Allow dyn pci vector allocation of MANA

[PATCH 1/2] PCI: hv: enable pci_hyperv to allow dynamic vector allocation

Posted by Shradha Gupta 8 months, 1 week ago

For supporting dynamic MSI vector allocation by pci controllers, enabling
the flag MSI_FLAG_PCI_MSIX_ALLOC_DYN is not enough, msix_prepare_msi_desc()
to prepare the desc is needed. Export pci_msix_prepare_desc() to allow pci
controllers like pci-hyperv to support dynamic MSI vector allocation.
Also, add the flag MSI_FLAG_PCI_MSIX_ALLOC_DYN and use
pci_msix_prepare_desc() in pci_hyperv controller

Signed-off-by: Shradha Gupta <shradhagupta@linux.microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: Long Li <longli@microsoft.com>
---
 drivers/pci/controller/pci-hyperv.c | 7 +++++--
 drivers/pci/msi/irqdomain.c         | 5 +++--
 include/linux/msi.h                 | 2 ++
 3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index ac27bda5ba26..f2fa6bdb6bb8 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -598,7 +598,8 @@ static unsigned int hv_msi_get_int_vector(struct irq_data *data)
 	return cfg->vector;
 }
 
-#define hv_msi_prepare		pci_msi_prepare
+#define hv_msi_prepare			pci_msi_prepare
+#define hv_msix_prepare_desc		pci_msix_prepare_desc
 
 /**
  * hv_arch_irq_unmask() - "Unmask" the IRQ by setting its current
@@ -727,6 +728,7 @@ static void hv_arch_irq_unmask(struct irq_data *data)
 #define FLOW_HANDLER		NULL
 #define FLOW_NAME		NULL
 #define hv_msi_prepare		NULL
+#define hv_msix_prepare_desc	NULL
 
 struct hv_pci_chip_data {
 	DECLARE_BITMAP(spi_map, HV_PCI_MSI_SPI_NR);
@@ -2063,6 +2065,7 @@ static struct irq_chip hv_msi_irq_chip = {
 static struct msi_domain_ops hv_msi_ops = {
 	.msi_prepare	= hv_msi_prepare,
 	.msi_free	= hv_msi_free,
+	.prepare_desc	= hv_msix_prepare_desc,
 };
 
 /**
@@ -2084,7 +2087,7 @@ static int hv_pcie_init_irq_domain(struct hv_pcibus_device *hbus)
 	hbus->msi_info.ops = &hv_msi_ops;
 	hbus->msi_info.flags = (MSI_FLAG_USE_DEF_DOM_OPS |
 		MSI_FLAG_USE_DEF_CHIP_OPS | MSI_FLAG_MULTI_PCI_MSI |
-		MSI_FLAG_PCI_MSIX);
+		MSI_FLAG_PCI_MSIX | MSI_FLAG_PCI_MSIX_ALLOC_DYN);
 	hbus->msi_info.handler = FLOW_HANDLER;
 	hbus->msi_info.handler_name = FLOW_NAME;
 	hbus->msi_info.data = hbus;
diff --git a/drivers/pci/msi/irqdomain.c b/drivers/pci/msi/irqdomain.c
index d7ba8795d60f..43129aa6d6c7 100644
--- a/drivers/pci/msi/irqdomain.c
+++ b/drivers/pci/msi/irqdomain.c
@@ -222,13 +222,14 @@ static void pci_irq_unmask_msix(struct irq_data *data)
 	pci_msix_unmask(irq_data_get_msi_desc(data));
 }
 
-static void pci_msix_prepare_desc(struct irq_domain *domain, msi_alloc_info_t *arg,
-				  struct msi_desc *desc)
+void pci_msix_prepare_desc(struct irq_domain *domain, msi_alloc_info_t *arg,
+			   struct msi_desc *desc)
 {
 	/* Don't fiddle with preallocated MSI descriptors */
 	if (!desc->pci.mask_base)
 		msix_prepare_msi_desc(to_pci_dev(desc->dev), desc);
 }
+EXPORT_SYMBOL_GPL(pci_msix_prepare_desc);
 
 static const struct msi_domain_template pci_msix_template = {
 	.chip = {
diff --git a/include/linux/msi.h b/include/linux/msi.h
index 86e42742fd0f..d5864d5e75c2 100644
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -691,6 +691,8 @@ struct irq_domain *pci_msi_create_irq_domain(struct fwnode_handle *fwnode,
 					     struct irq_domain *parent);
 u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev);
 struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev);
+void pci_msix_prepare_desc(struct irq_domain *domain, msi_alloc_info_t *arg,
+			   struct msi_desc *desc);
 #else /* CONFIG_PCI_MSI */
 static inline struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev)
 {
-- 
2.34.1

