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Commit faeba830 authored by Christian Borntraeger's avatar Christian Borntraeger Committed by Rusty Russell
Browse files

s390: use virtio_console for KVM on s390 



This patch enables virtio_console as the default console on kvm for
s390. We currently use the same notify hack as lguest for early
console output. I will try to address this for lguest and s390 later.

Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
parent 7721c494

arch/s390/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -565,6 +565,7 @@ bool "s390 guest support (EXPERIMENTAL)" 
	depends on 64BIT && EXPERIMENTAL

	select VIRTIO

	select VIRTIO_RING

	select VIRTIO_CONSOLE

	help

	  Select this option if you want to run the kernel under s390 linux

endmenu

arch/s390/kernel/setup.c

+3 −1
Original line number Diff line number Diff line
@@ -54,6 +54,7 @@ 
#include <asm/sections.h>

#include <asm/ebcdic.h>

#include <asm/compat.h>

#include <asm/kvm_virtio.h>



long psw_kernel_bits	= (PSW_BASE_BITS | PSW_MASK_DAT | PSW_ASC_PRIMARY |

			   PSW_MASK_MCHECK | PSW_DEFAULT_KEY);
@@ -766,7 +767,8 @@ setup_arch(char **cmdline_p) 
		printk("We are running under VM (64 bit mode)\n");

	else if (MACHINE_IS_KVM) {

		printk("We are running under KVM (64 bit mode)\n");

		add_preferred_console("ttyS", 1, NULL);

		add_preferred_console("hvc", 0, NULL);

		s390_virtio_console_init();

	} else

		printk("We are running native (64 bit mode)\n");

#endif /* CONFIG_64BIT */

drivers/s390/kvm/kvm_virtio.c

+20 −0
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
#include <linux/err.h>

#include <linux/virtio.h>

#include <linux/virtio_config.h>

#include <linux/virtio_console.h>

#include <linux/interrupt.h>

#include <linux/virtio_ring.h>

#include <linux/pfn.h>
@@ -333,6 +334,25 @@ static int __init kvm_devices_init(void) 
	return 0;

}



/* code for early console output with virtio_console */

static __init int early_put_chars(u32 vtermno, const char *buf, int count)

{

	char scratch[17];

	unsigned int len = count;



	if (len > sizeof(scratch) - 1)

		len = sizeof(scratch) - 1;

	scratch[len] = '\0';

	memcpy(scratch, buf, len);

	kvm_hypercall1(KVM_S390_VIRTIO_NOTIFY, __pa(scratch));

	return len;

}



void s390_virtio_console_init(void)

{

	virtio_cons_early_init(early_put_chars);

}



/*

 * We do this after core stuff, but before the drivers.

 */

include/asm-s390/kvm_virtio.h

+10 −0
Original line number Diff line number Diff line
@@ -50,4 +50,14 @@ struct kvm_vqconfig { 
#define KVM_S390_VIRTIO_RESET		1

#define KVM_S390_VIRTIO_SET_STATUS	2



#ifdef __KERNEL__

/* early virtio console setup */

#ifdef CONFIG_VIRTIO_CONSOLE

extern void s390_virtio_console_init(void);

#else

static inline void s390_virtio_console_init(void)

{

}

#endif /* CONFIG_VIRTIO_CONSOLE */

#endif /* __KERNEL__ */

#endif