Messages in this thread | | | From | Jork Loeser <> | Subject | RE: [PATCH 2/7] x86/hyper-v: fast hypercall implementation | Date | Fri, 7 Apr 2017 19:42:10 +0000 |
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> -----Original Message----- > From: Vitaly Kuznetsov [mailto:vkuznets@redhat.com] > Sent: Friday, April 7, 2017 04:27 > To: devel@linuxdriverproject.org; x86@kernel.org > Cc: linux-kernel@vger.kernel.org; KY Srinivasan <kys@microsoft.com>; > Haiyang Zhang <haiyangz@microsoft.com>; Stephen Hemminger > <sthemmin@microsoft.com>; Thomas Gleixner <tglx@linutronix.de>; Ingo > Molnar <mingo@redhat.com>; H. Peter Anvin <hpa@zytor.com>; Steven > Rostedt <rostedt@goodmis.org>; Jork Loeser <Jork.Loeser@microsoft.com> > Subject: [PATCH 2/7] x86/hyper-v: fast hypercall implementation
> diff --git a/arch/x86/include/asm/mshyperv.h > b/arch/x86/include/asm/mshyperv.h index 331e834..9a5f58b 100644 > --- a/arch/x86/include/asm/mshyperv.h > +++ b/arch/x86/include/asm/mshyperv.h > @@ -216,6 +216,43 @@ static inline u64 hv_do_hypercall(u64 control, void > *input, void *output) #endif /* !x86_64 */ } > > +/* Fast hypercall with 8 bytes of input and no output */ static inline > +u64 hv_do_fast_hypercall8(u16 code, u64 input1) { > + union hv_hypercall_input control = {0}; > + > + control.code = code; > + control.fast = 1; > +#ifdef CONFIG_X86_64 > + { > + u64 hv_status; > + > + __asm__ __volatile__("call *%3" > + : "=a" (hv_status) > + : "c" (control.as_uint64), "d" (input1), > + "m" (hv_hypercall_pg) > + : "cc", "r8", "%r9", "%r10", "%r11"); > + return hv_status; Clobber memory (are there such fast hypercalls)?
> + } > +#else > + { > + u32 hv_status_hi, hv_status_lo; > + > + __asm__ __volatile__ ("call *%6" > + : "=d"(hv_status_hi), > + "=a"(hv_status_lo) : > + "d" (control.as_uint32_hi), > + "a" (control.as_uint32_lo), > + "c" ((u32)input1), > + "b" ((u32)(input1 >> 32)), > + "m" (hv_hypercall_pg) > + : "cc"); > + > + return hv_status_lo | ((u64)hv_status_hi << 32); > + } > +#endif Please clobber ECX, EDI and ESI for x86. Clobber memory as well?
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