Re: [RFC PATCH v1 4/4] arm/arm64: vgic-new: Implement VGICv3 CPU interface access

[Christoffer Dall <christoffer.dall@linaro.org>]

On Wed, Jul 20, 2016 at 06:32:28PM +0530, vijay.kilari@gmail.com wrote:
> From: Vijaya Kumar K <Vijaya.Kumar@cavium.com>
> 
> CPU sysregs access size is always 64 bits. MPIDR value
> passed along with reg id is used to identify the CPU.

Please provide a decent commit message along with a 200+ lines patch.

Thanks,
-Christoffer

> 
> Signed-off-by: Pavel Fedin <p.fedin@samsung.com>
> Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@cavium.com>
> ---
>  arch/arm64/include/uapi/asm/kvm.h   |    9 ++
>  arch/arm64/kvm/Makefile             |    1 +
>  include/linux/irqchip/arm-gic-v3.h  |    4 +
>  virt/kvm/arm/vgic/vgic-kvm-device.c |   31 +++++
>  virt/kvm/arm/vgic/vgic-mmio-v2.c    |    4 +-
>  virt/kvm/arm/vgic/vgic-mmio-v3.c    |    6 +
>  virt/kvm/arm/vgic/vgic-sys-reg-v3.c |  225 +++++++++++++++++++++++++++++++++++
>  virt/kvm/arm/vgic/vgic.h            |    6 +
>  8 files changed, 284 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
> index a6b996e..35c4a99 100644
> --- a/arch/arm64/include/uapi/asm/kvm.h
> +++ b/arch/arm64/include/uapi/asm/kvm.h
> @@ -206,7 +206,16 @@ struct kvm_arch_memory_slot {
>  #define KVM_DEV_ARM_VGIC_GRP_NR_IRQS	3
>  #define KVM_DEV_ARM_VGIC_GRP_CTRL	4
>  #define KVM_DEV_ARM_VGIC_GRP_REDIST_REGS 5
> +#define KVM_DEV_ARM_VGIC_CPU_SYSREGS    6
> +
>  #define   KVM_DEV_ARM_VGIC_CTRL_INIT	0
> +#define   KVM_DEV_ARM_VGIC_SYSREG_MASK (KVM_REG_ARM64_SYSREG_OP0_MASK | \
> +					KVM_REG_ARM64_SYSREG_OP1_MASK | \
> +					KVM_REG_ARM64_SYSREG_CRN_MASK | \
> +					KVM_REG_ARM64_SYSREG_CRM_MASK | \
> +					KVM_REG_ARM64_SYSREG_OP2_MASK)
> +#define   KVM_DEV_ARM_VGIC_SYSREG(op0, op1, crn, crm, op2) \
> +					__ARM64_SYS_REG(op0, op1, crn, crm, op2)
>  
>  /* Device Control API on vcpu fd */
>  #define KVM_ARM_VCPU_PMU_V3_CTRL	0
> diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
> index f00b2cd..53400c1 100644
> --- a/arch/arm64/kvm/Makefile
> +++ b/arch/arm64/kvm/Makefile
> @@ -29,5 +29,6 @@ kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-mmio.o
>  kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-mmio-v2.o
>  kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-mmio-v3.o
>  kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-kvm-device.o
> +kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-sys-reg-v3.o
>  kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/arch_timer.o
>  kvm-$(CONFIG_KVM_ARM_PMU) += $(KVM)/arm/pmu.o
> diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
> index bfbd707..ae84cde 100644
> --- a/include/linux/irqchip/arm-gic-v3.h
> +++ b/include/linux/irqchip/arm-gic-v3.h
> @@ -288,6 +288,10 @@
>  
>  #define ICH_VMCR_CTLR_SHIFT		0
>  #define ICH_VMCR_CTLR_MASK		(0x21f << ICH_VMCR_CTLR_SHIFT)
> +#define ICH_VMCR_ENG0_SHIFT		0
