diff mbox

[v5,6/9] irqchip/gic-v3: Parse and export virtual GIC information

Message ID 1459769860-6629-7-git-send-email-julien.grall@arm.com
State Superseded
Headers show

Commit Message

Julien Grall April 4, 2016, 11:37 a.m. UTC
Fill up the recently introduced gic_kvm_info with the hardware
information used for virtualization.

Signed-off-by: Julien Grall <julien.grall@arm.com>

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Marc Zyngier <marc.zyngier@arm.com>

---
    Changes in v5:
        - Remove the alignment check for GICV. It's already done in the
        KVM code.
        - Fix initialization of KVM with ACPI.

    Changes in v4:
        - Change the flow to call gic_kvm_set_info only when all the
        mandatory information are valid.
        - Remove unecessary code in ACPI parsing (the virtual control
        interface doesn't exist for GICv3).
        - Rework commit message
        - Rework the ACPI support as it didn't collect hardware info for
        virtualization when there is more than 1 redistributor region

    Changes in v3:
        - Add ACPI support

    Changes in v2:
        - Use 0 rather than a negative value to know when the maintenance IRQ
        is not present.
        - Use resource for vcpu and vctrl
---
 drivers/irqchip/irq-gic-v3.c           | 110 ++++++++++++++++++++++++++++++++-
 include/linux/irqchip/arm-gic-common.h |   1 +
 2 files changed, 110 insertions(+), 1 deletion(-)

-- 
1.9.1

Comments

Christoffer Dall April 6, 2016, 5:22 p.m. UTC | #1
On Mon, Apr 04, 2016 at 12:37:37PM +0100, Julien Grall wrote:
> Fill up the recently introduced gic_kvm_info with the hardware

> information used for virtualization.

> 

> Signed-off-by: Julien Grall <julien.grall@arm.com>

> Cc: Thomas Gleixner <tglx@linutronix.de>

> Cc: Jason Cooper <jason@lakedaemon.net>

> Cc: Marc Zyngier <marc.zyngier@arm.com>

> 

> ---

>     Changes in v5:

>         - Remove the alignment check for GICV. It's already done in the

>         KVM code.

>         - Fix initialization of KVM with ACPI.

> 

>     Changes in v4:

>         - Change the flow to call gic_kvm_set_info only when all the

>         mandatory information are valid.

>         - Remove unecessary code in ACPI parsing (the virtual control

>         interface doesn't exist for GICv3).

>         - Rework commit message

>         - Rework the ACPI support as it didn't collect hardware info for

>         virtualization when there is more than 1 redistributor region

> 

>     Changes in v3:

>         - Add ACPI support

> 

>     Changes in v2:

>         - Use 0 rather than a negative value to know when the maintenance IRQ

>         is not present.

>         - Use resource for vcpu and vctrl

> ---

>  drivers/irqchip/irq-gic-v3.c           | 110 ++++++++++++++++++++++++++++++++-

>  include/linux/irqchip/arm-gic-common.h |   1 +

>  2 files changed, 110 insertions(+), 1 deletion(-)

> 

> diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c

> index 50e87e6..08afbfe 100644

> --- a/drivers/irqchip/irq-gic-v3.c

> +++ b/drivers/irqchip/irq-gic-v3.c

> @@ -28,6 +28,7 @@

>  #include <linux/slab.h>

>  

>  #include <linux/irqchip.h>

> +#include <linux/irqchip/arm-gic-common.h>

>  #include <linux/irqchip/arm-gic-v3.h>

>  

>  #include <asm/cputype.h>

> @@ -56,6 +57,8 @@ struct gic_chip_data {

>  static struct gic_chip_data gic_data __read_mostly;

>  static struct static_key supports_deactivate = STATIC_KEY_INIT_TRUE;

>  

> +static struct gic_kvm_info gic_v3_kvm_info;

> +

>  #define gic_data_rdist()		(this_cpu_ptr(gic_data.rdists.rdist))

>  #define gic_data_rdist_rd_base()	(gic_data_rdist()->rd_base)

>  #define gic_data_rdist_sgi_base()	(gic_data_rdist_rd_base() + SZ_64K)

> @@ -901,6 +904,30 @@ static int __init gic_validate_dist_version(void __iomem *dist_base)

