On 09/11/2012 07:48 AM, Rusty Russell wrote:
> Instead of overloading x86's KVM_GET_MSRS/KVM_SET_MSRS. The only basic
> difference is that the ids are 64 bit.
>
> This means we share the interface with PPC and S/390, though we don't
> actually share the code (yet?).
>
> Signed-off-by: Rusty Russell <rusty.russell@xxxxxxxxxx>
>
> diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
> index d730b93..b09438b 100644
> --- a/Documentation/virtual/kvm/api.txt
> +++ b/Documentation/virtual/kvm/api.txt
> @@ -1745,6 +1745,15 @@ registers, find a list below:
> | |
> PPC | KVM_REG_PPC_HIOR | 64
>
> +ARM registers are mapped using the lower 32 bits. The upper 16 of that
> +is the coprocessor number, or other ID:
> +
> +ARM 32-bit CP15 registers have the following id bit patterns:
> + 0x4002 0000 000F <zero:1> <crn:4> <crm:4> <opc1:4> <opc2:3>
> +
> +ARM 64-bit CP15 registers have the following id bit patterns:
> + 0x4003 0000 000F <zero:1> <zero:4> <crm:4> <opc1:4> <zero:3>
> +
>
> 4.69 KVM_GET_ONE_REG
>
> diff --git a/arch/arm/include/asm/kvm.h b/arch/arm/include/asm/kvm.h
> index d040a2a..d2a65e4 100644
> --- a/arch/arm/include/asm/kvm.h
> +++ b/arch/arm/include/asm/kvm.h
> @@ -85,35 +85,22 @@ struct kvm_sync_regs {
> struct kvm_arch_memory_slot {
> };
>
> -/* Based on x86, but we use KVM_GET_VCPU_MSR_INDEX_LIST. */
> -struct kvm_msr_entry {
> - __u32 index;
> - __u32 reserved;
> - __u64 data;
> -};
> -
> -/* for KVM_GET_MSRS and KVM_SET_MSRS */
> -struct kvm_msrs {
> - __u32 nmsrs; /* number of msrs in entries */
> - __u32 pad;
> -
> - struct kvm_msr_entry entries[0];
> -};
> -
> /* for KVM_VCPU_GET_MSR_INDEX_LIST */
> struct kvm_msr_list {
> - __u32 nmsrs; /* number of msrs in entries */
> - __u32 indices[0];
> + __u64 nmsrs; /* number of msrs in entries */
> + __u64 indices[0];
> };
>
> -/* If you need to interpret the index values, here's the key. */
> -#define KVM_ARM_MSR_COPROC_MASK 0xFFFF0000
> -#define KVM_ARM_MSR_64_BIT_MASK 0x00008000
> -#define KVM_ARM_MSR_64_OPC1_MASK 0x000000F0
> -#define KVM_ARM_MSR_64_CRM_MASK 0x0000000F
> -#define KVM_ARM_MSR_32_CRM_MASK 0x0000000F
> -#define KVM_ARM_MSR_32_OPC2_MASK 0x00000070
> -#define KVM_ARM_MSR_32_CRN_MASK 0x00000780
> -#define KVM_ARM_MSR_32_OPC1_MASK 0x00003800
> +/* If you need to interpret the index values, here is the key: */
> +#define KVM_REG_ARM_COPROC_MASK 0x000000000FFF0000
> +#define KVM_REG_ARM_COPROC_SHIFT 16
> +#define KVM_REG_ARM_32_OPC2_MASK 0x0000000000000007
> +#define KVM_REG_ARM_32_OPC2_SHIFT 0
> +#define KVM_REG_ARM_OPC1_MASK 0x0000000000000078
> +#define KVM_REG_ARM_OPC1_SHIFT 3
> +#define KVM_REG_ARM_CRM_MASK 0x0000000000000780
> +#define KVM_REG_ARM_CRM_SHIFT 7
> +#define KVM_REG_ARM_32_CRN_MASK 0x0000000000007800
> +#define KVM_REG_ARM_32_CRN_SHIFT 11
>
> #endif /* __ARM_KVM_H__ */
> diff --git a/arch/arm/include/asm/kvm_coproc.h b/arch/arm/include/asm/kvm_coproc.h
> index 894574c..d9c2f45 100644
> --- a/arch/arm/include/asm/kvm_coproc.h
> +++ b/arch/arm/include/asm/kvm_coproc.h
> @@ -28,11 +28,10 @@ int kvm_handle_cp14_access(struct kvm_vcpu *vcpu, struct kvm_run *run);
