----- Original Message ----- > From: "Ladi Prosek" <lpro...@redhat.com> > To: qemu-devel@nongnu.org > Cc: mar...@redhat.com, ge...@hostfission.com, m...@redhat.com, "alex > williamson" <alex.william...@redhat.com> > Sent: Friday, December 8, 2017 8:31:13 AM > Subject: [PATCH v2] msix: don't mask already masked vectors on reset > > msix_mask_all() is supposed to invoke the release vector notifier if the > state of the > respective vector changed from unmasked to masked. The way it's currently > called from > msix_reset(), though, may result in calling the release notifier even if the > vector > is already masked. > > 1) msix_reset() clears out the msix_cap field and the msix_table. > 2) msix_mask_all() runs with was_masked=false for all vectors because of 1), > which > results in calling the release notifier on all vectors. > 3) if msix_reset() is subsequently called again, it goes through the same > steps and > calls the release notifier on all vectors again. > > This commit moves msix_mask_all() up so it runs before the device state is > lost. And > it adds an assignment to msix_function_masked so that the device remembers > that > MSI-X is masked. > > This is likely a low impact issue, found while debugging an already broken > device. It > is however easy to fix and the expectation that the use and release notifier > invocations > are always balanced is very natural. > > Signed-off-by: Ladi Prosek <lpro...@redhat.com> > --- > > v1->v2: > * fixed typo in commit message "or" -> "to" (Marcel) > * directly set msix_function_masked to true instead of calling > msix_update_function_masked() (Marcel) > > > hw/pci/msix.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/hw/pci/msix.c b/hw/pci/msix.c > index c944c02135..d6a4dbdb6b 100644 > --- a/hw/pci/msix.c > +++ b/hw/pci/msix.c > @@ -500,11 +500,12 @@ void msix_reset(PCIDevice *dev) > return; > } > msix_clear_all_vectors(dev); > + msix_mask_all(dev, dev->msix_entries_nr); > dev->config[dev->msix_cap + MSIX_CONTROL_OFFSET] &= > ~dev->wmask[dev->msix_cap + MSIX_CONTROL_OFFSET]; > memset(dev->msix_table, 0, dev->msix_entries_nr * PCI_MSIX_ENTRY_SIZE); > memset(dev->msix_pba, 0, QEMU_ALIGN_UP(dev->msix_entries_nr, 64) / 8); > - msix_mask_all(dev, dev->msix_entries_nr); > + dev->msix_function_masked = true; > } > > /* PCI spec suggests that devices make it possible for software to configure > -- > 2.13.6 > >
Thanks Ladi! Reviewed-by: Marcel Apfelbaum <mar...@redhat.com>