Re: [PATCH 1/2] PCI: hv: enable pci_hyperv to allow dynamic vector allocation

Posted by Thomas Gleixner 8 months ago

On Wed, Apr 16 2025 at 08:36, Shradha Gupta wrote:
> For supporting dynamic MSI vector allocation by pci controllers, enabling
> the flag MSI_FLAG_PCI_MSIX_ALLOC_DYN is not enough, msix_prepare_msi_desc()
> to prepare the desc is needed. Export pci_msix_prepare_desc() to allow pci
> controllers like pci-hyperv to support dynamic MSI vector allocation.
> Also, add the flag MSI_FLAG_PCI_MSIX_ALLOC_DYN and use
> pci_msix_prepare_desc() in pci_hyperv controller

Seems your newline key is broken. Please structure changelogs properly
in paragraphs:

https://www.kernel.org/doc/html/latest/process/maintainer-tip.html#changelog

>  drivers/pci/controller/pci-hyperv.c | 7 +++++--
>  drivers/pci/msi/irqdomain.c         | 5 +++--
>  include/linux/msi.h                 | 2 ++

This wants to be split into a patch which exports
pci_msix_prepare_desc() and one which enables the functionality in
PCI/HV.

Thanks,

        tglx

Re: [PATCH 1/2] PCI: hv: enable pci_hyperv to allow dynamic vector allocation

Posted by Bjorn Helgaas 8 months, 1 week ago

[+to Thomas]

On Wed, Apr 16, 2025 at 08:36:06AM -0700, Shradha Gupta wrote:
> For supporting dynamic MSI vector allocation by pci controllers, enabling
> the flag MSI_FLAG_PCI_MSIX_ALLOC_DYN is not enough, msix_prepare_msi_desc()
> to prepare the desc is needed. Export pci_msix_prepare_desc() to allow pci
> controllers like pci-hyperv to support dynamic MSI vector allocation.
> Also, add the flag MSI_FLAG_PCI_MSIX_ALLOC_DYN and use
> pci_msix_prepare_desc() in pci_hyperv controller

Follow capitalization convention for subject line.  Probably remove
"pci_hyperv" since it already contains "PCI: hv" and add something
about MSI-X.

s/pci/PCI/

s/MSI vector/MSI-X vector/ since the context says you're concerned
with MSI-X.

This requires an ack from Thomas; moved him to "To:" line.

