RE: [PATCH RESEND 09/27] drivers:hv: Export the API to invoke a hypercall on Hyper-V

2015-12-14 Thread KY Srinivasan 


> -Original Message-
> From: Greg KH [mailto:gre...@linuxfoundation.org]
> Sent: Monday, December 14, 2015 7:08 PM
> To: KY Srinivasan 
> Cc: linux-kernel@vger.kernel.org; de...@linuxdriverproject.org;
> o...@aepfle.de; a...@canonical.com; vkuzn...@redhat.com;
> jasow...@redhat.com; Jake Oshins 
> Subject: Re: [PATCH RESEND 09/27] drivers:hv: Export the API to invoke a
> hypercall on Hyper-V
> 
> On Mon, Dec 14, 2015 at 04:01:40PM -0800, K. Y. Srinivasan wrote:
> > From: Jake Oshins 
> >
> > This patch exposes the function that hv_vmbus.ko uses to make hypercalls.
> This
> > is necessary for retargeting an interrupt when it is given a new affinity.
> >
> > Since we are exporting this API, rename the API as it will be visible 
> > outside
> > the hv.c file.
> >
> > Signed-off-by: Jake Oshins 
> > Signed-off-by: K. Y. Srinivasan 
> > ---
> >  drivers/hv/hv.c   |   20 ++--
> >  drivers/hv/hyperv_vmbus.h |2 +-
> >  include/linux/hyperv.h|1 +
> >  3 files changed, 12 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
> > index 6341be8..7a06933 100644
> > --- a/drivers/hv/hv.c
> > +++ b/drivers/hv/hv.c
> > @@ -89,9 +89,9 @@ static int query_hypervisor_info(void)
> >  }
> >
> >  /*
> > - * do_hypercall- Invoke the specified hypercall
> > + * hv_do_hypercall- Invoke the specified hypercall
> >   */
> > -static u64 do_hypercall(u64 control, void *input, void *output)
> > +u64 hv_do_hypercall(u64 control, void *input, void *output)
> >  {
> > u64 input_address = (input) ? virt_to_phys(input) : 0;
> > u64 output_address = (output) ? virt_to_phys(output) : 0;
> > @@ -132,6 +132,7 @@ static u64 do_hypercall(u64 control, void *input,
> void *output)
> > return hv_status_lo | ((u64)hv_status_hi << 32);
> >  #endif /* !x86_64 */
> >  }
> > +EXPORT_SYMBOL_GPL(hv_do_hypercall);
> >
> >  #ifdef CONFIG_X86_64
> >  static cycle_t read_hv_clock_tsc(struct clocksource *arg)
> > @@ -315,7 +316,7 @@ int hv_post_message(union hv_connection_id
> connection_id,
> >  {
> >
> > struct hv_input_post_message *aligned_msg;
> > -   u16 status;
> > +   u64 status;
> >
> > if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
> > return -EMSGSIZE;
> > @@ -329,11 +330,10 @@ int hv_post_message(union hv_connection_id
> connection_id,
> > aligned_msg->payload_size = payload_size;
> > memcpy((void *)aligned_msg->payload, payload, payload_size);
> >
> > -   status = do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL)
> > -   & 0x;
> > +   status = hv_do_hypercall(HVCALL_POST_MESSAGE, aligned_msg,
> NULL);
> >
> > put_cpu();
> > -   return status;
> > +   return status & 0x;
> >  }
> >
> >
> > @@ -343,13 +343,13 @@ int hv_post_message(union hv_connection_id
> connection_id,
> >   *
> >   * This involves a hypercall.
> >   */
> > -u16 hv_signal_event(void *con_id)
> > +int hv_signal_event(void *con_id)
> >  {
> > -   u16 status;
> > +   u64 status;
> >
> > -   status = (do_hypercall(HVCALL_SIGNAL_EVENT, con_id, NULL) &
> 0x);
> > +   status = hv_do_hypercall(HVCALL_SIGNAL_EVENT, con_id, NULL);
> >
> > -   return status;
> > +   return status & 0x;
> 
> This "feels" odd, as the return value isn't the traditional 0 or -ERROR,
> right?  Why are you masking off the top bits?
> 
> And, no one ever does anything with the return value of
> hv_signal_event(), so why have it return anything anyway?
> 
> I'll take this, but please fix up the area, it's messy...