>  	return 0;

>  }

>  

> +static void __init gic_of_setup_kvm_info(struct device_node *node)

> +{

> +	int ret;

> +	struct resource r;

> +	u32 gicv_idx;

> +

> +	gic_v3_kvm_info.type = GIC_V3;

> +

> +	gic_v3_kvm_info.maint_irq = irq_of_parse_and_map(node, 0);

> +	if (!gic_v3_kvm_info.maint_irq)

> +		return;

> +

> +	if (of_property_read_u32(node, "#redistributor-regions",

> +				 &gicv_idx))

> +		gicv_idx = 1;

> +

> +	gicv_idx += 3;	/* Also skip GICD, GICC, GICH */

> +	ret = of_address_to_resource(node, gicv_idx, &r);

> +	if (!ret)

> +		gic_v3_kvm_info.vcpu = r;

> +

> +	gic_set_kvm_info(&gic_v3_kvm_info);

> +}

> +

>  static int __init gic_of_init(struct device_node *node, struct device_node *parent)

>  {

>  	void __iomem *dist_base;

> @@ -952,8 +979,10 @@ static int __init gic_of_init(struct device_node *node, struct device_node *pare

>  

>  	err = gic_init_bases(dist_base, rdist_regs, nr_redist_regions,

>  			     redist_stride, &node->fwnode);

> -	if (!err)

> +	if (!err) {

> +		gic_of_setup_kvm_info(node);

>  		return 0;

> +	}

>  

>  out_unmap_rdist:

>  	for (i = 0; i < nr_redist_regions; i++)

> @@ -974,6 +1003,9 @@ static struct

>  	struct redist_region *redist_regs;

>  	u32 nr_redist_regions;

>  	bool single_redist;

> +	u32 maint_irq;

> +	int maint_irq_mode;

> +	phys_addr_t vcpu_base;

>  } acpi_data __initdata;

>  

>  static void __init

> @@ -1110,7 +1142,81 @@ static bool __init acpi_validate_gic_table(struct acpi_subtable_header *header,

>  	return true;

>  }

>  

> +static int __init gic_acpi_parse_virt_madt_gicc(struct acpi_subtable_header *header,

> +						const unsigned long end)

> +{

> +	struct acpi_madt_generic_interrupt *gicc =

> +		(struct acpi_madt_generic_interrupt *)header;

> +	int maint_irq_mode;

> +	static int first_madt = true;

> +

> +	maint_irq_mode = (gicc->flags & ACPI_MADT_VGIC_IRQ_MODE) ?

> +		ACPI_EDGE_SENSITIVE : ACPI_LEVEL_SENSITIVE;

> +

> +	if (first_madt) {

> +		first_madt = false;

> +

> +		acpi_data.maint_irq = gicc->vgic_interrupt;

> +		acpi_data.maint_irq_mode = maint_irq_mode;

> +		acpi_data.vcpu_base = gicc->gicv_base_address;

> +

> +		return 0;

> +	}

> +

> +	/*

> +	 * The maintenance interrupt and GICV should be the same for every CPU

> +	 */

> +	if ((acpi_data.maint_irq != gicc->vgic_interrupt) ||

> +	    (acpi_data.maint_irq_mode != maint_irq_mode) ||

> +	    (acpi_data.vcpu_base != gicc->gicv_base_address))

> +		return -EINVAL;

> +

> +	return 0;

> +}

> +

> +static bool __init gic_acpi_collect_virt_info(void)

> +{

> +	int count;

> +

> +	count = acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_INTERRUPT,

> +				      gic_acpi_parse_virt_madt_gicc, 0);

> +

> +	return (count > 0);

> +}

> +

>  #define ACPI_GICV3_DIST_MEM_SIZE (SZ_64K)

> +#define ACPI_GICV2_VCTRL_MEM_SIZE	(SZ_4K)

> +#define ACPI_GICV2_VCPU_MEM_SIZE	(SZ_8K)

> +

> +static void __init gic_acpi_setup_kvm_info(void)

> +{

> +	int irq;

> +

> +	if (!gic_acpi_collect_virt_info()) {

> +		pr_warn("Unable to get hardware information used for virtualization\n");


perhaps this should say something about gicv3 as well?

