| Message ID | 146913602256.26732.547184422534259409.stgit@bahia.lan |
|---|---|
| State | New |
| Headers | show |
On Thu, 21 Jul 2016 23:21:16 +0200 Greg Kurz <groug@kaod.org> wrote: > From: Greg Kurz <gkurz@linux.vnet.ibm.com> > > Without presuming if we got there because of a user mistake or some > more subtle bug in the tooling, it really does not make sense to > implement a non-functional device. > > Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com> > Reviewed-by: Marcel Apfelbaum <marcel@redhat.com> > Signed-off-by: Greg Kurz <groug@kaod.org> > --- > v4: - rephrased error message and provide a hint to the user > - split string literals to stay below 80 characters > - added Marcel's R-b tag > --- Marcel, I see that Michael has comments on your patch. If you feel this patch is valuable for 2.7, please consider carrying and pushing it, as I'm about to take a 1-month leave. Thanks. -- Greg > hw/virtio/virtio-pci.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c > index 755f9218b77d..72c4b392ffda 100644 > --- a/hw/virtio/virtio-pci.c > +++ b/hw/virtio/virtio-pci.c > @@ -1842,6 +1842,14 @@ static void virtio_pci_dc_realize(DeviceState *qdev, Error **errp) > VirtIOPCIProxy *proxy = VIRTIO_PCI(qdev); > PCIDevice *pci_dev = &proxy->pci_dev; > > + if (!(virtio_pci_modern(proxy) || virtio_pci_legacy(proxy))) { > + error_setg(errp, "device cannot work when both modern and legacy modes" > + " are disabled"); > + error_append_hint(errp, "Set either disable-modern or disable-legacy" > + " to off\n"); > + return; > + } > + > if (!(proxy->flags & VIRTIO_PCI_FLAG_DISABLE_PCIE) && > virtio_pci_modern(proxy)) { > pci_dev->cap_present |= QEMU_PCI_CAP_EXPRESS; > >
On 07/22/2016 12:55 AM, Greg Kurz wrote: > On Thu, 21 Jul 2016 23:21:16 +0200 > Greg Kurz <groug@kaod.org> wrote: > >> From: Greg Kurz <gkurz@linux.vnet.ibm.com> >> >> Without presuming if we got there because of a user mistake or some >> more subtle bug in the tooling, it really does not make sense to >> implement a non-functional device. >> >> Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com> >> Reviewed-by: Marcel Apfelbaum <marcel@redhat.com> >> Signed-off-by: Greg Kurz <groug@kaod.org> >> --- >> v4: - rephrased error message and provide a hint to the user >> - split string literals to stay below 80 characters >> - added Marcel's R-b tag >> --- > > Marcel, > > I see that Michael has comments on your patch. If you feel this patch is valuable > for 2.7, please consider carrying and pushing it, as I'm about to take a 1-month > leave. > I'll be sure to take it form here, thanks for the help! Marcel > Thanks. > > -- > Greg > >> hw/virtio/virtio-pci.c | 8 ++++++++ >> 1 file changed, 8 insertions(+) >> >> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c >> index 755f9218b77d..72c4b392ffda 100644 >> --- a/hw/virtio/virtio-pci.c >> +++ b/hw/virtio/virtio-pci.c >> @@ -1842,6 +1842,14 @@ static void virtio_pci_dc_realize(DeviceState *qdev, Error **errp) >> VirtIOPCIProxy *proxy = VIRTIO_PCI(qdev); >> PCIDevice *pci_dev = &proxy->pci_dev; >> >> + if (!(virtio_pci_modern(proxy) || virtio_pci_legacy(proxy))) { >> + error_setg(errp, "device cannot work when both modern and legacy modes" >> + " are disabled"); >> + error_append_hint(errp, "Set either disable-modern or disable-legacy" >> + " to off\n"); >> + return; >> + } >> + >> if (!(proxy->flags & VIRTIO_PCI_FLAG_DISABLE_PCIE) && >> virtio_pci_modern(proxy)) { >> pci_dev->cap_present |= QEMU_PCI_CAP_EXPRESS; >> >> >
