On 10/27/16 18:41, Radim Krčmář wrote: > 2016-10-26 23:40+0200, Laszlo Ersek: >> On 10/26/16 22:50, Radim Krčmář wrote: >>> [1/2] adds the emulation (and could be split into two patches if you'd like), >>> [2/2] just refactors the code. >>> >>> This should fix an issue that users are hitting. Laszlo found several reports: >>> - https://bugs.launchpad.net/qemu/+bug/1623276 >>> - https://bugzilla.proxmox.com/show_bug.cgi?id=1182 >>> - https://bugs.archlinux.org/task/50778 >>> >>> I have only tested it with a simple kvm-unit-tests, though. Reproducing the >>> iPXE issue is on the way ... >>> >>> >>> Radim Krčmář (2): >>> KVM: x86: emulate fxsave and fxrstor >>> KVM: x86: save one bit in ctxt->d >>> >>> arch/x86/kvm/emulate.c | 110 ++++++++++++++++++++++++++++++++++++++++++------- >>> 1 file changed, 94 insertions(+), 16 deletions(-) >>> >> >> I was just about to post iPXE patches that would disable the FXSAVE / >> FXRSTOR instructions in the CONFIG=qemu build (*), but you beat me to it >> with the KVM emulation code ;) >> >> (*) If you look at the iPXE commit that added them, they are a >> workaround for a Tivoli VMM bug; i.e., irrelevant for QEMU/KVM guests. >> >> ... Actually, those iPXE patches that conditionalize FXSAVE / FXRSTOR >> may still make sense -- we can rebuild iPXE, and bundle the refreshed >> binaries with QEMU v2.7.1, and swiftly at that. Whereas the KVM patches >> could take more time to propagate to users?... Not sure. What do you >> guys think? > > This series won't get into 4.9, so it would take almost half a year > before the kernel trickles into experimental distros. And updating > QEMU/iPXE isn't as dangerous as updating kernel, so I like the idea. > > I am just tempted to drop a KVM patch with positive diffstat that fixes > something that doesn't really need fixing anymore. :) Personally I can't argue either way; I'll just state that the iPXE patches aren't a done deal yet, either... We're still waiting for maintainer feedback. Thank you, Radim! Laszlo -- 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
