Drivers: hv: Use nested hypercall for post message and signal event

When running nested, these hypercalls must be sent to the L0 hypervisor
or VMBus will fail.

Remove hv_do_nested_hypercall() and hv_do_fast_nested_hypercall8()
altogether and open-code these cases, since there are only 2 and all
they do is add the nested bit.

Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Reviewed-by: Roman Kisel <romank@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Link: https://lore.kernel.org/r/1752261532-7225-2-git-send-email-nunodasneves@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <1752261532-7225-2-git-send-email-nunodasneves@linux.microsoft.com>

Author: NunoDasNeves

arch/x86/include/asm/mshyperv.h

@@ -112,12 +112,6 @@ static inline u64 hv_do_hypercall(u64 control, void *input, void *output)
 	return hv_status;
 }
 
-/* Hypercall to the L0 hypervisor */
-static inline u64 hv_do_nested_hypercall(u64 control, void *input, void *output)
-{
-	return hv_do_hypercall(control | HV_HYPERCALL_NESTED, input, output);
-}
-
 /* Fast hypercall with 8 bytes of input and no output */
 static inline u64 _hv_do_fast_hypercall8(u64 control, u64 input1)
 {
@@ -165,13 +159,6 @@ static inline u64 hv_do_fast_hypercall8(u16 code, u64 input1)
 	return _hv_do_fast_hypercall8(control, input1);
 }
 
-static inline u64 hv_do_fast_nested_hypercall8(u16 code, u64 input1)
-{
-	u64 control = (u64)code | HV_HYPERCALL_FAST_BIT | HV_HYPERCALL_NESTED;
-
-	return _hv_do_fast_hypercall8(control, input1);
-}
-
 /* Fast hypercall with 16 bytes of input */
 static inline u64 _hv_do_fast_hypercall16(u64 control, u64 input1, u64 input2)
 {
@@ -223,13 +210,6 @@ static inline u64 hv_do_fast_hypercall16(u16 code, u64 input1, u64 input2)
 	return _hv_do_fast_hypercall16(control, input1, input2);
 }
 
-static inline u64 hv_do_fast_nested_hypercall16(u16 code, u64 input1, u64 input2)
-{
-	u64 control = (u64)code | HV_HYPERCALL_FAST_BIT | HV_HYPERCALL_NESTED;
-
-	return _hv_do_fast_hypercall16(control, input1, input2);
-}
-
 extern struct hv_vp_assist_page **hv_vp_assist_page;
 
 static inline struct hv_vp_assist_page *hv_get_vp_assist_page(unsigned int cpu)

drivers/hv/connection.c

@@ -519,7 +519,10 @@ void vmbus_set_event(struct vmbus_channel *channel)
 		else
 			WARN_ON_ONCE(1);
 	} else {
-		hv_do_fast_hypercall8(HVCALL_SIGNAL_EVENT, channel->sig_event);
+		u64 control = HVCALL_SIGNAL_EVENT;
+
+		control |= hv_nested ? HV_HYPERCALL_NESTED : 0;
+		hv_do_fast_hypercall8(control, channel->sig_event);
 	}
 }
 EXPORT_SYMBOL_GPL(vmbus_set_event);

drivers/hv/hv.c

@@ -85,8 +85,10 @@ int hv_post_message(union hv_connection_id connection_id,
 		else
 			status = HV_STATUS_INVALID_PARAMETER;
 	} else {
-		status = hv_do_hypercall(HVCALL_POST_MESSAGE,
-					 aligned_msg, NULL);
+		u64 control = HVCALL_POST_MESSAGE;
+
+		control |= hv_nested ? HV_HYPERCALL_NESTED : 0;
+		status = hv_do_hypercall(control, aligned_msg, NULL);
 	}
 
 	local_irq_restore(flags);