search for: kvm_unlock_kick

...PREEMPT SMP Modules linked in: CPU: 1 PID: 1013 Comm: mkdir Not tainted 3.14.4-guest #21 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS Bochs 01/01/2011 task: ffff88007c8cf400 ti: ffff88007c7c6000 task.ti: ffff88007c7c6000 RIP: 0010:[<ffffffff8102ea86>] [<ffffffff8102ea86>] kvm_unlock_kick+0x69/0x73 RSP: 0000:ffff88007fc83ca8 EFLAGS: 00010046 RAX: 0000000000000005 RBX: 0000000000000000 RCX: 0000000000000002 RDX: 0000000000000002 RSI: ffff88007fd11d40 RDI: ffffffff8198f840 RBP: ffff88007fc83cc0 R08: 0000000000000000 R09: ffffffff8198f840 R10: 000000000000b5e0 R11: 0000000000000005 R1...

Paolo Bonzini <pbonzini at redhat.com> wrote: > Il 29/05/2014 19:45, Chris Webb ha scritto: >> Chris Webb <chris at arachsys.com> wrote: >> >>> My CPU flags inside the crashing guest look like this: >>> >>> fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush >>> mmx fxsr sse sse2 ht syscall nx mmxext

Paolo Bonzini <pbonzini at redhat.com> wrote: > Il 29/05/2014 19:45, Chris Webb ha scritto: >> Chris Webb <chris at arachsys.com> wrote: >> >>> My CPU flags inside the crashing guest look like this: >>> >>> fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush >>> mmx fxsr sse sse2 ht syscall nx mmxext

Running a 3.14.4 x86-64 SMP guest kernel on qemu-2.0, with kvm enabled and -cpu host on a 3.14.4 AMD Opteron host, I'm seeing a reliable kernel panic from the guest shortly after boot. I think is happening in kvm_unlock_kick() in the paravirt_ops code: divide error: 0000 [#1] PREEMPT SMP Modules linked in: CPU: 1 PID: 0 Comm: swapper/1 Not tainted 3.14.4-guest #16 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS Bochs 01/01/2011 task: ffff88007d384880 ti: ffff88007d3b2000 task.ti: ffff88007d3b2000 RIP: 0010:[...

Running a 3.14.4 x86-64 SMP guest kernel on qemu-2.0, with kvm enabled and -cpu host on a 3.14.4 AMD Opteron host, I'm seeing a reliable kernel panic from the guest shortly after boot. I think is happening in kvm_unlock_kick() in the paravirt_ops code: divide error: 0000 [#1] PREEMPT SMP Modules linked in: CPU: 1 PID: 0 Comm: swapper/1 Not tainted 3.14.4-guest #16 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS Bochs 01/01/2011 task: ffff88007d384880 ti: ffff88007d3b2000 task.ti: ffff88007d3b2000 RIP: 0010:[...

Il 29/05/2014 19:45, Chris Webb ha scritto: > Chris Webb <chris at arachsys.com> wrote: > >> My CPU flags inside the crashing guest look like this: >> >> fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush >> mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb lm rep_good nopl >> extd_apicid pni pclmulqdq ssse3 fma cx16

Chris Webb <chris at arachsys.com> wrote: > My CPU flags inside the crashing guest look like this: > > fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush > mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb lm rep_good nopl > extd_apicid pni pclmulqdq ssse3 fma cx16 sse4_1 sse4_2 x2apic popcnt aes xsave > avx f16c hypervisor lahf_lm

Chris Webb <chris at arachsys.com> wrote: > My CPU flags inside the crashing guest look like this: > > fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush > mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb lm rep_good nopl > extd_apicid pni pclmulqdq ssse3 fma cx16 sse4_1 sse4_2 x2apic popcnt aes xsave > avx f16c hypervisor lahf_lm

...s_feature(KVM_FEATURE_PV_UNHALT)) > return; > > +#ifdef CONFIG_QUEUE_SPINLOCK > + pv_lock_ops.kick_cpu = kvm_kick_cpu_type; > + pv_lock_ops.hibernate = kvm_hibernate; > +#else > pv_lock_ops.lock_spinning = PV_CALLEE_SAVE(kvm_lock_spinning); > pv_lock_ops.unlock_kick = kvm_unlock_kick; > +#endif This should also disable the unfair path. Paolo