> +		return;

> +	}

> +

> +	gic_v3_kvm_info.type = GIC_V3;

> +

> +	irq = acpi_register_gsi(NULL, acpi_data.maint_irq,

> +				acpi_data.maint_irq_mode,

> +				ACPI_ACTIVE_HIGH);

> +	if (irq <= 0)

> +		return;

> +

> +	gic_v3_kvm_info.maint_irq = irq;

> +

> +	if (acpi_data.vcpu_base) {

> +		struct resource *vcpu = &gic_v3_kvm_info.vcpu;

> +

> +		vcpu->flags = IORESOURCE_MEM;

> +		vcpu->start = acpi_data.vcpu_base;

> +		vcpu->end = vcpu->start + ACPI_GICV2_VCPU_MEM_SIZE - 1;

> +	}

> +

> +	gic_set_kvm_info(&gic_v3_kvm_info);

> +}

>  

>  static int __init

>  gic_acpi_init(struct acpi_subtable_header *header, const unsigned long end)

> @@ -1159,6 +1265,8 @@ gic_acpi_init(struct acpi_subtable_header *header, const unsigned long end)

>  		goto out_fwhandle_free;

>  

>  	acpi_set_irq_model(ACPI_IRQ_MODEL_GIC, domain_handle);

> +	gic_acpi_setup_kvm_info();

> +

>  	return 0;

>  

>  out_fwhandle_free:

> diff --git a/include/linux/irqchip/arm-gic-common.h b/include/linux/irqchip/arm-gic-common.h

> index ef34f6f..c647b05 100644

> --- a/include/linux/irqchip/arm-gic-common.h

> +++ b/include/linux/irqchip/arm-gic-common.h

> @@ -15,6 +15,7 @@

>  

>  enum gic_type {

>  	GIC_V2,

> +	GIC_V3,

>  };

>  

>  struct gic_kvm_info {

> -- 

> 1.9.1

> 


Otherwise (with my extremely limited acpi understanding):

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Julien Grall April 6, 2016, 5:45 p.m. UTC | #2
Hi Christoffer,

On 06/04/2016 18:22, Christoffer Dall wrote:
> On Mon, Apr 04, 2016 at 12:37:37PM +0100, Julien Grall wrote:

>> +static void __init gic_acpi_setup_kvm_info(void)

>> +{

>> +	int irq;

>> +

>> +	if (!gic_acpi_collect_virt_info()) {

>> +		pr_warn("Unable to get hardware information used for virtualization\n");

>

> perhaps this should say something about gicv3 as well?


Actually, none of the pr_* call contain GICv3 and there is no pr_fmt.

I'm thinking to send a patch to add pr_fmt in the GICv3 driver.

>

> Otherwise (with my extremely limited acpi understanding):

>

> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>


Thank you!

Regards,

-- 
Julien Grall
Hanjun Guo April 11, 2016, 5:27 a.m. UTC | #3
On 2016/4/4 19:37, Julien Grall wrote:
> Fill up the recently introduced gic_kvm_info with the hardware

> information used for virtualization.

>

> Signed-off-by: Julien Grall <julien.grall@arm.com>

> Cc: Thomas Gleixner <tglx@linutronix.de>

> Cc: Jason Cooper <jason@lakedaemon.net>

> Cc: Marc Zyngier <marc.zyngier@arm.com>

>

> ---

>      Changes in v5:

>          - Remove the alignment check for GICV. It's already done in the

>          KVM code.

>          - Fix initialization of KVM with ACPI.

>

>      Changes in v4:

>          - Change the flow to call gic_kvm_set_info only when all the

>          mandatory information are valid.

>          - Remove unecessary code in ACPI parsing (the virtual control

>          interface doesn't exist for GICv3).

>          - Rework commit message

>          - Rework the ACPI support as it didn't collect hardware info for

>          virtualization when there is more than 1 redistributor region

>

>      Changes in v3:

>          - Add ACPI support

>

>      Changes in v2:

>          - Use 0 rather than a negative value to know when the maintenance IRQ

>          is not present.

