Messages in this thread | | | Subject | Re: [Xen-devel] [PATCH] xen/hvc: If we use xen_raw_printk let it also work on HVM guests. | From | Ian Campbell <> | Date | Tue, 13 Aug 2013 23:20:05 +0100 |
| |
On Tue, 2013-08-13 at 21:59 +0100, Ian Campbell wrote:
> > What it should be is: > > > > > > > > void xen_raw_console_write(const char *str) > > > > { > > > > - dom0_write_console(0, str, strlen(str)); > > > > + if (!xen_domain()) > > > > + return; > > > > + > > > > + if (xen_pv_domain()) > > xen_domain() > > > > > > + dom0_write_console(0, str, strlen(str)); > > > > + else if (xen_hvm_domain() || xen_cpuid_base()) { > > > > else if (xen_cpuid_base()) { > > > > > > + /* The hyperpage has not been setup yet. */ > > > > + int i, len = strlen(str); > > > > + for (i = 0; i < len; i++) > > > > + outb(str[i], 0xe9); > > > > + } > > > > } > > > > And then that should adhere to what I wrote up. > > I think it does too.
Except as Daniel notes in <520A7145.5010306@tycho.nsa.gov> for unrelated reasons:
> HVM guests can still use the PV output - they just need to use the console > write hypercall instead of the HVM I/O port. I would think that PVH guests > would default to using the hypercall as it is more efficient (it takes a > string rather than one character per write). > > Actually, checking... the console_io hypercall would need to be added to > the hvm_hypercall{32,64}_table for an HVM guest to be able to use it; they > currently must use the I/O port. I didn't check the PVH patches.
Or did you actually try this code and it worked?
Ian.
| |