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authorJan H. Schönherr <jschoenh@amazon.de>2017-05-20 14:24:32 +0300
committerPaolo Bonzini <pbonzini@redhat.com>2017-05-26 19:01:21 +0300
commit52b5419016997f2960e9c8b6584c4acb3875d126 (patch)
tree8179887b77543d7caae5653560f5f1c95542e44b /arch/x86/kvm/lapic.c
parente1d39b17e044e8ae819827810d87d809ba5f58c0 (diff)
downloadlinux-52b5419016997f2960e9c8b6584c4acb3875d126.tar.xz
KVM: x86: Fix virtual wire mode
Intel SDM says, that at most one LAPIC should be configured with ExtINT delivery. KVM configures all LAPICs this way. This causes pic_unlock() to kick the first available vCPU from the internal KVM data structures. If this vCPU is not the BSP, but some not-yet-booted AP, the BSP may never realize that there is an interrupt. Fix that by enabling ExtINT delivery only for the BSP. This allows booting a Linux guest without a TSC in the above situation. Otherwise the BSP gets stuck in calibrate_delay_converge(). Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de> Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/lapic.c')
-rw-r--r--arch/x86/kvm/lapic.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 6e6f345adfe6..d24c8742d9b0 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1936,7 +1936,8 @@ void kvm_lapic_reset(struct kvm_vcpu *vcpu, bool init_event)
for (i = 0; i < KVM_APIC_LVT_NUM; i++)
kvm_lapic_set_reg(apic, APIC_LVTT + 0x10 * i, APIC_LVT_MASKED);
apic_update_lvtt(apic);
- if (kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_LINT0_REENABLED))
+ if (kvm_vcpu_is_reset_bsp(vcpu) &&
+ kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_LINT0_REENABLED))
kvm_lapic_set_reg(apic, APIC_LVT0,
SET_APIC_DELIVERY_MODE(0, APIC_MODE_EXTINT));
apic_manage_nmi_watchdog(apic, kvm_lapic_get_reg(apic, APIC_LVT0));