lkml.org 
[lkml]   [2017]   [Jun]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH v8 06/10] x86/hyper-v: implement rep hypercalls
    Date
    Rep hypercalls are normal hypercalls which perform multiple actions at
    once. Hyper-V guarantees to return exectution to the caller in not more
    than 50us and the caller needs to use hypercall continuation. Touch NMI
    watchdog between hypercall invocations.

    This is going to be used for HvFlushVirtualAddressList hypercall for
    remote TLB flushing.

    Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
    Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
    ---
    arch/x86/include/asm/mshyperv.h | 39 +++++++++++++++++++++++++++++++++++++++
    1 file changed, 39 insertions(+)

    diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
    index f3bedb4..ed8107d 100644
    --- a/arch/x86/include/asm/mshyperv.h
    +++ b/arch/x86/include/asm/mshyperv.h
    @@ -4,6 +4,7 @@
    #include <linux/types.h>
    #include <linux/interrupt.h>
    #include <linux/clocksource.h>
    +#include <linux/nmi.h>
    #include <asm/hyperv.h>

    /*
    @@ -211,7 +212,13 @@ static inline u64 hv_do_hypercall(u64 control, void *input, void *output)
    return hv_status;
    }

    +#define HV_HYPERCALL_RESULT_MASK GENMASK_ULL(15, 0)
    #define HV_HYPERCALL_FAST_BIT BIT(16)
    +#define HV_HYPERCALL_VARHEAD_OFFSET 17
    +#define HV_HYPERCALL_REP_COMP_OFFSET 32
    +#define HV_HYPERCALL_REP_COMP_MASK GENMASK_ULL(43, 32)
    +#define HV_HYPERCALL_REP_START_OFFSET 48
    +#define HV_HYPERCALL_REP_START_MASK GENMASK_ULL(59, 48)

    /* Fast hypercall with 8 bytes of input and no output */
    static inline u64 hv_do_fast_hypercall8(u16 code, u64 input1)
    @@ -245,6 +252,38 @@ static inline u64 hv_do_fast_hypercall8(u16 code, u64 input1)
    return hv_status;
    }

    +/*
    + * Rep hypercalls. Callers of this functions are supposed to ensure that
    + * rep_count and varhead_size comply with Hyper-V hypercall definition.
    + */
    +static inline u64 hv_do_rep_hypercall(u16 code, u16 rep_count, u16 varhead_size,
    + void *input, void *output)
    +{
    + u64 control = code;
    + u64 status;
    + u16 rep_comp;
    +
    + control |= (u64)varhead_size << HV_HYPERCALL_VARHEAD_OFFSET;
    + control |= (u64)rep_count << HV_HYPERCALL_REP_COMP_OFFSET;
    +
    + do {
    + status = hv_do_hypercall(control, input, output);
    + if ((status & HV_HYPERCALL_RESULT_MASK) != HV_STATUS_SUCCESS)
    + return status;
    +
    + /* Bits 32-43 of status have 'Reps completed' data. */
    + rep_comp = (status & HV_HYPERCALL_REP_COMP_MASK) >>
    + HV_HYPERCALL_REP_COMP_OFFSET;
    +
    + control &= ~HV_HYPERCALL_REP_START_MASK;
    + control |= (u64)rep_comp << HV_HYPERCALL_REP_START_OFFSET;
    +
    + touch_nmi_watchdog();
    + } while (rep_comp < rep_count);
    +
    + return status;
    +}
    +
    void hyperv_init(void);
    void hyperv_report_panic(struct pt_regs *regs);
    bool hv_is_hypercall_page_setup(void);
    --
    2.9.4
    \
     
     \ /
      Last update: 2017-06-12 01:48    [W:3.503 / U:0.092 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site