>          - Use resource for vcpu and vctrl

> ---

>   drivers/irqchip/irq-gic-v3.c           | 110 ++++++++++++++++++++++++++++++++-

>   include/linux/irqchip/arm-gic-common.h |   1 +

>   2 files changed, 110 insertions(+), 1 deletion(-)

>

> diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c

> index 50e87e6..08afbfe 100644

> --- a/drivers/irqchip/irq-gic-v3.c

> +++ b/drivers/irqchip/irq-gic-v3.c

> @@ -28,6 +28,7 @@

>   #include <linux/slab.h>

>

>   #include <linux/irqchip.h>

> +#include <linux/irqchip/arm-gic-common.h>

>   #include <linux/irqchip/arm-gic-v3.h>

>

>   #include <asm/cputype.h>

> @@ -56,6 +57,8 @@ struct gic_chip_data {

>   static struct gic_chip_data gic_data __read_mostly;

>   static struct static_key supports_deactivate = STATIC_KEY_INIT_TRUE;

>

> +static struct gic_kvm_info gic_v3_kvm_info;

> +

>   #define gic_data_rdist()		(this_cpu_ptr(gic_data.rdists.rdist))

>   #define gic_data_rdist_rd_base()	(gic_data_rdist()->rd_base)

>   #define gic_data_rdist_sgi_base()	(gic_data_rdist_rd_base() + SZ_64K)

> @@ -901,6 +904,30 @@ static int __init gic_validate_dist_version(void __iomem *dist_base)

>   	return 0;

>   }

>

> +static void __init gic_of_setup_kvm_info(struct device_node *node)

> +{

> +	int ret;

> +	struct resource r;

> +	u32 gicv_idx;

> +

> +	gic_v3_kvm_info.type = GIC_V3;

> +

> +	gic_v3_kvm_info.maint_irq = irq_of_parse_and_map(node, 0);

> +	if (!gic_v3_kvm_info.maint_irq)

> +		return;

> +

> +	if (of_property_read_u32(node, "#redistributor-regions",

> +				 &gicv_idx))

> +		gicv_idx = 1;

> +

> +	gicv_idx += 3;	/* Also skip GICD, GICC, GICH */

> +	ret = of_address_to_resource(node, gicv_idx, &r);

> +	if (!ret)

> +		gic_v3_kvm_info.vcpu = r;

> +

> +	gic_set_kvm_info(&gic_v3_kvm_info);

> +}

> +

>   static int __init gic_of_init(struct device_node *node, struct device_node *parent)

>   {

>   	void __iomem *dist_base;

> @@ -952,8 +979,10 @@ static int __init gic_of_init(struct device_node *node, struct device_node *pare

>

>   	err = gic_init_bases(dist_base, rdist_regs, nr_redist_regions,

>   			     redist_stride, &node->fwnode);

> -	if (!err)

> +	if (!err) {

> +		gic_of_setup_kvm_info(node);

>   		return 0;

> +	}

>

>   out_unmap_rdist:

>   	for (i = 0; i < nr_redist_regions; i++)

> @@ -974,6 +1003,9 @@ static struct

>   	struct redist_region *redist_regs;

>   	u32 nr_redist_regions;

>   	bool single_redist;

> +	u32 maint_irq;

> +	int maint_irq_mode;

> +	phys_addr_t vcpu_base;

>   } acpi_data __initdata;

>

>   static void __init

> @@ -1110,7 +1142,81 @@ static bool __init acpi_validate_gic_table(struct acpi_subtable_header *header,

>   	return true;

>   }

>

> +static int __init gic_acpi_parse_virt_madt_gicc(struct acpi_subtable_header *header,

> +						const unsigned long end)

> +{

> +	struct acpi_madt_generic_interrupt *gicc =

> +		(struct acpi_madt_generic_interrupt *)header;

> +	int maint_irq_mode;

> +	static int first_madt = true;

> +

> +	maint_irq_mode = (gicc->flags & ACPI_MADT_VGIC_IRQ_MODE) ?