> +#define ICH_VMCR_ENG0			(1 << ICH_VMCR_ENG0_SHIFT)
> +#define ICH_VMCR_ENG1_SHIFT		1
> +#define ICH_VMCR_ENG1			(1 << ICH_VMCR_ENG1_SHIFT)
>  #define ICH_VMCR_BPR1_SHIFT		18
>  #define ICH_VMCR_BPR1_MASK		(7 << ICH_VMCR_BPR1_SHIFT)
>  #define ICH_VMCR_BPR0_SHIFT		21
> diff --git a/virt/kvm/arm/vgic/vgic-kvm-device.c b/virt/kvm/arm/vgic/vgic-kvm-device.c
> index 996a720..78c50cc 100644
> --- a/virt/kvm/arm/vgic/vgic-kvm-device.c
> +++ b/virt/kvm/arm/vgic/vgic-kvm-device.c
> @@ -266,6 +266,7 @@ static int vgic_attr_regs_access(struct kvm_device *dev,
>  	int cpuid, ret, c;
>  	struct kvm_vcpu *vcpu, *tmp_vcpu;
>  	int vcpu_lock_idx = -1;
> +	u64 regid;
>  	struct vgic_dist *vgic = &dev->kvm->arch.vgic;
>  
>  	if (vgic->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V2) {
> @@ -322,6 +323,16 @@ static int vgic_attr_regs_access(struct kvm_device *dev,
>  		else
>  			ret = -EINVAL;
>  		break;
> +	case KVM_DEV_ARM_VGIC_CPU_SYSREGS:
> +		if (vgic->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3) {
> +			regid = (attr->attr & KVM_DEV_ARM_VGIC_SYSREG_MASK) |
> +				KVM_REG_SIZE_U64;
> +			ret = vgic_v3_cpu_sysregs_uaccess(vcpu, is_write,
> +							  regid, &reg->reg64);
> +		} else {
> +			ret = -EINVAL;
> +		}
> +		break;
>  	default:
>  		ret = -EINVAL;
>  		break;
> @@ -447,6 +458,15 @@ static int vgic_v3_set_attr(struct kvm_device *dev,
>  
>  		return vgic_attr_regs_access(dev, attr, &reg, true);
>  	}
> +	case KVM_DEV_ARM_VGIC_CPU_SYSREGS: {
> +		u64 __user *uaddr = (u64 __user *)(long)attr->addr;
> +		union ureg reg;
> +
> +		if (get_user(reg.reg64, uaddr))
> +			return -EFAULT;
> +
> +		return vgic_attr_regs_access(dev, attr, &reg, true);
> +	}
>  	}
>  	return -ENXIO;
>  }
> @@ -472,6 +492,16 @@ static int vgic_v3_get_attr(struct kvm_device *dev,
>  		ret = put_user(reg.reg32, uaddr);
>  		return ret;
>  	}
> +	case KVM_DEV_ARM_VGIC_CPU_SYSREGS: {
> +		u64 __user *uaddr = (u64 __user *)(long)attr->addr;
> +		union ureg reg;
> +
> +		ret = vgic_attr_regs_access(dev, attr, &reg, false);
> +		if (ret)
> +			return ret;
> +		ret = put_user(reg.reg64, uaddr);
> +		return ret;
> +	}
>  	}
>  
>  	return -ENXIO;
> @@ -490,6 +520,7 @@ static int vgic_v3_has_attr(struct kvm_device *dev,
>  		break;
>  	case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
>  	case KVM_DEV_ARM_VGIC_GRP_REDIST_REGS:
> +	case KVM_DEV_ARM_VGIC_CPU_SYSREGS:
>  		return vgic_v3_has_attr_regs(dev, attr);
>  	case KVM_DEV_ARM_VGIC_GRP_NR_IRQS:
>  		return 0;
> diff --git a/virt/kvm/arm/vgic/vgic-mmio-v2.c b/virt/kvm/arm/vgic/vgic-mmio-v2.c
> index a213936..97d94b2 100644
> --- a/virt/kvm/arm/vgic/vgic-mmio-v2.c
> +++ b/virt/kvm/arm/vgic/vgic-mmio-v2.c
> @@ -204,7 +204,7 @@ static void vgic_mmio_write_sgipends(struct kvm_vcpu *vcpu,
>  	}
>  }
>  
> -static void vgic_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr)
