[PATCH v7 08/14] KVM: s390: Move common code of mem_op functions into function

Janis Schoetterl-Glausch
2023-02-06T16:46:27Z

The vcpu and vm mem_op ioctl implementations share some functionality.
Move argument checking into a function and call it from both
implementations. This allows code reuse in case of additional future
mem_op operations.

Suggested-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
---
arch/s390/kvm/kvm-s390.c | 52 +++++++++++++++++++---------------------
1 file changed, 24 insertions(+), 28 deletions(-)

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index e4890e04b210..0367c1a7e69a 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -2764,24 +2764,32 @@ static int kvm_s390_handle_pv(struct kvm *kvm, struct kvm_pv_cmd *cmd)
return r;
}

-static bool access_key_invalid(u8 access_key)
+static int mem_op_validate_common(struct kvm_s390_mem_op *mop, u64 supported_flags)
{
- return access_key > 0xf;
+ if (mop->flags & ~supported_flags || !mop->size)
+ return -EINVAL;
+ if (mop->size > MEM_OP_MAX_SIZE)
+ return -E2BIG;
+ if (mop->flags & KVM_S390_MEMOP_F_SKEY_PROTECTION) {
+ if (mop->key > 0xf)
+ return -EINVAL;
+ } else {
+ mop->key = 0;
+ }
+ return 0;
}

static int kvm_s390_vm_mem_op(struct kvm *kvm, struct kvm_s390_mem_op *mop)
{
void __user *uaddr = (void __user *)mop->buf;
- u64 supported_flags;
void *tmpbuf = NULL;
int r, srcu_idx;

- supported_flags = KVM_S390_MEMOP_F_SKEY_PROTECTION
- | KVM_S390_MEMOP_F_CHECK_ONLY;
- if (mop->flags & ~supported_flags || !mop->size)
- return -EINVAL;
- if (mop->size > MEM_OP_MAX_SIZE)
- return -E2BIG;
+ r = mem_op_validate_common(mop, KVM_S390_MEMOP_F_SKEY_PROTECTION |
+ KVM_S390_MEMOP_F_CHECK_ONLY);
+ if (r)
+ return r;
+
/*
* This is technically a heuristic only, if the kvm->lock is not
* taken, it is not guaranteed that the vm is/remains non-protected.
@@ -2793,12 +2801,6 @@ static int kvm_s390_vm_mem_op(struct kvm *kvm, struct kvm_s390_mem_op *mop)
*/
if (kvm_s390_pv_get_handle(kvm))
return -EINVAL;
- if (mop->flags & KVM_S390_MEMOP_F_SKEY_PROTECTION) {
- if (access_key_invalid(mop->key))
- return -EINVAL;
- } else {
- mop->key = 0;
- }
if (!(mop->flags & KVM_S390_MEMOP_F_CHECK_ONLY)) {
tmpbuf = vmalloc(mop->size);
if (!tmpbuf)
@@ -5250,23 +5252,17 @@ static long kvm_s390_vcpu_mem_op(struct kvm_vcpu *vcpu,
{
void __user *uaddr = (void __user *)mop->buf;
void *tmpbuf = NULL;
- int r = 0;
- const u64 supported_flags = KVM_S390_MEMOP_F_INJECT_EXCEPTION
- | KVM_S390_MEMOP_F_CHECK_ONLY
- | KVM_S390_MEMOP_F_SKEY_PROTECTION;
+ int r;

- if (mop->flags & ~supported_flags || mop->ar >= NUM_ACRS || !mop->size)
+ r = mem_op_validate_common(mop, KVM_S390_MEMOP_F_INJECT_EXCEPTION |
+ KVM_S390_MEMOP_F_CHECK_ONLY |
+ KVM_S390_MEMOP_F_SKEY_PROTECTION);
+ if (r)
+ return r;
+ if (mop->ar >= NUM_ACRS)
return -EINVAL;
- if (mop->size > MEM_OP_MAX_SIZE)
- return -E2BIG;
if (kvm_s390_pv_cpu_is_protected(vcpu))
return -EINVAL;
- if (mop->flags & KVM_S390_MEMOP_F_SKEY_PROTECTION) {
- if (access_key_invalid(mop->key))
- return -EINVAL;
- } else {
- mop->key = 0;
- }
if (!(mop->flags & KVM_S390_MEMOP_F_CHECK_ONLY)) {
tmpbuf = vmalloc(mop->size);
if (!tmpbuf)
--
2.37.2