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| author | Peter Xu <peterx@redhat.com> | 2017-12-12 17:15:02 +0100 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2017-12-14 09:24:35 +0100 |
| commit | 5663d8f9bbe4bf15488f7351efb61ea20fa6de06 (patch) | |
| tree | 564627983617e766e472297585da264c056c59d0 /arch | |
| parent | d73235d17ba63b53dc0e1051dbc10a1f1be91b71 (diff) | |
| download | linux-5663d8f9bbe4bf15488f7351efb61ea20fa6de06.tar.gz linux-5663d8f9bbe4bf15488f7351efb61ea20fa6de06.tar.bz2 linux-5663d8f9bbe4bf15488f7351efb61ea20fa6de06.zip | |
kvm: x86: fix WARN due to uninitialized guest FPU state
------------[ cut here ]------------
Bad FPU state detected at kvm_put_guest_fpu+0xd8/0x2d0 [kvm], reinitializing FPU registers.
WARNING: CPU: 1 PID: 4594 at arch/x86/mm/extable.c:103 ex_handler_fprestore+0x88/0x90
CPU: 1 PID: 4594 Comm: qemu-system-x86 Tainted: G B OE 4.15.0-rc2+ #10
RIP: 0010:ex_handler_fprestore+0x88/0x90
Call Trace:
fixup_exception+0x4e/0x60
do_general_protection+0xff/0x270
general_protection+0x22/0x30
RIP: 0010:kvm_put_guest_fpu+0xd8/0x2d0 [kvm]
RSP: 0018:ffff8803d5627810 EFLAGS: 00010246
kvm_vcpu_reset+0x3b4/0x3c0 [kvm]
kvm_apic_accept_events+0x1c0/0x240 [kvm]
kvm_arch_vcpu_ioctl_run+0x1658/0x2fb0 [kvm]
kvm_vcpu_ioctl+0x479/0x880 [kvm]
do_vfs_ioctl+0x142/0x9a0
SyS_ioctl+0x74/0x80
do_syscall_64+0x15f/0x600
where kvm_put_guest_fpu is called without a prior kvm_load_guest_fpu.
To fix it, move kvm_load_guest_fpu to the very beginning of
kvm_arch_vcpu_ioctl_run.
Cc: stable@vger.kernel.org
Fixes: f775b13eedee2f7f3c6fdd4e90fb79090ce5d339
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kvm/x86.c | 12 |
1 files changed, 4 insertions, 8 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 154ea27746e9..56d036b9ad75 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -7264,13 +7264,12 @@ static int complete_emulated_mmio(struct kvm_vcpu *vcpu) int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) { - struct fpu *fpu = ¤t->thread.fpu; int r; - fpu__initialize(fpu); - kvm_sigset_activate(vcpu); + kvm_load_guest_fpu(vcpu); + if (unlikely(vcpu->arch.mp_state == KVM_MP_STATE_UNINITIALIZED)) { if (kvm_run->immediate_exit) { r = -EINTR; @@ -7296,14 +7295,12 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) } } - kvm_load_guest_fpu(vcpu); - if (unlikely(vcpu->arch.complete_userspace_io)) { int (*cui)(struct kvm_vcpu *) = vcpu->arch.complete_userspace_io; vcpu->arch.complete_userspace_io = NULL; r = cui(vcpu); if (r <= 0) - goto out_fpu; + goto out; } else WARN_ON(vcpu->arch.pio.count || vcpu->mmio_needed); @@ -7312,9 +7309,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) else r = vcpu_run(vcpu); -out_fpu: - kvm_put_guest_fpu(vcpu); out: + kvm_put_guest_fpu(vcpu); post_kvm_run_save(vcpu); kvm_sigset_deactivate(vcpu); |