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| author | Wanpeng Li <wanpeng.li@hotmail.com> | 2017-06-09 06:13:40 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2017-06-11 09:39:24 +0300 |
| commit | 9bc1f09f6fa76fdf31eb7d6a4a4df43574725f93 (patch) | |
| tree | f8ce9696eccc5d28ef8c0fcf59310086cdf27718 /arch/x86/kvm/x86.c | |
| parent | 9e53932d888b7f32475db72f859f8f38cc2135fb (diff) | |
| download | linux-9bc1f09f6fa76fdf31eb7d6a4a4df43574725f93.tar.xz | |
KVM: async_pf: avoid async pf injection when in guest mode
INFO: task gnome-terminal-:1734 blocked for more than 120 seconds.
Not tainted 4.12.0-rc4+ #8
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
gnome-terminal- D 0 1734 1015 0x00000000
Call Trace:
__schedule+0x3cd/0xb30
schedule+0x40/0x90
kvm_async_pf_task_wait+0x1cc/0x270
? __vfs_read+0x37/0x150
? prepare_to_swait+0x22/0x70
do_async_page_fault+0x77/0xb0
? do_async_page_fault+0x77/0xb0
async_page_fault+0x28/0x30
This is triggered by running both win7 and win2016 on L1 KVM simultaneously,
and then gives stress to memory on L1, I can observed this hang on L1 when
at least ~70% swap area is occupied on L0.
This is due to async pf was injected to L2 which should be injected to L1,
L2 guest starts receiving pagefault w/ bogus %cr2(apf token from the host
actually), and L1 guest starts accumulating tasks stuck in D state in
kvm_async_pf_task_wait() since missing PAGE_READY async_pfs.
This patch fixes the hang by doing async pf when executing L1 guest.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/x86.c')
| -rw-r--r-- | arch/x86/kvm/x86.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index a2cd0997343c..87d3cb901935 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -8607,8 +8607,7 @@ bool kvm_arch_can_inject_async_page_present(struct kvm_vcpu *vcpu) if (!(vcpu->arch.apf.msr_val & KVM_ASYNC_PF_ENABLED)) return true; else - return !kvm_event_needs_reinjection(vcpu) && - kvm_x86_ops->interrupt_allowed(vcpu); + return kvm_can_do_async_pf(vcpu); } void kvm_arch_start_assignment(struct kvm *kvm) |