[PATCH v6 6/7] arm/arm64: vgic-new: Implement VGICv3 CPU interface access
Marc Zyngier
marc.zyngier at arm.com
Thu Sep 22 05:24:52 PDT 2016
On 20/09/16 07:12, vijay.kilari at gmail.com wrote:
> From: Vijaya Kumar K <Vijaya.Kumar at cavium.com>
>
> VGICv3 CPU interface registers are accessed using
> KVM_DEV_ARM_VGIC_CPU_SYSREGS ioctl. These registers are accessed
> as 64-bit. The cpu MPIDR value is passed along with register id.
> is used to identify the cpu for registers access.
>
> The version of VGIC v3 specification is define here
> http://lists.infradead.org/pipermail/linux-arm-kernel/2016-July/445611.html
>
> Signed-off-by: Pavel Fedin <p.fedin at samsung.com>
> Signed-off-by: Vijaya Kumar K <Vijaya.Kumar at cavium.com>
> ---
> arch/arm64/include/uapi/asm/kvm.h | 3 +
> arch/arm64/kvm/Makefile | 1 +
> include/kvm/arm_vgic.h | 9 +
> virt/kvm/arm/vgic/vgic-kvm-device.c | 27 +++
> virt/kvm/arm/vgic/vgic-mmio-v3.c | 19 +++
> virt/kvm/arm/vgic/vgic-sys-reg-v3.c | 327 ++++++++++++++++++++++++++++++++++++
> virt/kvm/arm/vgic/vgic-v3.c | 7 +
> virt/kvm/arm/vgic/vgic.h | 4 +
> 8 files changed, 397 insertions(+)
>
> diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
> index 56dc08d..91c7137 100644
> --- a/arch/arm64/include/uapi/asm/kvm.h
> +++ b/arch/arm64/include/uapi/asm/kvm.h
> @@ -206,9 +206,12 @@ struct kvm_arch_memory_slot {
> (0xffffffffULL << KVM_DEV_ARM_VGIC_V3_MPIDR_SHIFT)
> #define KVM_DEV_ARM_VGIC_OFFSET_SHIFT 0
> #define KVM_DEV_ARM_VGIC_OFFSET_MASK (0xffffffffULL << KVM_DEV_ARM_VGIC_OFFSET_SHIFT)
> +#define KVM_DEV_ARM_VGIC_SYSREG_INSTR_MASK (0xffff)
> #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
>
> /* Device Control API on vcpu fd */
> diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
> index d50a82a..1a14e29 100644
> --- a/arch/arm64/kvm/Makefile
> +++ b/arch/arm64/kvm/Makefile
> @@ -32,5 +32,6 @@ 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) += $(KVM)/arm/vgic/vgic-its.o
> kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/irqchip.o
> +kvm-$(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/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
> index 002f092..b986c25 100644
> --- a/include/kvm/arm_vgic.h
> +++ b/include/kvm/arm_vgic.h
> @@ -71,6 +71,15 @@ struct vgic_global {
>
> /* GIC system register CPU interface */
> struct static_key_false gicv3_cpuif;
> +
> + /* Cache ICH_VTR_EL2 reg value */
> + u32 ich_vtr_el2;
> +
> + /* Cache guest priority bits */
> + u32 num_pri_bits;
> +
> + /* Cache guest interrupt ID bits */
> + u32 num_id_bits;
I'm going to cry now... Have you noticed that you are caching
guest-dependent values in a global structure? What happens when you have
more than one?
Caching the *host* values are fine, but the guest's? Come on...