> Signed-off-by: Shradha Gupta <shradhagupta@linux.microsoft.com>
> Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
> Reviewed-by: Long Li <longli@microsoft.com>
> ---
>  drivers/pci/controller/pci-hyperv.c | 7 +++++--
>  drivers/pci/msi/irqdomain.c         | 5 +++--
>  include/linux/msi.h                 | 2 ++
>  3 files changed, 10 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
> index ac27bda5ba26..f2fa6bdb6bb8 100644
> --- a/drivers/pci/controller/pci-hyperv.c
> +++ b/drivers/pci/controller/pci-hyperv.c
> @@ -598,7 +598,8 @@ static unsigned int hv_msi_get_int_vector(struct irq_data *data)
>  	return cfg->vector;
>  }
>  
> -#define hv_msi_prepare		pci_msi_prepare
> +#define hv_msi_prepare			pci_msi_prepare
> +#define hv_msix_prepare_desc		pci_msix_prepare_desc
>  
>  /**
>   * hv_arch_irq_unmask() - "Unmask" the IRQ by setting its current
> @@ -727,6 +728,7 @@ static void hv_arch_irq_unmask(struct irq_data *data)
>  #define FLOW_HANDLER		NULL
>  #define FLOW_NAME		NULL
>  #define hv_msi_prepare		NULL
> +#define hv_msix_prepare_desc	NULL
>  
>  struct hv_pci_chip_data {
>  	DECLARE_BITMAP(spi_map, HV_PCI_MSI_SPI_NR);
> @@ -2063,6 +2065,7 @@ static struct irq_chip hv_msi_irq_chip = {
>  static struct msi_domain_ops hv_msi_ops = {
>  	.msi_prepare	= hv_msi_prepare,
>  	.msi_free	= hv_msi_free,
> +	.prepare_desc	= hv_msix_prepare_desc,
>  };
>  
>  /**
> @@ -2084,7 +2087,7 @@ static int hv_pcie_init_irq_domain(struct hv_pcibus_device *hbus)
>  	hbus->msi_info.ops = &hv_msi_ops;
>  	hbus->msi_info.flags = (MSI_FLAG_USE_DEF_DOM_OPS |
>  		MSI_FLAG_USE_DEF_CHIP_OPS | MSI_FLAG_MULTI_PCI_MSI |
> -		MSI_FLAG_PCI_MSIX);
> +		MSI_FLAG_PCI_MSIX | MSI_FLAG_PCI_MSIX_ALLOC_DYN);
>  	hbus->msi_info.handler = FLOW_HANDLER;
>  	hbus->msi_info.handler_name = FLOW_NAME;
>  	hbus->msi_info.data = hbus;
> diff --git a/drivers/pci/msi/irqdomain.c b/drivers/pci/msi/irqdomain.c
> index d7ba8795d60f..43129aa6d6c7 100644
> --- a/drivers/pci/msi/irqdomain.c
> +++ b/drivers/pci/msi/irqdomain.c
> @@ -222,13 +222,14 @@ static void pci_irq_unmask_msix(struct irq_data *data)
>  	pci_msix_unmask(irq_data_get_msi_desc(data));
>  }
>  
> -static void pci_msix_prepare_desc(struct irq_domain *domain, msi_alloc_info_t *arg,
> -				  struct msi_desc *desc)
> +void pci_msix_prepare_desc(struct irq_domain *domain, msi_alloc_info_t *arg,
> +			   struct msi_desc *desc)
>  {
>  	/* Don't fiddle with preallocated MSI descriptors */
>  	if (!desc->pci.mask_base)
>  		msix_prepare_msi_desc(to_pci_dev(desc->dev), desc);
>  }
> +EXPORT_SYMBOL_GPL(pci_msix_prepare_desc);
>  
>  static const struct msi_domain_template pci_msix_template = {
>  	.chip = {
> diff --git a/include/linux/msi.h b/include/linux/msi.h
> index 86e42742fd0f..d5864d5e75c2 100644
> --- a/include/linux/msi.h
> +++ b/include/linux/msi.h
> @@ -691,6 +691,8 @@ struct irq_domain *pci_msi_create_irq_domain(struct fwnode_handle *fwnode,
>  					     struct irq_domain *parent);
>  u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev);
>  struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev);
> +void pci_msix_prepare_desc(struct irq_domain *domain, msi_alloc_info_t *arg,
> +			   struct msi_desc *desc);
>  #else /* CONFIG_PCI_MSI */
>  static inline struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev)
>  {
> -- 
> 2.34.1
>

Re: [PATCH 1/2] PCI: hv: enable pci_hyperv to allow dynamic vector allocation

Posted by Shradha Gupta 8 months ago

On Wed, Apr 16, 2025 at 01:30:42PM -0500, Bjorn Helgaas wrote:
> [+to Thomas]
> 
> On Wed, Apr 16, 2025 at 08:36:06AM -0700, Shradha Gupta wrote:
> > For supporting dynamic MSI vector allocation by pci controllers, enabling
> > the flag MSI_FLAG_PCI_MSIX_ALLOC_DYN is not enough, msix_prepare_msi_desc()
> > to prepare the desc is needed. Export pci_msix_prepare_desc() to allow pci
> > controllers like pci-hyperv to support dynamic MSI vector allocation.
> > Also, add the flag MSI_FLAG_PCI_MSIX_ALLOC_DYN and use
> > pci_msix_prepare_desc() in pci_hyperv controller
> 
> Follow capitalization convention for subject line.  Probably remove
> "pci_hyperv" since it already contains "PCI: hv" and add something
> about MSI-X.
> 
> s/pci/PCI/
> 
> s/MSI vector/MSI-X vector/ since the context says you're concerned
> with MSI-X.
> 
> This requires an ack from Thomas; moved him to "To:" line.
>
Thanks Bjorn. I will work on addressing these.

