| Message ID | 20230619155926.443668-1-anisinha@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3] hw/pci: prevent hotplug of devices on pcie-root-ports on the wrong slot | expand |
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
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;
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.