Commit 9a6fc8d0 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'bugfix' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen 

* 'bugfix' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen:
  xen: mask extended topology info in cpuid
  xen/hvc: make sure console output is always emitted, with explicit polling
parents d4116f82 82d64699

arch/x86/xen/enlighten.c

+10 −1
Original line number Diff line number Diff line
@@ -178,6 +178,7 @@ static __read_mostly unsigned int cpuid_leaf1_ecx_mask = ~0; 
static void xen_cpuid(unsigned int *ax, unsigned int *bx,

		      unsigned int *cx, unsigned int *dx)

{

	unsigned maskebx = ~0;

	unsigned maskecx = ~0;

	unsigned maskedx = ~0;
@@ -185,9 +186,16 @@ static void xen_cpuid(unsigned int *ax, unsigned int *bx, 
	 * Mask out inconvenient features, to try and disable as many

	 * unsupported kernel subsystems as possible.

	 */

	if (*ax == 1) {

	switch (*ax) {

	case 1:

		maskecx = cpuid_leaf1_ecx_mask;

		maskedx = cpuid_leaf1_edx_mask;

		break;



	case 0xb:

		/* Suppress extended topology stuff */

		maskebx = 0;

		break;

	}



	asm(XEN_EMULATE_PREFIX "cpuid"
@@ -197,6 +205,7 @@ static void xen_cpuid(unsigned int *ax, unsigned int *bx, 
		  "=d" (*dx)

		: "0" (*ax), "2" (*cx));



	*bx &= maskebx;

	*cx &= maskecx;

	*dx &= maskedx;

}

drivers/char/hvc_xen.c

+24 −1
Original line number Diff line number Diff line
@@ -55,7 +55,7 @@ static inline void notify_daemon(void) 
	notify_remote_via_evtchn(xen_start_info->console.domU.evtchn);

}



static int write_console(uint32_t vtermno, const char *data, int len)

static int __write_console(const char *data, int len)

{

	struct xencons_interface *intf = xencons_interface();

	XENCONS_RING_IDX cons, prod;
@@ -76,6 +76,29 @@ static int write_console(uint32_t vtermno, const char *data, int len) 
	return sent;

}



static int write_console(uint32_t vtermno, const char *data, int len)

{

	int ret = len;



	/*

	 * Make sure the whole buffer is emitted, polling if

	 * necessary.  We don't ever want to rely on the hvc daemon

	 * because the most interesting console output is when the

	 * kernel is crippled.

	 */

	while (len) {

		int sent = __write_console(data, len);

		

		data += sent;

		len -= sent;



		if (unlikely(len))

			HYPERVISOR_sched_op(SCHEDOP_yield, NULL);

	}



	return ret;

}



static int read_console(uint32_t vtermno, char *buf, int len)

{

	struct xencons_interface *intf = xencons_interface();