x86/hyper-v: Introduce fast hypercall implementation - kernel/git/torvalds/linux.git - Linux kernel source tree
- ️Wed Aug 02 2017
| author | Vitaly Kuznetsov <vkuznets@redhat.com> | 2017-08-02 18:09:15 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-08-10 16:50:22 +0200 |
| commit | 6a8edbd0c54ae266b12f4f63e406313481c9d4bc (patch) | |
| tree | cf8411957fdf7910e0fcb7d2abfa05d2c7717614 | |
| parent | fc53662f13b889a5a1c069e79ee1e3d4534df132 (diff) | |
| download | linux-6a8edbd0c54ae266b12f4f63e406313481c9d4bc.tar.gz |
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 <vkuznets@redhat.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Stephen 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: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | arch/x86/include/asm/mshyperv.h | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 6fa5e342cc8687..e484255bd9defb 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);