[PATCH v2 00/30] KVM: s390: enable zPCI for interpretive execution

Matthew Rosato
2022-01-14T20:31:57Z

Enable interpretive execution of zPCI instructions + adapter interruption
forwarding for s390x KVM vfio-pci. This is done by introducing a series
of new vfio-pci feature ioctls that are unique vfio-pci-zdev (s390x) and
are used to negotiate the various aspects of zPCI interpretation setup.
By allowing intepretation of zPCI instructions and firmware delivery of
interrupts to guests, we can significantly reduce the frequency of guest
SIE exits for zPCI. We then see additional gains by handling a hot-path
instruction that can still intercept to the hypervisor (RPCIT) directly
in kvm.

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.

Changes v1->v2:
- s/has_zpci_interp/has_zpci_lsi/ (Christian)
- Added many R-bs / ACKs (Thanks!)
- Re-work zpci_set_irq_ctrl (Niklas)
- Simplify changes made for zpci_get_mdd (Niklas, Christian)
- 'KVM: s390: pci: add basic kvm_zdev structure' changes (Pierre)
- only build s390/kvm/pci.o when CONFIG_PCI
- Related to the above, add some more checks for
IS_ENABLED(CONFIG_PCI) (Pierre)
- Drop set_kvm_facility until VSIE support (Christian)
- Use sclp check instead of stfle when setting ECB (Christian)
- remove unnecessary externs from header (Pierre)
- macro for checkling if shadow ioat is initialized (Pierre)
- Fix interrupt case where we have both AEN and alert list (Christian)
- Re-work AEN setup to satisfy firmware requirements on all supported
platforms
- V!=R changes (Niklas)
- vifo_pci_zdev_feat_* - check argz against data size (Pierre, Alex)
- vfio_pci_zdev_{open,release} switch to return void (Alex)
- Related to the above, make kvm_s390_pci_*_probe functions return error
if KVM is not registered for the device (Alex)
- Fix my probe implementation to ignore GET|SET, as these don't change
the result of the probe. I was erroneously performing the GET or SET
operation if specified along with PROBE.
- A few additional fixes regarding ioctl implementation. Return EINVAL
if none of PROBE|GET|SET are specified. Return EINVAL if both GET
and SET are specified (without PROBE).
- New patch to return status from zpci_refresh_trans (Pierre, Niklas)
- And use that status when possible for KVM rpcit intercept (Pierre)

Matthew Rosato (30):
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: export some routines related to RPCIT processing
s390/pci: stash dtsm and maxstbl
s390/pci: add helper function to find device by handle
s390/pci: get SHM information from list pci
s390/pci: return status from zpci_refresh_trans
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 interpretation
KVM: s390: pci: provide routines for enabling/disabling interrupt
forwarding
KVM: s390: pci: provide routines for enabling/disabling IOAT assist
KVM: s390: pci: handle refresh of PCI translations
KVM: s390: intercept the rpcit instruction
vfio/pci: re-introduce CONFIG_VFIO_PCI_ZDEV
vfio-pci/zdev: wire up group notifier
vfio-pci/zdev: wire up zPCI interpretive execution support
vfio-pci/zdev: wire up zPCI adapter interrupt forwarding support
vfio-pci/zdev: wire up zPCI IOAT assist support
vfio-pci/zdev: add DTSM to clp group capability
KVM: s390: introduce CPU feature for zPCI Interpretation
MAINTAINERS: additional files related kvm s390 pci passthrough

MAINTAINERS | 2 +
arch/s390/include/asm/airq.h | 7 +-
arch/s390/include/asm/kvm_host.h | 5 +
arch/s390/include/asm/kvm_pci.h | 62 +++
arch/s390/include/asm/pci.h | 12 +
arch/s390/include/asm/pci_clp.h | 11 +-
arch/s390/include/asm/pci_dma.h | 3 +
arch/s390/include/asm/pci_insn.h | 31 +-
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 | 2 +-
arch/s390/kvm/interrupt.c | 94 +++-
arch/s390/kvm/kvm-s390.c | 56 ++-
arch/s390/kvm/kvm-s390.h | 10 +
arch/s390/kvm/pci.c | 837 +++++++++++++++++++++++++++++++
arch/s390/kvm/pci.h | 59 +++
arch/s390/kvm/priv.c | 46 ++
arch/s390/pci/pci.c | 31 ++
arch/s390/pci/pci_clp.c | 31 +-
arch/s390/pci/pci_dma.c | 7 +-
arch/s390/pci/pci_insn.c | 15 +-
arch/s390/pci/pci_irq.c | 48 +-
drivers/iommu/s390-iommu.c | 4 +-
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/Kconfig | 11 +
drivers/vfio/pci/Makefile | 2 +-
drivers/vfio/pci/vfio_pci_core.c | 8 +
drivers/vfio/pci/vfio_pci_zdev.c | 290 ++++++++++-
include/linux/vfio_pci_core.h | 42 +-
include/uapi/linux/vfio.h | 22 +
include/uapi/linux/vfio_zdev.h | 51 ++
36 files changed, 1788 insertions(+), 66 deletions(-)
create mode 100644 arch/s390/include/asm/kvm_pci.h
create mode 100644 arch/s390/kvm/pci.c
create mode 100644 arch/s390/kvm/pci.h

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2.27.0