[v2,08/15] KVM: arm64: introduce ITS emulation file with stub functions
diff mbox

Message ID 1436538111-4294-9-git-send-email-andre.przywara@arm.com
State New
Headers show

Commit Message

Andre Przywara July 10, 2015, 2:21 p.m. UTC
The ARM GICv3 ITS emulation code goes into a separate file, but
needs to be connected to the GICv3 emulation, of which it is an
option.
Introduce the skeleton with function stubs to be filled later.
Introduce the basic ITS data structure and initialize it, but don't
return any success yet, as we are not yet ready for the show.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
---
 arch/arm64/kvm/Makefile            |   1 +
 include/kvm/arm_vgic.h             |   6 ++
 include/linux/irqchip/arm-gic-v3.h |   1 +
 virt/kvm/arm/its-emul.c            | 125 +++++++++++++++++++++++++++++++++++++
 virt/kvm/arm/its-emul.h            |  35 +++++++++++
 virt/kvm/arm/vgic-v3-emul.c        |  24 ++++++-
 6 files changed, 189 insertions(+), 3 deletions(-)
 create mode 100644 virt/kvm/arm/its-emul.c
 create mode 100644 virt/kvm/arm/its-emul.h

Comments

Eric Auger Aug. 13, 2015, 12:48 p.m. UTC | #1
On 07/10/2015 04:21 PM, Andre Przywara wrote:
> The ARM GICv3 ITS emulation code goes into a separate file, but
> needs to be connected to the GICv3 emulation, of which it is an
> option.
> Introduce the skeleton with function stubs to be filled later.
> Introduce the basic ITS data structure and initialize it, but don't
> return any success yet, as we are not yet ready for the show.
> 
> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> ---
>  arch/arm64/kvm/Makefile            |   1 +
>  include/kvm/arm_vgic.h             |   6 ++
>  include/linux/irqchip/arm-gic-v3.h |   1 +
>  virt/kvm/arm/its-emul.c            | 125 +++++++++++++++++++++++++++++++++++++
>  virt/kvm/arm/its-emul.h            |  35 +++++++++++
>  virt/kvm/arm/vgic-v3-emul.c        |  24 ++++++-
>  6 files changed, 189 insertions(+), 3 deletions(-)
>  create mode 100644 virt/kvm/arm/its-emul.c
>  create mode 100644 virt/kvm/arm/its-emul.h
> 
> diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
> index f90f4aa..9803307 100644
> --- a/arch/arm64/kvm/Makefile
> +++ b/arch/arm64/kvm/Makefile
> @@ -25,5 +25,6 @@ kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic-v2-emul.o
>  kvm-$(CONFIG_KVM_ARM_HOST) += vgic-v2-switch.o
>  kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic-v3.o
>  kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic-v3-emul.o
> +kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/its-emul.o
>  kvm-$(CONFIG_KVM_ARM_HOST) += vgic-v3-switch.o
>  kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/arch_timer.o
> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
> index 8c6cb0e..9e9d4aa 100644
> --- a/include/kvm/arm_vgic.h
> +++ b/include/kvm/arm_vgic.h
> @@ -156,6 +156,11 @@ struct vgic_io_device {
>  	struct kvm_io_device dev;
>  };
>  
> +struct vgic_its {
> +	bool			enabled;
> +	spinlock_t		lock;
> +};
> +
>  struct vgic_dist {
>  	spinlock_t		lock;
>  	bool			in_kernel;
> @@ -264,6 +269,7 @@ struct vgic_dist {
>  	u64			*pendbaser;
>  
>  	bool			lpis_enabled;
> +	struct vgic_its		its;
>  };
>  
>  struct vgic_v2_cpu_if {
> diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
> index ffbc034..df4e527 100644
> --- a/include/linux/irqchip/arm-gic-v3.h
> +++ b/include/linux/irqchip/arm-gic-v3.h
> @@ -177,6 +177,7 @@
>  #define GITS_CWRITER			0x0088
>  #define GITS_CREADR			0x0090
>  #define GITS_BASER			0x0100
> +#define GITS_IDREGS_BASE		0xffd0
>  #define GITS_PIDR2			GICR_PIDR2
>  
>  #define GITS_TRANSLATER			0x10040
> diff --git a/virt/kvm/arm/its-emul.c b/virt/kvm/arm/its-emul.c
> new file mode 100644
> index 0000000..659dd39
> --- /dev/null
> +++ b/virt/kvm/arm/its-emul.c
> @@ -0,0 +1,125 @@
> +/*
> + * GICv3 ITS emulation
> + *
> + * Copyright (C) 2015 ARM Ltd.
> + * Author: Andre Przywara <andre.przywara@arm.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program.  If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <linux/cpu.h>
> +#include <linux/kvm.h>
> +#include <linux/kvm_host.h>
> +#include <linux/interrupt.h>
> +
> +#include <linux/irqchip/arm-gic-v3.h>
> +#include <kvm/arm_vgic.h>
