Re: [PATCH] hw/pci/pcie: Move hot plug capability check to pre_plug callback
On Thu, Jun 04, 2020 at 12:57:55PM +0200, Igor Mammedov wrote: > On Mon, 1 Jun 2020 18:29:34 +0200 > Julia Suvorova wrote: > > > Check for hot plug capability earlier to avoid removing devices attached > > during the initialization process. > > > > Run qemu with an unattached drive: > > -drive file=$FILE,if=none,id=drive0 \ > > -device pcie-root-port,id=rp0,slot=3,bus=pcie.0,hotplug=off > > Hotplug a block device: > > device_add virtio-blk-pci,id=blk0,drive=drive0,bus=rp0 > > If hotplug fails on plug_cb, drive0 will be deleted. > > > > Signed-off-by: Julia Suvorova > > --- > > Hard to say if it's a bug or generally acceptable behaviour, but seems like > > hotplug_handler_plug should never fail. > > _unplug shouldn't fail the rest are allowed to, but it's hard to unwind > intialization cleanly to _plug stage so if it's possible to do checks > at _pre_plug time (i.e. before device's realize() is called) we should do so. > > Acked-by: Igor Mammedov Makes sense. Julia could you repost with a tweaked commit log and I'll apply. Thanks! > > > > hw/pci/pcie.c | 19 +++ > > 1 file changed, 11 insertions(+), 8 deletions(-) > > > > diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c > > index f50e10b8fb..5b9c022d91 100644 > > --- a/hw/pci/pcie.c > > +++ b/hw/pci/pcie.c > > @@ -407,6 +407,17 @@ static void pcie_cap_slot_plug_common(PCIDevice > > *hotplug_dev, DeviceState *dev, > > void pcie_cap_slot_pre_plug_cb(HotplugHandler *hotplug_dev, DeviceState > > *dev, > > Error **errp) > > { > > +PCIDevice *hotplug_pdev = PCI_DEVICE(hotplug_dev); > > +uint8_t *exp_cap = hotplug_pdev->config + hotplug_pdev->exp.exp_cap; > > +uint32_t sltcap = pci_get_word(exp_cap + PCI_EXP_SLTCAP); > > + > > +/* Check if hot-plug is disabled on the slot */ > > +if (dev->hotplugged && (sltcap & PCI_EXP_SLTCAP_HPC) == 0) { > > +error_setg(errp, "Hot-plug failed: unsupported by the port device > > '%s'", > > + DEVICE(hotplug_pdev)->id); > > +return; > > +} > > + > > pcie_cap_slot_plug_common(PCI_DEVICE(hotplug_dev), dev, errp); > > } > > > > @@ -415,7 +426,6 @@ void pcie_cap_slot_plug_cb(HotplugHandler *hotplug_dev, > > DeviceState *dev, > > { > > PCIDevice *hotplug_pdev = PCI_DEVICE(hotplug_dev); > > uint8_t *exp_cap = hotplug_pdev->config + hotplug_pdev->exp.exp_cap; > > -uint32_t sltcap = pci_get_word(exp_cap + PCI_EXP_SLTCAP); > > PCIDevice *pci_dev = PCI_DEVICE(dev); > > > > /* Don't send event when device is enabled during qemu machine > > creation: > > @@ -431,13 +441,6 @@ void pcie_cap_slot_plug_cb(HotplugHandler > > *hotplug_dev, DeviceState *dev, > > return; > > } > > > > -/* Check if hot-plug is disabled on the slot */ > > -if ((sltcap & PCI_EXP_SLTCAP_HPC) == 0) { > > -error_setg(errp, "Hot-plug failed: unsupported by the port device > > '%s'", > > - DEVICE(hotplug_pdev)->id); > > -return; > > -} > > - > > /* To enable multifunction hot-plug, we just ensure the function > > * 0 added last. When function 0 is added, we set the sltsta and > > * inform OS via event notification.
