Re: [Qemu-devel] [PATCH v3] hw/i386: Deprecate the machines pc-0.10 to pc-1.2

[Michael S. Tsirkin]

On Wed, Jul 12, 2017 at 05:56:46PM -0300, Eduardo Habkost wrote:
> On Wed, Jul 12, 2017 at 11:31:59PM +0300, Michael S. Tsirkin wrote:
> > On Wed, Jul 12, 2017 at 05:15:50PM -0300, Eduardo Habkost wrote:
> > > On Wed, Jul 12, 2017 at 06:17:55PM +0300, Michael S. Tsirkin wrote:
> > > > On Wed, Jul 12, 2017 at 11:51:21AM -0300, Eduardo Habkost wrote:
> > > > > On Wed, Jul 12, 2017 at 10:22:33AM +0200, Thomas Huth wrote:
> > > > > > We don't want to carry along old machine types forever. If we are 
> > > > > > able to
> > > > > > remove the pc machines up to 0.13 one day for example, this would 
> > > > > > allow
> > > > > > us to eventually kill the code for rombar=0 (i.e. where QEMU copies 
> > > > > > ROM
> > > > > > BARs directly to low memory). Everything up to pc-1.2 is also known 
> > > > > > to
> > > > > > have issues with migration.  So let's start with a deprecation 
> > > > > > message
> > > > > > for the old machine types so that the (hopefully) few users of 
> > > > > > these old
> > > > > > systems start switching over to newer machine types instead.
> > > > > > 
> > > > > > Signed-off-by: Thomas Huth <address@hidden>
> > > > > 
> > > > > Reviewed-by: Eduardo Habkost <address@hidden>
> > > > > 
> > > > > I suggest changing "-machine help" too.  Today it looks like this:
> > > > > 
> > > > >   Supported machines are:
> > > > >   pc-i440fx-2.9        Standard PC (i440FX + PIIX, 1996)
> > > > >   pc-i440fx-2.8        Standard PC (i440FX + PIIX, 1996)
> > > > >   pc-i440fx-2.7        Standard PC (i440FX + PIIX, 1996)
> > > > >   pc-i440fx-2.6        Standard PC (i440FX + PIIX, 1996)
> > > > >   pc-i440fx-2.5        Standard PC (i440FX + PIIX, 1996)
> > > > >   pc-i440fx-2.4        Standard PC (i440FX + PIIX, 1996)
> > > > >   pc-i440fx-2.3        Standard PC (i440FX + PIIX, 1996)
> > > > >   pc-i440fx-2.2        Standard PC (i440FX + PIIX, 1996)
> > > > >   pc                   Standard PC (i440FX + PIIX, 1996) (alias of 
> > > > > pc-i440fx-2.10)
> > > > >   pc-i440fx-2.10       Standard PC (i440FX + PIIX, 1996) (default)
> > > > >   pc-i440fx-2.1        Standard PC (i440FX + PIIX, 1996)
> > > > >   pc-i440fx-2.0        Standard PC (i440FX + PIIX, 1996)
> > > > >   pc-i440fx-1.7        Standard PC (i440FX + PIIX, 1996)
> > > > >   pc-i440fx-1.6        Standard PC (i440FX + PIIX, 1996)
> > > > >   pc-i440fx-1.5        Standard PC (i440FX + PIIX, 1996)
> > > > >   pc-i440fx-1.4        Standard PC (i440FX + PIIX, 1996)
> > > > >   pc-1.3               Standard PC (i440FX + PIIX, 1996)
> > > > >   pc-1.2               Standard PC (i440FX + PIIX, 1996)
> > > > >   pc-1.1               Standard PC (i440FX + PIIX, 1996)
> > > > >   pc-1.0               Standard PC (i440FX + PIIX, 1996)
> > > > >   pc-0.15              Standard PC (i440FX + PIIX, 1996)
> > > > >   pc-0.14              Standard PC (i440FX + PIIX, 1996)
> > > > >   pc-0.13              Standard PC (i440FX + PIIX, 1996)
> > > > >   pc-0.12              Standard PC (i440FX + PIIX, 1996)
> > > > >   pc-0.11              Standard PC (i440FX + PIIX, 1996)
> > > > >   pc-0.10              Standard PC (i440FX + PIIX, 1996)
> > > > >   pc-q35-2.9           Standard PC (Q35 + ICH9, 2009)
> > > > >   pc-q35-2.8           Standard PC (Q35 + ICH9, 2009)
> > > > >   pc-q35-2.7           Standard PC (Q35 + ICH9, 2009)
> > > > >   pc-q35-2.6           Standard PC (Q35 + ICH9, 2009)
> > > > >   pc-q35-2.5           Standard PC (Q35 + ICH9, 2009)
> > > > >   pc-q35-2.4           Standard PC (Q35 + ICH9, 2009)
> > > > >   q35                  Standard PC (Q35 + ICH9, 2009) (alias of 
> > > > > pc-q35-2.10)
> > > > >   pc-q35-2.10          Standard PC (Q35 + ICH9, 2009)
> > > > >   isapc                ISA-only PC
> > > > >   none                 empty machine
> > > > 
> > > > Any chance we can sort them reasonably too?
> > > 
> > > If we use strverscmp(), it will be sorted in a more reasonable
> > > way.  We could copy the gnulib version on systems without glibc.
> > > Life is too short for writing configure checks by hand, though; I
> > > will add this to the end of my wish-todo list.  If somebody wants
> > > to volunteer, be my guest.
> > > 
> > > I'm CCing Eric in case he has suggestions that would help import
> > > the gnulib module in an easy way.
> > > 
> > > -- 
> > > Eduardo
> > 
> > As we never have leading zeroes, and input comes from QEMU so
> > it's safe, it's probably easier to just open-code it:
> > 
> > /* compare string numerically: shorter strings give smaller numbers */
> > int mstcmp(const char *s1, const char *s2)
> > {
> >     int l1, l2;
> > 
> >     l1 = strlen(s1);
> >     l2 = strlen(s2);
> >     return l1 == l2 ? strcmp(s1, s2) : l1 - l2;
> > }
> > 
> 
> This doesn't work because strlen("pc-0.10") > strlen("pc-1.0").

Oh right. So you need to find dots and split at these points.
Something like the below? Completely untested.

int mstcmp(const char *s1, const char *s2)
{
        const char *e1, *e2;
        int l1, l2, c;

        do {
                e1 = strchr(s1, '.');
                e2 = strchr(s2, '.');

                l1 = e1 ? e1 - s1 + 1 : strlen(s1);
                l2 = e2 ? e2 - s2 + 1 : strlen(s2);

                /* compare numerically: shorter strings give smaller numbers */
                if (l1 != l2) {
                        break;
                }
                c = strncmp(s1, s2, l1);
                if (c) {
                        return c;
                }
                s1 += l1;
                s2 += l1;
        } while (l1);

        return l1 - l2;
}



> -- 
> Eduardo