On 4/4/22 20:17, Matthew Rosato wrote:
If the appropriate CPU facilty is available as well as the necessary
ZPCI_OP ioctl, then the underlying KVM host will enable load/store
intepretation for any guest device without a SHM bit in the guest
function handle. For a device that will be using interpretation
support, ensure the guest function handle matches the host function
handle; this value is re-checked every time the guest issues a SET PCI FN
to enable the guest device as it is the only opportunity to reflect
function handle changes.
By default, unless interpret=off is specified, interpretation support will
always be assumed and exploited if the necessary ioctl and features are
available on the host kernel. When these are unavailable, we will silently
revert to the interception model; this allows existing guest configurations
to work unmodified on hosts with and without zPCI interpretation support,
allowing QEMU to choose the best support model available.
Signed-off-by: Matthew Rosato <mjrosato@xxxxxxxxxxxxx>
---
hw/s390x/meson.build | 1 +
hw/s390x/s390-pci-bus.c | 66 ++++++++++++++++++++++++++++++++-
hw/s390x/s390-pci-inst.c | 12 ++++++
hw/s390x/s390-pci-kvm.c | 21 +++++++++++
include/hw/s390x/s390-pci-bus.h | 1 +
include/hw/s390x/s390-pci-kvm.h | 24 ++++++++++++
target/s390x/kvm/kvm.c | 7 ++++
target/s390x/kvm/kvm_s390x.h | 1 +
8 files changed, 132 insertions(+), 1 deletion(-)
create mode 100644 hw/s390x/s390-pci-kvm.c
create mode 100644 include/hw/s390x/s390-pci-kvm.h
...snip...
if (s390_pci_msix_init(pbdev)) {
@@ -1360,6 +1423,7 @@ static Property s390_pci_device_properties[] = {
DEFINE_PROP_UINT16("uid", S390PCIBusDevice, uid, UID_UNDEFINED),
DEFINE_PROP_S390_PCI_FID("fid", S390PCIBusDevice, fid),
DEFINE_PROP_STRING("target", S390PCIBusDevice, target),
+ DEFINE_PROP_BOOL("interpret", S390PCIBusDevice, interp, true),
DEFINE_PROP_END_OF_LIST(),
};
diff --git a/hw/s390x/s390-pci-inst.c b/hw/s390x/s390-pci-inst.c
index 6d400d4147..c898c8abe9 100644
--- a/hw/s390x/s390-pci-inst.c
+++ b/hw/s390x/s390-pci-inst.c
@@ -18,6 +18,8 @@
#include "sysemu/hw_accel.h"
#include "hw/s390x/s390-pci-inst.h"
#include "hw/s390x/s390-pci-bus.h"
+#include "hw/s390x/s390-pci-kvm.h"
+#include "hw/s390x/s390-pci-vfio.h"
#include "hw/s390x/tod.h"
#ifndef DEBUG_S390PCI_INST
@@ -246,6 +248,16 @@ int clp_service_call(S390CPU *cpu, uint8_t r2, uintptr_t ra)
goto out;
}
+ /*
+ * Take this opportunity to make sure we still have an accurate
+ * host fh. It's possible part of the handle changed while the
+ * device was disabled to the guest (e.g. vfio hot reset for
+ * ISM during plug)
+ */
+ if (pbdev->interp) {
+ /* Take this opportunity to make sure we are sync'd with host */
+ s390_pci_get_host_fh(pbdev, &pbdev->fh);
+ }
pbdev->fh |= FH_MASK_ENABLE;
Are we sure here that the PCI device is always enabled?
Shouldn't we check?
pbdev->state = ZPCI_FS_ENABLED;
stl_p(&ressetpci->fh, pbdev->fh);
diff --git a/hw/s390x/s390-pci-kvm.c b/hw/s390x/s390-pci-kvm.c
new file mode 100644
index 0000000000..8bfce9ef18
--- /dev/null
+++ b/hw/s390x/s390-pci-kvm.c
@@ -0,0 +1,21 @@
+/*
+ * s390 zPCI KVM interfaces
+ *
+ * Copyright 2022 IBM Corp.
+ * Author(s): Matthew Rosato <mjrosato@xxxxxxxxxxxxx>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or (at
+ * your option) any later version. See the COPYING file in the top-level
+ * directory.
+ */
+
+#include "qemu/osdep.h"
+
+#include "kvm/kvm_s390x.h"
+#include "hw/s390x/s390-pci-kvm.h"
+#include "cpu_models.h"
+
+bool s390_pci_kvm_interp_allowed(void)
+{
+ return s390_has_feat(S390_FEAT_ZPCI_INTERP) && kvm_s390_get_zpci_op();
+}
ZPCI is not supported by the PV currently but I do not see what could
prevent it to be enable in the future.
As the code of QEMU zPCI is not PV compatible, I would like to add a
check for PV.
... && !s390_is_pv())
diff --git a/include/hw/s390x/s390-pci-bus.h b/include/hw/s390x/s390-pci-bus.h
index da3cde2bb4..a9843dfe97 100644
--- a/include/hw/s390x/s390-pci-bus.h
+++ b/include/hw/s390x/s390-pci-bus.h
@@ -350,6 +350,7 @@ struct S390PCIBusDevice {
IndAddr *indicator;
bool pci_unplug_request_processed;
bool unplug_requested;
+ bool interp;
QTAILQ_ENTRY(S390PCIBusDevice) link;
};
...snip...
--
Pierre Morel
IBM Lab Boeblingen