Re: [PATCH] hw/pci/pcie: Move hot plug capability check to pre_plug callback
On Mon, 1 Jun 2020 18:29:34 +0200 Julia Suvorova wrote: > Check for hot plug capability earlier to avoid removing devices attached > during the initialization process. > > Run qemu with an unattached drive: > -drive file=$FILE,if=none,id=drive0 \ > -device pcie-root-port,id=rp0,slot=3,bus=pcie.0,hotplug=off > Hotplug a block device: > device_add virtio-blk-pci,id=blk0,drive=drive0,bus=rp0 > If hotplug fails on plug_cb, drive0 will be deleted. > > Signed-off-by: Julia Suvorova > --- > Hard to say if it's a bug or generally acceptable behaviour, but seems like > hotplug_handler_plug should never fail. _unplug shouldn't fail the rest are allowed to, but it's hard to unwind intialization cleanly to _plug stage so if it's possible to do checks at _pre_plug time (i.e. before device's realize() is called) we should do so. Acked-by: Igor Mammedov > > hw/pci/pcie.c | 19 +++ > 1 file changed, 11 insertions(+), 8 deletions(-) > > diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c > index f50e10b8fb..5b9c022d91 100644 > --- a/hw/pci/pcie.c > +++ b/hw/pci/pcie.c > @@ -407,6 +407,17 @@ static void pcie_cap_slot_plug_common(PCIDevice > *hotplug_dev, DeviceState *dev, > void pcie_cap_slot_pre_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev, > Error **errp) > { > +PCIDevice *hotplug_pdev = PCI_DEVICE(hotplug_dev); > +uint8_t *exp_cap = hotplug_pdev->config + hotplug_pdev->exp.exp_cap; > +uint32_t sltcap = pci_get_word(exp_cap + PCI_EXP_SLTCAP); > + > +/* Check if hot-plug is disabled on the slot */ > +if (dev->hotplugged && (sltcap & PCI_EXP_SLTCAP_HPC) == 0) { > +error_setg(errp, "Hot-plug failed: unsupported by the port device > '%s'", > + DEVICE(hotplug_pdev)->id); > +return; > +} > + > pcie_cap_slot_plug_common(PCI_DEVICE(hotplug_dev), dev, errp); > } > > @@ -415,7 +426,6 @@ void pcie_cap_slot_plug_cb(HotplugHandler *hotplug_dev, > DeviceState *dev, > { > PCIDevice *hotplug_pdev = PCI_DEVICE(hotplug_dev); > uint8_t *exp_cap = hotplug_pdev->config + hotplug_pdev->exp.exp_cap; > -uint32_t sltcap = pci_get_word(exp_cap + PCI_EXP_SLTCAP); > PCIDevice *pci_dev = PCI_DEVICE(dev); > > /* Don't send event when device is enabled during qemu machine creation: > @@ -431,13 +441,6 @@ void pcie_cap_slot_plug_cb(HotplugHandler *hotplug_dev, > DeviceState *dev, > return; > } > > -/* Check if hot-plug is disabled on the slot */ > -if ((sltcap & PCI_EXP_SLTCAP_HPC) == 0) { > -error_setg(errp, "Hot-plug failed: unsupported by the port device > '%s'", > - DEVICE(hotplug_pdev)->id); > -return; > -} > - > /* To enable multifunction hot-plug, we just ensure the function > * 0 added last. When function 0 is added, we set the sltsta and > * inform OS via event notification.
Re: [PATCH] hw/pci/pcie: Move hot plug capability check to pre_plug callback
On Tue, Jun 2, 2020 at 5:54 AM Michael S. Tsirkin wrote: > > On Mon, Jun 01, 2020 at 06:29:34PM +0200, Julia Suvorova wrote: > > Check for hot plug capability earlier to avoid removing devices attached > > during the initialization process. > > > > Run qemu with an unattached drive: > > -drive file=$FILE,if=none,id=drive0 \ > > -device pcie-root-port,id=rp0,slot=3,bus=pcie.0,hotplug=off > > Hotplug a block device: > > device_add virtio-blk-pci,id=blk0,drive=drive0,bus=rp0 > > If hotplug fails on plug_cb, drive0 will be deleted. > > > > Signed-off-by: Julia Suvorova > > > Fixes: 0501e1aa1d32a6 ("hw/pci/pcie: Forbid hot-plug if it's disabled on the > slot") > > correct? Yes. > > --- > > Hard to say if it's a bug or generally acceptable behaviour, but seems like > > hotplug_handler_plug should never fail. > > > > hw/pci/pcie.c | 19 +++ > > 1 file changed, 11 insertions(+), 8 deletions(-) > > > > diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c > > index f50e10b8fb..5b9c022d91 100644 > > --- a/hw/pci/pcie.c > > +++ b/hw/pci/pcie.c > > @@ -407,6 +407,17 @@ static void pcie_cap_slot_plug_common(PCIDevice > > *hotplug_dev, DeviceState *dev, > > void pcie_cap_slot_pre_plug_cb(HotplugHandler *hotplug_dev, DeviceState > > *dev, > > Error **errp) > > { > > +PCIDevice *hotplug_pdev = PCI_DEVICE(hotplug_dev); > > +uint8_t *exp_cap = hotplug_pdev->config + hotplug_pdev->exp.exp_cap; > > +uint32_t sltcap = pci_get_word(exp_cap + PCI_EXP_SLTCAP); > > + > > +/* Check if hot-plug is disabled on the slot */ > > +if (dev->hotplugged && (sltcap & PCI_EXP_SLTCAP_HPC) == 0) { > > +error_setg(errp, "Hot-plug failed: unsupported by the port device > > '%s'", > > + DEVICE(hotplug_pdev)->id); > > +return; > > +} > > + > > pcie_cap_slot_plug_common(PCI_DEVICE(hotplug_dev), dev, errp); > > } > > > > @@ -415,7 +426,6 @@ void pcie_cap_slot_plug_cb(HotplugHandler *hotplug_dev, > > DeviceState *dev, > > { > > PCIDevice *hotplug_pdev = PCI_DEVICE(hotplug_dev); > > uint8_t *exp_cap = hotplug_pdev->config + hotplug_pdev->exp.exp_cap; > > -uint32_t sltcap = pci_get_word(exp_cap + PCI_EXP_SLTCAP); > > PCIDevice *pci_dev = PCI_DEVICE(dev); > > > > /* Don't send event when device is enabled during qemu machine > > creation: > > @@ -431,13 +441,6 @@ void pcie_cap_slot_plug_cb(HotplugHandler > > *hotplug_dev, DeviceState *dev, > > return; > > } > > > > -/* Check if hot-plug is disabled on the slot */ > > -if ((sltcap & PCI_EXP_SLTCAP_HPC) == 0) { > > -error_setg(errp, "Hot-plug failed: unsupported by the port device > > '%s'", > > - DEVICE(hotplug_pdev)->id); > > -return; > > -} > > - > > /* To enable multifunction hot-plug, we just ensure the function > > * 0 added last. When function 0 is added, we set the sltsta and > > * inform OS via event notification. > > -- > > 2.25.4 >
Re: [PATCH] hw/pci/pcie: Move hot plug capability check to pre_plug callback
On Mon, Jun 01, 2020 at 06:29:34PM +0200, Julia Suvorova wrote: > Check for hot plug capability earlier to avoid removing devices attached > during the initialization process. > > Run qemu with an unattached drive: > -drive file=$FILE,if=none,id=drive0 \ > -device pcie-root-port,id=rp0,slot=3,bus=pcie.0,hotplug=off > Hotplug a block device: > device_add virtio-blk-pci,id=blk0,drive=drive0,bus=rp0 > If hotplug fails on plug_cb, drive0 will be deleted. > > Signed-off-by: Julia Suvorova Fixes: 0501e1aa1d32a6 ("hw/pci/pcie: Forbid hot-plug if it's disabled on the slot") correct? > --- > Hard to say if it's a bug or generally acceptable behaviour, but seems like > hotplug_handler_plug should never fail. > > hw/pci/pcie.c | 19 +++ > 1 file changed, 11 insertions(+), 8 deletions(-) > > diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c > index f50e10b8fb..5b9c022d91 100644 > --- a/hw/pci/pcie.c > +++ b/hw/pci/pcie.c > @@ -407,6 +407,17 @@ static void pcie_cap_slot_plug_common(PCIDevice > *hotplug_dev, DeviceState *dev, > void pcie_cap_slot_pre_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev, > Error **errp) > { > +PCIDevice *hotplug_pdev = PCI_DEVICE(hotplug_dev); > +uint8_t *exp_cap = hotplug_pdev->config + hotplug_pdev->exp.exp_cap; > +uint32_t sltcap = pci_get_word(exp_cap + PCI_EXP_SLTCAP); > + > +/* Check if hot-plug is disabled on the slot */ > +if (dev->hotplugged && (sltcap & PCI_EXP_SLTCAP_HPC) == 0) { > +error_setg(errp, "Hot-plug failed: unsupported by the port device > '%s'", > + DEVICE(hotplug_pdev)->id); > +return; > +} > + > pcie_cap_slot_plug_common(PCI_DEVICE(hotplug_dev), dev, errp); > } > > @@ -415,7 +426,6 @@ void pcie_cap_slot_plug_cb(HotplugHandler *hotplug_dev, > DeviceState *dev, > { > PCIDevice *hotplug_pdev = PCI_DEVICE(hotplug_dev); > uint8_t *exp_cap = hotplug_pdev->config + hotplug_pdev->exp.exp_cap; > -uint32_t sltcap = pci_get_word(exp_cap + PCI_EXP_SLTCAP); > PCIDevice *pci_dev = PCI_DEVICE(dev); > > /* Don't send event when device is enabled during qemu machine creation: > @@ -431,13 +441,6 @@ void pcie_cap_slot_plug_cb(HotplugHandler *hotplug_dev, > DeviceState *dev, > return; > } > > -/* Check if hot-plug is disabled on the slot */ > -if ((sltcap & PCI_EXP_SLTCAP_HPC) == 0) { > -error_setg(errp, "Hot-plug failed: unsupported by the port device > '%s'", > - DEVICE(hotplug_pdev)->id); > -return; > -} > - > /* To enable multifunction hot-plug, we just ensure the function > * 0 added last. When function 0 is added, we set the sltsta and > * inform OS via event notification. > -- > 2.25.4