From: Yi Sun <yi.y....@linux.intel.com> Sent: Friday, September 21, 2018 12:25
AM
> +
> +#define pr_fmt(fmt) "hv: " fmt
Other Hyper-V messages use "Hyper-V: " as the prefix, not "hv: ". Take
a quick look at 'dmesg' output for reference.
> +
> +#include <linux/kernel_stat.h>
> +#include <linux/spinlock.h>
> +#include <linux/debugfs.h>
> +#include <linux/log2.h>
> +#include <linux/gfp.h>
Some of these #includes look like they might be leftovers from
some other code. Please check and see whether kernel_stat.h,
debugsfs.h, log2.h, and gfp.h are actually needed.
> +static void hv_qlock_wait(u8 *byte, u8 val)
> +{
> + unsigned long msr_val;
> +
> + if (READ_ONCE(*byte) != val)
> + return;
> +
> + /*
> + * Read HV_X64_MSR_GUEST_IDLE MSR can trigger the guest's
> + * transition to the idle power state which can be exited
> + * by an IPI even if IF flag is disabled.
> + */
> + if (ms_hyperv.features & HV_X64_MSR_GUEST_IDLE_AVAILABLE)
I can't see a case where this test is actually needed. hv_qlock_wait()
can only get called if the flag is set when hv_init_spinlocks() is run, and
the flag value doesn't change after it is set.
> + rdmsrl(HV_X64_MSR_GUEST_IDLE, msr_val);
> +}
Michael
