Commit bf65014d authored by Radim Krčmář's avatar Radim Krčmář

Merge tag 'kvm-s390-next-4.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux

KVM: s390: Changes for 4.10 (via kvm/next)

Two small optimizations to not do register reloading in
vcpu_put/get, instead do it in the ioctl path. This reduces
the overhead for schedule-intense workload that does not
exit to QEMU. (e.g. KVM guest with eventfd/irqfd that
does a lot of context switching with vhost or iothreads).
parents 8370c3d0 e1788bb9
......@@ -415,7 +415,7 @@ static int __write_machine_check(struct kvm_vcpu *vcpu,
int rc;
mci.val = mchk->mcic;
/* take care of lazy register loading via vcpu load/put */
/* take care of lazy register loading */
save_fpu_regs();
save_access_regs(vcpu->run->s.regs.acrs);
......
......@@ -1812,22 +1812,7 @@ __u64 kvm_s390_get_cpu_timer(struct kvm_vcpu *vcpu)
void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
/* Save host register state */
save_fpu_regs();
vcpu->arch.host_fpregs.fpc = current->thread.fpu.fpc;
vcpu->arch.host_fpregs.regs = current->thread.fpu.regs;
if (MACHINE_HAS_VX)
current->thread.fpu.regs = vcpu->run->s.regs.vrs;
else
current->thread.fpu.regs = vcpu->run->s.regs.fprs;
current->thread.fpu.fpc = vcpu->run->s.regs.fpc;
if (test_fp_ctl(current->thread.fpu.fpc))
/* User space provided an invalid FPC, let's clear it */
current->thread.fpu.fpc = 0;
save_access_regs(vcpu->arch.host_acrs);
restore_access_regs(vcpu->run->s.regs.acrs);
gmap_enable(vcpu->arch.enabled_gmap);
atomic_or(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);
if (vcpu->arch.cputm_enabled && !is_vcpu_idle(vcpu))
......@@ -1844,16 +1829,6 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
vcpu->arch.enabled_gmap = gmap_get_enabled();
gmap_disable(vcpu->arch.enabled_gmap);
/* Save guest register state */
save_fpu_regs();
vcpu->run->s.regs.fpc = current->thread.fpu.fpc;
/* Restore host register state */
current->thread.fpu.fpc = vcpu->arch.host_fpregs.fpc;
current->thread.fpu.regs = vcpu->arch.host_fpregs.regs;
save_access_regs(vcpu->run->s.regs.acrs);
restore_access_regs(vcpu->arch.host_acrs);
}
static void kvm_s390_vcpu_initial_reset(struct kvm_vcpu *vcpu)
......@@ -2243,7 +2218,6 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
{
memcpy(&vcpu->run->s.regs.acrs, &sregs->acrs, sizeof(sregs->acrs));
memcpy(&vcpu->arch.sie_block->gcr, &sregs->crs, sizeof(sregs->crs));
restore_access_regs(vcpu->run->s.regs.acrs);
return 0;
}
......@@ -2257,11 +2231,9 @@ int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
{
/* make sure the new values will be lazily loaded */
save_fpu_regs();
if (test_fp_ctl(fpu->fpc))
return -EINVAL;
current->thread.fpu.fpc = fpu->fpc;
vcpu->run->s.regs.fpc = fpu->fpc;
if (MACHINE_HAS_VX)
convert_fp_to_vx((__vector128 *) vcpu->run->s.regs.vrs,
(freg_t *) fpu->fprs);
......@@ -2279,7 +2251,7 @@ int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
(__vector128 *) vcpu->run->s.regs.vrs);
else
memcpy(fpu->fprs, vcpu->run->s.regs.fprs, sizeof(fpu->fprs));
fpu->fpc = current->thread.fpu.fpc;
fpu->fpc = vcpu->run->s.regs.fpc;
return 0;
}
......@@ -2740,6 +2712,20 @@ static void sync_regs(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
if (riccb->valid)
vcpu->arch.sie_block->ecb3 |= 0x01;
}
save_access_regs(vcpu->arch.host_acrs);
restore_access_regs(vcpu->run->s.regs.acrs);
/* save host (userspace) fprs/vrs */
save_fpu_regs();
vcpu->arch.host_fpregs.fpc = current->thread.fpu.fpc;
vcpu->arch.host_fpregs.regs = current->thread.fpu.regs;
if (MACHINE_HAS_VX)
current->thread.fpu.regs = vcpu->run->s.regs.vrs;
else
current->thread.fpu.regs = vcpu->run->s.regs.fprs;
current->thread.fpu.fpc = vcpu->run->s.regs.fpc;
if (test_fp_ctl(current->thread.fpu.fpc))
/* User space provided an invalid FPC, let's clear it */
current->thread.fpu.fpc = 0;
kvm_run->kvm_dirty_regs = 0;
}
......@@ -2758,6 +2744,15 @@ static void store_regs(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
kvm_run->s.regs.pft = vcpu->arch.pfault_token;
kvm_run->s.regs.pfs = vcpu->arch.pfault_select;
kvm_run->s.regs.pfc = vcpu->arch.pfault_compare;
save_access_regs(vcpu->run->s.regs.acrs);
restore_access_regs(vcpu->arch.host_acrs);
/* Save guest register state */
save_fpu_regs();
vcpu->run->s.regs.fpc = current->thread.fpu.fpc;
/* Restore will be done lazily at return */
current->thread.fpu.fpc = vcpu->arch.host_fpregs.fpc;
current->thread.fpu.regs = vcpu->arch.host_fpregs.regs;
}
int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
......@@ -2874,7 +2869,7 @@ int kvm_s390_vcpu_store_status(struct kvm_vcpu *vcpu, unsigned long addr)
{
/*
* The guest FPRS and ACRS are in the host FPRS/ACRS due to the lazy
* copying in vcpu load/put. Lets update our copies before we save
* switch in the run ioctl. Let's update our copies before we save
* it into the save area
*/
save_fpu_regs();
......
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