On Thu, 21 Jul 2016 23:21:16 +0200 Greg Kurz <groug@kaod.org> wrote: > From: Greg Kurz <gkurz@linux.vnet.ibm.com> > > Without presuming if we got there because of a user mistake or some > more subtle bug in the tooling, it really does not make sense to > implement a non-functional device. > > Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com> > Reviewed-by: Marcel Apfelbaum <marcel@redhat.com> > Signed-off-by: Greg Kurz <groug@kaod.org> > --- > v4: - rephrased error message and provide a hint to the user > - split string literals to stay below 80 characters > - added Marcel's R-b tag > --- > hw/virtio/virtio-pci.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c > index 755f9218b77d..72c4b392ffda 100644 > --- a/hw/virtio/virtio-pci.c > +++ b/hw/virtio/virtio-pci.c > @@ -1842,6 +1842,14 @@ static void virtio_pci_dc_realize(DeviceState *qdev, Error **errp) > VirtIOPCIProxy *proxy = VIRTIO_PCI(qdev); > PCIDevice *pci_dev = &proxy->pci_dev; > > + if (!(virtio_pci_modern(proxy) || virtio_pci_legacy(proxy))) { I'm not sure that I didn't mess up the sequence of the realize callbacks, but could disable_legacy still be AUTO here? In that case, we'd fail for disable-modern=on and disable-legacy unset (i.e., AUTO), which would be ok for pcie but not for !pcie. > + error_setg(errp, "device cannot work when both modern and legacy modes" > + " are disabled"); > + error_append_hint(errp, "Set either disable-modern or disable-legacy" > + " to off\n"); > + return; > + } > + > if (!(proxy->flags & VIRTIO_PCI_FLAG_DISABLE_PCIE) && > virtio_pci_modern(proxy)) { > pci_dev->cap_present |= QEMU_PCI_CAP_EXPRESS; >
On Fri, 22 Jul 2016 10:04:35 +0200 Cornelia Huck <cornelia.huck@de.ibm.com> wrote: > On Thu, 21 Jul 2016 23:21:16 +0200 > Greg Kurz <groug@kaod.org> wrote: > > > From: Greg Kurz <gkurz@linux.vnet.ibm.com> > > > > Without presuming if we got there because of a user mistake or some > > more subtle bug in the tooling, it really does not make sense to > > implement a non-functional device. > > > > Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com> > > Reviewed-by: Marcel Apfelbaum <marcel@redhat.com> > > Signed-off-by: Greg Kurz <groug@kaod.org> > > --- > > v4: - rephrased error message and provide a hint to the user > > - split string literals to stay below 80 characters > > - added Marcel's R-b tag > > --- > > hw/virtio/virtio-pci.c | 8 ++++++++ > > 1 file changed, 8 insertions(+) > > > > diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c > > index 755f9218b77d..72c4b392ffda 100644 > > --- a/hw/virtio/virtio-pci.c > > +++ b/hw/virtio/virtio-pci.c > > @@ -1842,6 +1842,14 @@ static void virtio_pci_dc_realize(DeviceState *qdev, Error **errp) > > VirtIOPCIProxy *proxy = VIRTIO_PCI(qdev); > > PCIDevice *pci_dev = &proxy->pci_dev; > > > > + if (!(virtio_pci_modern(proxy) || virtio_pci_legacy(proxy))) { > > I'm not sure that I didn't mess up the sequence of the realize > callbacks, but could disable_legacy still be AUTO here? In that case, > we'd fail for disable-modern=on and disable-legacy unset (i.e., AUTO), > which would be ok for pcie but not for !pcie. > Marcel made the same comment in: https://lists.gnu.org/archive/html/qemu-devel/2016-07/msg05225.html If the user explicitly disables modern, she shouldn't rely on QEMU implicitly enabling legacy, hence the suggestion in error_append_hint(). > > + error_setg(errp, "device cannot work when both modern and legacy modes" > > + " are disabled"); > > + error_append_hint(errp, "Set either disable-modern or disable-legacy" > > + " to off\n"); > > + return; > > + } > > + > > if (!(proxy->flags & VIRTIO_PCI_FLAG_DISABLE_PCIE) && > > virtio_pci_modern(proxy)) { > > pci_dev->cap_present |= QEMU_PCI_CAP_EXPRESS; > > >
On Fri, 22 Jul 2016 12:11:11 +0200 Greg Kurz <groug@kaod.org> wrote: > On Fri, 22 Jul 2016 10:04:35 +0200 > Cornelia Huck <cornelia.huck@de.ibm.com> wrote: > > > On Thu, 21 Jul 2016 23:21:16 +0200 > > Greg Kurz <groug@kaod.org> wrote: > > > > > From: Greg Kurz <gkurz@linux.vnet.ibm.com> > > > > > > Without presuming if we got there because of a user mistake or some > > > more subtle bug in the tooling, it really does not make sense to > > > implement a non-functional device. > > > > > > Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com> > > > Reviewed-by: Marcel Apfelbaum <marcel@redhat.com> > > > Signed-off-by: Greg Kurz <groug@kaod.org> > > > --- > > > v4: - rephrased error message and provide a hint to the user > > > - split string literals to stay below 80 characters > > > - added Marcel's R-b tag > > > --- > > > hw/virtio/virtio-pci.c | 8 ++++++++ > > > 1 file changed, 8 insertions(+) > > > > > > diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c > > > index 755f9218b77d..72c4b392ffda 100644 > > > --- a/hw/virtio/virtio-pci.c > > > +++ b/hw/virtio/virtio-pci.c > > > @@ -1842,6 +1842,14 @@ static void virtio_pci_dc_realize(DeviceState *qdev, Error **errp) > > > VirtIOPCIProxy *proxy = VIRTIO_PCI(qdev); > > > PCIDevice *pci_dev = &proxy->pci_dev; > > > > > > + if (!