> +
> +#include <asm/kvm_emulate.h>
> +#include <asm/kvm_arm.h>
> +#include <asm/kvm_mmu.h>
> +
> +#include "vgic.h"
> +#include "its-emul.h"
> +
> +static bool handle_mmio_misc_gits(struct kvm_vcpu *vcpu,
> +				  struct kvm_exit_mmio *mmio,
> +				  phys_addr_t offset)
> +{
> +	return false;
> +}
> +
> +static bool handle_mmio_gits_idregs(struct kvm_vcpu *vcpu,
> +				    struct kvm_exit_mmio *mmio,
> +				    phys_addr_t offset)
> +{
> +	return false;
> +}
> +
> +static bool handle_mmio_gits_cbaser(struct kvm_vcpu *vcpu,
> +				    struct kvm_exit_mmio *mmio,
> +				    phys_addr_t offset)
> +{
> +	return false;
> +}
> +
> +static bool handle_mmio_gits_cwriter(struct kvm_vcpu *vcpu,
> +				     struct kvm_exit_mmio *mmio,
> +				     phys_addr_t offset)
> +{
> +	return false;
> +}
> +
> +static bool handle_mmio_gits_creadr(struct kvm_vcpu *vcpu,
> +				    struct kvm_exit_mmio *mmio,
> +				    phys_addr_t offset)
> +{
> +	return false;
> +}
> +
> +static const struct vgic_io_range vgicv3_its_ranges[] = {
> +	{
> +		.base		= GITS_CTLR,
> +		.len		= 0x10,
> +		.bits_per_irq	= 0,
> +		.handle_mmio	= handle_mmio_misc_gits,
> +	},
> +	{
> +		.base		= GITS_CBASER,
> +		.len		= 0x08,
> +		.bits_per_irq	= 0,
> +		.handle_mmio	= handle_mmio_gits_cbaser,
> +	},
> +	{
> +		.base		= GITS_CWRITER,
> +		.len		= 0x08,
> +		.bits_per_irq	= 0,
> +		.handle_mmio	= handle_mmio_gits_cwriter,
> +	},
> +	{
> +		.base		= GITS_CREADR,
> +		.len		= 0x08,
> +		.bits_per_irq	= 0,
> +		.handle_mmio	= handle_mmio_gits_creadr,
> +	},
> +	{
> +		/* We don't need any memory from the guest. */
> +		.base		= GITS_BASER,
> +		.len		= 0x40,
> +		.bits_per_irq	= 0,
> +		.handle_mmio	= handle_mmio_raz_wi,
> +	},
> +	{
> +		.base		= GITS_IDREGS_BASE,
> +		.len		= 0x30,
> +		.bits_per_irq	= 0,
> +		.handle_mmio	= handle_mmio_gits_idregs,
> +	},
> +};
> +
> +/* This is called on setting the LPI enable bit in the redistributor. */
> +void vgic_enable_lpis(struct kvm_vcpu *vcpu)
> +{
> +}
> +
> +int vits_init(struct kvm *kvm)
> +{
> +	struct vgic_dist *dist = &kvm->arch.vgic;
> +	struct vgic_its *its = &dist->its;
> +
> +	spin_lock_init(&its->lock);
> +
> +	its->enabled = false;
> +
> +	return -ENXIO;
> +}
> diff --git a/virt/kvm/arm/its-emul.h b/virt/kvm/arm/its-emul.h
> new file mode 100644
> index 0000000..5dc8e2f
> --- /dev/null
> +++ b/virt/kvm/arm/its-emul.h
> @@ -0,0 +1,35 @@
> +/*
> + * GICv3 ITS emulation definitions
> + *
> + * Copyright (C) 2015 ARM Ltd.
> + * Author: Andre Przywara <andre.przywara@arm.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program.  If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#ifndef __KVM_ITS_EMUL_H__
> +#define __KVM_ITS_EMUL_H__
> +
> +#include <linux/kvm.h>
> +#include <linux/kvm_host.h>
> +
> +#include <asm/kvm_emulate.h>
> +#include <asm/kvm_arm.h>
> +#include <asm/kvm_mmu.h>
> +
> +#include "vgic.h"
> +
> +void vgic_enable_lpis(struct kvm_vcpu *vcpu);
> +int vits_init(struct kvm *kvm);
> +
> +#endif
> diff --git a/virt/kvm/arm/vgic-v3-emul.c b/virt/kvm/arm/vgic-v3-emul.c
> index 5269ad1..f5865e7 100644
> --- a/virt/kvm/arm/vgic-v3-emul.c
> +++ b/virt/kvm/arm/vgic-v3-emul.c
> @@ -48,6 +48,7 @@
>  #include <asm/kvm_mmu.h>
>  
>  #include "vgic.h"
> +#include "its-emul.h"
>  
>  static bool handle_mmio_rao_wi(struct kvm_vcpu *vcpu,
>  			       struct kvm_exit_mmio *mmio, phys_addr_t offset)
> @@ -530,9 +531,20 @@ static bool handle_mmio_ctlr_redist(struct kvm_vcpu *vcpu,
>  				    struct kvm_exit_mmio *mmio,
>  				    phys_addr_t offset)
>  {
> -	/* since we don't support LPIs, this register is zero for now */
> -	vgic_reg_access(mmio, NULL, offset,
> -			ACCESS_READ_RAZ | ACCESS_WRITE_IGNORED);
> +	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
> +	u32 reg;
> +
> +	if (!vgic_has_its(vcpu->kvm)) {
> +		vgic_reg_access(mmio, NULL, offset,
> +				ACCESS_READ_RAZ | ACCESS_WRITE_IGNORED);
> +		return false;
> +	}
can't we remove above block and ...
> +	reg = dist->lpis_enabled ? GICR_CTLR_ENABLE_LPIS : 0;
> +	vgic_reg_access(mmio, &reg, offset,
> +			ACCESS_READ_VALUE | ACCESS_WRITE_VALUE);
> +	if (!dist->lpis_enabled && (reg & GICR_CTLR_ENABLE_LPIS
add vgic_has_its(vcpu->kvm) && above?