Thanks Greg. Will do.

K. Y
> 
> greg k-h
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Re: [PATCH RESEND 09/27] drivers:hv: Export the API to invoke a hypercall on Hyper-V

2015-12-14 Thread Greg KH 
On Mon, Dec 14, 2015 at 04:01:40PM -0800, K. Y. Srinivasan wrote:
> From: Jake Oshins 
> 
> This patch exposes the function that hv_vmbus.ko uses to make hypercalls.  
> This
> is necessary for retargeting an interrupt when it is given a new affinity.
> 
> Since we are exporting this API, rename the API as it will be visible outside
> the hv.c file.
> 
> Signed-off-by: Jake Oshins 
> Signed-off-by: K. Y. Srinivasan 
> ---
>  drivers/hv/hv.c   |   20 ++--
>  drivers/hv/hyperv_vmbus.h |2 +-
>  include/linux/hyperv.h|1 +
>  3 files changed, 12 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
> index 6341be8..7a06933 100644
> --- a/drivers/hv/hv.c
> +++ b/drivers/hv/hv.c
> @@ -89,9 +89,9 @@ static int query_hypervisor_info(void)
>  }
>  
>  /*
> - * do_hypercall- Invoke the specified hypercall
> + * hv_do_hypercall- Invoke the specified hypercall
>   */
> -static u64 do_hypercall(u64 control, void *input, void *output)
> +u64 hv_do_hypercall(u64 control, void *input, void *output)
>  {
>   u64 input_address = (input) ? virt_to_phys(input) : 0;
>   u64 output_address = (output) ? virt_to_phys(output) : 0;
> @@ -132,6 +132,7 @@ static u64 do_hypercall(u64 control, void *input, void 
> *output)
>   return hv_status_lo | ((u64)hv_status_hi << 32);
>  #endif /* !x86_64 */
>  }
> +EXPORT_SYMBOL_GPL(hv_do_hypercall);
>  
>  #ifdef CONFIG_X86_64
>  static cycle_t read_hv_clock_tsc(struct clocksource *arg)
> @@ -315,7 +316,7 @@ int hv_post_message(union hv_connection_id connection_id,
>  {
>  
>   struct hv_input_post_message *aligned_msg;
> - u16 status;
> + u64 status;
>  
>   if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
>   return -EMSGSIZE;
> @@ -329,11 +330,10 @@ int hv_post_message(union hv_connection_id 
> connection_id,
>   aligned_msg->payload_size = payload_size;
>   memcpy((void *)aligned_msg->payload, payload, payload_size);
>  
> - status = do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL)
> - & 0x;
> + status = hv_do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL);
>  
>   put_cpu();
> - return status;
> + return status & 0x;
>  }
>  
>  
> @@ -343,13 +343,13 @@ int hv_post_message(union hv_connection_id 
> connection_id,
>   *
>   * This involves a hypercall.
>   */
> -u16 hv_signal_event(void *con_id)
> +int hv_signal_event(void *con_id)
>  {
> - u16 status;
> + u64 status;
>  
> - status = (do_hypercall(HVCALL_SIGNAL_EVENT, con_id, NULL) & 0x);
> + status = hv_do_hypercall(HVCALL_SIGNAL_EVENT, con_id, NULL);
>  
> - return status;
> + return status & 0x;

This "feels" odd, as the return value isn't the traditional 0 or -ERROR,
right?  Why are you masking off the top bits?

And, no one ever does anything with the return value of
hv_signal_event(), so why have it return anything anyway?

