[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [PATCH v1 2/2] xen/console: unify printout behavior for UART emulators
On Wed, Jun 04, 2025 at 12:48:05PM +0200, Jan Beulich wrote: > On 31.05.2025 02:04, dmkhn@xxxxxxxxx wrote: > > --- a/xen/arch/x86/hvm/hvm.c > > +++ b/xen/arch/x86/hvm/hvm.c > > @@ -577,7 +577,7 @@ static int cf_check hvm_print_line( > > if ( (cd->pbuf_idx == (DOMAIN_PBUF_SIZE - 1)) || (c == '\n') ) > > { > > cd->pbuf[cd->pbuf_idx] = '\0'; > > - guest_printk(cd, XENLOG_G_DEBUG "%s\n", cd->pbuf); > > + guest_printk(cd, "%s\n", cd->pbuf); > > cd->pbuf_idx = 0; > > } > > Why this and ... > > > @@ -755,7 +765,7 @@ static long > > guest_console_write(XEN_GUEST_HANDLE_PARAM(char) buffer, > > else > > { > > cd->pbuf[cd->pbuf_idx] = '\0'; > > - guest_printk(cd, XENLOG_G_DEBUG "%s%s\n", cd->pbuf, kbuf); > > + guest_printk(cd, "%s%s\n", cd->pbuf, kbuf); > > cd->pbuf_idx = 0; > > } > > ... this change? There's no compensation for it ... > > > @@ -1013,12 +1023,21 @@ void printk(const char *fmt, ...) > > va_end(args); > > } > > > > +/* > > + * Print message from the guest on the diagnostic console. > > + * Prefixes all messages w/ "(dX)" if domain X does not own physical > > console > > + * focus. > > + */ > > void guest_printk(const struct domain *d, const char *fmt, ...) > > { > > va_list args; > > - char prefix[16]; > > + char prefix[16] = ""; > > + struct domain *consd; > > > > - snprintf(prefix, sizeof(prefix), "(d%d) ", d->domain_id); > > + consd = console_get_domain(); > > + if ( consd != d ) > > + snprintf(prefix, sizeof(prefix), "(d%d) ", d->domain_id); > > + console_put_domain(consd); > > > > va_start(args, fmt); > > vprintk_common(fmt, args, prefix); > > ... here afaics, so it looks like you're undermining rate-limiting of > those messages. I droppped behavior change for I/O debug port on x86 and HYPERVISOR_console_io hypercall. But my understanding is that all guest debugging facilities, if enabled, should not be rate-limited. > > Jan
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