> +		ACPI_EDGE_SENSITIVE : ACPI_LEVEL_SENSITIVE;

> +

> +	if (first_madt) {

> +		first_madt = false;

> +

> +		acpi_data.maint_irq = gicc->vgic_interrupt;

> +		acpi_data.maint_irq_mode = maint_irq_mode;

> +		acpi_data.vcpu_base = gicc->gicv_base_address;

> +

> +		return 0;

> +	}

> +

> +	/*

> +	 * The maintenance interrupt and GICV should be the same for every CPU

> +	 */

> +	if ((acpi_data.maint_irq != gicc->vgic_interrupt) ||

> +	    (acpi_data.maint_irq_mode != maint_irq_mode) ||

> +	    (acpi_data.vcpu_base != gicc->gicv_base_address))

> +		return -EINVAL;

> +

> +	return 0;

> +}

> +

> +static bool __init gic_acpi_collect_virt_info(void)

> +{

> +	int count;

> +

> +	count = acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_INTERRUPT,

> +				      gic_acpi_parse_virt_madt_gicc, 0);

> +

> +	return (count > 0);

> +}

> +

>   #define ACPI_GICV3_DIST_MEM_SIZE (SZ_64K)

> +#define ACPI_GICV2_VCTRL_MEM_SIZE	(SZ_4K)

> +#define ACPI_GICV2_VCPU_MEM_SIZE	(SZ_8K)

> +

> +static void __init gic_acpi_setup_kvm_info(void)

> +{

> +	int irq;

> +

> +	if (!gic_acpi_collect_virt_info()) {

> +		pr_warn("Unable to get hardware information used for virtualization\n");

> +		return;

> +	}

> +

> +	gic_v3_kvm_info.type = GIC_V3;

> +

> +	irq = acpi_register_gsi(NULL, acpi_data.maint_irq,

> +				acpi_data.maint_irq_mode,

> +				ACPI_ACTIVE_HIGH);

> +	if (irq <= 0)

> +		return;

> +

> +	gic_v3_kvm_info.maint_irq = irq;

> +

> +	if (acpi_data.vcpu_base) {


Sorry, I'm not familiar with KVM, but I got a question here, will
KVM works without valid vcpu_base in GICv3 mode?

Thanks
Hanjun
Julien Grall April 11, 2016, 2:03 p.m. UTC | #4
On 09/04/16 03:29, Shanker Donthineni wrote:
> Hi Julien,


Hello Shanker,

> On 04/04/2016 06:37 AM, Julien Grall wrote:

>> +static int __init gic_acpi_parse_virt_madt_gicc(struct

>> acpi_subtable_header *header,

>> +						const unsigned long end)

>> +{

>> +	struct acpi_madt_generic_interrupt *gicc =

>> +		(struct acpi_madt_generic_interrupt *)header;

>> +	int maint_irq_mode;

>> +	static int first_madt = true;

>> +

>> +	maint_irq_mode = (gicc->flags & ACPI_MADT_VGIC_IRQ_MODE) ?

>> +		ACPI_EDGE_SENSITIVE : ACPI_LEVEL_SENSITIVE;

>> +

> Do you think GICC parameters are valid for an unusable processor?


Good point. We don't know if the value will be valid when the processor 
is unusable.

> If not we need a validation check here, some thing like this to skip

> GICC subtable entry.

>

>              if (!(gicc->flags & ACPI_MADT_ENABLED))

>                  return 0;


I will add this check.

Regards,

-- 
Julien Grall
Julien Grall April 11, 2016, 2:27 p.m. UTC | #5
Hello Hanjun,

On 11/04/16 06:27, Hanjun Guo wrote:
> On 2016/4/4 19:37, Julien Grall wrote:

>> +static void __init gic_acpi_setup_kvm_info(void)

>> +{

>> +    int irq;

>> +

>> +    if (!gic_acpi_collect_virt_info()) {

>> +        pr_warn("Unable to get hardware information used for

>> virtualization\n");

>> +        return;

>> +    }

>> +

>> +    gic_v3_kvm_info.type = GIC_V3;

>> +

>> +    irq = acpi_register_gsi(NULL, acpi_data.maint_irq,

>> +                acpi_data.maint_irq_mode,

>> +                ACPI_ACTIVE_HIGH);

>> +    if (irq <= 0)

>> +        return;

>> +

>> +    gic_v3_kvm_info.maint_irq = irq;

>> +

>> +    if (acpi_data.vcpu_base) {

>

> Sorry, I'm not familiar with KVM, but I got a question here, will

> KVM works without valid vcpu_base in GICv3 mode?


vcpu_base is only required for supporting GICv2 on GICv3.

