diff options
| author | Avi Kivity <avi@redhat.com> | 2012-05-09 16:10:46 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-05-12 09:32:20 -0700 |
| commit | a4dfde33d7f8448d65d066392ecccbbf50d55fd8 (patch) | |
| tree | 76c67909964aa834cd8f20f71fbae4ba8af2b234 /arch | |
| parent | 8a4a30bf172a05f53714f0f54af2e044a6ede7a8 (diff) | |
KVM: VMX: Fix kvm_set_shared_msr() called in preemptible context
(cherry picked from commit 2225fd56049643c1a7d645c0ce9d499d43c7974e)
kvm_set_shared_msr() may not be called in preemptible context,
but vmx_set_msr() does so:
BUG: using smp_processor_id() in preemptible [00000000] code: qemu-kvm/22713
caller is kvm_set_shared_msr+0x32/0xa0 [kvm]
Pid: 22713, comm: qemu-kvm Not tainted 3.4.0-rc3+ #39
Call Trace:
[<ffffffff8131fa82>] debug_smp_processor_id+0xe2/0x100
[<ffffffffa0328ae2>] kvm_set_shared_msr+0x32/0xa0 [kvm]
[<ffffffffa03a103b>] vmx_set_msr+0x28b/0x2d0 [kvm_intel]
...
Making kvm_set_shared_msr() work in preemptible is cleaner, but
it's used in the fast path. Making two variants is overkill, so
this patch just disables preemption around the call.
Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kvm/vmx.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 7f33e337b152..a7a6f6011002 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2219,9 +2219,12 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data) msr = find_msr_entry(vmx, msr_index); if (msr) { msr->data = data; - if (msr - vmx->guest_msrs < vmx->save_nmsrs) + if (msr - vmx->guest_msrs < vmx->save_nmsrs) { + preempt_disable(); kvm_set_shared_msr(msr->index, msr->data, msr->mask); + preempt_enable(); + } break; } ret = kvm_set_msr_common(vcpu, msr_index, data); |