On Thu, Dec 7, 2017 at 7:27 PM, Michael S. Tsirkin <m...@redhat.com> wrote: > On Wed, Nov 22, 2017 at 03:22:50PM +0200, Marcel Apfelbaum wrote: >> On 22/11/2017 14:32, Ladi Prosek wrote: >> > On Wed, Nov 22, 2017 at 11:46 AM, Marcel Apfelbaum <mar...@redhat.com> >> > wrote: >> > > Hi Ladi, >> > > >> > > On 20/11/2017 16:22, Ladi Prosek wrote: >> > > > >> > > > msix_mask_all() is supposed to invoke the release vector notifier if >> > > > the >> > > > state of the >> > > > respective vector changed from unmasked or masked. >> > > >> > > >> > > You mean from unmasked "to" masked right? >> > >> > Yes, that's a typo. >> > >> > > 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. >> > > > >> > > >> > > As far as I can see in the code you are right.(very reset will trigger >> > > the >> > > release notifiers >> > > again) >> > > >> > > > This commit moves msix_mask_all() up so it runs before the device >> > > > state is >> > > > lost. >> > > >> > > >> > > OK >> > > >> > > > And >> > > > it adds a call to msix_update_function_masked() so that the device >> > > > remembers that >> > > > MSI-X is masked. >> > > > >> > > >> > > msix_update_function_masked checks the msix is enabled or masked-off. >> > > You are building on the fact the msix will not be enabled to set >> > > "msix_function_masked" to "true", right? >> > > (I just want to be sure I understand the patch) >> > >> > Correct. msix_enabled() will return false because we've just reset >> > >> > dev->config[dev->msix_cap + MSIX_CONTROL_OFFSET] >> > >> > I guess we could also simply assign true to it: >> > >> > dev->msix_function_masked = true; >> > >> > just like msix_init() does. >> >> Yes, is preferable - I think. >> If you intend to send V2, please wait first for Alex's remarks if he has any. >> >> Thanks, >> Marcel >> >> > >> > > > 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. >> > > > >> > > >> > > I would leave it (maybe) out of 2.11 because it may expose other bugs >> > > and we are after rc2 already. >> > > >> > > Adding Alex Williamson to see it does not affect device assignment, >> > > other than that the patch looks OK to me. >> > > >> > > >> > > Thanks, >> > > Marcel >> > > >> > > >> > > > Signed-off-by: Ladi Prosek <lpro...@redhat.com> >> > > > --- >> > > > 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..34656de9b0 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); >> > > > + msix_update_function_masked(dev); >> > > > } >> > > > /* PCI spec suggests that devices make it possible for software to >> > > > configure >> > > > >> > > > > Do you intend to post v2 or need Marcel to?
I'll post v2 tomorrow.
