpu_ioctl+0x342/0x700 [kvm]
> [ 434.697984] [<ffffffff810c4a7d>] ? __lock_is_held+0x4d/0x70
> [ 434.703655] [<ffffffff812351ae>] ? __fget+0xfe/0x200
> [ 434.708719] [<ffffffff812291f1>] do_vfs_ioctl+0x301/0x550
> [ 434.714208] [<ffffffff8123531a>] ? __fget_light+0x2a/0x90
> [ 434.719700] [<ffffffff81229481>] SyS_ioctl+0x41/0x70
> [ 434.724754] [<ffffffff8185cb36>] entry_SYSCALL_64_fastpath+0x16/0x7a
> [ 437.411818] kvm [2400]: vcpu0 unhandled rdmsr: 0x606
> [ 437.416898] kvm [2400]: vcpu0 unhandled rdmsr: 0x34
>
>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2015-12-10 17:38 [PATCH] kvm: x86: move tracepoints outside extended quiescent state Paolo Bonzini
2015-12-10 18:09 ` Borislav Petkov
2015-12-10 18:15 ` Paolo Bonzini
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