s390x/pci: reset ISM passthrough devices on shutdown and system reset

ISM device firmware stores unique state information that can
can cause a wholesale unmap of the associated IOMMU (e.g. when
we get a termination signal for QEMU) to trigger firmware errors
because firmware believes we are attempting to invalidate entries
that are still in-use by the guest OS (when in fact that guest is
in the process of being terminated or rebooted).
To alleviate this, register both a shutdown notifier (for unexpected
termination cases e.g. virsh destroy) as well as a reset callback
(for cases like guest OS reboot).  For each of these scenarios, trigger
PCI device reset; this is enough to indicate to firmware that the IOMMU
is no longer in-use by the guest OS, making it safe to invalidate any
associated IOMMU entries.

Fixes: 15d0e7942d ("s390x/pci: don't fence interpreted devices without MSI-X")
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Message-Id: <20221209195700.263824-1-mjrosato@linux.ibm.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
[thuth: Adjusted the hunk in s390-pci-vfio.c due to different context]
Signed-off-by: Thomas Huth <thuth@redhat.com>
This commit is contained in:
Matthew Rosato 2022-12-09 14:57:00 -05:00 committed by Thomas Huth
parent df202e3ff3
commit 03451953c7
3 changed files with 35 additions and 0 deletions

View file

@ -39,6 +39,9 @@
#define UID_CHECKING_ENABLED 0x01
#define ZPCI_DTSM 0x40
/* zPCI Function Types */
#define ZPCI_PFT_ISM 5
OBJECT_DECLARE_SIMPLE_TYPE(S390pciState, S390_PCI_HOST_BRIDGE)
OBJECT_DECLARE_SIMPLE_TYPE(S390PCIBus, S390_PCI_BUS)
OBJECT_DECLARE_SIMPLE_TYPE(S390PCIBusDevice, S390_PCI_DEVICE)
@ -344,6 +347,7 @@ struct S390PCIBusDevice {
uint16_t noi;
uint16_t maxstbl;
uint8_t sum;
uint8_t pft;
S390PCIGroup *pci_group;
ClpRspQueryPci zpci_fn;
S390MsixInfo msix;
@ -352,6 +356,7 @@ struct S390PCIBusDevice {
MemoryRegion msix_notify_mr;
IndAddr *summary_ind;
IndAddr *indicator;
Notifier shutdown_notifier;
bool pci_unplug_request_processed;
bool unplug_requested;
bool interp;