> +void vgic_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr)
>  {
>  	if (kvm_vgic_global_state.type == VGIC_V2)
>  		vgic_v2_set_vmcr(vcpu, vmcr);
> @@ -212,7 +212,7 @@ static void vgic_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr)
>  		vgic_v3_set_vmcr(vcpu, vmcr);
>  }
>  
> -static void vgic_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr)
> +void vgic_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr)
>  {
>  	if (kvm_vgic_global_state.type == VGIC_V2)
>  		vgic_v2_get_vmcr(vcpu, vmcr);
> diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
> index f6a4e97..aa63f39 100644
> --- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
> +++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
> @@ -23,6 +23,7 @@
>  
>  #include "vgic.h"
>  #include "vgic-mmio.h"
> +#include "sys_regs.h"
>  
>  /* extract @num bytes at @offset bytes offset in data */
>  static unsigned long extract_bytes(unsigned long data, unsigned int offset,
> @@ -382,6 +383,11 @@ int vgic_v3_has_attr_regs(struct kvm_device *dev, struct kvm_device_attr *attr)
>  		nr_regions = rd_dev->nr_regions;
>  		break;
>  	}
> +	case KVM_DEV_ARM_VGIC_CPU_SYSREGS: {
> +		u64 reg;
> +
> +		return vgic_v3_has_cpu_sysregs_attr(vcpu, 0, cpuid, &reg);
> +	}
>  	default:
>  		return -ENXIO;
>  	}
> diff --git a/virt/kvm/arm/vgic/vgic-sys-reg-v3.c b/virt/kvm/arm/vgic/vgic-sys-reg-v3.c
> new file mode 100644
> index 0000000..d877cd8
> --- /dev/null
> +++ b/virt/kvm/arm/vgic/vgic-sys-reg-v3.c
> @@ -0,0 +1,225 @@
> +#include <linux/irqchip/arm-gic-v3.h>
> +#include <linux/kvm.h>
> +#include <linux/kvm_host.h>
> +#include <kvm/iodev.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 "vgic-mmio.h"
> +#include "sys_regs.h"
> +
> +static bool access_gic_ctlr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
> +			    const struct sys_reg_desc *r)
> +{
> +	struct vgic_vmcr vmcr;
> +
> +	vgic_get_vmcr(vcpu, &vmcr);
> +	if (p->is_write) {
> +		vmcr.ctlr = (u32)p->regval;
> +		vgic_set_vmcr(vcpu, &vmcr);
> +	} else {
> +		p->regval = vmcr.ctlr;
> +	}
> +
> +	return true;
> +}
> +
> +static bool access_gic_pmr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
> +			   const struct sys_reg_desc *r)
> +{
> +	struct vgic_vmcr vmcr;
> +
> +	vgic_get_vmcr(vcpu, &vmcr);
> +	if (p->is_write) {
> +		vmcr.pmr = (u32)p->regval;
> +		vgic_set_vmcr(vcpu, &vmcr);
> +	} else {
> +		p->regval = vmcr.pmr;
> +	}
> +
> +	return true;
> +}
> +
> +static bool access_gic_bpr0(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
> +			    const struct sys_reg_desc *r)
> +{
> +	struct vgic_vmcr vmcr;
> +
> +	vgic_get_vmcr(vcpu, &vmcr);
> +	if (p->is_write) {
> +		vmcr.bpr = (u32)p->regval;
> +		vgic_set_vmcr(vcpu, &vmcr);
> +	} else {
> +		p->regval = vmcr.bpr;
> +	}
> +
> +	return true;
> +}
> +
> +static bool access_gic_bpr1(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
