diff mbox

qemu-kvm: fix improper nmi emulation (was: Re: [PATCH] qemu: Fix inject-nmi)

Message ID 4E928B54.1070707@cn.fujitsu.com
State New
Headers show

Commit Message

Lai Jiangshan Oct. 10, 2011, 6:06 a.m. UTC
From: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>

Currently, NMI interrupt is blindly sent to all the vCPUs when NMI
button event happens. This doesn't properly emulate real hardware on
which NMI button event triggers LINT1. Because of this, NMI is sent to
the processor even when LINT1 is maskied in LVT. For example, this
causes the problem that kdump initiated by NMI sometimes doesn't work
on KVM, because kdump assumes NMI is masked on CPUs other than CPU0.

With this patch, inject-nmi request is handled as follows.

- When in-kernel irqchip is disabled, inject LINT1 instead of NMI
  interrupt.
- When in-kernel irqchip is enabled, send nmi event to kernel as the
  current code does. LINT1 should be emulated in kernel.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Tested-by: Lai Jiangshan <laijs@cn.fujitsu.com>
---
 hw/apic.c |   16 ++++++++++++++++
 hw/apic.h |    1 +
 monitor.c |    5 ++---
 3 files changed, 19 insertions(+), 3 deletions(-)

Comments

Jan Kiszka Oct. 10, 2011, 6:49 a.m. UTC | #1
On 2011-10-10 08:06, Lai Jiangshan wrote:
> From: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
> 
> Currently, NMI interrupt is blindly sent to all the vCPUs when NMI
> button event happens. This doesn't properly emulate real hardware on
> which NMI button event triggers LINT1. Because of this, NMI is sent to
> the processor even when LINT1 is maskied in LVT. For example, this
> causes the problem that kdump initiated by NMI sometimes doesn't work
> on KVM, because kdump assumes NMI is masked on CPUs other than CPU0.
> 
> With this patch, inject-nmi request is handled as follows.
> 
> - When in-kernel irqchip is disabled, inject LINT1 instead of NMI
>   interrupt.
> - When in-kernel irqchip is enabled, send nmi event to kernel as the
>   current code does. LINT1 should be emulated in kernel.
> 
> Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
> Tested-by: Lai Jiangshan <laijs@cn.fujitsu.com>

This is targeting uq/master?

Please make sure your patch passes checkpatch.pl

> ---
>  hw/apic.c |   16 ++++++++++++++++
>  hw/apic.h |    1 +
>  monitor.c |    5 ++---
>  3 files changed, 19 insertions(+), 3 deletions(-)
> 
> Index: qemu-kvm/hw/apic.c
> ===================================================================
> --- qemu-kvm.orig/hw/apic.c
> +++ qemu-kvm/hw/apic.c
> @@ -205,6 +205,22 @@ void apic_deliver_pic_intr(DeviceState *
>      }
>  }
>  
> +void apic_deliver_nmi(CPUState *env)
> +{
> +    APICState *apic;
> +
> +    if (kvm_enabled() && kvm_irqchip_in_kernel()) {
> +        cpu_interrupt(env, CPU_INTERRUPT_NMI);
> +	return;
> +    }
> +
> +    apic = DO_UPCAST(APICState, busdev.qdev, env->apic_state);
> +    if (!apic)
> +        cpu_interrupt(env, CPU_INTERRUPT_NMI);

Testing for !apic and handling the non-APIC case here looks a bit
strange. Let's move the !env->apic_state test to the caller to make it
consistent with other APIC services.

The KVM case should be a separate qemu-kvm patch on top for now. (We may
implement calls into APIC models differently when pushing in-kernel
irqchip support upstream.)

Jan
Andreas Färber Oct. 10, 2011, 9:47 a.m. UTC | #2
Am 10.10.2011 08:49, schrieb Jan Kiszka:
> On 2011-10-10 08:06, Lai Jiangshan wrote:
>> From: Kenji Kaneshige<kaneshige.kenji@jp.fujitsu.com>
>>
>> Currently, NMI interrupt is blindly sent to all the vCPUs when NMI
>> button event happens. This doesn't properly emulate real hardware on
>> which NMI button event triggers LINT1. Because of this, NMI is sent to
>> the processor even when LINT1 is maskied in LVT. For example, this
[...]
> This is targeting uq/master?
>
> Please make sure your patch passes checkpatch.pl

While at it: masked?

Andreas
diff mbox

Patch

Index: qemu-kvm/hw/apic.c
===================================================================
--- qemu-kvm.orig/hw/apic.c
+++ qemu-kvm/hw/apic.c
@@ -205,6 +205,22 @@  void apic_deliver_pic_intr(DeviceState *
     }
 }
 
+void apic_deliver_nmi(CPUState *env)
+{
+    APICState *apic;
+
+    if (kvm_enabled() && kvm_irqchip_in_kernel()) {
+        cpu_interrupt(env, CPU_INTERRUPT_NMI);
+	return;
+    }
+
+    apic = DO_UPCAST(APICState, busdev.qdev, env->apic_state);
+    if (!apic)
+        cpu_interrupt(env, CPU_INTERRUPT_NMI);
+    else
+        apic_local_deliver(apic, APIC_LVT_LINT1);
+}
+
 #define foreach_apic(apic, deliver_bitmask, code) \
 {\
     int __i, __j, __mask;\
Index: qemu-kvm/hw/apic.h
===================================================================
--- qemu-kvm.orig/hw/apic.h
+++ qemu-kvm/hw/apic.h
@@ -10,6 +10,7 @@  void apic_deliver_irq(uint8_t dest, uint
                              uint8_t trigger_mode);
 int apic_accept_pic_intr(DeviceState *s);
 void apic_deliver_pic_intr(DeviceState *s, int level);
+void apic_deliver_nmi(CPUState *env);
 int apic_get_interrupt(DeviceState *s);
 void apic_reset_irq_delivered(void);
 int apic_get_irq_delivered(void);
Index: qemu-kvm/monitor.c
===================================================================
--- qemu-kvm.orig/monitor.c
+++ qemu-kvm/monitor.c
@@ -2615,9 +2615,8 @@  static int do_inject_nmi(Monitor *mon, c
 {
     CPUState *env;
 
-    for (env = first_cpu; env != NULL; env = env->next_cpu) {
-        cpu_interrupt(env, CPU_INTERRUPT_NMI);
-    }
+    for (env = first_cpu; env != NULL; env = env->next_cpu)
+	apic_deliver_nmi(env);
 
     return 0;
 }