From f439ed27f8b8b90d243ae15acb193d37f96eebe0 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Thu, 2 Oct 2014 13:53:24 +0200 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: [] put_page+0x9/0x30 PGD 1e15067 PUD 1e17067 PMD 0 Oops: 0000 [#1] PREEMPT SMP [] ? kvm_vcpu_reload_apic_access_page+0x5d/0x70 [kvm] [] vmx_vcpu_reset+0x21b/0x470 [kvm_intel] [] ? kvm_pmu_reset+0x76/0xb0 [kvm] [] kvm_vcpu_reset+0x15a/0x1b0 [kvm] [] kvm_arch_vcpu_setup+0x2c/0x50 [kvm] [] kvm_vm_ioctl+0x200/0x780 [kvm] [] do_vfs_ioctl+0x2d0/0x4b0 [] ? __mmdrop+0x69/0xb0 [] SyS_ioctl+0x81/0xa0 [] ? __audit_syscall_exit+0x1f6/0x2a0 [] 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 [] put_page+0x5/0x50 when not using the in-kernel irqchip ("-machine kernel_irqchip=off" with QEMU). The fix is to make the same check in kvm_vcpu_reload_apic_access_page that we already have in vmx.c's vm_need_virtualize_apic_accesses(). Reported-by: Jan Kiszka Tested-by: Jan Kiszka Fixes: 4256f43f9fab91e1c17b5846a240cf4b66a768a8 Signed-off-by: Paolo Bonzini --- 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; -- 2.20.1