Messages in this thread Patch in this message | | | From | Vitaly Kuznetsov <> | Subject | [PATCH v7 04/10] x86/hyper-v: fast hypercall implementation | Date | Wed, 7 Jun 2017 13:00:55 +0200 |
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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 <vkuznets@redhat.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> --- 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 506b580..dc91a17 100644 --- a/arch/x86/include/asm/mshyperv.h +++ b/arch/x86/include/asm/mshyperv.h @@ -211,6 +211,40 @@ 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); -- 2.9.4
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