> int kvm_handle_cp15_32(struct kvm_vcpu *vcpu, struct kvm_run *run);
> int kvm_handle_cp15_64(struct kvm_vcpu *vcpu, struct kvm_run *run);
>
> -int kvm_arm_get_msrs(struct kvm_vcpu *vcpu,
> - struct kvm_msr_entry __user *entries, u32 num);
> -int kvm_arm_set_msrs(struct kvm_vcpu *vcpu,
> - struct kvm_msr_entry __user *entries, u32 num);
> unsigned long kvm_arm_num_guest_msrs(struct kvm_vcpu *vcpu);
> -int kvm_arm_copy_msrindices(struct kvm_vcpu *vcpu, u32 __user *uindices);
> +int kvm_arm_copy_msrindices(struct kvm_vcpu *vcpu, u64 __user *uindices);
> void kvm_coproc_table_init(void);
> +
> +int kvm_arm_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg);
> +int kvm_arm_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg);
> #endif /* __ARM_KVM_COPROC_H__ */
> diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
> index fd93d37..896e13f 100644
> --- a/arch/arm/include/asm/kvm_host.h
> +++ b/arch/arm/include/asm/kvm_host.h
> @@ -25,6 +25,7 @@
> #define KVM_MEMORY_SLOTS 32
> #define KVM_PRIVATE_MEM_SLOTS 4
> #define KVM_COALESCED_MMIO_PAGE_OFFSET 1
> +#define KVM_HAVE_ONE_REG
>
> #include <asm/kvm_vgic.h>
>
> diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
> index 4a01b42..271ea92 100644
> --- a/arch/arm/kvm/arm.c
> +++ b/arch/arm/kvm/arm.c
> @@ -201,6 +201,7 @@ int kvm_dev_ioctl_check_extension(long ext)
> #endif
> case KVM_CAP_USER_MEMORY:
> case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:
> + case KVM_CAP_ONE_REG:
> r = 1;
> break;
> case KVM_CAP_COALESCED_MMIO:
> @@ -768,6 +769,16 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
> return kvm_vcpu_set_target(vcpu, &init);
>
> }
> + case KVM_SET_ONE_REG:
> + case KVM_GET_ONE_REG: {
> + struct kvm_one_reg reg;
> + if (copy_from_user(®, argp, sizeof(reg)))
> + return -EFAULT;
> + if (ioctl == KVM_SET_ONE_REG)
> + return kvm_arm_set_reg(vcpu, ®);
> + else
> + return kvm_arm_get_reg(vcpu, ®);
> + }
> case KVM_VCPU_GET_MSR_INDEX_LIST: {
> struct kvm_msr_list __user *user_msr_list = argp;
> struct kvm_msr_list msr_list;
> @@ -783,20 +794,6 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
> return -E2BIG;
> return kvm_arm_copy_msrindices(vcpu, user_msr_list->indices);
> }
> - case KVM_GET_MSRS: {
> - struct kvm_msrs msrs;
> - struct kvm_msrs __user *umsrs = argp;
> - if (copy_from_user(&msrs, umsrs, sizeof(msrs)) != 0)
> - return -EFAULT;
> - return kvm_arm_get_msrs(vcpu, umsrs->entries, msrs.nmsrs);
> - }
> - case KVM_SET_MSRS: {
> - struct kvm_msrs msrs;
> - struct kvm_msrs __user *umsrs = argp;
> - if (copy_from_user(&msrs, umsrs, sizeof(msrs)) != 0)
> - return -EFAULT;
> - return kvm_arm_set_msrs(vcpu, umsrs->entries, msrs.nmsrs);
> - }
> #ifdef CONFIG_KVM_ARM_VGIC
> case KVM_IRQ_LINE: {
> struct kvm_irq_level irq_event;
> diff --git a/arch/arm/kvm/coproc.c b/arch/arm/kvm/coproc.c
> index 72a3f64..5a0a7e0 100644
> --- a/arch/arm/kvm/coproc.c
> +++ b/arch/arm/kvm/coproc.c
> @@ -565,42 +565,63 @@ int kvm_handle_cp15_32(struct kvm_vcpu *vcpu, struct kvm_run *run)
> * Userspace API
> *****************************************************************************/
>
> -/* Given a simple mask, get those bits. */
