Konrad Rzeszutek Wilk
2013-Oct-28 15:48 UTC
Re: [PATCH] xen/hvc-console: Make it work with HVM guests.
On Sat, Oct 26, 2013 at 09:27:08AM +0100, Ian Campbell wrote:> On Fri, 2013-10-25 at 15:38 -0400, Konrad Rzeszutek Wilk wrote: > > On Thu, Oct 24, 2013 at 05:43:54PM +0100, Ian Campbell wrote: > > > But stepping back how/why is this function called on x86 when not > > > running under Xen? Wouldn''t the use have to be using console=hvc or > > > earlyprintk=xen or something -- which strikes me as user error... IOW > > > can we not just nuke the check > > > > It shouldn''t - ever. On x86 it is called from the early PV bootup code. > > > > I occasionaly use it when developing/debugging and as such want it working > > in HVM even during early bootup. > > Does earlyprintk=ttyS0,cough not Just Work for HVM guests? That would > avoid all of this stuff and assuming it works would be preferable IMHO.It works OK. But this is an alternative avenue of using ''xen_raw_printk'' for both PV and HVM.> > Anyway, if not, then given that the xen_cpuid_base case is entirely x86 > specific perhaps we can abstract this as something like: > > if (xen_arch_raw_console(str)) > return > > dom0_write_console(...) > > Then ARM: > #define xen_arch_raw_console 0 > and x86 > static inline int xen_arch_raw_console(str) > { > if (xen_domain()) > return 0; > > /* Do the outb thing */ > return 1; > } > > This would also avoid the need for #ifdef x86 in the main function which > Julien pointed out.OK.> > Ian. >