Messages in this thread | | | From | Matthew Rosato <> | Subject | [PATCH v5 00/21] KVM: s390: enable zPCI for interpretive execution | Date | Mon, 4 Apr 2022 13:43:28 -0400 |
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Note: in this version, all IOMMU changes have been removed to be pursued as a follow-on / in conjunction with IOMMUFD. This series proposes to add only exploitation of the interpretive execution facilities.
Enable interpretive execution of zPCI instructions + adapter interruption forwarding for s390x KVM vfio-pci. This is done by triggering a routine when the VFIO group is associated with the KVM guest, transmitting to firmware a special token (GISA designation) to enable that specific guest for interpretive execution on that zPCI device. Load/store interpreation enablement is then controlled by userspace (based upon whether or not a SHM bit is placed in the virtual function handle). Adapter Event Notification interpretation is controlled from userspace via a new KVM ioctl.
By allowing intepretation of zPCI instructions and firmware delivery of interrupts to guests, we can reduce the frequency of guest SIE exits for zPCI.
From the perspective of guest configuration, you passthrough zPCI devices in the same manner as before, with intepretation support being used by default if available in kernel+qemu.
Will reply with a link to the associated QEMU series.
Changelog v4->v5: - Remove all IOMMU changes - this series will continue to use vfio type1 for mapping; RPCIT enhancements will be pursued as a follow-on in coordination with the IOMMUFD project - Remove most of the ops from the proposed KVM ioctl -- combine the notion of 'start' and 'enable interpretation' into a single operation that occurs in response to assigning a KVM association to the VFIO group - a new kvm ioctl is still being used to register/unregister for adapter event notification forwarding. But teach it to use pin_user_pages instead of gfn_to_page and perform accounting. - Because we now attempt to enable interpretation for all devices (even if the virtual PCI device has a SHM bit on) avoid setting the GISA for the device and the ECB bits for the guest on hardware without SHM. - found a bug with "s390/pci: stash associated GISA designation", namely that CLP SET PCI FN (disable) expects the gisa designation to always be 0. Now that we set the gisa earlier, vfio-pci can trip this when triggering restore for ISM. - Add a single routine to determine if interpretation support is usable on this host, to be used in multiple spots. - eliminated arch/s390/include/asm/kvm_pci.h, moving most elements into arch/s390/kvm/pci.h with one exception to asm/kvm_host.h
Matthew Rosato (21): s390/sclp: detect the zPCI load/store interpretation facility s390/sclp: detect the AISII facility s390/sclp: detect the AENI facility s390/sclp: detect the AISI facility s390/airq: pass more TPI info to airq handlers s390/airq: allow for airq structure that uses an input vector s390/pci: externalize the SIC operation controls and routine s390/pci: stash associated GISA designation s390/pci: stash dtsm and maxstbl KVM: s390: pci: add basic kvm_zdev structure KVM: s390: pci: do initial setup for AEN interpretation KVM: s390: pci: enable host forwarding of Adapter Event Notifications KVM: s390: mechanism to enable guest zPCI Interpretation KVM: s390: pci: provide routines for enabling/disabling interrupt forwarding KVM: s390: pci: add routines to start/stop interpretive execution KVM: vfio: add s390x hook to register KVM guest designation vfio-pci/zdev: add function handle to clp base capability vfio-pci/zdev: different maxstbl for interpreted devices KVM: s390: add KVM_S390_ZPCI_OP to manage guest zPCI devices KVM: s390: introduce CPU feature for zPCI Interpretation MAINTAINERS: additional files related kvm s390 pci passthrough
Documentation/virt/kvm/api.rst | 45 +++ MAINTAINERS | 1 + arch/s390/include/asm/airq.h | 7 +- arch/s390/include/asm/kvm_host.h | 16 + arch/s390/include/asm/pci.h | 10 + arch/s390/include/asm/pci_clp.h | 9 +- arch/s390/include/asm/pci_insn.h | 29 +- arch/s390/include/asm/sclp.h | 4 + arch/s390/include/asm/tpi.h | 13 + arch/s390/include/uapi/asm/kvm.h | 1 + arch/s390/kvm/Makefile | 1 + arch/s390/kvm/interrupt.c | 95 ++++- arch/s390/kvm/kvm-s390.c | 81 +++- arch/s390/kvm/kvm-s390.h | 10 + arch/s390/kvm/pci.c | 666 +++++++++++++++++++++++++++++++ arch/s390/kvm/pci.h | 86 ++++ arch/s390/pci/pci.c | 15 + arch/s390/pci/pci_clp.c | 7 + arch/s390/pci/pci_insn.c | 4 +- arch/s390/pci/pci_irq.c | 48 ++- drivers/s390/char/sclp_early.c | 4 + drivers/s390/cio/airq.c | 12 +- drivers/s390/cio/qdio_thinint.c | 6 +- drivers/s390/crypto/ap_bus.c | 9 +- drivers/s390/virtio/virtio_ccw.c | 6 +- drivers/vfio/pci/vfio_pci_zdev.c | 11 +- include/uapi/linux/kvm.h | 31 ++ include/uapi/linux/vfio_zdev.h | 7 + virt/kvm/vfio.c | 35 +- 29 files changed, 1216 insertions(+), 53 deletions(-) create mode 100644 arch/s390/kvm/pci.c create mode 100644 arch/s390/kvm/pci.h
-- 2.27.0
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