> +			    const struct sys_reg_desc *r)
> +{
> +	struct vgic_vmcr vmcr;
> +
> +	vgic_get_vmcr(vcpu, &vmcr);
> +	if (p->is_write) {
> +		vmcr.abpr = (u32)p->regval;
> +		vgic_set_vmcr(vcpu, &vmcr);
> +	} else {
> +		p->regval = vmcr.abpr;
> +	}
> +
> +	return true;
> +}
> +
> +static bool access_gic_grpen0(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
> +			      const struct sys_reg_desc *r)
> +{
> +	struct vgic_v3_cpu_if *vgicv3 = &vcpu->arch.vgic_cpu.vgic_v3;
> +
> +	if (p->is_write) {
> +		vgicv3->vgic_vmcr &= ~ICH_VMCR_ENG0;
> +		vgicv3->vgic_vmcr |= (p->regval << ICH_VMCR_ENG0_SHIFT) &
> +				      ICH_VMCR_ENG0;
> +	} else {
> +		p->regval = (vgicv3->vgic_vmcr & ICH_VMCR_ENG0) >>
> +			     ICH_VMCR_ENG0_SHIFT;
> +	}
> +
> +	return true;
> +}
> +
> +static bool access_gic_grpen1(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
> +			      const struct sys_reg_desc *r)
> +{
> +	struct vgic_v3_cpu_if *vgicv3 = &vcpu->arch.vgic_cpu.vgic_v3;
> +
> +	if (p->is_write) {
> +		vgicv3->vgic_vmcr &= ~ICH_VMCR_ENG1;
> +		vgicv3->vgic_vmcr |= (p->regval << ICH_VMCR_ENG1_SHIFT) &
> +				      ICH_VMCR_ENG1;
> +	} else {
> +		p->regval = (vgicv3->vgic_vmcr & ICH_VMCR_ENG1) >>
> +			     ICH_VMCR_ENG1_SHIFT;
> +	}
> +
> +	return true;
> +}
> +
> +static bool access_gic_ap0r(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
> +			    const struct sys_reg_desc *r)
> +{
> +	struct vgic_v3_cpu_if *vgicv3 = &vcpu->arch.vgic_cpu.vgic_v3;
> +	u8 idx = r->Op2 & 3;
> +
> +	if (p->is_write)
> +		vgicv3->vgic_ap0r[idx] = p->regval;
> +	else
> +		p->regval = vgicv3->vgic_ap0r[idx];
> +
> +	return true;
> +}
> +
> +static bool access_gic_ap1r(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
> +			    const struct sys_reg_desc *r)
> +{
> +	struct vgic_v3_cpu_if *vgicv3 = &vcpu->arch.vgic_cpu.vgic_v3;
> +	u8 idx = r->Op2 & 3;
> +
> +	if (p->is_write)
> +		vgicv3->vgic_ap1r[idx] = p->regval;
> +	else
> +		p->regval = vgicv3->vgic_ap1r[idx];
> +
> +	return true;
> +}
> +
> +static const struct sys_reg_desc gic_v3_icc_reg_descs[] = {
> +	/* ICC_PMR_EL1 */
> +	{ Op0(0b11), Op1(0b000), CRn(0b0100), CRm(0b0110), Op2(0b000),
> +	  access_gic_pmr },
> +	/* ICC_BPR0_EL1 */
> +	{ Op0(0b11), Op1(0b000), CRn(0b1100), CRm(0b1000), Op2(0b011),
> +	  access_gic_bpr0 },
> +	/* ICC_AP0R0_EL1 */
> +	{ Op0(0b11), Op1(0b000), CRn(0b1100), CRm(0b1000), Op2(0b100),
> +	  access_gic_ap0r },
> +	/* ICC_AP0R1_EL1 */
> +	{ Op0(0b11), Op1(0b000), CRn(0b1100), CRm(0b1000), Op2(0b101),
> +	  access_gic_ap0r },
> +	/* ICC_AP0R2_EL1 */
> +	{ Op0(0b11), Op1(0b000), CRn(0b1100), CRm(0b1000), Op2(0b110),
> +	  access_gic_ap0r },
> +	/* ICC_AP0R3_EL1 */
> +	{ Op0(0b11), Op1(0b000), CRn(0b1100), CRm(0b1000), Op2(0b111),
> +	  access_gic_ap0r },
> +	/* ICC_AP1R0_EL1 */
> +	{ Op0(0b11), Op1(0b000), CRn(0b1100), CRm(0b1001), Op2(0b000),
> +	  access_gic_ap1r },
> +	/* ICC_AP1R1_EL1 */