Regards,

-- 
Julien Grall
Hanjun Guo April 13, 2016, 10:11 a.m. UTC | #6
Hi Shanker, Julien,

On 2016/4/11 23:25, Shanker Donthineni wrote:
> Hi Julien,

>

> On 04/11/2016 09:27 AM, Julien Grall wrote:

>> Hello Hanjun,

>>

>> On 11/04/16 06:27, Hanjun Guo wrote:

>>> On 2016/4/4 19:37, Julien Grall wrote:

>>>> +static void __init gic_acpi_setup_kvm_info(void)

>>>> +{

>>>> +    int irq;

>>>> +

>>>> +    if (!gic_acpi_collect_virt_info()) {

>>>> +        pr_warn("Unable to get hardware information used for

>>>> virtualization\n");

>>>> +        return;

>>>> +    }

>>>> +

>>>> +    gic_v3_kvm_info.type = GIC_V3;

>>>> +

>>>> +    irq = acpi_register_gsi(NULL, acpi_data.maint_irq,

>>>> +                acpi_data.maint_irq_mode,

>>>> +                ACPI_ACTIVE_HIGH);

>>>> +    if (irq <= 0)

>>>> +        return;

>>>> +

>>>> +    gic_v3_kvm_info.maint_irq = irq;

>>>> +

>>>> +    if (acpi_data.vcpu_base) {

>>>

>>> Sorry, I'm not familiar with KVM, but I got a question here, will

>>> KVM works without valid vcpu_base in GICv3 mode?

>>

> Yes, KVM works without vcpu_base in GICv3 mode. The vcpu_base will be used

> for emulatingvGICv2 feature. The vGICv3 emulation isdone through the

> system registers.

>

>> vcpu_base is only required for supporting GICv2 on GICv3.

>>

> Yes, you are right,


Thanks for the clarify.

Hanjun
diff mbox

Patch

diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index 50e87e6..08afbfe 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -28,6 +28,7 @@ 
 #include <linux/slab.h>
 
 #include <linux/irqchip.h>
+#include <linux/irqchip/arm-gic-common.h>
 #include <linux/irqchip/arm-gic-v3.h>
 
 #include <asm/cputype.h>
@@ -56,6 +57,8 @@  struct gic_chip_data {
 static struct gic_chip_data gic_data __read_mostly;
 static struct static_key supports_deactivate = STATIC_KEY_INIT_TRUE;
 
+static struct gic_kvm_info gic_v3_kvm_info;
+
 #define gic_data_rdist()		(this_cpu_ptr(gic_data.rdists.rdist))
 #define gic_data_rdist_rd_base()	(gic_data_rdist()->rd_base)
 #define gic_data_rdist_sgi_base()	(gic_data_rdist_rd_base() + SZ_64K)
@@ -901,6 +904,30 @@  static int __init gic_validate_dist_version(void __iomem *dist_base)
 	return 0;
 }
 
+static void __init gic_of_setup_kvm_info(struct device_node *node)
+{
+	int ret;
+	struct resource r;
+	u32 gicv_idx;
+
+	gic_v3_kvm_info.type = GIC_V3;
+
+	gic_v3_kvm_info.maint_irq = irq_of_parse_and_map(node, 0);
+	if (!gic_v3_kvm_info.maint_irq)
+		return;
+
+	if (of_property_read_u32(node, "#redistributor-regions",
+				 &gicv_idx))
+		gicv_idx = 1;
+
+	gicv_idx += 3;	/* Also skip GICD, GICC, GICH */
+	ret = of_address_to_resource(node, gicv_idx, &r);
+	if (!ret)
+		gic_v3_kvm_info.vcpu = r;
+
+	gic_set_kvm_info(&gic_v3_kvm_info);
+}
+
 static int __init gic_of_init(struct device_node *node, struct device_node *parent)
 {
 	void __iomem *dist_base;
@@ -952,8 +979,10 @@  static int __init gic_of_init(struct device_node *node, struct device_node *pare
 
 	err = gic_init_bases(dist_base, rdist_regs, nr_redist_regions,
 			     redist_stride, &node->fwnode);
-	if (!err)
+	if (!err) {
+		gic_of_setup_kvm_info(node);
 		return 0;
+	}
 
 out_unmap_rdist:
 	for (i = 0; i < nr_redist_regions; i++)
@@ -974,6 +1003,9 @@  static struct
 	struct redist_region *redist_regs;
 	u32 nr_redist_regions;
 	bool single_redist;
+	u32 maint_irq;
+	int maint_irq_mode;
+	phys_addr_t vcpu_base;
 } acpi_data __initdata;
 
 static void __init
@@ -1110,7 +1142,81 @@  static bool __init acpi_validate_gic_table(struct acpi_subtable_header *header,
 	return true;
 }
 