....orig/arch/x86/kernel/kvm.c +++ linux-2.6/arch/x86/kernel/kvm.c @@ -569,6 +569,7 @@ static void kvm_kick_cpu(int cpu) kvm_hypercall2(KVM_HC_KICK_CPU, flags, apicid); } +#ifndef CONFIG_QUEUE_SPINLOCK enum kvm_contention_stat { TAKEN_SLOW, TAKEN_SLOW_PICKUP, @@ -796,6 +797,51 @@ static void kvm_unlock_kick(struct arch_ } } } +#else /* QUEUE_SPINLOCK */ + +#include <asm-generic/qspinlock.h> + +PV_CALLEE_SAVE_REGS_THUNK(__pv_init_node); +PV_CALLEE_SAVE_REGS_THUNK(__pv_link_and_wait_node); +PV_CALLEE_SAVE_REGS_THUNK(__pv_kick_node); + +PV_CALLEE_SAVE_REGS_THUNK(__pv_wait_head); +PV_CALLEE_SA...

...s_feature(KVM_FEATURE_PV_UNHALT)) > return; > > +#ifdef CONFIG_QUEUE_SPINLOCK > + pv_lock_ops.kick_cpu = kvm_kick_cpu_type; > + pv_lock_ops.hibernate = kvm_hibernate; > +#else > pv_lock_ops.lock_spinning = PV_CALLEE_SAVE(kvm_lock_spinning); > pv_lock_ops.unlock_kick = kvm_unlock_kick; > +#endif This should also disable the unfair path. Paolo

...100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -568,6 +568,7 @@ static void kvm_kick_cpu(int cpu) kvm_hypercall2(KVM_HC_KICK_CPU, flags, apicid); } +#ifndef CONFIG_QUEUE_SPINLOCK enum kvm_contention_stat { TAKEN_SLOW, TAKEN_SLOW_PICKUP, @@ -795,6 +796,55 @@ static void kvm_unlock_kick(struct arch_spinlock *lock, __ticket_t ticket) } } } +#else /* !CONFIG_QUEUE_SPINLOCK */ + +#ifdef CONFIG_KVM_DEBUG_FS +static struct dentry *d_spin_debug; +static struct dentry *d_kvm_debug; +static u32 lh_kick_stats; /* Lock holder kick count */ +static u32 qh_kick_stats; /* Queue head kick...

...100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -568,6 +568,7 @@ static void kvm_kick_cpu(int cpu) kvm_hypercall2(KVM_HC_KICK_CPU, flags, apicid); } +#ifndef CONFIG_QUEUE_SPINLOCK enum kvm_contention_stat { TAKEN_SLOW, TAKEN_SLOW_PICKUP, @@ -795,6 +796,87 @@ static void kvm_unlock_kick(struct arch_spinlock *lock, __ticket_t ticket) } } } +#else /* !CONFIG_QUEUE_SPINLOCK */ + +#ifdef CONFIG_KVM_DEBUG_FS +static struct dentry *d_spin_debug; +static struct dentry *d_kvm_debug; +static u32 lh_kick_stats; /* Lock holder kick count */ +static u32 qh_kick_stats; /* Queue head kick...

...h/x86/kernel/kvm.c > @@ -568,6 +568,7 @@ static void kvm_kick_cpu(int cpu) > kvm_hypercall2(KVM_HC_KICK_CPU, flags, apicid); > } > > +#ifndef CONFIG_QUEUE_SPINLOCK > enum kvm_contention_stat { > TAKEN_SLOW, > TAKEN_SLOW_PICKUP, > @@ -795,6 +796,55 @@ static void kvm_unlock_kick(struct arch_spinlock *lock, __ticket_t ticket) > } > } > } > +#else /* !CONFIG_QUEUE_SPINLOCK */ > + > +#ifdef CONFIG_KVM_DEBUG_FS > +static struct dentry *d_spin_debug; > +static struct dentry *d_kvm_debug; > +static u32 lh_kick_stats; /* Lock holder kick count */...

...h/x86/kernel/kvm.c > @@ -568,6 +568,7 @@ static void kvm_kick_cpu(int cpu) > kvm_hypercall2(KVM_HC_KICK_CPU, flags, apicid); > } > > +#ifndef CONFIG_QUEUE_SPINLOCK > enum kvm_contention_stat { > TAKEN_SLOW, > TAKEN_SLOW_PICKUP, > @@ -795,6 +796,55 @@ static void kvm_unlock_kick(struct arch_spinlock *lock, __ticket_t ticket) > } > } > } > +#else /* !CONFIG_QUEUE_SPINLOCK */ > + > +#ifdef CONFIG_KVM_DEBUG_FS > +static struct dentry *d_spin_debug; > +static struct dentry *d_kvm_debug; > +static u32 lh_kick_stats; /* Lock holder kick count */...

