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Merge tag 'kvm-s390-master-4.16-1' of git://git.kernel.org/pub/scm/li…
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…nux/kernel/git/kvms390/linux into HEAD

KVM: s390: Fixes and improvements for 4.16

- optimization for the exitless interrupt support that was merged
  in 4.16-rc1
- improve the branch prediction blocking for nested KVM
- replace some jump tables with switch statements to improve
  expoline performance
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@bonzini
bonzini committed Feb 14, 2018
2 parents 7928b2c + baabee6 commit 722c2cd
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Showing 5 changed files with 200 additions and 154 deletions.
51 changes: 29 additions & 22 deletions arch/s390/kvm/intercept.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -22,22 +22,6 @@
#include "trace.h"
#include "trace-s390.h"


static const intercept_handler_t instruction_handlers[256] = {
[0x01] = kvm_s390_handle_01,
[0x82] = kvm_s390_handle_lpsw,
[0x83] = kvm_s390_handle_diag,
[0xaa] = kvm_s390_handle_aa,
[0xae] = kvm_s390_handle_sigp,
[0xb2] = kvm_s390_handle_b2,
[0xb6] = kvm_s390_handle_stctl,
[0xb7] = kvm_s390_handle_lctl,
[0xb9] = kvm_s390_handle_b9,
[0xe3] = kvm_s390_handle_e3,
[0xe5] = kvm_s390_handle_e5,
[0xeb] = kvm_s390_handle_eb,
};

u8 kvm_s390_get_ilen(struct kvm_vcpu *vcpu)
{
struct kvm_s390_sie_block *sie_block = vcpu->arch.sie_block;
Expand Down Expand Up @@ -129,16 +113,39 @@ static int handle_validity(struct kvm_vcpu *vcpu)

static int handle_instruction(struct kvm_vcpu *vcpu)
{
intercept_handler_t handler;

vcpu->stat.exit_instruction++;
trace_kvm_s390_intercept_instruction(vcpu,
vcpu->arch.sie_block->ipa,
vcpu->arch.sie_block->ipb);
handler = instruction_handlers[vcpu->arch.sie_block->ipa >> 8];
if (handler)
return handler(vcpu);
return -EOPNOTSUPP;

switch (vcpu->arch.sie_block->ipa >> 8) {
case 0x01:
return kvm_s390_handle_01(vcpu);
case 0x82:
return kvm_s390_handle_lpsw(vcpu);
case 0x83:
return kvm_s390_handle_diag(vcpu);
case 0xaa:
return kvm_s390_handle_aa(vcpu);
case 0xae:
return kvm_s390_handle_sigp(vcpu);
case 0xb2:
return kvm_s390_handle_b2(vcpu);
case 0xb6:
return kvm_s390_handle_stctl(vcpu);
case 0xb7:
return kvm_s390_handle_lctl(vcpu);
case 0xb9:
return kvm_s390_handle_b9(vcpu);
case 0xe3:
return kvm_s390_handle_e3(vcpu);
case 0xe5:
return kvm_s390_handle_e5(vcpu);
case 0xeb:
return kvm_s390_handle_eb(vcpu);
default:
return -EOPNOTSUPP;
}
}

static int inject_prog_on_prog_intercept(struct kvm_vcpu *vcpu)
Expand Down
98 changes: 60 additions & 38 deletions arch/s390/kvm/interrupt.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -187,12 +187,6 @@ static int cpu_timer_irq_pending(struct kvm_vcpu *vcpu)
return kvm_s390_get_cpu_timer(vcpu) >> 63;
}

static inline int is_ioirq(unsigned long irq_type)
{
return ((irq_type >= IRQ_PEND_IO_ISC_7) &&
(irq_type <= IRQ_PEND_IO_ISC_0));
}

static uint64_t isc_to_isc_bits(int isc)
{
return (0x80 >> isc) << 24;
Expand Down Expand Up @@ -236,10 +230,15 @@ static inline int kvm_s390_gisa_tac_ipm_gisc(struct kvm_s390_gisa *gisa, u32 gis
return test_and_clear_bit_inv(IPM_BIT_OFFSET + gisc, (unsigned long *) gisa);
}

static inline unsigned long pending_irqs(struct kvm_vcpu *vcpu)
static inline unsigned long pending_irqs_no_gisa(struct kvm_vcpu *vcpu)
{
return vcpu->kvm->arch.float_int.pending_irqs |
vcpu->arch.local_int.pending_irqs |
vcpu->arch.local_int.pending_irqs;
}

static inline unsigned long pending_irqs(struct kvm_vcpu *vcpu)
{
return pending_irqs_no_gisa(vcpu) |
kvm_s390_gisa_get_ipm(vcpu->kvm->arch.gisa) << IRQ_PEND_IO_ISC_7;
}

