RE: [PATCH] KVM: Qemu: push_nmi should be only used by I386 Arch.

Zhang, Xiantao
2008-12-02T02:03:54Z

Oops, seems we introduced the issue together.

Acked-by Xiantao Zhang <xiantao.zhang@intel.com>

-----Original Message-----
From: jan.kiszka@web.de [mailto:jan.kiszka@web.de]
Sent: Tuesday, December 02, 2008 7:03 AM
To: Hollis Blanchard
Cc: Avi Kivity; Zhang, Xiantao; kvm@vger.kernel.org; kvm-ia64@vger.kernel.org
Subject: Re: [PATCH] KVM: Qemu: push_nmi should be only used by I386 Arch.

Hollis Blanchard wrote:
> On Fri, 2008-11-28 at 10:26 +0100, Jan Kiszka wrote:
>> Zhang, Xiantao wrote:
>>> >From c25fa2e4de40e500bd364c3267d5be89a9cfbb4d Mon Sep 17 00:00:00 2001
>>> From: Xiantao Zhang <xiantao.zhang@intel.com>
>>> Date: Fri, 28 Nov 2008 09:38:46 +0800
>>> Subject: [PATCH] KVM: Qemu: push_nmi should be only used by I386 Arch.
>>>
>>> Use TARGET_I386 to exclude other archs.
>>> Signed-off-by: Xiantao Zhang <xiantao.zhang@intel.com>
>>> ---
>>> libkvm/libkvm.c | 4 ++--
>>> qemu/qemu-kvm.c | 4 ++++
>>> 2 files changed, 6 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/libkvm/libkvm.c b/libkvm/libkvm.c
>>> index 40c95ce..851a93a 100644
>>> --- a/libkvm/libkvm.c
>>> +++ b/libkvm/libkvm.c
>>> @@ -868,7 +868,7 @@ int kvm_run(kvm_context_t kvm, int vcpu, void *env)
>>> struct kvm_run *run = kvm->run[vcpu];
>>>
>>> again:
>>> -#ifdef KVM_CAP_NMI
>>> +#ifdef TARGET_I386
>>> push_nmi(kvm);
>>> #endif
>>> #if !defined(__s390__)
>>> @@ -1032,7 +1032,7 @@ int kvm_has_sync_mmu(kvm_context_t kvm)
>>>
>>> int kvm_inject_nmi(kvm_context_t kvm, int vcpu)
>>> {
>>> -#ifdef KVM_CAP_NMI
>>> +#ifdef TARGET_I386
>>> return ioctl(kvm->vcpu_fd[vcpu], KVM_NMI);
>>> #else
>>> return -ENOSYS;
>>> diff --git a/qemu/qemu-kvm.c b/qemu/qemu-kvm.c
>>> index cf0e85d..b6c8288 100644
>>> --- a/qemu/qemu-kvm.c
>>> +++ b/qemu/qemu-kvm.c
>>> @@ -154,10 +154,12 @@ static int try_push_interrupts(void *opaque)
>>> return kvm_arch_try_push_interrupts(opaque);
>>> }
>>>
>>> +#ifdef TARGET_I386
>>> static void push_nmi(void *opaque)
>>> {
>>> kvm_arch_push_nmi(opaque);
>>> }
>>> +#endif
>>>
>>> static void post_kvm_run(void *opaque, void *data)
>>> {
>>> @@ -742,7 +744,9 @@ static struct kvm_callbacks qemu_kvm_ops = {
>>> .shutdown = kvm_shutdown,
>>> .io_window = kvm_io_window,
>>> .try_push_interrupts = try_push_interrupts,
>>> +#ifdef TARGET_I386
>>> .push_nmi = push_nmi,
>>> +#endif
>>> .post_kvm_run = post_kvm_run,
>>> .pre_kvm_run = pre_kvm_run,
>>> #ifdef TARGET_I386
>> This will now break when KVM_CAP_NMI is undefined, ie. when there is no
>> KVM_NMI IOCTL (=> older kvm module sets).
>
> Guys, we already have stubs for this (although they've been turned into
> dead code). Jan broke IA64 and PowerPC builds when he renamed
> "kvm_arch_try_push_nmi" to "kvm_arch_push_nmi", and the obvious fix is
> to update the stubs to match. That avoids all these ifdefs and
> associated problems.

Ouch - I'm sorry.

>
> Avi, could you revert a8d12f98755be9330fcde055134511f76ecaa538 please?
>

Here is a patch that reverts change and fixes the root of the issue.

-----------

Subject: Fix non-x86 NMI hooks

My previous x86-only change to the NMI push hook broke PPC and IA64.
This is a proper fix plus a cleanup of the #ifdef-based approach to
solve the breakage.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---

qemu/qemu-kvm-ia64.c | 3 +--
qemu/qemu-kvm-powerpc.c | 3 +--
qemu/qemu-kvm.c | 4 ----
3 files changed, 2 insertions(+), 8 deletions(-)

diff --git a/qemu/qemu-kvm-ia64.c b/qemu/qemu-kvm-ia64.c
index 8380f39..a6b17af 100644
--- a/qemu/qemu-kvm-ia64.c
+++ b/qemu/qemu-kvm-ia64.c
@@ -57,9 +57,8 @@ int kvm_arch_try_push_interrupts(void *opaque)
return 1;
}

-int kvm_arch_try_push_nmi(void *opaque)
+void kvm_arch_push_nmi(void *opaque)
{
- return 1;
}

void kvm_arch_update_regs_for_sipi(CPUState *env)
diff --git a/qemu/qemu-kvm-powerpc.c b/qemu/qemu-kvm-powerpc.c
index 19fde40..fa534ed 100644
--- a/qemu/qemu-kvm-powerpc.c
+++ b/qemu/qemu-kvm-powerpc.c
@@ -188,12 +188,11 @@ int kvm_arch_try_push_interrupts(void *opaque)
return 0;
}

-int kvm_arch_try_push_nmi(void *opaque)
+void kvm_arch_push_nmi(void *opaque)
{
/* no nmi irq, so discard that call for now and return success.
* This might later get mapped to something on powerpc too if we want
* to support the nmi monitor command somwhow */
- return 0;
}

void kvm_arch_update_regs_for_sipi(CPUState *env)
diff --git a/qemu/qemu-kvm.c b/qemu/qemu-kvm.c
index b6c8288..cf0e85d 100644
--- a/qemu/qemu-kvm.c
+++ b/qemu/qemu-kvm.c
@@ -154,12 +154,10 @@ static int try_push_interrupts(void *opaque)
return kvm_arch_try_push_interrupts(opaque);
}

-#ifdef TARGET_I386
static void push_nmi(void *opaque)
{
kvm_arch_push_nmi(opaque);
}
-#endif

static void post_kvm_run(void *opaque, void *data)
{
@@ -744,9 +742,7 @@ static struct kvm_callbacks qemu_kvm_ops = {
.shutdown = kvm_shutdown,
.io_window = kvm_io_window,
.try_push_interrupts = try_push_interrupts,
-#ifdef TARGET_I386
.push_nmi = push_nmi,
-#endif
.post_kvm_run = post_kvm_run,
.pre_kvm_run = pre_kvm_run,
#ifdef TARGET_I386