user/sven/linux.git/include/linux/kvm_host.h, branch stable/5.2.y

KVM: Fix leak vCPU's VMCS value into other pCPU

2019-08-16T08:11:11Z

commit 17e433b54393a6269acbcb792da97791fe1592d8 upstream. After commit d73eb57b80b (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 Cc: Radim Krčmář Cc: Christian Borntraeger Cc: Marc Zyngier 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 Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 499

2019-06-19T15:09:53Z

Based on 1 normalized pattern(s): this work is licensed under the terms of the gnu gpl version 2 see the copying file in the top level directory extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 35 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Kate Stewart Reviewed-by: Enrico Weigelt Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.797835076@linutronix.de Signed-off-by: Greg Kroah-Hartman

Merge tag 'kvm-ppc-next-5.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into HEAD

2019-05-15T21:39:38Z

PPC KVM update for 5.2 * Support for guests to access the new POWER9 XIVE interrupt controller hardware directly, reducing interrupt latency and overhead for guests. * In-kernel implementation of the H_PAGE_INIT hypercall. * Reduce memory usage of sparsely-populated IOMMU tables. * Several bug fixes. Second PPC KVM update for 5.2 * Fix a bug, fix a spelling mistake, remove some useless code.

KVM: Introduce a new guest mapping API

2019-04-30T19:32:51Z

In KVM, specially for nested guests, there is a dominant pattern of: => map guest memory -> do_something -> unmap guest memory In addition to all this unnecessarily noise in the code due to boiler plate code, most of the time the mapping function does not properly handle memory that is not backed by "struct page". This new guest mapping API encapsulate most of this boiler plate code and also handles guest memory that is not backed by "struct page". The current implementation of this API is using memremap for memory that is not backed by a "struct page" which would lead to a huge slow-down if it was used for high-frequency mapping operations. The API does not have any effect on current setups where guest memory is backed by a "struct page". Further patches are going to also introduce a pfn-cache which would significantly improve the performance of the memremap case. Signed-off-by: KarimAllah Ahmed Reviewed-by: Konrad Rzeszutek Wilk Signed-off-by: Paolo Bonzini

Merge tag 'kvm-s390-next-5.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

2019-04-30T19:29:14Z

KVM: s390: Features and fixes for 5.2 - VSIE crypto fixes - new guest features for gen15 - disable halt polling for nested virtualization with overcommit

KVM: Introduce a 'release' method for KVM devices

2019-04-30T09:35:16Z

When a P9 sPAPR VM boots, the CAS negotiation process determines which interrupt mode to use (XICS legacy or XIVE native) and invokes a machine reset to activate the chosen mode. To be able to switch from one interrupt mode to another, we introduce the capability to release a KVM device without destroying the VM. The KVM device interface is extended with a new 'release' method which is called when the file descriptor of the device is closed. Once 'release' is called, the 'destroy' method will not be called anymore as the device is removed from the device list of the VM. Cc: Paolo Bonzini Signed-off-by: Cédric Le Goater Reviewed-by: David Gibson Signed-off-by: Paul Mackerras

KVM: Introduce a 'mmap' method for KVM devices

2019-04-30T09:35:16Z

Some KVM devices will want to handle special mappings related to the underlying HW. For instance, the XIVE interrupt controller of the POWER9 processor has MMIO pages for thread interrupt management and for interrupt source control that need to be exposed to the guest when the OS has the required support. Cc: Paolo Bonzini Signed-off-by: Cédric Le Goater Reviewed-by: David Gibson Signed-off-by: Paul Mackerras

KVM: polling: add architecture backend to disable polling

2019-04-26T07:08:17Z

There are cases where halt polling is unwanted. For example when running KVM on an over committed LPAR we rather want to give back the CPU to neighbour LPARs instead of polling. Let us provide a callback that allows architectures to disable polling. Signed-off-by: Christian Borntraeger Acked-by: Paolo Bonzini Reviewed-by: Cornelia Huck Signed-off-by: Christian Borntraeger

KVM: fix spectrev1 gadgets

2019-04-16T13:38:07Z

These were found with smatch, and then generalized when applicable. Signed-off-by: Paolo Bonzini

KVM: Expose the initial start value in grow_halt_poll_ns() as a module parameter

2019-02-20T21:48:50Z

The hard-coded value 10000 in grow_halt_poll_ns() stands for the initial start value when raising up vcpu->halt_poll_ns. It actually sets the first timeout to the first polling session. This value has significant effect on how tolerant we are to outliers. On the standard case, higher value is better - we will spend more time in the polling busyloop, handle events/interrupts faster and result in better performance. But on outliers it puts us in a busy loop that does nothing. Even if the shrink factor is zero, we will still waste time on the first iteration. The optimal value changes between different workloads. It depends on outliers rate and polling sessions length. As this value has significant effect on the dynamic halt-polling algorithm, it should be configurable and exposed. Reviewed-by: Boris Ostrovsky Reviewed-by: Liran Alon Signed-off-by: Nir Weiner Signed-off-by: Paolo Bonzini