Currently, the only code that needs to deduce the proper size of a
KVM core register on arm64 is validate_core_offset().
In order to make this code easier to reuse, this patch factors out
the size determination into a separate function
core_reg_size_from_offset().
Since validate_core_offset() can be relevant in situations where
only a register ID is available, this patch also modifies the
interface to validate_core_offset() to take a register ID instead
of a struct kvm_one_reg. In order to avoid confusion, the function
is renamed to validate_core_reg_id() to reflect the changed
semantics.
Subsequent patches will make use of these changes.
No functional change.
Signed-off-by: Dave Martin <dave.mar...@arm.com>
---
arch/arm64/kvm/guest.c | 35 ++++++++++++++++++-----------------
1 file changed, 18 insertions(+), 17 deletions(-)
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index dd436a5..b0a63fc 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -57,11 +57,8 @@ static u64 core_reg_offset_from_id(u64 id)
return id & ~(KVM_REG_ARCH_MASK | KVM_REG_SIZE_MASK | KVM_REG_ARM_CORE);
}
-static int validate_core_offset(const struct kvm_one_reg *reg)
+static int core_reg_size_from_offset(u64 off)
{
- u64 off = core_reg_offset_from_id(reg->id);
- int size;
-
switch (off) {
case KVM_REG_ARM_CORE_REG(regs.regs[0]) ...
KVM_REG_ARM_CORE_REG(regs.regs[30]):
@@ -72,25 +69,29 @@ static int validate_core_offset(const struct kvm_one_reg
*reg)
case KVM_REG_ARM_CORE_REG(elr_el1):
case KVM_REG_ARM_CORE_REG(spsr[0]) ...
KVM_REG_ARM_CORE_REG(spsr[KVM_NR_SPSR - 1]):
- size = sizeof(__u64);
- break;
+ return sizeof(__u64);
case KVM_REG_ARM_CORE_REG(fp_regs.vregs[0]) ...
KVM_REG_ARM_CORE_REG(fp_regs.vregs[31]):
- size = sizeof(__uint128_t);
- break;
+ return sizeof(__uint128_t);
case KVM_REG_ARM_CORE_REG(fp_regs.fpsr):
case KVM_REG_ARM_CORE_REG(fp_regs.fpcr):
- size = sizeof(__u32);
- break;
-
- default:
- return -EINVAL;
+ return sizeof(__u32);
}
- if (KVM_REG_SIZE(reg->id) == size &&
- IS_ALIGNED(off, size / sizeof(__u32)))
+ return -EINVAL;
+}
+
+static int validate_core_reg_id(u64 id)
+{
+ u64 off = core_reg_offset_from_id(id);
+ int size = core_reg_size_from_offset(off);
+
+ if (size < 0)
+ return size;
+
+ if (KVM_REG_SIZE(id) == size && IS_ALIGNED(off, size / sizeof(__u32)))
return 0;
return -EINVAL;
@@ -115,7 +116,7 @@ static int get_core_reg(struct kvm_vcpu *vcpu, const struct
kvm_one_reg *reg)
(off + (KVM_REG_SIZE(reg->id) / sizeof(__u32))) >= nr_regs)
return -ENOENT;
- if (validate_core_offset(reg))
+ if (validate_core_reg_id(reg->id))
return -EINVAL;
if (copy_to_user(uaddr, ((u32 *)regs) + off, KVM_REG_SIZE(reg->id)))
@@ -140,7 +141,7 @@ static int set_core_reg(struct kvm_vcpu *vcpu, const struct
kvm_one_reg *reg)
(off + (KVM_REG_SIZE(reg->id) / sizeof(__u32))) >= nr_regs)
return -ENOENT;
- if (validate_core_offset(reg))
+ if (validate_core_reg_id(reg->id))
return -EINVAL;
if (KVM_REG_SIZE(reg->id) > sizeof(tmp))
--
2.1.4
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