(virtio_pci_modern(proxy) || virtio_pci_legacy(proxy))) { > > > > I'm not sure that I didn't mess up the sequence of the realize > > callbacks, but could disable_legacy still be AUTO here? In that case, > > we'd fail for disable-modern=on and disable-legacy unset (i.e., AUTO), > > which would be ok for pcie but not for !pcie. > > > > Marcel made the same comment in: > > https://lists.gnu.org/archive/html/qemu-devel/2016-07/msg05225.html > > If the user explicitly disables modern, she shouldn't rely on QEMU > implicitly enabling legacy, hence the suggestion in error_append_hint(). I don't know, I'd find that a bit surprising, especially as I would end up with a legacy-capable device if I did not specify anything in the !pcie case. > > > > + error_setg(errp, "device cannot work when both modern and legacy modes" > > > + " are disabled"); Suggest to change this wording to: "device cannot work as neither modern nor legacy mode is enabled" as this more accurately reflects what happened (the user did not actively disable legacy in the case above). > > > + error_append_hint(errp, "Set either disable-modern or disable-legacy" > > > + " to off\n"); The hint looks fine to me :) > > > + return; > > > + } > > > + > > > if (!(proxy->flags & VIRTIO_PCI_FLAG_DISABLE_PCIE) && > > > virtio_pci_modern(proxy)) { > > > pci_dev->cap_present |= QEMU_PCI_CAP_EXPRESS; > > > > > >
On Fri, 22 Jul 2016 12:32:24 +0200 Cornelia Huck <cornelia.huck@de.ibm.com> wrote: > On Fri, 22 Jul 2016 12:11:11 +0200 > Greg Kurz <groug@kaod.org> wrote: > > > On Fri, 22 Jul 2016 10:04:35 +0200 > > Cornelia Huck <cornelia.huck@de.ibm.com> wrote: > > > > > On Thu, 21 Jul 2016 23:21:16 +0200 > > > Greg Kurz <groug@kaod.org> wrote: > > > > > > > From: Greg Kurz <gkurz@linux.vnet.ibm.com> > > > > > > > > Without presuming if we got there because of a user mistake or some > > > > more subtle bug in the tooling, it really does not make sense to > > > > implement a non-functional device. > > > > > > > > Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com> > > > > Reviewed-by: Marcel Apfelbaum <marcel@redhat.com> > > > > Signed-off-by: Greg Kurz <groug@kaod.org> > > > > --- > > > > v4: - rephrased error message and provide a hint to the user > > > > - split string literals to stay below 80 characters > > > > - added Marcel's R-b tag > > > > --- > > > > hw/virtio/virtio-pci.c | 8 ++++++++ > > > > 1 file changed, 8 insertions(+) > > > > > > > > diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c > > > > index 755f9218b77d..72c4b392ffda 100644 > > > > --- a/hw/virtio/virtio-pci.c > > > > +++ b/hw/virtio/virtio-pci.c > > > > @@ -1842,6 +1842,14 @@ static void virtio_pci_dc_realize(DeviceState *qdev, Error **errp) > > > > VirtIOPCIProxy *proxy = VIRTIO_PCI(qdev); > > > > PCIDevice *pci_dev = &proxy->pci_dev; > > > > > > > > + if (!(virtio_pci_modern(proxy) || virtio_pci_legacy(proxy))) { > > > > > > I'm not sure that I didn't mess up the sequence of the realize > > > callbacks, but could disable_legacy still be AUTO here? In that case, > > > we'd fail for disable-modern=on and disable-legacy unset (i.e., AUTO), > > > which would be ok for pcie but not for !pcie. > > > > > > > Marcel made the same comment in: > > > > https://lists.gnu.org/archive/html/qemu-devel/2016-07/msg05225.html > > > > If the user explicitly disables modern, she shouldn't rely on QEMU > > implicitly enabling legacy, hence the suggestion in error_append_hint(). > > I don't know, I'd find that a bit surprising, especially as I would end > up with a legacy-capable device if I did not specify anything in > the !pcie case. > Isn't it already what happens with legacy being the default in pre-2.7 QEMU ? Do you think we should have separate checks for pcie and !pcie ? > > > > > > + error_setg(errp, "device cannot work when both modern and legacy modes" > > > > + " are disabled"); > > Suggest to change this wording to: > > "device cannot work as neither modern nor legacy mode is enabled" > > as this more accurately reflects what happened (the user did not > actively disable legacy in the case above). > Thanks ! This is THE wording I was looking for :) > > > > + error_append_hint(errp, "Set either disable-modern or disable-legacy" > > > > + " to off\n"); > > The hint looks fine to me :) > It was the easy part :) > > > > + return; > > > > + } > > > > + > > > > if (!