> };
>
> extern struct vgic_global kvm_vgic_global_state;
> diff --git a/virt/kvm/arm/vgic/vgic-kvm-device.c b/virt/kvm/arm/vgic/vgic-kvm-device.c
> index 6c7d30c..da532d1 100644
> --- a/virt/kvm/arm/vgic/vgic-kvm-device.c
> +++ b/virt/kvm/arm/vgic/vgic-kvm-device.c
> @@ -504,6 +504,14 @@ static int vgic_v3_attr_regs_access(struct kvm_device *dev,
> if (!is_write)
> *reg = tmp32;
> break;
> + case KVM_DEV_ARM_VGIC_CPU_SYSREGS: {
> + u64 regid;
> +
> + regid = (attr->attr & KVM_DEV_ARM_VGIC_SYSREG_INSTR_MASK);
> + ret = vgic_v3_cpu_sysregs_uaccess(vcpu, is_write,
> + regid, reg);
> + break;
> + }
> default:
> ret = -EINVAL;
> break;
> @@ -537,6 +545,15 @@ static int vgic_v3_set_attr(struct kvm_device *dev,
> reg = tmp32;
> return vgic_v3_attr_regs_access(dev, attr, ®, true);
> }
> + case KVM_DEV_ARM_VGIC_CPU_SYSREGS: {
> + u64 __user *uaddr = (u64 __user *)(long)attr->addr;
> + u64 reg;
> +
> + if (get_user(reg, uaddr))
> + return -EFAULT;
> +
> + return vgic_v3_attr_regs_access(dev, attr, ®, true);
> + }
> }
> return -ENXIO;
> }
> @@ -563,6 +580,15 @@ static int vgic_v3_get_attr(struct kvm_device *dev,
> tmp32 = reg;
> return put_user(tmp32, uaddr);
> }
> + case KVM_DEV_ARM_VGIC_CPU_SYSREGS: {
> + u64 __user *uaddr = (u64 __user *)(long)attr->addr;
> + u64 reg;
> +
> + ret = vgic_v3_attr_regs_access(dev, attr, ®, false);
> + if (ret)
> + return ret;
> + return put_user(reg, uaddr);
> + }
> }
>
> return -ENXIO;
> @@ -581,6 +607,7 @@ 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-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
> index b35fb83..8f46e61 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 */
> unsigned long extract_bytes(u64 data, unsigned int offset,
> @@ -639,6 +640,24 @@ int vgic_v3_has_attr_regs(struct kvm_device *dev, struct kvm_device_attr *attr)
> nr_regions = ARRAY_SIZE(vgic_v3_rdbase_registers);
> break;
> }
> + case KVM_DEV_ARM_VGIC_CPU_SYSREGS: {
> + u64 reg, id;
> + unsigned long vgic_mpidr, mpidr_reg;
> + struct kvm_vcpu *vcpu;
> +
> + vgic_mpidr = (attr->attr & KVM_DEV_ARM_VGIC_V3_MPIDR_MASK) >>
> + KVM_DEV_ARM_VGIC_V3_MPIDR_SHIFT;
> +
> + /* Convert plain mpidr value to MPIDR reg format */
> + mpidr_reg = VGIC_TO_MPIDR(mpidr_reg);
> +
> + vcpu = kvm_mpidr_to_vcpu(dev->kvm, mpidr_reg);
> + if (!vcpu)
> + return -EINVAL;
> +
> + id = (attr->attr & KVM_DEV_ARM_VGIC_SYSREG_INSTR_MASK);
> + return vgic_v3_has_cpu_sysregs_attr(vcpu, 0, id, ®);
> + }
> 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..769920f
> --- /dev/null
> +++ b/virt/kvm/arm/vgic/vgic-sys-reg-v3.c
> @@ -0,0 +1,327 @@
> +#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;
> + u64 val;
> + u32 hw_pri_bits, num_pri_bits, hw_id_bits, num_id_bits;
> +
> + vgic_get_vmcr(vcpu, &vmcr);
> + if (p->is_write) {
> + val = p->regval;
> +
> + /*
> + * Does not allow update of ICC_CTLR_EL1 if HW does not support
> + * guest programmed ID and PRI bits
> + */
> + hw_pri_bits = ((kvm_vgic_global_state.ich_vtr_el2 &
> + ICH_VTR_PRI_BITS_MASK) >>
> + ICH_VTR_PRI_BITS_SHIFT) + 1;
> + num_pri_bits = ((val & ICC_CTLR_EL1_PRI_BITS_MASK) >>
> + ICC_CTLR_EL1_PRI_BITS_SHIFT) + 1;
> + if (num_pri_bits > hw_pri_bits)
> + return false;
> +
> + kvm_vgic_global_state.num_pri_bits = num_pri_bits;
And here we go...
I've stopped reading here, because you can't possibly have tested this.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
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