On 11/24/2014 09:14 AM, Wu, Feng wrote: > > >> -----Original Message----- >> From: Eric Auger [mailto:eric.auger@xxxxxxxxxx] >> Sent: Monday, November 24, 2014 2:36 AM >> To: eric.auger@xxxxxx; eric.auger@xxxxxxxxxx; christoffer.dall@xxxxxxxxxx; >> marc.zyngier@xxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; >> kvmarm@xxxxxxxxxxxxxxxxxxxxx; kvm@xxxxxxxxxxxxxxx; >> alex.williamson@xxxxxxxxxx; joel.schopp@xxxxxxx; >> kim.phillips@xxxxxxxxxxxxx; paulus@xxxxxxxxx; gleb@xxxxxxxxxx; >> pbonzini@xxxxxxxxxx; agraf@xxxxxxx >> Cc: linux-kernel@xxxxxxxxxxxxxxx; patches@xxxxxxxxxx; will.deacon@xxxxxxx; >> a.motakis@xxxxxxxxxxxxxxxxxxxxxx; a.rigo@xxxxxxxxxxxxxxxxxxxxxx; >> john.liuli@xxxxxxxxxx; ming.lei@xxxxxxxxxxxxx; Wu, Feng >> Subject: [PATCH v3 0/8] KVM-VFIO IRQ forward control >> >> This series proposes an integration of "ARM: Forwarding physical >> interrupts to a guest VM" (http://lwn.net/Articles/603514/) in >> KVM. >> >> It enables to transform a VFIO platform driver IRQ into a forwarded >> IRQ. >> >> When a physical IRQ is forwarded (to a guest), the host does not >> deactivates this latter. Completion ownership is transferred to the >> guest. When the guest deactivates the associated virtual IRQ, >> the interrupt controler automatically completes the physical IRQ. >> Obviously this requires some dedicated HW support in the interrupt >> controler. >> >> The direct benefit is that, for a level sensitive IRQ, it avoids a >> VM exit on forwarded IRQ completion. >> >> When the IRQ is forwarded, the VFIO platform driver does not need to >> mask the physical IRQ anymore before signaling the eventfd. Indeed >> genirq lowers the running priority, enabling other physical IRQ to hit >> except that one. >> >> Besides, the injection still is based on irqfd triggering. The only >> impact on irqfd process is resamplefd is not called anymore on >> virtual IRQ completion since this latter becomes "transparent". >> >> The current integration is based on an extension of the KVM-VFIO >> device, previously used by KVM to interact with VFIO groups. The >> patch series now enables KVM to directly interact with a VFIO >> platform device. The VFIO external API was extended for that purpose. >> >> Th KVM-VFIO device can get/put the vfio platform device, check its >> integrity and type, get the IRQ number associated to an IRQ index. >> >> The IRQ forward programming is architecture specific (virtual interrupt >> controller programming basically). However the whole infrastructure is >> kept generic. >> >> from a user point of view, the functionality is provided through a >> new KVM-VFIO group named KVM_DEV_VFIO_DEVICE and 2 associated >> attributes: >> - KVM_DEV_VFIO_DEVICE_FORWARD_IRQ, >> - KVM_DEV_VFIO_DEVICE_UNFORWARD_IRQ. >> >> The capability can be checked with KVM_HAS_DEVICE_ATTR. >> >> Forwarding must be activated before VFIO signaling mechanism is set >> using VFIO_DEVICE_SET_IRQS and unset while the signaling is disabled. >> >> --- >> >> This patch series has the following dependencies: >> - "ARM: Forwarding physical interrupts to a guest VM" >> (http://lwn.net/Articles/603514/) >> - [PATCH v9 00/19] VFIO support for platform and AMBA devices on ARM >> (http://www.spinics.net/lists/kvm-arm/msg11745.html) >> - [PATCH v2 0/6] vfio: type1: support for ARM SMMUS with >> VFIO_IOMMU_TYPE1 >> (http://www.spinics.net/lists/kvm-arm/msg11738.html) >> >> Integrated pieces can be found at >> ssh://git.linaro.org/people/eric.auger/linux.git >> on branch irqfd_integ_v8 >> >> This was