Besides Reviewed-by: Eric Auger <eric.auger@linaro.org>

Eric
)) {
> +		/* Eventually do something */
> +	}
>  	return false;
>  }
>  
> @@ -861,6 +873,12 @@ static int vgic_v3_map_resources(struct kvm *kvm,
>  		rdbase += GIC_V3_REDIST_SIZE;
>  	}
>  
> +	if (vgic_has_its(kvm)) {
> +		ret = vits_init(kvm);
> +		if (ret)
> +			goto out_unregister;
> +	}
> +
>  	dist->redist_iodevs = iodevs;
>  	dist->ready = true;
>  	goto out;
> 

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Andre Przywara Aug. 25, 2015, 9:39 a.m. UTC | #2
Salut Eric,

....

>> diff --git a/virt/kvm/arm/vgic-v3-emul.c b/virt/kvm/arm/vgic-v3-emul.c
>> index 5269ad1..f5865e7 100644
>> --- a/virt/kvm/arm/vgic-v3-emul.c
>> +++ b/virt/kvm/arm/vgic-v3-emul.c
>> @@ -48,6 +48,7 @@
>>  #include <asm/kvm_mmu.h>
>>  
>>  #include "vgic.h"
>> +#include "its-emul.h"
>>  
>>  static bool handle_mmio_rao_wi(struct kvm_vcpu *vcpu,
>>  			       struct kvm_exit_mmio *mmio, phys_addr_t offset)
>> @@ -530,9 +531,20 @@ static bool handle_mmio_ctlr_redist(struct kvm_vcpu *vcpu,
>>  				    struct kvm_exit_mmio *mmio,
>>  				    phys_addr_t offset)
>>  {
>> -	/* since we don't support LPIs, this register is zero for now */
>> -	vgic_reg_access(mmio, NULL, offset,
>> -			ACCESS_READ_RAZ | ACCESS_WRITE_IGNORED);
>> +	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
>> +	u32 reg;
>> +
>> +	if (!vgic_has_its(vcpu->kvm)) {
>> +		vgic_reg_access(mmio, NULL, offset,
>> +				ACCESS_READ_RAZ | ACCESS_WRITE_IGNORED);
>> +		return false;
>> +	}
> can't we remove above block and ...
>> +	reg = dist->lpis_enabled ? GICR_CTLR_ENABLE_LPIS : 0;
>> +	vgic_reg_access(mmio, &reg, offset,
>> +			ACCESS_READ_VALUE | ACCESS_WRITE_VALUE);
>> +	if (!dist->lpis_enabled && (reg & GICR_CTLR_ENABLE_LPIS
> add vgic_has_its(vcpu->kvm) && above?

