David Gibson <da...@gibson.dropbear.id.au> writes: >> It looks like the hflags MSR_LE is being updated correctly with TCG. But >> with KVM we only touch it on system_reset > > Ah.. right. I think to fix that we'd want an hreg_compute_hflags() at > the end of sucking the state out of KVM. >
Hm.. The hflags is a TCG thing that does not get used with KVM at all, except for that one bit in the monitor disas function. I'd rather keep it completely out of kvm_enabled code. Couldn't we perhaps make it conditional on the acceleration type? Using kvm_enabled() or some ifdef. Thanks >> (and possibly h_cede? I don't >> know if it is QEMU who handles it). > > It's KVM. If we used the qemu one it would add an awful lot of > latency to cedes. >> >> So I would let hflags be. >> >> >> ... Actually, I don't really know the purpose of hflags. It comes from: >> >> commit 3f3373166227b13e762e20d2fb51eadfa6a2d653 >> Author: Fabrice Bellard <fabr...@bellard.org> >> Date: Wed Aug 20 23:02:09 2003 +0000 >> >> pop ss, mov ss, x and sti disable irqs for the next instruction - >> began dispatch optimization by adding new x86 cpu 'hidden' flags >> >> >> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@372 >> c046a42c-6fe2-441c-8c8c-71466251a162 >> >> Could any one clarify that? > > Not really. It's really, really old, in the cruft bits of TCG I don't > much understand.
