Message ID | 1438003477-5769-1-git-send-email-mst@redhat.com |
---|---|
State | New |
Headers | show |
On 27/07/2015 15:24, Michael S. Tsirkin wrote: > +static void virtio_pci_modern_region_unmap(VirtIOPCIProxy *proxy, > + VirtIOPCIRegion *region) > +{ > + memory_region_del_subregion(&proxy->modern_bar, > + ®ion->mr); > +} > + > /* This is called by virtio-bus just after the device is plugged. */ > static void virtio_pci_device_plugged(DeviceState *d, Error **errp) > { > @@ -1520,8 +1527,16 @@ static void virtio_pci_device_plugged(DeviceState *d, Error **errp) > static void virtio_pci_device_unplugged(DeviceState *d) > { > VirtIOPCIProxy *proxy = VIRTIO_PCI(d); > + bool modern = !(proxy->flags & VIRTIO_PCI_FLAG_DISABLE_MODERN); > > virtio_pci_stop_ioeventfd(proxy); > + > + if (modern) { > + virtio_pci_modern_region_unmap(proxy, &proxy->common); > + virtio_pci_modern_region_unmap(proxy, &proxy->isr); > + virtio_pci_modern_region_unmap(proxy, &proxy->device); > + virtio_pci_modern_region_unmap(proxy, &proxy->notify); > + } > } Actually this is not necessary. memory_region_del_subregion is only needed inasmuch as it prevents further guest access to the region, so it's enough that the toplevel region (the modern_bar itself) is unmapped. The PCI core does that automatically. That said, it's polite to unmap everything, so if you want this patch: Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Paolo
On 27/07/2015 15:30, Paolo Bonzini wrote: > > > On 27/07/2015 15:24, Michael S. Tsirkin wrote: >> +static void virtio_pci_modern_region_unmap(VirtIOPCIProxy *proxy, >> + VirtIOPCIRegion *region) >> +{ >> + memory_region_del_subregion(&proxy->modern_bar, >> + ®ion->mr); >> +} >> + >> /* This is called by virtio-bus just after the device is plugged. */ >> static void virtio_pci_device_plugged(DeviceState *d, Error **errp) >> { >> @@ -1520,8 +1527,16 @@ static void virtio_pci_device_plugged(DeviceState *d, Error **errp) >> static void virtio_pci_device_unplugged(DeviceState *d) >> { >> VirtIOPCIProxy *proxy = VIRTIO_PCI(d); >> + bool modern = !(proxy->flags & VIRTIO_PCI_FLAG_DISABLE_MODERN); >> >> virtio_pci_stop_ioeventfd(proxy); >> + >> + if (modern) { >> + virtio_pci_modern_region_unmap(proxy, &proxy->common); >> + virtio_pci_modern_region_unmap(proxy, &proxy->isr); >> + virtio_pci_modern_region_unmap(proxy, &proxy->device); >> + virtio_pci_modern_region_unmap(proxy, &proxy->notify); >> + } >> } > > Actually this is not necessary. memory_region_del_subregion is only > needed inasmuch as it prevents further guest access to the region, so > it's enough that the toplevel region (the modern_bar itself) is > unmapped. The PCI core does that automatically. > > That said, it's polite to unmap everything, so if you want this patch: > > Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> After discussing on IRC the problem (which is that memory_region_add_subregion add a reference to the VirtioPCIProxy object, and you want to remove it), this is indeed the correct fix. Paolo
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c index db8f27c..c024161 100644 --- a/hw/virtio/virtio-pci.c +++ b/hw/virtio/virtio-pci.c @@ -1414,6 +1414,13 @@ static void virtio_pci_modern_region_map(VirtIOPCIProxy *proxy, virtio_pci_add_mem_cap(proxy, cap); } +static void virtio_pci_modern_region_unmap(VirtIOPCIProxy *proxy, + VirtIOPCIRegion *region) +{ + memory_region_del_subregion(&proxy->modern_bar, + ®ion->mr); +} + /* This is called by virtio-bus just after the device is plugged. */ static void virtio_pci_device_plugged(DeviceState *d, Error **errp) { @@ -1520,8 +1527,16 @@ static void virtio_pci_device_plugged(DeviceState *d, Error **errp) static void virtio_pci_device_unplugged(DeviceState *d) { VirtIOPCIProxy *proxy = VIRTIO_PCI(d); + bool modern = !(proxy->flags & VIRTIO_PCI_FLAG_DISABLE_MODERN); virtio_pci_stop_ioeventfd(proxy); + + if (modern) { + virtio_pci_modern_region_unmap(proxy, &proxy->common); + virtio_pci_modern_region_unmap(proxy, &proxy->isr); + virtio_pci_modern_region_unmap(proxy, &proxy->device); + virtio_pci_modern_region_unmap(proxy, &proxy->notify); + } } static void virtio_pci_realize(PCIDevice *pci_dev, Error **errp)
Each memory_region_add_subregion must be paired with memory_region_del_subregion. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> --- hw/virtio/virtio-pci.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+)