+static int __init gic_acpi_parse_virt_madt_gicc(struct acpi_subtable_header *header,
+						const unsigned long end)
+{
+	struct acpi_madt_generic_interrupt *gicc =
+		(struct acpi_madt_generic_interrupt *)header;
+	int maint_irq_mode;
+	static int first_madt = true;
+
+	maint_irq_mode = (gicc->flags & ACPI_MADT_VGIC_IRQ_MODE) ?
+		ACPI_EDGE_SENSITIVE : ACPI_LEVEL_SENSITIVE;
+
+	if (first_madt) {
+		first_madt = false;
+
+		acpi_data.maint_irq = gicc->vgic_interrupt;
+		acpi_data.maint_irq_mode = maint_irq_mode;
+		acpi_data.vcpu_base = gicc->gicv_base_address;
+
+		return 0;
+	}
+
+	/*
+	 * The maintenance interrupt and GICV should be the same for every CPU
+	 */
+	if ((acpi_data.maint_irq != gicc->vgic_interrupt) ||
+	    (acpi_data.maint_irq_mode != maint_irq_mode) ||
+	    (acpi_data.vcpu_base != gicc->gicv_base_address))
+		return -EINVAL;
+
+	return 0;
+}
+
+static bool __init gic_acpi_collect_virt_info(void)
+{
+	int count;
+
+	count = acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_INTERRUPT,
+				      gic_acpi_parse_virt_madt_gicc, 0);
+
+	return (count > 0);
+}
+
 #define ACPI_GICV3_DIST_MEM_SIZE (SZ_64K)
+#define ACPI_GICV2_VCTRL_MEM_SIZE	(SZ_4K)
+#define ACPI_GICV2_VCPU_MEM_SIZE	(SZ_8K)
+
+static void __init gic_acpi_setup_kvm_info(void)
+{
+	int irq;
+
+	if (!gic_acpi_collect_virt_info()) {
+		pr_warn("Unable to get hardware information used for virtualization\n");
+		return;
+	}
+
+	gic_v3_kvm_info.type = GIC_V3;
+
+	irq = acpi_register_gsi(NULL, acpi_data.maint_irq,
+				acpi_data.maint_irq_mode,
+				ACPI_ACTIVE_HIGH);
+	if (irq <= 0)
+		return;
+
+	gic_v3_kvm_info.maint_irq = irq;
+
+	if (acpi_data.vcpu_base) {
+		struct resource *vcpu = &gic_v3_kvm_info.vcpu;
+
+		vcpu->flags = IORESOURCE_MEM;
+		vcpu->start = acpi_data.vcpu_base;
+		vcpu->end = vcpu->start + ACPI_GICV2_VCPU_MEM_SIZE - 1;
+	}
+
+	gic_set_kvm_info(&gic_v3_kvm_info);
+}
 
 static int __init
 gic_acpi_init(struct acpi_subtable_header *header, const unsigned long end)
@@ -1159,6 +1265,8 @@  gic_acpi_init(struct acpi_subtable_header *header, const unsigned long end)
 		goto out_fwhandle_free;
 
 	acpi_set_irq_model(ACPI_IRQ_MODEL_GIC, domain_handle);
+	gic_acpi_setup_kvm_info();
+
 	return 0;
 
 out_fwhandle_free:
diff --git a/include/linux/irqchip/arm-gic-common.h b/include/linux/irqchip/arm-gic-common.h
index ef34f6f..c647b05 100644
--- a/include/linux/irqchip/arm-gic-common.h
+++ b/include/linux/irqchip/arm-gic-common.h
@@ -15,6 +15,7 @@ 
 
 enum gic_type {
 	GIC_V2,
+	GIC_V3,
 };
 
 struct gic_kvm_info {