...100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -568,6 +568,7 @@ static void kvm_kick_cpu(int cpu) kvm_hypercall2(KVM_HC_KICK_CPU, flags, apicid); } +#ifndef CONFIG_QUEUE_SPINLOCK enum kvm_contention_stat { TAKEN_SLOW, TAKEN_SLOW_PICKUP, @@ -795,6 +796,82 @@ static void kvm_unlock_kick(struct arch_spinlock *lock, __ticket_t ticket) } } } +#else /* !CONFIG_QUEUE_SPINLOCK */ + +#ifdef CONFIG_KVM_DEBUG_FS +static struct dentry *d_spin_debug; +static struct dentry *d_kvm_debug; +static u32 kick_stats; /* CPU kick count */ +static u32 hibernate_stats; /* Hibernation count */...

...rch/x86/kernel/kvm.c > @@ -568,6 +568,7 @@ static void kvm_kick_cpu(int cpu) > kvm_hypercall2(KVM_HC_KICK_CPU, flags, apicid); > } > > +#ifndef CONFIG_QUEUE_SPINLOCK > enum kvm_contention_stat { > TAKEN_SLOW, > TAKEN_SLOW_PICKUP, > @@ -795,6 +796,82 @@ static void kvm_unlock_kick(struct arch_spinlock *lock, __ticket_t ticket) > } > } > } > +#else /* !CONFIG_QUEUE_SPINLOCK */ > + > +#ifdef CONFIG_KVM_DEBUG_FS > +static struct dentry *d_spin_debug; > +static struct dentry *d_kvm_debug; > +static u32 kick_stats; /* CPU kick count */ > +s...

...rch/x86/kernel/kvm.c > @@ -568,6 +568,7 @@ static void kvm_kick_cpu(int cpu) > kvm_hypercall2(KVM_HC_KICK_CPU, flags, apicid); > } > > +#ifndef CONFIG_QUEUE_SPINLOCK > enum kvm_contention_stat { > TAKEN_SLOW, > TAKEN_SLOW_PICKUP, > @@ -795,6 +796,82 @@ static void kvm_unlock_kick(struct arch_spinlock *lock, __ticket_t ticket) > } > } > } > +#else /* !CONFIG_QUEUE_SPINLOCK */ > + > +#ifdef CONFIG_KVM_DEBUG_FS > +static struct dentry *d_spin_debug; > +static struct dentry *d_kvm_debug; > +static u32 kick_stats; /* CPU kick count */ > +s...

.../x86/kernel/kvm.c > @@ -567,6 +567,7 @@ static void kvm_kick_cpu(int cpu) > kvm_hypercall2(KVM_HC_KICK_CPU, flags, apicid); > } > > +#ifndef CONFIG_QUEUE_SPINLOCK > enum kvm_contention_stat { > TAKEN_SLOW, > TAKEN_SLOW_PICKUP, > @@ -794,6 +795,134 @@ static void kvm_unlock_kick(struct arch_spinlock *lock, __ticket_t ticket) > } > } > } > +#else /* !CONFIG_QUEUE_SPINLOCK */ > + > +#ifdef CONFIG_KVM_DEBUG_FS > +static struct dentry *d_spin_debug; > +static struct dentry *d_kvm_debug; > +static u32 kick_nohlt_stats; /* Kick but not halt count...

.../x86/kernel/kvm.c > @@ -567,6 +567,7 @@ static void kvm_kick_cpu(int cpu) > kvm_hypercall2(KVM_HC_KICK_CPU, flags, apicid); > } > > +#ifndef CONFIG_QUEUE_SPINLOCK > enum kvm_contention_stat { > TAKEN_SLOW, > TAKEN_SLOW_PICKUP, > @@ -794,6 +795,134 @@ static void kvm_unlock_kick(struct arch_spinlock *lock, __ticket_t ticket) > } > } > } > +#else /* !CONFIG_QUEUE_SPINLOCK */ > + > +#ifdef CONFIG_KVM_DEBUG_FS > +static struct dentry *d_spin_debug; > +static struct dentry *d_kvm_debug; > +static u32 kick_nohlt_stats; /* Kick but not halt count...