KVM Arm64 and Linux-RT issues

Hi all, I have been playing with the latest branch of Linux RT (5.2-rt1) and notice the following splat when starting a KVM guest. [ 122.336254] 003: BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:968 [ 122.336263] 003: in_atomic(): 1, irqs_disabled(): 0,

Re: [PATCH v2 8/9] KVM: arm/arm64: vgic-its: Check the LPI translation cache on MSI injection

Hi Eric, On 23/07/2019 16:10, Auger Eric wrote: > Hi Marc, > > On 6/11/19 7:03 PM, Marc Zyngier wrote: >> When performing an MSI injection, let's first check if the translation >> is already in the cache. If so, let's inject it quickly without >> going through the whole translation process. >>

Re: [PATCH v2 7/9] KVM: arm/arm64: vgic-its: Cache successful MSI->LPI translation

Hi Marc, On 6/11/19 7:03 PM, Marc Zyngier wrote: > On a successful translation, preserve the parameters in the LPI > translation cache. Each translation is reusing the last slot > in the list, naturally evincting the least recently used entry. evicting > > Signed-off-by: Marc Zyngier > --- >

Re: [PATCH v2 9/9] KVM: arm/arm64: vgic-irqfd: Implement kvm_arch_set_irq_inatomic

Hi Marc, On 6/11/19 7:03 PM, Marc Zyngier wrote: > Now that we have a cache of MSI->LPI translations, it is pretty > easy to implement kvm_arch_set_irq_inatomic (this cache can be > parsed without sleeping). > > Hopefully, this will improve some LPI-heavy workloads. > > Signed-off-by: Marc

Re: [PATCH v2 8/9] KVM: arm/arm64: vgic-its: Check the LPI translation cache on MSI injection

Hi Marc, On 6/11/19 7:03 PM, Marc Zyngier wrote: > When performing an MSI injection, let's first check if the translation > is already in the cache. If so, let's inject it quickly without > going through the whole translation process. > > Signed-off-by: Marc Zyngier > --- >

Re: [PATCH v2 5/9] KVM: arm/arm64: vgic-its: Invalidate MSI-LPI translation cache on disabling LPIs

Hi Marc, On 6/11/19 7:03 PM, Marc Zyngier wrote: > If a vcpu disables LPIs at its redistributor level, we need to make sure > we won't pend more interrupts. For this, we need to invalidate the LPI > translation cache. > > Signed-off-by: Marc Zyngier Reviewed-by: Eric Auger Thanks Eric > ---

Re: [PATCH v2 6/9] KVM: arm/arm64: vgic-its: Invalidate MSI-LPI translation cache on vgic teardown

Hi Marc, On 6/11/19 7:03 PM, Marc Zyngier wrote: > In order to avoid leaking vgic_irq structures on teardown, we need to > drop all references to LPIs before deallocating the cache itself. > > This is done by invalidating the cache on vgic teardown. > > Signed-off-by: Marc Zyngier > --- >

Re: [PATCH v2 4/9] KVM: arm/arm64: vgic-its: Invalidate MSI-LPI translation cache on specific commands

Hi Marc, On 7/23/19 2:43 PM, Marc Zyngier wrote: > On 23/07/2019 13:25, Auger Eric wrote: >> Hi Marc, >> >> On 7/22/19 12:54 PM, Marc Zyngier wrote: >>> Hi Eric, >>> >>> On 01/07/2019 13:38, Auger Eric wrote: Hi Marc, On 6/11/19 7:03 PM, Marc Zyngier wrote: > The LPI

Re: [PATCH v2 1/9] KVM: arm/arm64: vgic: Add LPI translation cache definition

Hi Marc, On 6/11/19 7:03 PM, Marc Zyngier wrote: > Add the basic data structure that expresses an MSI to LPI > translation as well as the allocation/release hooks. > > THe size of the cache is arbitrarily defined as 4*nr_vcpus. The > > Signed-off-by: Marc Zyngier > --- > include/kvm/arm_vgic.h

Re: [PATCH v2 4/9] KVM: arm/arm64: vgic-its: Invalidate MSI-LPI translation cache on specific commands

On 23/07/2019 13:25, Auger Eric wrote: > Hi Marc, > > On 7/22/19 12:54 PM, Marc Zyngier wrote: >> Hi Eric, >> >> On 01/07/2019 13:38, Auger Eric wrote: >>> Hi Marc, >>> >>> On 6/11/19 7:03 PM, Marc Zyngier wrote: The LPI translation cache needs to be discarded when an ITS command may

Re: [PATCH v2 3/9] KVM: arm/arm64: vgic-its: Add MSI-LPI translation cache invalidation

Hi Marc, On 6/11/19 7:03 PM, Marc Zyngier wrote: > There's a number of cases where we need to invalidate the caching > of translations, so let's add basic support for that. > > Signed-off-by: Marc Zyngier Reviewed-by: Eric Auger Thanks Eric > --- > virt/kvm/arm/vgic/vgic-its.c | 23

Re: [PATCH v2 4/9] KVM: arm/arm64: vgic-its: Invalidate MSI-LPI translation cache on specific commands

Hi Marc, On 7/22/19 12:54 PM, Marc Zyngier wrote: > Hi Eric, > > On 01/07/2019 13:38, Auger Eric wrote: >> Hi Marc, >> >> On 6/11/19 7:03 PM, Marc Zyngier wrote: >>> The LPI translation cache needs to be discarded when an ITS command >>> may affect the translation of an LPI (DISCARD and MAPD

Re: [PATCH v2 0/9] KVM: arm/arm64: vgic: ITS translation cache

On Tue, 11 Jun 2019 18:03:27 +0100 Marc Zyngier wrote: Hi, > It recently became apparent[1] that our LPI injection path is not as > efficient as it could be when injecting interrupts coming from a VFIO > assigned device. > > Although the proposed patch wasn't 100% correct, it outlined at least

Re: [PATCH v2] KVM: arm/arm64: Introduce kvm_pmu_vcpu_init() to setup PMU counter idx

On 2019-07-23 09:17, Julien Thierry wrote: Hi Zenghui, On 18/07/2019 09:15, Zenghui Yu wrote: We use "pmc->idx" and the "chained" bitmap to determine if the pmc is chained, in kvm_pmu_pmc_is_chained(). But idx might be uninitialized (and random) when we doing this decision, through a

Re: [PATCH v2] KVM: arm/arm64: Introduce kvm_pmu_vcpu_init() to setup PMU counter idx

Hi Zenghui, On 18/07/2019 09:15, Zenghui Yu wrote: > We use "pmc->idx" and the "chained" bitmap to determine if the pmc is > chained, in kvm_pmu_pmc_is_chained(). But idx might be uninitialized > (and random) when we doing this decision, through a KVM_ARM_VCPU_INIT > ioctl ->