I'll take this, but please fix up the area, it's messy...

greg k-h
--
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Re: [PATCH RESEND 09/27] drivers:hv: Export the API to invoke a hypercall on Hyper-V

2015-12-14 Thread Greg KH 
On Mon, Dec 14, 2015 at 04:01:40PM -0800, K. Y. Srinivasan wrote:
> From: Jake Oshins 
> 
> This patch exposes the function that hv_vmbus.ko uses to make hypercalls.  
> This
> is necessary for retargeting an interrupt when it is given a new affinity.
> 
> Since we are exporting this API, rename the API as it will be visible outside
> the hv.c file.
> 
> Signed-off-by: Jake Oshins 
> Signed-off-by: K. Y. Srinivasan 
> ---
>  drivers/hv/hv.c   |   20 ++--
>  drivers/hv/hyperv_vmbus.h |2 +-
>  include/linux/hyperv.h|1 +
>  3 files changed, 12 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
> index 6341be8..7a06933 100644
> --- a/drivers/hv/hv.c
> +++ b/drivers/hv/hv.c
> @@ -89,9 +89,9 @@ static int query_hypervisor_info(void)
>  }
>  
>  /*
> - * do_hypercall- Invoke the specified hypercall
> + * hv_do_hypercall- Invoke the specified hypercall
>   */
> -static u64 do_hypercall(u64 control, void *input, void *output)
> +u64 hv_do_hypercall(u64 control, void *input, void *output)
>  {
>   u64 input_address = (input) ? virt_to_phys(input) : 0;
>   u64 output_address = (output) ? virt_to_phys(output) : 0;
> @@ -132,6 +132,7 @@ static u64 do_hypercall(u64 control, void *input, void 
> *output)
>   return hv_status_lo | ((u64)hv_status_hi << 32);
>  #endif /* !x86_64 */
>  }
> +EXPORT_SYMBOL_GPL(hv_do_hypercall);
>  
>  #ifdef CONFIG_X86_64
>  static cycle_t read_hv_clock_tsc(struct clocksource *arg)
> @@ -315,7 +316,7 @@ int hv_post_message(union hv_connection_id connection_id,
>  {
>  
>   struct hv_input_post_message *aligned_msg;
> - u16 status;
> + u64 status;
>  
>   if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
>   return -EMSGSIZE;
> @@ -329,11 +330,10 @@ int hv_post_message(union hv_connection_id 
> connection_id,
>   aligned_msg->payload_size = payload_size;
>   memcpy((void *)aligned_msg->payload, payload, payload_size);
>  
> - status = do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL)
> - & 0x;
> + status = hv_do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL);
>  
>   put_cpu();
> - return status;
> + return status & 0x;
>  }
>  
>  
> @@ -343,13 +343,13 @@ int hv_post_message(union hv_connection_id 
> connection_id,
>   *
>   * This involves a hypercall.
>   */
> -u16 hv_signal_event(void *con_id)
> +int hv_signal_event(void *con_id)
>  {
> - u16 status;
> + u64 status;
>  
> - status = (do_hypercall(HVCALL_SIGNAL_EVENT, con_id, NULL) & 0x);
> + status = hv_do_hypercall(HVCALL_SIGNAL_EVENT, con_id, NULL);
>  
> - return status;
> + return status & 0x;

This "feels" odd, as the return value isn't the traditional 0 or -ERROR,
right?  Why are you masking off the top bits?

And, no one ever does anything with the return value of
hv_signal_event(), so why have it return anything anyway?

