Skip to content

Commit

Permalink
KVM: s390: use switch vs jump table in priv.c
Browse files Browse the repository at this point in the history 
Instead of having huge jump tables for function selection,
let's use normal switch/case statements for the instruction
handlers in priv.c

This allows the compiler to make the right decision depending
on the situation (e.g. avoid jump-tables for thunks).

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
  • Loading branch information
Christian Borntraeger committed Feb 14, 2018
1 parent f315104 commit 6db4263
Showing 1 changed file with 91 additions and 92 deletions.
183 changes: 91 additions & 92 deletions arch/s390/kvm/priv.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -795,55 +795,60 @@ static int handle_stsi(struct kvm_vcpu *vcpu)
return rc;
}

static const intercept_handler_t b2_handlers[256] = {
[0x02] = handle_stidp,
[0x04] = handle_set_clock,
[0x10] = handle_set_prefix,
[0x11] = handle_store_prefix,
[0x12] = handle_store_cpu_address,
[0x14] = kvm_s390_handle_vsie,
[0x21] = handle_ipte_interlock,
[0x29] = handle_iske,
[0x2a] = handle_rrbe,
[0x2b] = handle_sske,
[0x2c] = handle_test_block,
[0x30] = handle_io_inst,
[0x31] = handle_io_inst,
[0x32] = handle_io_inst,
[0x33] = handle_io_inst,
[0x34] = handle_io_inst,
[0x35] = handle_io_inst,
[0x36] = handle_io_inst,
[0x37] = handle_io_inst,
[0x38] = handle_io_inst,
[0x39] = handle_io_inst,
[0x3a] = handle_io_inst,
[0x3b] = handle_io_inst,
[0x3c] = handle_io_inst,
[0x50] = handle_ipte_interlock,
[0x56] = handle_sthyi,
[0x5f] = handle_io_inst,
[0x74] = handle_io_inst,
[0x76] = handle_io_inst,
[0x7d] = handle_stsi,
[0xb1] = handle_stfl,
[0xb2] = handle_lpswe,
};

int kvm_s390_handle_b2(struct kvm_vcpu *vcpu)
{
intercept_handler_t handler;

/*
* A lot of B2 instructions are priviledged. Here we check for
* the privileged ones, that we can handle in the kernel.
* Anything else goes to userspace.
*/
handler = b2_handlers[vcpu->arch.sie_block->ipa & 0x00ff];
if (handler)
return handler(vcpu);

return -EOPNOTSUPP;
switch (vcpu->arch.sie_block->ipa & 0x00ff) {
case 0x02:
return handle_stidp(vcpu);
case 0x04:
return handle_set_clock(vcpu);
case 0x10:
return handle_set_prefix(vcpu);
case 0x11:
return handle_store_prefix(vcpu);
case 0x12:
return handle_store_cpu_address(vcpu);
case 0x14:
return kvm_s390_handle_vsie(vcpu);
case 0x21:
case 0x50:
return handle_ipte_interlock(vcpu);
case 0x29:
return handle_iske(vcpu);
case 0x2a:
return handle_rrbe(vcpu);
case 0x2b:
return handle_sske(vcpu);
case 0x2c:
return handle_test_block(vcpu);
case 0x30:
case 0x31:
case 0x32:
case 0x33:
case 0x34:
case 0x35:
case 0x36:
case 0x37:
case 0x38:
case 0x39:
case 0x3a:
case 0x3b:
case 0x3c:
case 0x5f:
case 0x74:
case 0x76:
return handle_io_inst(vcpu);
case 0x56:
return handle_sthyi(vcpu);
case 0x7d:
return handle_stsi(vcpu);
case 0xb1:
return handle_stfl(vcpu);
case 0xb2:
return handle_lpswe(vcpu);
default:
return -EOPNOTSUPP;
}
}

static int handle_epsw(struct kvm_vcpu *vcpu)
Expand Down Expand Up @@ -1105,25 +1110,22 @@ static int handle_essa(struct kvm_vcpu *vcpu)
return 0;
}

static const intercept_handler_t b9_handlers[256] = {
[0x8a] = handle_ipte_interlock,
[0x8d] = handle_epsw,
[0x8e] = handle_ipte_interlock,
[0x8f] = handle_ipte_interlock,
[0xab] = handle_essa,
[0xaf] = handle_pfmf,
};

int kvm_s390_handle_b9(struct kvm_vcpu *vcpu)
{
intercept_handler_t handler;

