From: Michael Kelley <mikelley@xxxxxxxxxxxxx>
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@xxxxxxxxxxxxx>
---
Changed since v1:
* Incorporated x86_hyper check into hv_is_hyperv_initialized() per
KY Srinivasan's comment that it is still needed
* Removed now redundant call to hv_is_hyperv_initialized() in hv_init()
Changed since v2:
* Fixed block comment style in hv_is_hyperv_initialized()
* Fixed my Reply-To email address
---
arch/x86/hyperv/hv_init.c | 21 ++++++++++++++-------
arch/x86/include/asm/mshyperv.h | 4 ++--
drivers/hv/hv.c | 3 ---
drivers/hv/vmbus_drv.c | 5 ++---
4 files changed, 18 insertions(+), 15 deletions(-)
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index aeb8edf..e5372c9 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 != &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 bd89104..740dc97 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -311,11 +311,11 @@ static inline int hv_cpu_number_to_vp_number(int cpu_number)
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
--- 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 8fe13cd..574668c 100644
--- 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>
@@ -1049,7 +1048,7 @@ 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;
@@ -1711,7 +1710,7 @@ static int __init hv_acpi_init(void)
{
int ret, t;
- if (x86_hyper != &x86_hyper_ms_hyperv)
+ if (!hv_is_hyperv_initialized())
return -ENODEV;
init_completion(&probe_event);
--
1.8.3.1
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