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

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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
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28
hw/s390x/s390-pci-bus.c
View File

@ -24,6 +24,8 @@
#include "hw/pci/msi.h"
#include "qemu/error-report.h"
#include "qemu/module.h"
#include "sysemu/reset.h"
#include "sysemu/runstate.h"
#ifndef DEBUG_S390PCI_BUS
#define DEBUG_S390PCI_BUS 0
@ -150,10 +152,30 @@ out:
psccb->header.response_code = cpu_to_be16(rc);
}
static void s390_pci_shutdown_notifier(Notifier *n, void *opaque)
{
S390PCIBusDevice *pbdev = container_of(n, S390PCIBusDevice,
shutdown_notifier);
pci_device_reset(pbdev->pdev);
}
static void s390_pci_reset_cb(void *opaque)
{
S390PCIBusDevice *pbdev = opaque;
pci_device_reset(pbdev->pdev);
}
static void s390_pci_perform_unplug(S390PCIBusDevice *pbdev)
{
HotplugHandler *hotplug_ctrl;
if (pbdev->pft == ZPCI_PFT_ISM) {
notifier_remove(&pbdev->shutdown_notifier);
qemu_unregister_reset(s390_pci_reset_cb, pbdev);
}
/* Unplug the PCI device */
if (pbdev->pdev) {
DeviceState *pdev = DEVICE(pbdev->pdev);
@ -1111,6 +1133,12 @@ static void s390_pcihost_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
pbdev->fh |= FH_SHM_VFIO;
pbdev->forwarding_assist = false;
}
/* Register shutdown notifier and reset callback for ISM devices */
if (pbdev->pft == ZPCI_PFT_ISM) {
pbdev->shutdown_notifier.notify = s390_pci_shutdown_notifier;
qemu_register_shutdown_notifier(&pbdev->shutdown_notifier);
qemu_register_reset(s390_pci_reset_cb, pbdev);
}
} else {
pbdev->fh |= FH_SHM_EMUL;
/* Always intercept emulated devices */

2
hw/s390x/s390-pci-vfio.c
View File

@ -124,6 +124,8 @@ static void s390_pci_read_base(S390PCIBusDevice *pbdev,
/* The following values remain 0 until we support other FMB formats */
pbdev->zpci_fn.fmbl = 0;
pbdev->zpci_fn.pft = 0;
/* Store function type separately for type-specific behavior */
pbdev->pft = cap->pft;
/*
* If appropriate, reduce the size of the supported DMA aperture reported

5
include/hw/s390x/s390-pci-bus.h
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;