On 06.02.2018 12:21, Christian Borntraeger wrote:
> instead of having huge jump tables for function selection,
> lets use normal switch/case statements for the instruction
> handlers in priv.c
>
> bloat-o-meter shows that the saving are even bigger than
> just the removed jump tables.
>
> add/remove: 0/11 grow/shrink: 8/0 up/down: 1934/-10246 (-8312)
> Function old new delta
> kvm_s390_handle_b2 42 958 +916
> handle_iske 178 558 +380
> handle_rrbe 178 546 +368
> kvm_s390_handle_b9 42 222 +180
> kvm_s390_handle_01 42 74 +32
> kvm_s390_handle_eb 42 70 +28
> handle_sckpf 176 204 +28
> handle_lctlg 628 630 +2
> handle_ptff 36 - -36
> handle_sckpf.part 78 - -78
> handle_epsw 154 - -154
> handle_stfl 316 - -316
> handle_rrbe.part 470 - -470
> handle_iske.part 482 - -482
> handle_io_inst 518 - -518
> x01_handlers 2048 - -2048
> eb_handlers 2048 - -2048
> b9_handlers 2048 - -2048
> b2_handlers 2048 - -2048
>
> Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
> ---
> arch/s390/kvm/priv.c | 183 +++++++++++++++++++++++++--------------------------
> 1 file changed, 91 insertions(+), 92 deletions(-)
>
> diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
> index c4c4e157c036..a74578cdd3f3 100644
> --- a/arch/s390/kvm/priv.c
> +++ b/arch/s390/kvm/priv.c
> @@ -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)
> @@ -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)
> @@ -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)
> @@ -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)
> @@ -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;
> + }
> }
>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
--
Thanks,
David / dhildenb
