linux/arch/s390/kvm/diag.c
Cornelia Huck 85dfe87e24 KVM: s390: use cookies for ioeventfd
Make use of cookies for the virtio ccw notification hypercall to speed up
lookup of devices on the io bus.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
[Small fix to a comment. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-07-18 12:29:24 +02:00

163 lines
4.4 KiB
C

/*
* handling diagnose instructions
*
* Copyright IBM Corp. 2008, 2011
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License (version 2 only)
* as published by the Free Software Foundation.
*
* Author(s): Carsten Otte <cotte@de.ibm.com>
* Christian Borntraeger <borntraeger@de.ibm.com>
*/
#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <asm/virtio-ccw.h>
#include "kvm-s390.h"
#include "trace.h"
#include "trace-s390.h"
static int diag_release_pages(struct kvm_vcpu *vcpu)
{
unsigned long start, end;
unsigned long prefix = vcpu->arch.sie_block->prefix;
start = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4];
end = vcpu->run->s.regs.gprs[vcpu->arch.sie_block->ipa & 0xf] + 4096;
if (start & ~PAGE_MASK || end & ~PAGE_MASK || start > end
|| start < 2 * PAGE_SIZE)
return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
VCPU_EVENT(vcpu, 5, "diag release pages %lX %lX", start, end);
vcpu->stat.diagnose_10++;
/* we checked for start > end above */
if (end < prefix || start >= prefix + 2 * PAGE_SIZE) {
gmap_discard(start, end, vcpu->arch.gmap);
} else {
if (start < prefix)
gmap_discard(start, prefix, vcpu->arch.gmap);
if (end >= prefix)
gmap_discard(prefix + 2 * PAGE_SIZE,
end, vcpu->arch.gmap);
}
return 0;
}
static int __diag_time_slice_end(struct kvm_vcpu *vcpu)
{
VCPU_EVENT(vcpu, 5, "%s", "diag time slice end");
vcpu->stat.diagnose_44++;
kvm_vcpu_on_spin(vcpu);
return 0;
}
static int __diag_time_slice_end_directed(struct kvm_vcpu *vcpu)
{
struct kvm *kvm = vcpu->kvm;
struct kvm_vcpu *tcpu;
int tid;
int i;
tid = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4];
vcpu->stat.diagnose_9c++;
VCPU_EVENT(vcpu, 5, "diag time slice end directed to %d", tid);
if (tid == vcpu->vcpu_id)
return 0;
kvm_for_each_vcpu(i, tcpu, kvm)
if (tcpu->vcpu_id == tid) {
kvm_vcpu_yield_to(tcpu);
break;
}
return 0;
}
static int __diag_ipl_functions(struct kvm_vcpu *vcpu)
{
unsigned int reg = vcpu->arch.sie_block->ipa & 0xf;
unsigned long subcode = vcpu->run->s.regs.gprs[reg] & 0xffff;
VCPU_EVENT(vcpu, 5, "diag ipl functions, subcode %lx", subcode);
switch (subcode) {
case 3:
vcpu->run->s390_reset_flags = KVM_S390_RESET_CLEAR;
break;
case 4:
vcpu->run->s390_reset_flags = 0;
break;
default:
return -EOPNOTSUPP;
}
atomic_set_mask(CPUSTAT_STOPPED, &vcpu->arch.sie_block->cpuflags);
vcpu->run->s390_reset_flags |= KVM_S390_RESET_SUBSYSTEM;
vcpu->run->s390_reset_flags |= KVM_S390_RESET_IPL;
vcpu->run->s390_reset_flags |= KVM_S390_RESET_CPU_INIT;
vcpu->run->exit_reason = KVM_EXIT_S390_RESET;
VCPU_EVENT(vcpu, 3, "requesting userspace resets %llx",
vcpu->run->s390_reset_flags);
trace_kvm_s390_request_resets(vcpu->run->s390_reset_flags);
return -EREMOTE;
}
static int __diag_virtio_hypercall(struct kvm_vcpu *vcpu)
{
int ret, idx;
/* No virtio-ccw notification? Get out quickly. */
if (!vcpu->kvm->arch.css_support ||
(vcpu->run->s.regs.gprs[1] != KVM_S390_VIRTIO_CCW_NOTIFY))
return -EOPNOTSUPP;
idx = srcu_read_lock(&vcpu->kvm->srcu);
/*
* The layout is as follows:
* - gpr 2 contains the subchannel id (passed as addr)
* - gpr 3 contains the virtqueue index (passed as datamatch)
* - gpr 4 contains the index on the bus (optionally)
*/
ret = kvm_io_bus_write_cookie(vcpu->kvm, KVM_VIRTIO_CCW_NOTIFY_BUS,
vcpu->run->s.regs.gprs[2],
8, &vcpu->run->s.regs.gprs[3],
vcpu->run->s.regs.gprs[4]);
srcu_read_unlock(&vcpu->kvm->srcu, idx);
/*
* Return cookie in gpr 2, but don't overwrite the register if the
* diagnose will be handled by userspace.
*/
if (ret != -EOPNOTSUPP)
vcpu->run->s.regs.gprs[2] = ret;
/* kvm_io_bus_write_cookie returns -EOPNOTSUPP if it found no match. */
return ret < 0 ? ret : 0;
}
int kvm_s390_handle_diag(struct kvm_vcpu *vcpu)
{
int code = (vcpu->arch.sie_block->ipb & 0xfff0000) >> 16;
if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
trace_kvm_s390_handle_diag(vcpu, code);
switch (code) {
case 0x10:
return diag_release_pages(vcpu);
case 0x44:
return __diag_time_slice_end(vcpu);
case 0x9c:
return __diag_time_slice_end_directed(vcpu);
case 0x308:
return __diag_ipl_functions(vcpu);
case 0x500:
return __diag_virtio_hypercall(vcpu);
default:
return -EOPNOTSUPP;
}
}