On Mon, Aug 27, 2012 at 07:12:27PM +0000, Blue Swirl wrote: > On Mon, Aug 27, 2012 at 7:06 PM, Michael S. Tsirkin <mst@xxxxxxxxxx> wrote: > > On Mon, Aug 27, 2012 at 06:58:29PM +0000, Blue Swirl wrote: > >> On Mon, Aug 27, 2012 at 12:20 PM, Michael S. Tsirkin <mst@xxxxxxxxxx> wrote: > >> > In preparation for adding PV EOI support, disable PV EOI by default for > >> > 1.1 and older machine types, to avoid CPUID changing during migration. > >> > > >> > PV EOI can still be enabled/disabled by specifying it explicitly. > >> > Enable for 1.1 > >> > -M pc-1.1 -cpu kvm64,+kvm_pv_eoi > >> > Disable for 1.2 > >> > -M pc-1.2 -cpu kvm64,-kvm_pv_eoi > >> > > >> > Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx> > >> > --- > >> > hw/Makefile.objs | 2 +- > >> > hw/cpu_flags.c | 32 ++++++++++++++++++++++++++++++++ > >> > hw/cpu_flags.h | 9 +++++++++ > >> > hw/pc_piix.c | 2 ++ > >> > target-i386/cpu.c | 8 ++++++++ > >> > 5 files changed, 52 insertions(+), 1 deletion(-) > >> > create mode 100644 hw/cpu_flags.c > >> > create mode 100644 hw/cpu_flags.h > >> > > >> > diff --git a/hw/Makefile.objs b/hw/Makefile.objs > >> > index 850b87b..3f2532a 100644 > >> > --- a/hw/Makefile.objs > >> > +++ b/hw/Makefile.objs > >> > @@ -1,5 +1,5 @@ > >> > hw-obj-y = usb/ ide/ > >> > -hw-obj-y += loader.o > >> > +hw-obj-y += loader.o cpu_flags.o > >> > hw-obj-$(CONFIG_VIRTIO) += virtio-console.o > >> > hw-obj-$(CONFIG_VIRTIO_PCI) += virtio-pci.o > >> > hw-obj-y += fw_cfg.o > >> > diff --git a/hw/cpu_flags.c b/hw/cpu_flags.c > >> > new file mode 100644 > >> > index 0000000..2422d20 > >> > --- /dev/null > >> > +++ b/hw/cpu_flags.c > >> > @@ -0,0 +1,32 @@ > >> > +/* > >> > + * CPU compatibility flags. > >> > + * > >> > + * Copyright (c) 2012 Red Hat Inc. > >> > + * Author: Michael S. Tsirkin. > >> > + * > >> > + * This program is free software; you can redistribute it and/or modify > >> > + * it under the terms of the GNU General Public License as published by > >> > + * the Free Software Foundation; either version 2 of the License, or > >> > + * (at your option) any later version. > >> > + * > >> > + * This program is distributed in the hope that it will be useful, > >> > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > >> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > >> > + * GNU General Public License for more details. > >> > + * > >> > + * You should have received a copy of the GNU General Public License along > >> > + * with this program; if not, see <http://www.gnu.org/licenses/>. > >> > + */ > >> > +#include "hw/cpu_flags.h" > >> > + > >> > +static bool __kvm_pv_eoi_disabled; > >> > >> Don't use identifiers with leading underscores. > > > > C99 spec says " > > Any other predefined macro names > > shall begin with a leading underscore followed by an uppercase letter or > > a second underscore. > > " > > > > what are chances of compiler predefining macro __kvm_pv_eoi_disabled? > > Why do you even consider that since it's trivially easy to use > something else? If a standard (and HACKING in our case) specifies > something, why do you want to fight it? I missed this in HACKING, you are right: 2.4. Reserved namespaces in C and POSIX Underscore capital, double underscore, and underscore 't' suffixes should be avoided. so _kvm_pv_eoi_disabled is ok __kvm_pv_eoi_disabled is not. Will fix. > > > > But OK, will rename _kvm_pv_eoi_disabled. > > _ + lower case is guaranteed OK. > > No, just use kvm_pv_eoi_disabled, the underscore is useless. It isn't useless, this avoids conflict with function name. _ says it's an internal variable used to implement kvm_pv_eoi_disabled in a very clear way. -- MST -- 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