/* This is handled just as for the B2 instructions. */
handler = b9_handlers[vcpu->arch.sie_block->ipa & 0x00ff];
if (handler)
return handler(vcpu);

return -EOPNOTSUPP;
switch (vcpu->arch.sie_block->ipa & 0x00ff) {
case 0x8a:
case 0x8e:
case 0x8f:
return handle_ipte_interlock(vcpu);
case 0x8d:
return handle_epsw(vcpu);
case 0xab:
return handle_essa(vcpu);
case 0xaf:
return handle_pfmf(vcpu);
default:
return -EOPNOTSUPP;
}
}

int kvm_s390_handle_lctl(struct kvm_vcpu *vcpu)
Expand Down Expand Up @@ -1271,22 +1273,20 @@ static int handle_stctg(struct kvm_vcpu *vcpu)
return rc ? kvm_s390_inject_prog_cond(vcpu, rc) : 0;
}

static const intercept_handler_t eb_handlers[256] = {
[0x2f] = handle_lctlg,
[0x25] = handle_stctg,
[0x60] = handle_ri,
[0x61] = handle_ri,
[0x62] = handle_ri,
};

int kvm_s390_handle_eb(struct kvm_vcpu *vcpu)
{
intercept_handler_t handler;

handler = eb_handlers[vcpu->arch.sie_block->ipb & 0xff];
if (handler)
return handler(vcpu);
return -EOPNOTSUPP;
switch (vcpu->arch.sie_block->ipb & 0x000000ff) {
case 0x25:
return handle_stctg(vcpu);
case 0x2f:
return handle_lctlg(vcpu);
case 0x60:
case 0x61:
case 0x62:
return handle_ri(vcpu);
default:
return -EOPNOTSUPP;
}
}

static int handle_tprot(struct kvm_vcpu *vcpu)
Expand Down Expand Up @@ -1346,10 +1346,12 @@ static int handle_tprot(struct kvm_vcpu *vcpu)

int kvm_s390_handle_e5(struct kvm_vcpu *vcpu)
{
/* For e5xx... instructions we only handle TPROT */
if ((vcpu->arch.sie_block->ipa & 0x00ff) == 0x01)
switch (vcpu->arch.sie_block->ipa & 0x00ff) {
case 0x01:
return handle_tprot(vcpu);
return -EOPNOTSUPP;
default:
return -EOPNOTSUPP;
}
}

static int handle_sckpf(struct kvm_vcpu *vcpu)
Expand Down Expand Up @@ -1380,17 +1382,14 @@ static int handle_ptff(struct kvm_vcpu *vcpu)
return 0;
}

static const intercept_handler_t x01_handlers[256] = {
[0x04] = handle_ptff,
[0x07] = handle_sckpf,
};

int kvm_s390_handle_01(struct kvm_vcpu *vcpu)
{
intercept_handler_t handler;

handler = x01_handlers[vcpu->arch.sie_block->ipa & 0x00ff];
if (handler)
return handler(vcpu);
return -EOPNOTSUPP;
switch (vcpu->arch.sie_block->ipa & 0x00ff) {
case 0x04:
return handle_ptff(vcpu);
case 0x07:
return handle_sckpf(vcpu);
default:
return -EOPNOTSUPP;
}
}

0 comments on commit 6db4263

Please sign in to comment.