Drivers: hv: vmbus: Remove x86-isms from arch independent drivers

hv_is_hypercall_page_setup() is used to check if Hyper-V is
initialized, but a 'hypercall page' is an x86 implementation detail
that isn't necessarily present on other architectures. Rename to the
architecture independent hv_is_hyperv_initialized() and add check
that x86_hyper is pointing to Hyper-V.  Use this function instead of
direct references to x86-specific data structures in vmbus_drv.c,
and remove now redundant call in hv_init(). Also remove 'x86' from
the string name passed to cpuhp_setup_state().

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 14 insertions, 7 deletions

diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 189a398290dbb..a0a206556919e 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -239,17 +239,24 @@ void hyperv_report_panic(struct pt_regs *regs, long err)
 }
 EXPORT_SYMBOL_GPL(hyperv_report_panic);
 
-bool hv_is_hypercall_page_setup(void)
+bool hv_is_hyperv_initialized(void)
 {
 	union hv_x64_msr_hypercall_contents hypercall_msr;
 
-	/* Check if the hypercall page is setup */
+	/*
+	 * Ensure that we're really on Hyper-V, and not a KVM or Xen
+	 * emulation of Hyper-V
+	 */
+	if (x86_hyper_type != X86_HYPER_MS_HYPERV)
+		return false;
+
+	/*
+	 * Verify that earlier initialization succeeded by checking
+	 * that the hypercall page is setup
+	 */
 	hypercall_msr.as_uint64 = 0;
 	rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 
-	if (!hypercall_msr.enable)
-		return false;
-
-	return true;
+	return hypercall_msr.enable;
 }
-EXPORT_SYMBOL_GPL(hv_is_hypercall_page_setup);
+EXPORT_SYMBOL_GPL(hv_is_hyperv_initialized);