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KVM: PPC: Add generic single register ioctls 

Right now we transfer a static struct every time we want to get or set
registers. Unfortunately, over time we realize that there are more of
these than we thought of before and the extensibility and flexibility of
transferring a full struct every time is limited.

So this is a new approach to the problem. With these new ioctls, we can
get and set a single register that is identified by an ID. This allows for
very precise and limited transmittal of data. When we later realize that
it's a better idea to shove over multiple registers at once, we can reuse
most of the infrastructure and simply implement a GET_MANY_REGS / SET_MANY_REGS
interface.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
hifive-unleashed-5.1
Alexander Graf 2011-09-14 10:02:41 +02:00 committed by Avi Kivity
parent 6b75e6bfef
commit e24ed81fed
3 changed files with 119 additions and 3 deletions
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46
Documentation/virtual/kvm/api.txt
View File

@ -1533,7 +1533,7 @@ following algorithm:
Some guests configure the LINT1 NMI input to cause a panic, aiding in
debugging.
4.64 KVM_S390_UCAS_MAP
4.65 KVM_S390_UCAS_MAP
Capability: KVM_CAP_S390_UCONTROL
Architectures: s390
@ -1552,7 +1552,7 @@ This ioctl maps the memory at "user_addr" with the length "length" to
the vcpu's address space starting at "vcpu_addr". All parameters need to
be alligned by 1 megabyte.
4.65 KVM_S390_UCAS_UNMAP
4.66 KVM_S390_UCAS_UNMAP
Capability: KVM_CAP_S390_UCONTROL
Architectures: s390
@ -1571,7 +1571,7 @@ This ioctl unmaps the memory in the vcpu's address space starting at
"vcpu_addr" with the length "length". The field "user_addr" is ignored.
All parameters need to be alligned by 1 megabyte.
4.66 KVM_S390_VCPU_FAULT
4.67 KVM_S390_VCPU_FAULT
Capability: KVM_CAP_S390_UCONTROL
Architectures: s390
@ -1587,6 +1587,46 @@ table upfront. This is useful to handle validity intercepts for user
controlled virtual machines to fault in the virtual cpu's lowcore pages
prior to calling the KVM_RUN ioctl.
4.68 KVM_SET_ONE_REG
Capability: KVM_CAP_ONE_REG
Architectures: all
Type: vcpu ioctl
Parameters: struct kvm_one_reg (in)
Returns: 0 on success, negative value on failure
struct kvm_one_reg {
__u64 id;
__u64 addr;
};
Using this ioctl, a single vcpu register can be set to a specific value
defined by user space with the passed in struct kvm_one_reg, where id
refers to the register identifier as described below and addr is a pointer
to a variable with the respective size. There can be architecture agnostic
and architecture specific registers. Each have their own range of operation
and their own constants and width. To keep track of the implemented
registers, find a list below:
Arch | Register | Width (bits)
| |
4.69 KVM_GET_ONE_REG
Capability: KVM_CAP_ONE_REG
Architectures: all
Type: vcpu ioctl
Parameters: struct kvm_one_reg (in and out)
Returns: 0 on success, negative value on failure
This ioctl allows to receive the value of a single register implemented
in a vcpu. The register to read is indicated by the "id" field of the
kvm_one_reg struct passed in. On success, the register value can be found
at the memory location pointed to by "addr".
The list of registers accessible using this interface is identical to the
list in 4.64.
5. The kvm_run structure
Application code obtains a pointer to the kvm_run structure by