(proxy->flags & VIRTIO_PCI_FLAG_DISABLE_PCIE) && > > > > virtio_pci_modern(proxy)) { > > > > pci_dev->cap_present |= QEMU_PCI_CAP_EXPRESS; > > > > > > > > > > >
On Fri, 22 Jul 2016 15:23:19 +0200 Greg Kurz <groug@kaod.org> wrote: > On Fri, 22 Jul 2016 12:32:24 +0200 > Cornelia Huck <cornelia.huck@de.ibm.com> wrote: > > > On Fri, 22 Jul 2016 12:11:11 +0200 > > Greg Kurz <groug@kaod.org> wrote: > > > > > On Fri, 22 Jul 2016 10:04:35 +0200 > > > Cornelia Huck <cornelia.huck@de.ibm.com> wrote: > > > > > > > On Thu, 21 Jul 2016 23:21:16 +0200 > > > > Greg Kurz <groug@kaod.org> wrote: > > > > > > > > > From: Greg Kurz <gkurz@linux.vnet.ibm.com> > > > > > > > > > > Without presuming if we got there because of a user mistake or some > > > > > more subtle bug in the tooling, it really does not make sense to > > > > > implement a non-functional device. > > > > > > > > > > Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com> > > > > > Reviewed-by: Marcel Apfelbaum <marcel@redhat.com> > > > > > Signed-off-by: Greg Kurz <groug@kaod.org> > > > > > --- > > > > > v4: - rephrased error message and provide a hint to the user > > > > > - split string literals to stay below 80 characters > > > > > - added Marcel's R-b tag > > > > > --- > > > > > hw/virtio/virtio-pci.c | 8 ++++++++ > > > > > 1 file changed, 8 insertions(+) > > > > > > > > > > diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c > > > > > index 755f9218b77d..72c4b392ffda 100644 > > > > > --- a/hw/virtio/virtio-pci.c > > > > > +++ b/hw/virtio/virtio-pci.c > > > > > @@ -1842,6 +1842,14 @@ static void virtio_pci_dc_realize(DeviceState *qdev, Error **errp) > > > > > VirtIOPCIProxy *proxy = VIRTIO_PCI(qdev); > > > > > PCIDevice *pci_dev = &proxy->pci_dev; > > > > > > > > > > + if (!(virtio_pci_modern(proxy) || virtio_pci_legacy(proxy))) { > > > > > > > > I'm not sure that I didn't mess up the sequence of the realize > > > > callbacks, but could disable_legacy still be AUTO here? In that case, > > > > we'd fail for disable-modern=on and disable-legacy unset (i.e., AUTO), > > > > which would be ok for pcie but not for !pcie. > > > > > > > > > > Marcel made the same comment in: > > > > > > https://lists.gnu.org/archive/html/qemu-devel/2016-07/msg05225.html > > > > > > If the user explicitly disables modern, she shouldn't rely on QEMU > > > implicitly enabling legacy, hence the suggestion in error_append_hint(). > > > > I don't know, I'd find that a bit surprising, especially as I would end > > up with a legacy-capable device if I did not specify anything in > > the !pcie case. > > > > Isn't it already what happens with legacy being the default in pre-2.7 QEMU ? Well, that is exactly my point; users may be surprised. > > Do you think we should have separate checks for pcie and !pcie ? I don't think we should overengineer this. > > > > > > > > > + error_setg(errp, "device cannot work when both modern and legacy modes" > > > > > + " are disabled"); > > > > Suggest to change this wording to: > > > > "device cannot work as neither modern nor legacy mode is enabled" > > > > as this more accurately reflects what happened (the user did not > > actively disable legacy in the case above). > > > > Thanks ! This is THE wording I was looking for :) :) I'm fine with the patch with the changed wording, as it less confusing for the user. <I'll be offline next week so please just attach my Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> if the only thing you change is the message>