Regards,
Shradha. 
> > Signed-off-by: Shradha Gupta <shradhagupta@linux.microsoft.com>
> > Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
> > Reviewed-by: Long Li <longli@microsoft.com>
> > ---
> >  drivers/pci/controller/pci-hyperv.c | 7 +++++--
> >  drivers/pci/msi/irqdomain.c         | 5 +++--
> >  include/linux/msi.h                 | 2 ++
> >  3 files changed, 10 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
> > index ac27bda5ba26..f2fa6bdb6bb8 100644
> > --- a/drivers/pci/controller/pci-hyperv.c
> > +++ b/drivers/pci/controller/pci-hyperv.c
> > @@ -598,7 +598,8 @@ static unsigned int hv_msi_get_int_vector(struct irq_data *data)
> >  	return cfg->vector;
> >  }
> >  
> > -#define hv_msi_prepare		pci_msi_prepare
> > +#define hv_msi_prepare			pci_msi_prepare
> > +#define hv_msix_prepare_desc		pci_msix_prepare_desc
> >  
> >  /**
> >   * hv_arch_irq_unmask() - "Unmask" the IRQ by setting its current
> > @@ -727,6 +728,7 @@ static void hv_arch_irq_unmask(struct irq_data *data)
> >  #define FLOW_HANDLER		NULL
> >  #define FLOW_NAME		NULL
> >  #define hv_msi_prepare		NULL
> > +#define hv_msix_prepare_desc	NULL
> >  
> >  struct hv_pci_chip_data {
> >  	DECLARE_BITMAP(spi_map, HV_PCI_MSI_SPI_NR);
> > @@ -2063,6 +2065,7 @@ static struct irq_chip hv_msi_irq_chip = {
> >  static struct msi_domain_ops hv_msi_ops = {
> >  	.msi_prepare	= hv_msi_prepare,
> >  	.msi_free	= hv_msi_free,
> > +	.prepare_desc	= hv_msix_prepare_desc,
> >  };
> >  
> >  /**
> > @@ -2084,7 +2087,7 @@ static int hv_pcie_init_irq_domain(struct hv_pcibus_device *hbus)
> >  	hbus->msi_info.ops = &hv_msi_ops;
> >  	hbus->msi_info.flags = (MSI_FLAG_USE_DEF_DOM_OPS |
> >  		MSI_FLAG_USE_DEF_CHIP_OPS | MSI_FLAG_MULTI_PCI_MSI |
> > -		MSI_FLAG_PCI_MSIX);
> > +		MSI_FLAG_PCI_MSIX | MSI_FLAG_PCI_MSIX_ALLOC_DYN);
> >  	hbus->msi_info.handler = FLOW_HANDLER;
> >  	hbus->msi_info.handler_name = FLOW_NAME;
> >  	hbus->msi_info.data = hbus;
> > diff --git a/drivers/pci/msi/irqdomain.c b/drivers/pci/msi/irqdomain.c
> > index d7ba8795d60f..43129aa6d6c7 100644
> > --- a/drivers/pci/msi/irqdomain.c
> > +++ b/drivers/pci/msi/irqdomain.c
> > @@ -222,13 +222,14 @@ static void pci_irq_unmask_msix(struct irq_data *data)
> >  	pci_msix_unmask(irq_data_get_msi_desc(data));
> >  }
> >  
> > -static void pci_msix_prepare_desc(struct irq_domain *domain, msi_alloc_info_t *arg,
> > -				  struct msi_desc *desc)
> > +void pci_msix_prepare_desc(struct irq_domain *domain, msi_alloc_info_t *arg,
> > +			   struct msi_desc *desc)
> >  {
> >  	/* Don't fiddle with preallocated MSI descriptors */
> >  	if (!desc->pci.mask_base)
> >  		msix_prepare_msi_desc(to_pci_dev(desc->dev), desc);
> >  }
> > +EXPORT_SYMBOL_GPL(pci_msix_prepare_desc);
> >  
> >  static const struct msi_domain_template pci_msix_template = {
> >  	.chip = {
> > diff --git a/include/linux/msi.h b/include/linux/msi.h
> > index 86e42742fd0f..d5864d5e75c2 100644
> > --- a/include/linux/msi.h
> > +++ b/include/linux/msi.h
> > @@ -691,6 +691,8 @@ struct irq_domain *pci_msi_create_irq_domain(struct fwnode_handle *fwnode,
> >  					     struct irq_domain *parent);
> >  u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev);
> >  struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev);
> > +void pci_msix_prepare_desc(struct irq_domain *domain, msi_alloc_info_t *arg,
> > +			   struct msi_desc *desc);
> >  #else /* CONFIG_PCI_MSI */
> >  static inline struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev)
> >  {
> > -- 
> > 2.34.1
> >

[PATCH 1/2] PCI: hv: enable pci_hyperv to allow dynamic vector allocation
[PATCH 2/2] net: mana: Allow MANA driver to allocate PCI vector dynamically