Wanpeng Li 2bc73d9141 KVM: Fix leak vCPU's VMCS value into other pCPU ... commit 17e433b543 upstream. After commit d73eb57b80 (KVM: Boost vCPUs that are delivering interrupts), a five years old bug is exposed. Running ebizzy benchmark in three 80 vCPUs VMs on one 80 pCPUs Skylake server, a lot of rcu_sched stall warning splatting in the VMs after stress testing: INFO: rcu_sched detected stalls on CPUs/tasks: { 4 41 57 62 77} (detected by 15, t=60004 jiffies, g=899, c=898, q=15073) Call Trace: flush_tlb_mm_range+0x68/0x140 tlb_flush_mmu.part.75+0x37/0xe0 tlb_finish_mmu+0x55/0x60 zap_page_range+0x142/0x190 SyS_madvise+0x3cd/0x9c0 system_call_fastpath+0x1c/0x21 swait_active() sustains to be true before finish_swait() is called in kvm_vcpu_block(), voluntarily preempted vCPUs are taken into account by kvm_vcpu_on_spin() loop greatly increases the probability condition kvm_arch_vcpu_runnable(vcpu) is checked and can be true, when APICv is enabled the yield-candidate vCPU's VMCS RVI field leaks(by vmx_sync_pir_to_irr()) into spinning-on-a-taken-lock vCPU's current VMCS. This patch fixes it by checking conservatively a subset of events. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Marc Zyngier <Marc.Zyngier@arm.com> Cc: stable@vger.kernel.org Fixes: 98f4a1467 (KVM: add kvm_arch_vcpu_runnable() test to kvm_vcpu_on_spin() loop) Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2019-08-16 10:12:53 +02:00
..
arm	KVM: arm/arm64: vgic: Fix kvm_device leak in vgic_its_destroy	2019-07-14 08:11:10 +02:00
async_pf.c	sched/swait: Rename to exclusive	2018-06-20 11:35:56 +02:00
async_pf.h	KVM: fix checkpatch.pl errors in kvm/async_pf.h	2015-06-19 17:16:25 +02:00
coalesced_mmio.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
coalesced_mmio.h	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
eventfd.c	Miscellaneous bugfixes, plus a small patchlet related to Spectre v2.	2018-07-18 11:08:44 -07:00
irqchip.c	KVM: fix spectrev1 gadgets	2019-05-16 19:41:22 +02:00
Kconfig	KVM: arm64: Prevent KVM_COMPAT from being selected	2018-06-21 17:17:50 +01:00
kvm_main.c	KVM: Fix leak vCPU's VMCS value into other pCPU	2019-08-16 10:12:53 +02:00
vfio.c	vfio: New external user group/file match	2017-06-28 13:50:05 -06:00
vfio.h	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00