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[PATCH v5 08/10] x86: hyperv: Add mshv_handler irq handler and setup function

Nuno Das Neves posted 10 patches 11 months, 2 weeks ago
There is a newer version of this series
[PATCH v5 08/10] x86: hyperv: Add mshv_handler irq handler and setup function
Posted by Nuno Das Neves 11 months, 2 weeks ago 
This will handle SYNIC interrupts such as intercepts, doorbells, and
scheduling messages intended for the mshv driver.

Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
Reviewed-by: Tianyu Lan <tiala@microsoft.com>
---
 arch/x86/kernel/cpu/mshyperv.c | 9 +++++++++
 drivers/hv/hv_common.c         | 5 +++++
 include/asm-generic/mshyperv.h | 1 +
 3 files changed, 15 insertions(+)

diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 0116d0e96ef9..616e9a5d77b4 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -107,6 +107,7 @@ void hv_set_msr(unsigned int reg, u64 value)
 }
 EXPORT_SYMBOL_GPL(hv_set_msr);
 
+static void (*mshv_handler)(void);
 static void (*vmbus_handler)(void);
 static void (*hv_stimer0_handler)(void);
 static void (*hv_kexec_handler)(void);
@@ -117,6 +118,9 @@ DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_callback)
 	struct pt_regs *old_regs = set_irq_regs(regs);
 
 	inc_irq_stat(irq_hv_callback_count);
+	if (mshv_handler)
+		mshv_handler();
+
 	if (vmbus_handler)
 		vmbus_handler();
 
@@ -126,6 +130,11 @@ DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_callback)
 	set_irq_regs(old_regs);
 }
 
+void hv_setup_mshv_handler(void (*handler)(void))
+{
+	mshv_handler = handler;
+}
+
 void hv_setup_vmbus_handler(void (*handler)(void))
 {
 	vmbus_handler = handler;
diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
index 2763cb6d3678..f5a07fd9a03b 100644
--- a/drivers/hv/hv_common.c
+++ b/drivers/hv/hv_common.c
@@ -677,6 +677,11 @@ void __weak hv_remove_vmbus_handler(void)
 }
 EXPORT_SYMBOL_GPL(hv_remove_vmbus_handler);
 
+void __weak hv_setup_mshv_handler(void (*handler)(void))
+{
+}
+EXPORT_SYMBOL_GPL(hv_setup_mshv_handler);
+
 void __weak hv_setup_kexec_handler(void (*handler)(void))
 {
 }
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index 1f46d19a16aa..a05f12e63ccd 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -208,6 +208,7 @@ void hv_setup_kexec_handler(void (*handler)(void));
 void hv_remove_kexec_handler(void);
 void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs));
 void hv_remove_crash_handler(void);
+void hv_setup_mshv_handler(void (*handler)(void));
 
 extern int vmbus_interrupt;
 extern int vmbus_irq;
-- 
2.34.1
Re: [PATCH v5 08/10] x86: hyperv: Add mshv_handler irq handler and setup function
Posted by Stanislav Kinsburskii 11 months, 2 weeks ago 
On Wed, Feb 26, 2025 at 03:08:02PM -0800, Nuno Das Neves wrote:
> This will handle SYNIC interrupts such as intercepts, doorbells, and
> scheduling messages intended for the mshv driver.
> 
> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
> Reviewed-by: Wei Liu <wei.liu@kernel.org>
> Reviewed-by: Tianyu Lan <tiala@microsoft.com>
> ---
>  arch/x86/kernel/cpu/mshyperv.c | 9 +++++++++
>  drivers/hv/hv_common.c         | 5 +++++
>  include/asm-generic/mshyperv.h | 1 +
>  3 files changed, 15 insertions(+)
> 
> diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
> index 0116d0e96ef9..616e9a5d77b4 100644
> --- a/arch/x86/kernel/cpu/mshyperv.c
> +++ b/arch/x86/kernel/cpu/mshyperv.c
> @@ -107,6 +107,7 @@ void hv_set_msr(unsigned int reg, u64 value)
>  }
>  EXPORT_SYMBOL_GPL(hv_set_msr);
>  
> +static void (*mshv_handler)(void);
>  static void (*vmbus_handler)(void);
>  static void (*hv_stimer0_handler)(void);
>  static void (*hv_kexec_handler)(void);
> @@ -117,6 +118,9 @@ DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_callback)
>  	struct pt_regs *old_regs = set_irq_regs(regs);
>  
>  	inc_irq_stat(irq_hv_callback_count);
> +	if (mshv_handler)
> +		mshv_handler();

Can mshv_handler be defined as a weak symbol doing nothing instead
of defining it a null pointer?
This should allow to simplify this code and get rid of
hv_setup_mshv_handler, which looks redundant.

Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>

> +
>  	if (vmbus_handler)
>  		vmbus_handler();
>  
> @@ -126,6 +130,11 @@ DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_callback)
>  	set_irq_regs(old_regs);
>  }
>  
> +void hv_setup_mshv_handler(void (*handler)(void))
> +{
> +	mshv_handler = handler;
> +}
> +
>  void hv_setup_vmbus_handler(void (*handler)(void))
>  {
>  	vmbus_handler = handler;
> diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
> index 2763cb6d3678..f5a07fd9a03b 100644
> --- a/drivers/hv/hv_common.c
> +++ b/drivers/hv/hv_common.c
> @@ -677,6 +677,11 @@ void __weak hv_remove_vmbus_handler(void)
>  }
>  EXPORT_SYMBOL_GPL(hv_remove_vmbus_handler);
>  
> +void __weak hv_setup_mshv_handler(void (*handler)(void))
> +{
> +}
> +EXPORT_SYMBOL_GPL(hv_setup_mshv_handler);
> +
>  void __weak hv_setup_kexec_handler(void (*handler)(void))
>  {
>  }
> diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
> index 1f46d19a16aa..a05f12e63ccd 100644
> --- a/include/asm-generic/mshyperv.h
> +++ b/include/asm-generic/mshyperv.h
> @@ -208,6 +208,7 @@ void hv_setup_kexec_handler(void (*handler)(void));
>  void hv_remove_kexec_handler(void);
>  void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs));
>  void hv_remove_crash_handler(void);
> +void hv_setup_mshv_handler(void (*handler)(void));
>  
>  extern int vmbus_interrupt;
>  extern int vmbus_irq;
> -- 
> 2.34.1
>
Re: [PATCH v5 08/10] x86: hyperv: Add mshv_handler irq handler and setup function
Posted by Nuno Das Neves 11 months, 2 weeks ago 
On 2/26/2025 3:43 PM, Stanislav Kinsburskii wrote:
> On Wed, Feb 26, 2025 at 03:08:02PM -0800, Nuno Das Neves wrote:
>> This will handle SYNIC interrupts such as intercepts, doorbells, and
>> scheduling messages intended for the mshv driver.
>>
>> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
>> Reviewed-by: Wei Liu <wei.liu@kernel.org>
>> Reviewed-by: Tianyu Lan <tiala@microsoft.com>
>> ---
>>  arch/x86/kernel/cpu/mshyperv.c | 9 +++++++++
>>  drivers/hv/hv_common.c         | 5 +++++
>>  include/asm-generic/mshyperv.h | 1 +
>>  3 files changed, 15 insertions(+)
>>
>> diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
>> index 0116d0e96ef9..616e9a5d77b4 100644
>> --- a/arch/x86/kernel/cpu/mshyperv.c
>> +++ b/arch/x86/kernel/cpu/mshyperv.c
>> @@ -107,6 +107,7 @@ void hv_set_msr(unsigned int reg, u64 value)
>>  }
>>  EXPORT_SYMBOL_GPL(hv_set_msr);
>>  
>> +static void (*mshv_handler)(void);
>>  static void (*vmbus_handler)(void);
>>  static void (*hv_stimer0_handler)(void);
>>  static void (*hv_kexec_handler)(void);
>> @@ -117,6 +118,9 @@ DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_callback)
>>  	struct pt_regs *old_regs = set_irq_regs(regs);
>>  
>>  	inc_irq_stat(irq_hv_callback_count);
>> +	if (mshv_handler)
>> +		mshv_handler();
> 
> Can mshv_handler be defined as a weak symbol doing nothing instead
> of defining it a null pointer?
> This should allow to simplify this code and get rid of
> hv_setup_mshv_handler, which looks redundant.
> 
Interesting, I tested this and it does seems to work! It seems like
a good change, thanks.

> Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
> 
>> +
>>  	if (vmbus_handler)
>>  		vmbus_handler();
>>  
>> @@ -126,6 +130,11 @@ DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_callback)
>>  	set_irq_regs(old_regs);
>>  }
>>  
>> +void hv_setup_mshv_handler(void (*handler)(void))
>> +{
>> +	mshv_handler = handler;
>> +}
>> +
>>  void hv_setup_vmbus_handler(void (*handler)(void))
>>  {
>>  	vmbus_handler = handler;
>> diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
>> index 2763cb6d3678..f5a07fd9a03b 100644
>> --- a/drivers/hv/hv_common.c
>> +++ b/drivers/hv/hv_common.c
>> @@ -677,6 +677,11 @@ void __weak hv_remove_vmbus_handler(void)
>>  }
>>  EXPORT_SYMBOL_GPL(hv_remove_vmbus_handler);
>>  
>> +void __weak hv_setup_mshv_handler(void (*handler)(void))
>> +{
>> +}
>> +EXPORT_SYMBOL_GPL(hv_setup_mshv_handler);
>> +
>>  void __weak hv_setup_kexec_handler(void (*handler)(void))
>>  {
>>  }
>> diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
>> index 1f46d19a16aa..a05f12e63ccd 100644
>> --- a/include/asm-generic/mshyperv.h
>> +++ b/include/asm-generic/mshyperv.h
>> @@ -208,6 +208,7 @@ void hv_setup_kexec_handler(void (*handler)(void));
>>  void hv_remove_kexec_handler(void);
>>  void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs));
>>  void hv_remove_crash_handler(void);
>> +void hv_setup_mshv_handler(void (*handler)(void));
>>  
>>  extern int vmbus_interrupt;
>>  extern int vmbus_irq;
>> -- 
>> 2.34.1
>>

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