hw/pci/pci.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)
When a device is plugged into a PCIE root port, it can only be plugged into slot
0. Hotplugging a device into a slot other than slot 0 is invalid and should be
prevented. This change ensures that we throw an error if the user tries to plug
a device into a pcie root port on any slot other than slot 0.
CC: jusual@redhat.com
CC: imammedo@redhat.com
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2128929
Signed-off-by: Ani Sinha <anisinha@redhat.com>
---
hw/pci/pci.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
changelog:
v2: addressed issue with multifunction pcie root ports. Should allow
hotplug on functions other than function 0.
v3: improved commit message.
diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index bf38905b7d..66999352cc 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -64,6 +64,7 @@ bool pci_available = true;
static char *pcibus_get_dev_path(DeviceState *dev);
static char *pcibus_get_fw_dev_path(DeviceState *dev);
static void pcibus_reset(BusState *qbus);
+static bool pcie_has_upstream_port(PCIDevice *dev);
static Property pci_props[] = {
DEFINE_PROP_PCI_DEVFN("addr", PCIDevice, devfn, -1),
@@ -1182,6 +1183,11 @@ static PCIDevice *do_pci_register_device(PCIDevice *pci_dev,
} else if (dev->hotplugged &&
!pci_is_vf(pci_dev) &&
pci_get_function_0(pci_dev)) {
+ /*
+ * populating function 0 triggers a bus scan from the guest that
+ * exposes other non-zero functions. Hence we need to ensure that
+ * function 0 is available.
+ */
error_setg(errp, "PCI: slot %d function 0 already occupied by %s,"
" new func %s cannot be exposed to guest.",
PCI_SLOT(pci_get_function_0(pci_dev)->devfn),
@@ -1189,6 +1195,16 @@ static PCIDevice *do_pci_register_device(PCIDevice *pci_dev,
name);
return NULL;
+ } else if (dev->hotplugged &&
+ !pci_is_vf(pci_dev) &&
+ pcie_has_upstream_port(pci_dev) && PCI_SLOT(devfn)) {
+ /*
+ * If the device is being plugged into an upstream PCIE port,
+ * like a pcie root port, we only support one device at slot 0
+ */
+ error_setg(errp, "PCI: slot %d is not valid for %s",
+ PCI_SLOT(devfn), name);
+ return NULL;
}
pci_dev->devfn = devfn;
--
2.39.1
On Mon, Jun 19, 2023 at 09:29:26PM +0530, Ani Sinha wrote: > When a device is plugged into a PCIE root port, it can only be plugged into slot > 0. Hotplugging a device into a slot other than slot 0 is invalid and should be > prevented. This change ensures that we throw an error if the user tries to plug > a device into a pcie root port on any slot other than slot 0. > > CC: jusual@redhat.com > CC: imammedo@redhat.com > Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2128929 > Signed-off-by: Ani Sinha <anisinha@redhat.com> > --- > hw/pci/pci.c | 16 ++++++++++++++++ > 1 file changed, 16 insertions(+) > > changelog: > v2: addressed issue with multifunction pcie root ports. Should allow > hotplug on functions other than function 0. > v3: improved commit message. Weird. You say you improved it but it still only mentions root port while code works for downstream ports too. Improve it some more please I guess ;) > diff --git a/hw/pci/pci.c b/hw/pci/pci.c > index bf38905b7d..66999352cc 100644 > --- a/hw/pci/pci.c > +++ b/hw/pci/pci.c > @@ -64,6 +64,7 @@ bool pci_available = true; > static char *pcibus_get_dev_path(DeviceState *dev); > static char *pcibus_get_fw_dev_path(DeviceState *dev); > static void pcibus_reset(BusState *qbus); > +static bool pcie_has_upstream_port(PCIDevice *dev); > > static Property pci_props[] = { > DEFINE_PROP_PCI_DEVFN("addr", PCIDevice, devfn, -1), > @@ -1182,6 +1183,11 @@ static PCIDevice *do_pci_register_device(PCIDevice *pci_dev, > } else if (dev->hotplugged && > !pci_is_vf(pci_dev) && > pci_get_function_0(pci_dev)) { > + /* > + * populating function 0 triggers a bus scan from the guest that > + * exposes other non-zero functions. Hence we need to ensure that > + * function 0 is available. available -> wasn't added yet > + */ > error_setg(errp, "PCI: slot %d function 0 already occupied by %s," > " new func %s cannot be exposed to guest.", > PCI_SLOT(pci_get_function_0(pci_dev)->devfn), > @@ -1189,6 +1195,16 @@ static PCIDevice *do_pci_register_device(PCIDevice *pci_dev, > name); > > return NULL; > + } else if (dev->hotplugged && > + !pci_is_vf(pci_dev) && > + pcie_has_upstream_port(pci_dev) && PCI_SLOT(devfn)) { > + /* > + * If the device is being plugged into an upstream PCIE port, No, it's not plugged into an upstream port. It *has* an upstream port. > + * like a pcie root port, we only support one device at slot 0 this is wrong too, in that "device" here is a pci function, we support only slot 0, but many functions. > + */ > + error_setg(errp, "PCI: slot %d is not valid for %s", Let's not just complain, explain why ;) > + PCI_SLOT(devfn), name); > + return NULL; > } > > pci_dev->devfn = devfn; > -- > 2.39.1
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