EBX of Implementation Recommendations MSR (0x40000004) indicates recommended number of attempts to retry a spinlock failure before notifying the hypervisor about the failures.
0xFFFFFFFF indicates never to retry. Signed-off-by: Yi Sun <[email protected]> Cc: "K. Y. Srinivasan" <[email protected]> Cc: Haiyang Zhang <[email protected]> Cc: Stephen Hemminger <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Michael Kelley (EOSG) <[email protected]> Cc: Juergen Gross <[email protected]> --- arch/x86/include/asm/mshyperv.h | 3 +++ arch/x86/kernel/cpu/mshyperv.c | 1 + 2 files changed, 4 insertions(+) diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h index 0d6271c..f909365 100644 --- a/arch/x86/include/asm/mshyperv.h +++ b/arch/x86/include/asm/mshyperv.h @@ -11,10 +11,13 @@ #define VP_INVAL U32_MAX +#define HYPERV_SPINLOCK_RETRY_NEVER U32_MAX + struct ms_hyperv_info { u32 features; u32 misc_features; u32 hints; + u32 num_spin_retry; u32 nested_features; u32 max_vp_index; u32 max_lp_index; diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index 1c72f38..04f480a 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -222,6 +222,7 @@ static void __init ms_hyperv_init_platform(void) ms_hyperv.features = cpuid_eax(HYPERV_CPUID_FEATURES); ms_hyperv.misc_features = cpuid_edx(HYPERV_CPUID_FEATURES); ms_hyperv.hints = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO); + ms_hyperv.num_spin_retry = cpuid_ebx(HYPERV_CPUID_ENLIGHTMENT_INFO); pr_info("Hyper-V: features 0x%x, hints 0x%x\n", ms_hyperv.features, ms_hyperv.hints); -- 1.9.1