> +	{ Op0(0b11), Op1(0b000), CRn(0b1100), CRm(0b1001), Op2(0b001),
> +	  access_gic_ap1r },
> +	/* ICC_AP1R2_EL1 */
> +	{ Op0(0b11), Op1(0b000), CRn(0b1100), CRm(0b1001), Op2(0b010),
> +	  access_gic_ap1r },
> +	/* ICC_AP1R3_EL1 */
> +	{ Op0(0b11), Op1(0b000), CRn(0b1100), CRm(0b1001), Op2(0b011),
> +	  access_gic_ap1r },
> +	/* ICC_BPR1_EL1 */
> +	{ Op0(0b11), Op1(0b000), CRn(0b1100), CRm(0b1100), Op2(0b011),
> +	  access_gic_bpr1 },
> +	/* ICC_CTLR_EL1 */
> +	{ Op0(0b11), Op1(0b000), CRn(0b1100), CRm(0b1100), Op2(0b100),
> +	  access_gic_ctlr },
> +	/* ICC_IGRPEN0_EL1 */
> +	{ Op0(0b11), Op1(0b000), CRn(0b1100), CRm(0b1100), Op2(0b110),
> +	  access_gic_grpen0 },
> +	/* ICC_GRPEN1_EL1 */
> +	{ Op0(0b11), Op1(0b000), CRn(0b1100), CRm(0b1100), Op2(0b111),
> +	  access_gic_grpen1 },
> +};
> +
> +int vgic_v3_has_cpu_sysregs_attr(struct kvm_vcpu *vcpu, bool is_write, u64 id,
> +				u64 *reg)
> +{
> +	struct sys_reg_params params;
> +
> +	params.regval = le64_to_cpu(*reg);
> +	params.is_write = is_write;
> +	params.is_aarch32 = false;
> +	params.is_32bit = false;
> +
> +	return find_reg_by_id(id, &params, gic_v3_icc_reg_descs,
> +			      ARRAY_SIZE(gic_v3_icc_reg_descs)) ?
> +		0 : -ENXIO;
> +}
> +
> +int vgic_v3_cpu_sysregs_uaccess(struct kvm_vcpu *vcpu, bool is_write, u64 id,
> +				u64 *reg)
> +{
> +	struct sys_reg_params params;
> +	const struct sys_reg_desc *r;
> +
> +	if (is_write)
> +		params.regval = le64_to_cpu(*reg);
> +	params.is_write = is_write;
> +	params.is_aarch32 = false;
> +	params.is_32bit = false;
> +
> +	r = find_reg_by_id(id, &params, gic_v3_icc_reg_descs,
> +			   ARRAY_SIZE(gic_v3_icc_reg_descs));
> +	if (!r)
> +		return -ENXIO;
> +
> +	if (!r->access(vcpu, &params, r))
> +		return -EINVAL;
> +
> +	if (!is_write)
> +		*reg = cpu_to_le64(params.regval);
> +
> +	return 0;
> +}
> +
> diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
> index 8637690..23db38d 100644
> --- a/virt/kvm/arm/vgic/vgic.h
> +++ b/virt/kvm/arm/vgic/vgic.h
> @@ -79,6 +79,10 @@ int vgic_v3_dist_uaccess(struct kvm_vcpu *vcpu, bool is_write,
>  			 int offset, u32 *val);
>  int vgic_v3_redist_uaccess(struct kvm_vcpu *vcpu, bool is_write,
>  			 int offset, u32 *val);
> +int vgic_v3_cpu_sysregs_uaccess(struct kvm_vcpu *vcpu, bool is_write,
> +			 u64 id, u64 *val);
> +int vgic_v3_has_cpu_sysregs_attr(struct kvm_vcpu *vcpu, bool is_write, u64 id,
> +				u64 *reg);
>  #else
>  static inline void vgic_v3_process_maintenance(struct kvm_vcpu *vcpu)
>  {
> @@ -132,6 +136,8 @@ static inline int vgic_register_redist_iodevs(struct kvm *kvm,
>  }
>  #endif
>  
> +void vgic_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr);
> +void vgic_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr);
>  void kvm_register_vgic_device(unsigned long type);
>  int vgic_lazy_init(struct kvm *kvm);
>  int vgic_init(struct kvm *kvm);
> -- 
> 1.7.9.5
>