I'll take this, but please fix up the area, it's messy...

greg k-h
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

RE: [PATCH RESEND 09/27] drivers:hv: Export the API to invoke a hypercall on Hyper-V

2015-12-14 Thread KY Srinivasan 


> -Original Message-
> From: Greg KH [mailto:gre...@linuxfoundation.org]
> Sent: Monday, December 14, 2015 7:08 PM
> To: KY Srinivasan 
> Cc: linux-kernel@vger.kernel.org; de...@linuxdriverproject.org;
> o...@aepfle.de; a...@canonical.com; vkuzn...@redhat.com;
> jasow...@redhat.com; Jake Oshins 
> Subject: Re: [PATCH RESEND 09/27] drivers:hv: Export the API to invoke a
> hypercall on Hyper-V
> 
> On Mon, Dec 14, 2015 at 04:01:40PM -0800, K. Y. Srinivasan wrote:
> > From: Jake Oshins 
> >
> > This patch exposes the function that hv_vmbus.ko uses to make hypercalls.
> This
> > is necessary for retargeting an interrupt when it is given a new affinity.
> >
> > Since we are exporting this API, rename the API as it will be visible 
> > outside
> > the hv.c file.
> >
> > Signed-off-by: Jake Oshins 
> > Signed-off-by: K. Y. Srinivasan 
> > ---
> >  drivers/hv/hv.c   |   20 ++--
> >  drivers/hv/hyperv_vmbus.h |2 +-
> >  include/linux/hyperv.h|1 +
> >  3 files changed, 12 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
> > index 6341be8..7a06933 100644
> > --- a/drivers/hv/hv.c
> > +++ b/drivers/hv/hv.c
> > @@ -89,9 +89,9 @@ static int query_hypervisor_info(void)
> >  }
> >
> >  /*
> > - * do_hypercall- Invoke the specified hypercall
> > + * hv_do_hypercall- Invoke the specified hypercall
> >   */
> > -static u64 do_hypercall(u64 control, void *input, void *output)
> > +u64 hv_do_hypercall(u64 control, void *input, void *output)
> >  {
> > u64 input_address = (input) ? virt_to_phys(input) : 0;
> > u64 output_address = (output) ? virt_to_phys(output) : 0;
> > @@ -132,6 +132,7 @@ static u64 do_hypercall(u64 control, void *input,
> void *output)
> > return hv_status_lo | ((u64)hv_status_hi << 32);
> >  #endif /* !x86_64 */
> >  }
> > +EXPORT_SYMBOL_GPL(hv_do_hypercall);
> >
> >  #ifdef CONFIG_X86_64
> >  static cycle_t read_hv_clock_tsc(struct clocksource *arg)
> > @@ -315,7 +316,7 @@ int hv_post_message(union hv_connection_id
> connection_id,
> >  {
> >
> > struct hv_input_post_message *aligned_msg;
> > -   u16 status;
> > +   u64 status;
> >
> > if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
> > return -EMSGSIZE;
> > @@ -329,11 +330,10 @@ int hv_post_message(union hv_connection_id
> connection_id,
> > aligned_msg->payload_size = payload_size;
> > memcpy((void *)aligned_msg->payload, payload, payload_size);
> >
> > -   status = do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL)
> > -   & 0x;
> > +   status = hv_do_hypercall(HVCALL_POST_MESSAGE, aligned_msg,
> NULL);
> >
> > put_cpu();
> > -   return status;
> > +   return status & 0x;
> >  }
> >
> >
> > @@ -343,13 +343,13 @@ int hv_post_message(union hv_connection_id
> connection_id,
> >   *
> >   * This involves a hypercall.
> >   */
> > -u16 hv_signal_event(void *con_id)
> > +int hv_signal_event(void *con_id)
> >  {
> > -   u16 status;
> > +   u64 status;
> >
> > -   status = (do_hypercall(HVCALL_SIGNAL_EVENT, con_id, NULL) &
> 0x);
> > +   status = hv_do_hypercall(HVCALL_SIGNAL_EVENT, con_id, NULL);
> >
> > -   return status;
> > +   return status & 0x;
> 
> This "feels" odd, as the return value isn't the traditional 0 or -ERROR,
> right?  Why are you masking off the top bits?
> 
> And, no one ever does anything with the return value of
> hv_signal_event(), so why have it return anything anyway?
> 
> I'll take this, but please fix up the area, it's messy...

Thanks Greg. Will do.

K. Y
> 
> greg k-h
--
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