Yeah, makes some sense. Changed that.
> 
> Besides Reviewed-by: Eric Auger <eric.auger@linaro.org>

Merci!

André

> 
> Eric
> )) {
>> +		/* Eventually do something */
>> +	}
>>  	return false;
>>  }
>>  
>> @@ -861,6 +873,12 @@ static int vgic_v3_map_resources(struct kvm *kvm,
>>  		rdbase += GIC_V3_REDIST_SIZE;
>>  	}
>>  
>> +	if (vgic_has_its(kvm)) {
>> +		ret = vits_init(kvm);
>> +		if (ret)
>> +			goto out_unregister;
>> +	}
>> +
>>  	dist->redist_iodevs = iodevs;
>>  	dist->ready = true;
>>  	goto out;
>>
> 
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Patch
diff mbox

diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
index f90f4aa..9803307 100644
--- a/arch/arm64/kvm/Makefile
+++ b/arch/arm64/kvm/Makefile
@@ -25,5 +25,6 @@  kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic-v2-emul.o
 kvm-$(CONFIG_KVM_ARM_HOST) += vgic-v2-switch.o
 kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic-v3.o
 kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic-v3-emul.o
+kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/its-emul.o
 kvm-$(CONFIG_KVM_ARM_HOST) += vgic-v3-switch.o
 kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/arch_timer.o
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 8c6cb0e..9e9d4aa 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -156,6 +156,11 @@  struct vgic_io_device {
 	struct kvm_io_device dev;
 };
 
+struct vgic_its {
+	bool			enabled;
+	spinlock_t		lock;
+};
+
 struct vgic_dist {
 	spinlock_t		lock;
 	bool			in_kernel;
@@ -264,6 +269,7 @@  struct vgic_dist {
 	u64			*pendbaser;
 
 	bool			lpis_enabled;
+	struct vgic_its		its;
 };
 
 struct vgic_v2_cpu_if {
diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
index ffbc034..df4e527 100644
--- a/include/linux/irqchip/arm-gic-v3.h
+++ b/include/linux/irqchip/arm-gic-v3.h
@@ -177,6 +177,7 @@ 
 #define GITS_CWRITER			0x0088
 #define GITS_CREADR			0x0090
 #define GITS_BASER			0x0100
+#define GITS_IDREGS_BASE		0xffd0
 #define GITS_PIDR2			GICR_PIDR2
 
