Commit-ID: 6a8edbd0c54ae266b12f4f63e406313481c9d4bc Gitweb: http://git.kernel.org/tip/6a8edbd0c54ae266b12f4f63e406313481c9d4bc Author: Vitaly Kuznetsov <vkuzn...@redhat.com> AuthorDate: Wed, 2 Aug 2017 18:09:15 +0200 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Thu, 10 Aug 2017 16:50:22 +0200
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: Vitaly Kuznetsov <vkuzn...@redhat.com> Reviewed-by: Andy Shevchenko <andy.shevche...@gmail.com> Reviewed-by: Stephen Hemminger <sthem...@microsoft.com> Cc: Andy Lutomirski <l...@kernel.org> Cc: Haiyang Zhang <haiya...@microsoft.com> Cc: Jork Loeser <jork.loe...@microsoft.com> Cc: K. Y. Srinivasan <k...@microsoft.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Simon Xiao <six...@microsoft.com> Cc: Steven Rostedt <rost...@goodmis.org> Cc: Thomas Gleixner <t...@linutronix.de> Cc: de...@linuxdriverproject.org Link: http://lkml.kernel.org/r/20170802160921.21791-4-vkuzn...@redhat.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/include/asm/mshyperv.h | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h index 6fa5e34..e484255 100644 --- a/arch/x86/include/asm/mshyperv.h +++ b/arch/x86/include/asm/mshyperv.h @@ -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);