41
arch/powerpc/kvm/powerpc.c
View File

@ -217,6 +217,7 @@ int kvm_dev_ioctl_check_extension(long ext)
case KVM_CAP_PPC_UNSET_IRQ:
case KVM_CAP_PPC_IRQ_LEVEL:
case KVM_CAP_ENABLE_CAP:
case KVM_CAP_ONE_REG:
r = 1;
break;
#ifndef CONFIG_KVM_BOOK3S_64_HV
@ -645,6 +646,32 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
return r;
}
static int kvm_vcpu_ioctl_get_one_reg(struct kvm_vcpu *vcpu,
struct kvm_one_reg *reg)
{
int r = -EINVAL;
switch (reg->id) {
default:
break;
}
return r;
}
static int kvm_vcpu_ioctl_set_one_reg(struct kvm_vcpu *vcpu,
struct kvm_one_reg *reg)
{
int r = -EINVAL;
switch (reg->id) {
default:
break;
}
return r;
}
int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
struct kvm_mp_state *mp_state)
{
@ -684,6 +711,20 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
break;
}
case KVM_SET_ONE_REG:
case KVM_GET_ONE_REG:
{
struct kvm_one_reg reg;
r = -EFAULT;
if (copy_from_user(&reg, argp, sizeof(reg)))
goto out;
if (ioctl == KVM_SET_ONE_REG)
r = kvm_vcpu_ioctl_set_one_reg(vcpu, &reg);
else
r = kvm_vcpu_ioctl_get_one_reg(vcpu, &reg);
break;
}
#ifdef CONFIG_KVM_E500
case KVM_DIRTY_TLB: {
struct kvm_dirty_tlb dirty;

35
include/linux/kvm.h
View File

@ -582,6 +582,7 @@ struct kvm_ppc_pvinfo {
#define KVM_CAP_MAX_VCPUS 66 /* returns max vcpus per vm */
#define KVM_CAP_PPC_PAPR 68
#define KVM_CAP_SW_TLB 69
#define KVM_CAP_ONE_REG 70
#define KVM_CAP_S390_GMAP 71
#define KVM_CAP_TSC_DEADLINE_TIMER 72
#define KVM_CAP_S390_UCONTROL 73
@ -680,6 +681,37 @@ struct kvm_dirty_tlb {
__u32 num_dirty;
};
/* Available with KVM_CAP_ONE_REG */
#define KVM_REG_ARCH_MASK 0xff00000000000000ULL
#define KVM_REG_GENERIC 0x0000000000000000ULL
/*
* Architecture specific registers are to be defined in arch headers and
* ORed with the arch identifier.
*/
#define KVM_REG_PPC 0x1000000000000000ULL
#define KVM_REG_X86 0x2000000000000000ULL
#define KVM_REG_IA64 0x3000000000000000ULL
#define KVM_REG_ARM 0x4000000000000000ULL
#define KVM_REG_S390 0x5000000000000000ULL
#define KVM_REG_SIZE_SHIFT 52
#define KVM_REG_SIZE_MASK 0x00f0000000000000ULL
#define KVM_REG_SIZE_U8 0x0000000000000000ULL
#define KVM_REG_SIZE_U16 0x0010000000000000ULL
#define KVM_REG_SIZE_U32 0x0020000000000000ULL
#define KVM_REG_SIZE_U64 0x0030000000000000ULL
#define KVM_REG_SIZE_U128 0x0040000000000000ULL
#define KVM_REG_SIZE_U256 0x0050000000000000ULL
#define KVM_REG_SIZE_U512 0x0060000000000000ULL
#define KVM_REG_SIZE_U1024 0x0070000000000000ULL
struct kvm_one_reg {
__u64 id;
__u64 addr;
};
/*
* ioctls for VM fds
*/
@ -819,6 +851,9 @@ struct kvm_s390_ucas_mapping {
#define KVM_ALLOCATE_RMA _IOR(KVMIO, 0xa9, struct kvm_allocate_rma)
/* Available with KVM_CAP_SW_TLB */
#define KVM_DIRTY_TLB _IOW(KVMIO, 0xaa, struct kvm_dirty_tlb)
/* Available with KVM_CAP_ONE_REG */
#define KVM_GET_ONE_REG _IOW(KVMIO, 0xab, struct kvm_one_reg)
#define KVM_SET_ONE_REG _IOW(KVMIO, 0xac, struct kvm_one_reg)
#define KVM_DEV_ASSIGN_ENABLE_IOMMU (1 << 0)