 #define GITS_TRANSLATER			0x10040
diff --git a/virt/kvm/arm/its-emul.c b/virt/kvm/arm/its-emul.c
new file mode 100644
index 0000000..659dd39
--- /dev/null
+++ b/virt/kvm/arm/its-emul.c
@@ -0,0 +1,125 @@ 
+/*
+ * GICv3 ITS emulation
+ *
+ * Copyright (C) 2015 ARM Ltd.
+ * Author: Andre Przywara <andre.przywara@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/cpu.h>
+#include <linux/kvm.h>
+#include <linux/kvm_host.h>
+#include <linux/interrupt.h>
+
+#include <linux/irqchip/arm-gic-v3.h>
+#include <kvm/arm_vgic.h>
+
+#include <asm/kvm_emulate.h>
+#include <asm/kvm_arm.h>
+#include <asm/kvm_mmu.h>
+
+#include "vgic.h"
+#include "its-emul.h"
+
+static bool handle_mmio_misc_gits(struct kvm_vcpu *vcpu,
+				  struct kvm_exit_mmio *mmio,
+				  phys_addr_t offset)
+{
+	return false;
+}
+
+static bool handle_mmio_gits_idregs(struct kvm_vcpu *vcpu,
+				    struct kvm_exit_mmio *mmio,
+				    phys_addr_t offset)
+{
+	return false;
+}
+
+static bool handle_mmio_gits_cbaser(struct kvm_vcpu *vcpu,
+				    struct kvm_exit_mmio *mmio,
+				    phys_addr_t offset)
+{
+	return false;
+}
+
+static bool handle_mmio_gits_cwriter(struct kvm_vcpu *vcpu,
+				     struct kvm_exit_mmio *mmio,
+				     phys_addr_t offset)
+{
+	return false;
+}
+
+static bool handle_mmio_gits_creadr(struct kvm_vcpu *vcpu,
+				    struct kvm_exit_mmio *mmio,
+				    phys_addr_t offset)
+{
+	return false;
+}
+
+static const struct vgic_io_range vgicv3_its_ranges[] = {
+	{
+		.base		= GITS_CTLR,
+		.len		= 0x10,
+		.bits_per_irq	= 0,
+		.handle_mmio	= handle_mmio_misc_gits,
+	},
+	{
+		.base		= GITS_CBASER,
+		.len		= 0x08,
+		.bits_per_irq	= 0,
+		.handle_mmio	= handle_mmio_gits_cbaser,
+	},
+	{
+		.base		= GITS_CWRITER,
+		.len		= 0x08,
+		.bits_per_irq	= 0,
+		.handle_mmio	= handle_mmio_gits_cwriter,
+	},
+	{
+		.base		= GITS_CREADR,
+		.len		= 0x08,
+		.bits_per_irq	= 0,
+		.handle_mmio	= handle_mmio_gits_creadr,
+	},
+	{
+		/* We don't need any memory from the guest. */
+		.base		= GITS_BASER,
+		.len		= 0x40,
+		.bits_per_irq	= 0,
+		.handle_mmio	= handle_mmio_raz_wi,
+	},
+	{
+		.base		= GITS_IDREGS_BASE,
+		.len		= 0x30,
+		.bits_per_irq	= 0,
+		.handle_mmio	= handle_mmio_gits_idregs,
+	},
+};
+
+/* This is called on setting the LPI enable bit in the redistributor. */
+void vgic_enable_lpis(struct kvm_vcpu *vcpu)
+{
+}
+
+int vits_init(struct kvm *kvm)
+{
+	struct vgic_dist *dist = &kvm->arch.vgic;
+	struct vgic_its *its = &dist->its;
+
+	spin_lock_init(&its->lock);
+
+	its->enabled = false;
+
+	return -ENXIO;
+}
diff --git a/virt/kvm/arm/its-emul.h b/virt/kvm/arm/its-emul.h
new file mode 100644
index 0000000..5dc8e2f
--- /dev/null
+++ b/virt/kvm/arm/its-emul.h
@@ -0,0 +1,35 @@ 
+/*
+ * GICv3 ITS emulation definitions
+ *
+ * Copyright (C) 2015 ARM Ltd.
+ * Author: Andre Przywara <andre.przywara@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __KVM_ITS_EMUL_H__
+#define __KVM_ITS_EMUL_H__
+
+#include <linux/kvm.h>
+#include <linux/kvm_host.h>
+
+#include <asm/kvm_emulate.h>
+#include <asm/kvm_arm.h>
+#include <asm/kvm_mmu.h>
+
+#include "vgic.h"
+
+void vgic_enable_lpis(struct kvm_vcpu *vcpu);
+int vits_init(struct kvm *kvm);
+
+#endif
diff --git a/virt/kvm/arm/vgic-v3-emul.c b/virt/kvm/arm/vgic-v3-emul.c
index 5269ad1..f5865e7 100644
--- a/virt/kvm/arm/vgic-v3-emul.c
+++ b/virt/kvm/arm/vgic-v3-emul.c
@@ -48,6 +48,7 @@ 
 #include <asm/kvm_mmu.h>
 
 #include "vgic.h"
+#include "its-emul.h"
 
 static bool handle_mmio_rao_wi(struct kvm_vcpu *vcpu,
 			       struct kvm_exit_mmio *mmio, phys_addr_t offset)
@@ -530,9 +531,20 @@  static bool handle_mmio_ctlr_redist(struct kvm_vcpu *vcpu,
 				    struct kvm_exit_mmio *mmio,
 				    phys_addr_t offset)
 {
-	/* since we don't support LPIs, this register is zero for now */
-	vgic_reg_access(mmio, NULL, offset,
-			ACCESS_READ_RAZ | ACCESS_WRITE_IGNORED);
+	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+	u32 reg;
+
+	if (!vgic_has_its(vcpu->kvm)) {
+		vgic_reg_access(mmio, NULL, offset,
+				ACCESS_READ_RAZ | ACCESS_WRITE_IGNORED);
+		return false;
+	}
+	reg = dist->lpis_enabled ? GICR_CTLR_ENABLE_LPIS : 0;
+	vgic_reg_access(mmio, &reg, offset,
+			ACCESS_READ_VALUE | ACCESS_WRITE_VALUE);
+	if (!dist->lpis_enabled && (reg & GICR_CTLR_ENABLE_LPIS)) {
+		/* Eventually do something */
+	}
 	return false;
 }
 
@@ -861,6 +873,12 @@  static int vgic_v3_map_resources(struct kvm *kvm,
 		rdbase += GIC_V3_REDIST_SIZE;
 	}
 
+	if (vgic_has_its(kvm)) {
+		ret = vits_init(kvm);
+		if (ret)
+			goto out_unregister;
+	}
+
 	dist->redist_iodevs = iodevs;
 	dist->ready = true;
 	goto out;