Expand Down Expand Up @@ -337,7 +336,7 @@ static void __reset_intercept_indicators(struct kvm_vcpu *vcpu)

static void set_intercept_indicators_io(struct kvm_vcpu *vcpu)
{
if (!(pending_irqs(vcpu) & IRQ_PEND_IO_MASK))
if (!(pending_irqs_no_gisa(vcpu) & IRQ_PEND_IO_MASK))
return;
else if (psw_ioint_disabled(vcpu))
kvm_s390_set_cpuflags(vcpu, CPUSTAT_IO_INT);
Expand Down Expand Up @@ -1011,24 +1010,6 @@ static int __must_check __deliver_io(struct kvm_vcpu *vcpu,
return rc;
}

typedef int (*deliver_irq_t)(struct kvm_vcpu *vcpu);

static const deliver_irq_t deliver_irq_funcs[] = {
[IRQ_PEND_MCHK_EX] = __deliver_machine_check,
[IRQ_PEND_MCHK_REP] = __deliver_machine_check,
[IRQ_PEND_PROG] = __deliver_prog,
[IRQ_PEND_EXT_EMERGENCY] = __deliver_emergency_signal,
[IRQ_PEND_EXT_EXTERNAL] = __deliver_external_call,
[IRQ_PEND_EXT_CLOCK_COMP] = __deliver_ckc,
[IRQ_PEND_EXT_CPU_TIMER] = __deliver_cpu_timer,
[IRQ_PEND_RESTART] = __deliver_restart,
[IRQ_PEND_SET_PREFIX] = __deliver_set_prefix,
[IRQ_PEND_PFAULT_INIT] = __deliver_pfault_init,
[IRQ_PEND_EXT_SERVICE] = __deliver_service,
[IRQ_PEND_PFAULT_DONE] = __deliver_pfault_done,
[IRQ_PEND_VIRTIO] = __deliver_virtio,
};

/* Check whether an external call is pending (deliverable or not) */
int kvm_s390_ext_call_pending(struct kvm_vcpu *vcpu)
{
Expand Down Expand Up @@ -1192,7 +1173,6 @@ void kvm_s390_clear_local_irqs(struct kvm_vcpu *vcpu)
int __must_check kvm_s390_deliver_pending_interrupts(struct kvm_vcpu *vcpu)
{
struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
deliver_irq_t func;
int rc = 0;
unsigned long irq_type;
unsigned long irqs;
Expand All @@ -1212,16 +1192,57 @@ int __must_check kvm_s390_deliver_pending_interrupts(struct kvm_vcpu *vcpu)
while ((irqs = deliverable_irqs(vcpu)) && !rc) {
/* bits are in the reverse order of interrupt priority */
irq_type = find_last_bit(&irqs, IRQ_PEND_COUNT);
if (is_ioirq(irq_type)) {
switch (irq_type) {
case IRQ_PEND_IO_ISC_0:
case IRQ_PEND_IO_ISC_1:
case IRQ_PEND_IO_ISC_2:
case IRQ_PEND_IO_ISC_3:
case IRQ_PEND_IO_ISC_4:
case IRQ_PEND_IO_ISC_5:
case IRQ_PEND_IO_ISC_6:
case IRQ_PEND_IO_ISC_7:
rc = __deliver_io(vcpu, irq_type);
} else {
func = deliver_irq_funcs[irq_type];
if (!func) {
WARN_ON_ONCE(func == NULL);
clear_bit(irq_type, &li->pending_irqs);
continue;
}
rc = func(vcpu);
break;
case IRQ_PEND_MCHK_EX:
case IRQ_PEND_MCHK_REP:
rc = __deliver_machine_check(vcpu);
break;
case IRQ_PEND_PROG:
rc = __deliver_prog(vcpu);
break;
case IRQ_PEND_EXT_EMERGENCY:
rc = __deliver_emergency_signal(vcpu);
break;
case IRQ_PEND_EXT_EXTERNAL:
rc = __deliver_external_call(vcpu);
break;
case IRQ_PEND_EXT_CLOCK_COMP:
rc = __deliver_ckc(vcpu);
break;
case IRQ_PEND_EXT_CPU_TIMER:
rc = __deliver_cpu_timer(vcpu);
break;
case IRQ_PEND_RESTART:
rc = __deliver_restart(vcpu);
break;
case IRQ_PEND_SET_PREFIX:
rc = __deliver_set_prefix(vcpu);
break;
case IRQ_PEND_PFAULT_INIT:
rc = __deliver_pfault_init(vcpu);
break;
case IRQ_PEND_EXT_SERVICE:
rc = __deliver_service(vcpu);
break;
case IRQ_PEND_PFAULT_DONE:
rc = __deliver_pfault_done(vcpu);
break;
case IRQ_PEND_VIRTIO:
rc = __deliver_virtio(vcpu);
break;
default:
WARN_ONCE(1, "Unknown pending irq type %ld", irq_type);
clear_bit(irq_type, &li->pending_irqs);
}
}

Expand Down Expand Up @@ -1701,7 +1722,8 @@ static void __floating_irq_kick(struct kvm *kvm, u64 type)
kvm_s390_set_cpuflags(dst_vcpu, CPUSTAT_STOP_INT);
break;
case KVM_S390_INT_IO_MIN...KVM_S390_INT_IO_MAX:
kvm_s390_set_cpuflags(dst_vcpu, CPUSTAT_IO_INT);
if (!(type & KVM_S390_INT_IO_AI_MASK && kvm->arch.gisa))
kvm_s390_set_cpuflags(dst_vcpu, CPUSTAT_IO_INT);
break;
default:
kvm_s390_set_cpuflags(dst_vcpu, CPUSTAT_EXT_INT);
Expand Down
2 changes: 0 additions & 2 deletions arch/s390/kvm/kvm-s390.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -19,8 +19,6 @@
#include <asm/processor.h>
#include <asm/sclp.h>

typedef int (*intercept_handler_t)(struct kvm_vcpu *vcpu);

/* Transactional Memory Execution related macros */
#define IS_TE_ENABLED(vcpu) ((vcpu->arch.sie_block->ecb & ECB_TE))
#define TDB_FORMAT1 1
Expand Down
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