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>

diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 189a398..a0a2065 100644 (file)
--- 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);

diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 5400add..b623a42 100644 (file)
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -312,11 +312,11 @@ void hyperv_init(void);
 void hyperv_setup_mmu_ops(void);
 void hyper_alloc_mmu(void);
 void hyperv_report_panic(struct pt_regs *regs, long err);
-bool hv_is_hypercall_page_setup(void);
+bool hv_is_hyperv_initialized(void);
 void hyperv_cleanup(void);
 #else /* CONFIG_HYPERV */
 static inline void hyperv_init(void) {}
-static inline bool hv_is_hypercall_page_setup(void) { return false; }
+static inline bool hv_is_hyperv_initialized(void) { return false; }
 static inline void hyperv_cleanup(void) {}
 static inline void hyperv_setup_mmu_ops(void) {}
 #endif /* CONFIG_HYPERV */

diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index 8267439..fe96aab 100644 (file)
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -49,9 +49,6 @@ struct hv_context hv_context = {
  */
 int hv_init(void)
 {
-       if (!hv_is_hypercall_page_setup())
-               return -ENOTSUPP;
-
        hv_context.cpu_context = alloc_percpu(struct hv_per_cpu_context);
        if (!hv_context.cpu_context)
                return -ENOMEM;

diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 610223f..398643b 100644 (file)
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -37,7 +37,6 @@
 #include <linux/sched/task_stack.h>
 
 #include <asm/hyperv.h>
-#include <asm/hypervisor.h>
 #include <asm/mshyperv.h>
 #include <linux/notifier.h>
 #include <linux/ptrace.h>
@@ -1053,7 +1052,7 @@ static int vmbus_bus_init(void)
         * Initialize the per-cpu interrupt state and
         * connect to the host.
         */
-       ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/hyperv:online",
+       ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hyperv/vmbus:online",
                                hv_synic_init, hv_synic_cleanup);
        if (ret < 0)
                goto err_alloc;
@@ -1717,7 +1716,7 @@ static int __init hv_acpi_init(void)
 {
        int ret, t;
 
-       if (x86_hyper_type != X86_HYPER_MS_HYPERV)
+       if (!hv_is_hyperv_initialized())
                return -ENODEV;
 
        init_completion(&probe_event);