Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 6a8edbd0 authored by Vitaly Kuznetsov's avatar Vitaly Kuznetsov Committed by Ingo Molnar
Browse files

x86/hyper-v: Introduce fast hypercall implementation 



Hyper-V supports 'fast' hypercalls when all parameters are passed through
registers. Implement an inline version of a simpliest of these calls:
hypercall with one 8-byte input and no output.

Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: default avatarAndy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: default avatarStephen Hemminger <sthemmin@microsoft.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Jork Loeser <Jork.Loeser@microsoft.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Simon Xiao <sixiao@microsoft.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: devel@linuxdriverproject.org
Link: http://lkml.kernel.org/r/20170802160921.21791-4-vkuznets@redhat.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent fc53662f

arch/x86/include/asm/mshyperv.h

+34 −0
Original line number Diff line number Diff line
@@ -209,6 +209,40 @@ static inline u64 hv_do_hypercall(u64 control, void *input, void *output) 
	return hv_status;

}



#define HV_HYPERCALL_FAST_BIT		BIT(16)



/* Fast hypercall with 8 bytes of input and no output */

static inline u64 hv_do_fast_hypercall8(u16 code, u64 input1)

{

	u64 hv_status, control = (u64)code | HV_HYPERCALL_FAST_BIT;

	register void *__sp asm(_ASM_SP);



#ifdef CONFIG_X86_64

	{

		__asm__ __volatile__("call *%4"

				     : "=a" (hv_status), "+r" (__sp),

				       "+c" (control), "+d" (input1)

				     : "m" (hv_hypercall_pg)

				     : "cc", "r8", "r9", "r10", "r11");

	}

#else

	{

		u32 input1_hi = upper_32_bits(input1);

		u32 input1_lo = lower_32_bits(input1);



		__asm__ __volatile__ ("call *%5"

				      : "=A"(hv_status),

					"+c"(input1_lo),

					"+r"(__sp)

				      :	"A" (control),

					"b" (input1_hi),

					"m" (hv_hypercall_pg)

				      : "cc", "edi", "esi");

	}

#endif

		return hv_status;

}



void hyperv_init(void);

void hyperv_report_panic(struct pt_regs *regs);

bool hv_is_hypercall_page_setup(void);