2014-10-02 12:00:35

by Paolo Bonzini

Subject: [PATCH] kvm: do not handle APIC access page if in-kernel irqchip is not in use

This fixes the following OOPS:

loaded kvm module (v3.17-rc1-168-gcec26bc)
BUG: unable to handle kernel paging request at fffffffffffffffe
IP: [<ffffffff81168449>] put_page+0x9/0x30
PGD 1e15067 PUD 1e17067 PMD 0
Oops: 0000 [#1] PREEMPT SMP
[<ffffffffa063271d>] ? kvm_vcpu_reload_apic_access_page+0x5d/0x70 [kvm]
[<ffffffffa013b6db>] vmx_vcpu_reset+0x21b/0x470 [kvm_intel]
[<ffffffffa0658816>] ? kvm_pmu_reset+0x76/0xb0 [kvm]
[<ffffffffa064032a>] kvm_vcpu_reset+0x15a/0x1b0 [kvm]
[<ffffffffa06403ac>] kvm_arch_vcpu_setup+0x2c/0x50 [kvm]
[<ffffffffa062e540>] kvm_vm_ioctl+0x200/0x780 [kvm]
[<ffffffff81212170>] do_vfs_ioctl+0x2d0/0x4b0
[<ffffffff8108bd99>] ? __mmdrop+0x69/0xb0
[<ffffffff812123d1>] SyS_ioctl+0x81/0xa0
[<ffffffff8112a6f6>] ? __audit_syscall_exit+0x1f6/0x2a0
[<ffffffff817229e9>] system_call_fastpath+0x16/0x1b
Code: c6 78 ce a3 81 4c 89 e7 e8 d9 80 ff ff 0f 0b 4c 89 e7 e8 8f f6 ff ff e9 fa fe ff ff 66 2e 0f 1f 84 00 00 00 00 00 66 66 66 66 90 <48> f7 07 00 c0 00 00 55 48 89 e5 75 1e 8b 47 1c 85 c0 74 27 f0
RIP [<ffffffff81193045>] put_page+0x5/0x50

when not using the in-kernel irqchip ("-machine kernel_irqchip=off"
with QEMU).

Reported-by: Jan Kiszka <[email protected]>
Fixes: 4256f43f9fab91e1c17b5846a240cf4b66a768a8
Signed-off-by: Paolo Bonzini <[email protected]>
---
arch/x86/kvm/x86.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 6857257f3810..5430e4b0af29 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6030,6 +6030,9 @@ void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu)
{
struct page *page = NULL;

+ if (!irqchip_in_kernel(vcpu->kvm))
+ return;
+
if (!kvm_x86_ops->set_apic_access_page_addr)
return;

--
1.8.3.1

2014-10-02 16:50:27

by Jan Kiszka

Subject: Re: [PATCH] kvm: do not handle APIC access page if in-kernel irqchip is not in use

On 2014-10-02 14:00, Paolo Bonzini wrote:
> This fixes the following OOPS:
>
> loaded kvm module (v3.17-rc1-168-gcec26bc)
> BUG: unable to handle kernel paging request at fffffffffffffffe
> IP: [<ffffffff81168449>] put_page+0x9/0x30
> PGD 1e15067 PUD 1e17067 PMD 0
> Oops: 0000 [#1] PREEMPT SMP
> [<ffffffffa063271d>] ? kvm_vcpu_reload_apic_access_page+0x5d/0x70 [kvm]
> [<ffffffffa013b6db>] vmx_vcpu_reset+0x21b/0x470 [kvm_intel]
> [<ffffffffa0658816>] ? kvm_pmu_reset+0x76/0xb0 [kvm]
> [<ffffffffa064032a>] kvm_vcpu_reset+0x15a/0x1b0 [kvm]
> [<ffffffffa06403ac>] kvm_arch_vcpu_setup+0x2c/0x50 [kvm]
> [<ffffffffa062e540>] kvm_vm_ioctl+0x200/0x780 [kvm]
> [<ffffffff81212170>] do_vfs_ioctl+0x2d0/0x4b0
> [<ffffffff8108bd99>] ? __mmdrop+0x69/0xb0
> [<ffffffff812123d1>] SyS_ioctl+0x81/0xa0
> [<ffffffff8112a6f6>] ? __audit_syscall_exit+0x1f6/0x2a0
> [<ffffffff817229e9>] system_call_fastpath+0x16/0x1b
> Code: c6 78 ce a3 81 4c 89 e7 e8 d9 80 ff ff 0f 0b 4c 89 e7 e8 8f f6 ff ff e9 fa fe ff ff 66 2e 0f 1f 84 00 00 00 00 00 66 66 66 66 90 <48> f7 07 00 c0 00 00 55 48 89 e5 75 1e 8b 47 1c 85 c0 74 27 f0
> RIP [<ffffffff81193045>] put_page+0x5/0x50
>
> when not using the in-kernel irqchip ("-machine kernel_irqchip=off"
> with QEMU).
>
> Reported-by: Jan Kiszka <[email protected]>
> Fixes: 4256f43f9fab91e1c17b5846a240cf4b66a768a8
> Signed-off-by: Paolo Bonzini <[email protected]>
> ---
> arch/x86/kvm/x86.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 6857257f3810..5430e4b0af29 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -6030,6 +6030,9 @@ void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu)
> {
> struct page *page = NULL;
>
> + if (!irqchip_in_kernel(vcpu->kvm))
> + return;
> +
> if (!kvm_x86_ops->set_apic_access_page_addr)
> return;
>
>

Works fine here.

Jan

--
Siemens AG, Corporate Technology, CT RTC ITP SES-DE
Corporate Competence Center Embedded Linux