On Fri, 22 Jul 2016 15:42:48 +0200 Cornelia Huck <cornelia.huck@de.ibm.com> wrote: > [...] > > > > > On Thu, 21 Jul 2016 23:21:16 +0200 > > > > > Greg Kurz <groug@kaod.org> wrote: > > > > > > > > > > > From: Greg Kurz <gkurz@linux.vnet.ibm.com> > > > > > > > > > > > > Without presuming if we got there because of a user mistake or some > > > > > > more subtle bug in the tooling, it really does not make sense to > > > > > > implement a non-functional device. > > > > > > > > > > > > Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com> > > > > > > Reviewed-by: Marcel Apfelbaum <marcel@redhat.com> > > > > > > Signed-off-by: Greg Kurz <groug@kaod.org> > > > > > > --- > > > > > > v4: - rephrased error message and provide a hint to the user > > > > > > - split string literals to stay below 80 characters > > > > > > - added Marcel's R-b tag > > > > > > --- > > > > > > hw/virtio/virtio-pci.c | 8 ++++++++ > > > > > > 1 file changed, 8 insertions(+) > > > > > > > > > > > > diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c > > > > > > index 755f9218b77d..72c4b392ffda 100644 > > > > > > --- a/hw/virtio/virtio-pci.c > > > > > > +++ b/hw/virtio/virtio-pci.c > > > > > > @@ -1842,6 +1842,14 @@ static void virtio_pci_dc_realize(DeviceState *qdev, Error **errp) > > > > > > VirtIOPCIProxy *proxy = VIRTIO_PCI(qdev); > > > > > > PCIDevice *pci_dev = &proxy->pci_dev; > > > > > > > > > > > > + if (!(virtio_pci_modern(proxy) || virtio_pci_legacy(proxy))) { > > > > > > > > > > I'm not sure that I didn't mess up the sequence of the realize > > > > > callbacks, but could disable_legacy still be AUTO here? In that case, > > > > > we'd fail for disable-modern=on and disable-legacy unset (i.e., AUTO), > > > > > which would be ok for pcie but not for !pcie. > > > > > > > > > > > > > Marcel made the same comment in: > > > > > > > > https://lists.gnu.org/archive/html/qemu-devel/2016-07/msg05225.html > > > > > > > > If the user explicitly disables modern, she shouldn't rely on QEMU > > > > implicitly enabling legacy, hence the suggestion in error_append_hint(). > > > > > > I don't know, I'd find that a bit surprising, especially as I would end > > > up with a legacy-capable device if I did not specify anything in > > > the !pcie case. > > > > > > > Isn't it already what happens with legacy being the default in pre-2.7 QEMU ? > > Well, that is exactly my point; users may be surprised. > One day legacy will be hopefully buried :) > > > > Do you think we should have separate checks for pcie and !pcie ? > > I don't think we should overengineer this. > Agreed. > > > > > > > > > > > > + error_setg(errp, "device cannot work when both modern and legacy modes" > > > > > > + " are disabled"); > > > > > > Suggest to change this wording to: > > > > > > "device cannot work as neither modern nor legacy mode is enabled" > > > > > > as this more accurately reflects what happened (the user did not > > > actively disable legacy in the case above). > > > > > > > Thanks ! This is THE wording I was looking for :) > > :) > > I'm fine with the patch with the changed wording, as it less confusing > for the user. > > <I'll be offline next week so please just attach my > > Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> > > if the only thing you change is the message> > I'll do this right away as I'll be offline for 1 month starting... just after I post v5 :) Cheers. -- Greg
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c index 755f9218b77d..72c4b392ffda 100644 --- a/hw/virtio/virtio-pci.c +++ b/hw/virtio/virtio-pci.c @@ -1842,6 +1842,14 @@ static void virtio_pci_dc_realize(DeviceState *qdev, Error **errp) VirtIOPCIProxy *proxy = VIRTIO_PCI(qdev); PCIDevice *pci_dev = &proxy->pci_dev; + if (!(virtio_pci_modern(proxy) || virtio_pci_legacy(proxy))) { + error_setg(errp, "device cannot work when both modern and legacy modes" + " are disabled"); + error_append_hint(errp, "Set either disable-modern or disable-legacy" + " to off\n"); + return; + } + if (!(proxy->flags & VIRTIO_PCI_FLAG_DISABLE_PCIE) && virtio_pci_modern(proxy)) { pci_dev->cap_present |= QEMU_PCI_CAP_EXPRESS;