On Thu, May 07, 2015 at 12:50:50PM +0200, Jérémy Fanguède wrote: > On Wed, May 6, 2015 at 4:12 PM, Christoffer Dall > <christoffer.dall@xxxxxxxxxx> wrote: > > Hi Jérémy, > > > > On Tue, May 05, 2015 at 11:13:11AM +0200, Jérémy Fanguède wrote: > >> To maintain cache coherency on ARM, we may need a mechanism to flush > >> the data cache. > > > > In addition to generally just making this functionality available (see > > below), do you have an actual use case in mind for this? To solve the > > VGA issue, for example, we already have a patch series from Drew trying > > to address this. Does that not work for you? > > > > There was a long discussion about this here: > > https://lists.cs.columbia.edu/pipermail/kvmarm/2015-February/013593.html > > > > Drew then created a patch set, here: > > https://lists.nongnu.org/archive/html/qemu-devel/2015-03/msg01254.html > > > > and replied to himself, here: > > https://www.marc.info/?l=android-virt&m=142670523929132&w=3 > > > > Which basically says that he doesn't like having to do flushes all over > > QEMU (IIUC), so he sent this version instead: > > https://lists.cs.columbia.edu/pipermail/kvmarm/2015-March/014027.html > > > > Which he now said he'd respin. > > In fact, I used this ioctl in pairs with this QEMU patch series: > https://lists.nongnu.org/archive/html/qemu-devel/2015-05/msg00407.html > My current work doesn't do anything about vga ram, so vga issue > probably still persists, but it solves others issues with some > emulated devices (mainly PCI) which were failing before and now work > fine with this patch. Why does Drew's approach not work and your approach works here? What is the case that we haven't though about yet? -Christoffer -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
