Messages in this thread | | | Date | Wed, 23 Oct 2013 23:08:01 +0100 | From | Julien Grall <> | Subject | Re: [Xen-devel] [PATCH] xen/hvc-console: Make it work with HVM guests. |
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On 10/23/2013 05:15 PM, Konrad Rzeszutek Wilk wrote: > On Sun, Oct 06, 2013 at 09:52:40PM +0100, Julien Grall wrote: >> On 09/30/2013 03:45 PM, Konrad Rzeszutek Wilk wrote: >>> On Fri, Sep 27, 2013 at 10:49:37PM +0100, Julien Grall wrote: >>>> On 09/27/2013 10:25 PM, Konrad Rzeszutek Wilk wrote: >>>> >>>>> @@ -641,7 +641,20 @@ struct console xenboot_console = { >>>>> >>>>> void xen_raw_console_write(const char *str) >>>>> { >>>>> - dom0_write_console(0, str, strlen(str)); >>>>> + ssize_t len = strlen(str); >>>>> + int rc = 0; >>>>> + >>>>> + if (xen_domain()) { >>>>> + dom0_write_console(0, str, len); >>>>> + if (rc == -ENOSYS && xen_hvm_domain()) >>>>> + goto outb_print; >>>>> + >>>>> + } else if (xen_cpuid_base()) { >>>>> + int i; >>>>> +outb_print: >>>>> + for (i = 0; i < len; i++) >>>>> + outb(str[i], 0xe9); >>>>> + } >>>>> } >>>> >>>> xen_cpuid_base and outb(0xe9) is x86 specific and won't compile on ARM. >>> >>> Odd, I see outb defined in arch/arm and arch/arm64 ?(arch/arm[|64]/include/asm.io.h) >> >> On ARM32 the IO access is memory mapped (the exact address depends >> on Linux configuration). >> The main problem is not the outb macro but the ioport 0xe9.On ARM, >> this ioport is not trapped by Xen. >> >>> You are of course right about xen_cpuid_base. >>> >>> How about this: >> >> For the ARM side, the code looks good. > > Can I that as 'Acked-by' ? thanks
Actually, I looked closer the code, with the new solution xen_raw_printk/xen_raw_console_write can't be call on ARM during early init.
On ARM, xen_domain_type is initialized during a core initcall. So it's not possible to call the function before.
>>> From 04b772d2b819f0dda2163e3193fa7cd447a6245c Mon Sep 17 00:00:00 2001 >>> From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> >>> Date: Fri, 27 Sep 2013 17:18:13 -0400 >>> Subject: [PATCH] xen/hvc: If we use xen_raw_printk let it also work on HVM >>> guests. >>> >>> The xen_raw_printk works great for debugging purposes. We use >>> for PV guests and we can also use it for HVM guests. >>> >>> However, for HVM guests we have a fallback of using the 0xe9 >>> port in case the hypervisor does not support an HVM guest of >>> using the console_io hypercall. As such lets use 0xe9 during >>> early bootup, and once the hyper-page is setup and if the >>> console_io hypercall is supported - use that. Otherwise we >>> will fallback to using the 0xe9 after early bootup. >>> >>> We also alter the return value for dom0_write_console to return >>> an error value instead of zero. The HVC API has been supporting >>> returning error values for quite some time. >>> >>> P.S. >>> To use (and to see the output in the Xen ring buffer) one has to build >>> the hypervisor with 'debug=y'. >>> >>> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> >>> [v1: ifdef xen_cpuid_base as it is X86 specific] >>> --- >>> drivers/tty/hvc/hvc_xen.c | 19 +++++++++++++++++-- >>> 1 file changed, 17 insertions(+), 2 deletions(-) >>> >>> diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c >>> index e61c36c..6458c9f 100644 >>> --- a/drivers/tty/hvc/hvc_xen.c >>> +++ b/drivers/tty/hvc/hvc_xen.c >>> @@ -183,7 +183,7 @@ static int dom0_write_console(uint32_t vtermno, const char *str, int len) >>> { >>> int rc = HYPERVISOR_console_io(CONSOLEIO_write, len, (char *)str); >>> if (rc < 0) >>> - return 0; >>> + return rc; >>> >>> return len; >>> } >>> @@ -641,7 +641,22 @@ struct console xenboot_console = { >>> >>> void xen_raw_console_write(const char *str) >>> { >>> - dom0_write_console(0, str, strlen(str)); >>> + ssize_t len = strlen(str); >>> + int rc = 0; >>> + >>> + if (xen_domain()) { >>> + rc = dom0_write_console(0, str, len); >>> +#ifdef CONFIG_X86 >>> + if (rc == -ENOSYS && xen_hvm_domain()) >>> + goto outb_print; >>> + >>> + } else if (xen_cpuid_base()) { >>> + int i; >>> +outb_print: >>> + for (i = 0; i < len; i++) >>> + outb(str[i], 0xe9); >>> +#endif >>> + } >>> } >>> >>> void xen_raw_printk(const char *fmt, ...)
-- Julien Grall
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