> -static inline u32 get_bits(u32 index, u32 mask)
> -{
> - return (index & mask) >> (ffs(mask) - 1);
> -}
> +static bool index_to_params(u64 id, struct coproc_params *params)
> +{
> + switch (id & KVM_REG_SIZE_MASK) {
> + case KVM_REG_SIZE_U32:
> + /* Any unused index bits means it's not valid. */
> + if (id & ~(KVM_REG_ARCH_MASK | KVM_REG_SIZE_MASK
> + | KVM_REG_ARM_COPROC_MASK
> + | KVM_REG_ARM_32_CRN_MASK
> + | KVM_REG_ARM_CRM_MASK
> + | KVM_REG_ARM_OPC1_MASK
> + | KVM_REG_ARM_32_OPC2_MASK))
> + return false;
>
> -static void index_to_params(u32 index, struct coproc_params *params)
> -{
> - if (get_bits(index, KVM_ARM_MSR_64_BIT_MASK)) {
> + params->is_64bit = false;
> + params->CRn = ((id & KVM_REG_ARM_32_CRN_MASK)
> + >> KVM_REG_ARM_32_CRN_SHIFT);
> + params->CRm = ((id & KVM_REG_ARM_CRM_MASK)
> + >> KVM_REG_ARM_CRM_SHIFT);
> + params->Op1 = ((id & KVM_REG_ARM_OPC1_MASK)
> + >> KVM_REG_ARM_OPC1_SHIFT);
> + params->Op2 = ((id & KVM_REG_ARM_32_OPC2_MASK)
> + >> KVM_REG_ARM_32_OPC2_SHIFT);
> + return true;
> + case KVM_REG_SIZE_U64:
> + /* Any unused index bits means it's not valid. */
> + if (id & ~(KVM_REG_ARCH_MASK | KVM_REG_SIZE_MASK
> + | KVM_REG_ARM_COPROC_MASK
> + | KVM_REG_ARM_CRM_MASK
> + | KVM_REG_ARM_OPC1_MASK))
> + return false;
> params->is_64bit = true;
> - params->CRm = get_bits(index, KVM_ARM_MSR_64_CRM_MASK);
> - params->Op1 = get_bits(index, KVM_ARM_MSR_64_OPC1_MASK);
> + params->CRm = ((id & KVM_REG_ARM_CRM_MASK)
> + >> KVM_REG_ARM_CRM_SHIFT);
> + params->Op1 = ((id & KVM_REG_ARM_OPC1_MASK)
> + >> KVM_REG_ARM_OPC1_SHIFT);
> params->Op2 = 0;
> params->CRn = 0;
> - } else {
> - params->is_64bit = false;
> - params->CRn = get_bits(index, KVM_ARM_MSR_32_CRN_MASK);
> - params->CRm = get_bits(index, KVM_ARM_MSR_32_CRM_MASK);
> - params->Op1 = get_bits(index, KVM_ARM_MSR_32_OPC1_MASK);
> - params->Op2 = get_bits(index, KVM_ARM_MSR_32_OPC2_MASK);
> + return true;
> + default:
> + return false;
> }
> }
>
> /* Decode an index value, and find the cp15 coproc_reg entry. */
> static const struct coproc_reg *index_to_coproc_reg(struct kvm_vcpu *vcpu,
> - u32 index)
> + u64 id)
> {
> size_t num;
> const struct coproc_reg *table, *r;
> struct coproc_params params;
>
> /* We only do cp15 for now. */
> - if (get_bits(index, KVM_ARM_MSR_COPROC_MASK != 15))
> + if ((id & KVM_REG_ARM_COPROC_MASK) >> KVM_REG_ARM_COPROC_SHIFT != 15)
> return NULL;
>
> - index_to_params(index, ¶ms);
> + if (!index_to_params(id, ¶ms))
> + return NULL;
>
> table = get_target_table(vcpu->arch.target, &num);
> r = find_reg(¶ms, table, num);
> @@ -687,30 +708,54 @@ static struct coproc_reg invariant_cp15[] = {
> { CRn( 0), CRm( 0), Op1( 1), Op2( 7), is32, NULL, get_AIDR },
> };
>
> -static int get_invariant_cp15(u32 index, u64 *val)
> +static int reg_from_user(void *val, const void __user *uaddr, u64 id)
> +{
> + /* This Just Works because we are little endian. */
> + if (copy_from_user(val, uaddr, KVM_REG_SIZE(id)) != 0)
Sorry if I'm asking the obvious. How do you make sure that 32 bit
registers are always accessed with 32bit reg ids?
Alex
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