was tested on Calxeda Midway, assigning the xgmac main IRQ. >> > > Hi Eric, > > Did you send out the latest QEMU part for this patch set, I notice that v6 of > The QEMU part is sent out, but seems some structure in this new version > has been changed, such as, struct kvm_arch_forwarded_irq (subindex is added > in this version), so a new patchset in QEMU is also needed. Hi Feng, v7 is available at: http://lists.gnu.org/archive/html/qemu-devel/2014-10/msg03804.html. It already illustrates KVM-VFIO device usage. v8 which will indeed integrate subindex addition will be delivered this week. Best Regards Eric > > Thanks, > Feng > > >> v2 -> v3: >> - kvm_fwd_irq_action enum replaced by a bool (KVM_VFIO_IRQ_CLEANUP does >> not >> exist anymore) >> - a new struct local to vfio.c was introduced to wrap kvm_fw_irq and make it >> linkable: kvm_vfio_fwd_irq_node >> - kvm_fwd_irq now is self-contained (includes struct vfio_device *) >> - a single list of kvm_vfio_fwd_irq_irq_node is used instead of having >> a list of devices and a list of forward irq per device. Having 2 lists >> brought extra complexity. >> - the VFIO device ref counter is incremented each time a new IRQ is forwarded. >> It is not attempted anymore to hold a single reference whatever the number >> of forwarded IRQs. >> - subindex added on top of index to be closer to VFIO API >> - platform device check moved in the arm specific implementation >> - enable the KVM-VFIO device for arm64 >> - forwarded state change only can happen while the VFIO IRQ handler is not >> set; in other words, when the VFIO IRQ signaling is not set. >> >> v1 -> v2: >> - forward control is moved from architecture specific file into generic >> vfio.c module. >> only kvm_arch_set_fwd_state remains architecture specific >> - integrate Kim's patch which enables KVM-VFIO for ARM >> - fix vgic state bypass in vgic_queue_hwirq >> - struct kvm_arch_forwarded_irq moved from >> arch/arm/include/uapi/asm/kvm.h >> to include/uapi/linux/kvm.h >> also irq_index renamed into index and guest_irq renamed into gsi >> - ASSIGN/DEASSIGN renamed into FORWARD/UNFORWARD >> - vfio_external_get_base_device renamed into vfio_external_base_device >> - vfio_external_get_type removed >> - kvm_vfio_external_get_base_device renamed into >> kvm_vfio_external_base_device >> - __KVM_HAVE_ARCH_KVM_VFIO renamed into >> __KVM_HAVE_ARCH_KVM_VFIO_FORWARD >> >> >> Eric Auger (7): >> KVM: arm64: Enable the KVM-VFIO device >> VFIO: platform: forwarded state tested when selecting IRQ handler >> KVM: kvm-vfio: User API for IRQ forwarding >> VFIO: External user API device helpers >> KVM: kvm-vfio: wrapper to VFIO external API device helpers >> KVM: kvm-vfio: generic forwarding control >> KVM: arm: kvm-vfio: forwarding control >> >> Kim Phillips (1): >> KVM: arm: Enable the KVM-VFIO device >> >> Documentation/virtual/kvm/devices/vfio.txt | 34 +++- >> arch/arm/include/asm/kvm_host.h | 7 + >> arch/arm/kvm/Kconfig | 1 + >> arch/arm/kvm/Makefile | 4 +- >> arch/arm/kvm/kvm_vfio_arm.c | 101 ++++++++++ >> arch/arm64/kvm/Kconfig | 1 + >> arch/arm64/kvm/Makefile | 2 +- >> drivers/vfio/platform/vfio_platform_irq.c | 7 +- >> drivers/vfio/vfio.c | 24 +++ >> include/linux/kvm_host.h | 28 +++ >> include/linux/vfio.h | 3 + >> include/uapi/linux/kvm.h | 10 + >> virt/kvm/vfio.c | 294 >> ++++++++++++++++++++++++++++- >> 13 files changed, 503 insertions(+), 13 deletions(-) >> create mode 100644 arch/arm/kvm/kvm_vfio_arm.c >> >> -- >> 1.9.1 > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
