Commit b028ee3e authored by David Hildenbrand's avatar David Hildenbrand Committed by Christian Borntraeger
Browse files

KVM: s390: synchronize more registers with kvm_run 



In order to reduce the number of syscalls when dropping to user space, this
patch enables the synchronization of the following "registers" with kvm_run:
- ARCH0: CPU timer, clock comparator, TOD programmable register,
         guest breaking-event register, program parameter
- PFAULT: pfault parameters (token, select, compare)

The registers are grouped to reduce the overhead when syncing.

As this grows the number of sync registers quite a bit, let's move the code
synchronizing registers with kvm_run from kvm_arch_vcpu_ioctl_run() into
separate helper routines.

Signed-off-by: default avatarDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
parent c3950b66

arch/s390/include/uapi/asm/kvm.h

+10 −0
Original line number Diff line number Diff line
@@ -111,12 +111,22 @@ struct kvm_guest_debug_arch { 
#define KVM_SYNC_GPRS   (1UL << 1)

#define KVM_SYNC_ACRS   (1UL << 2)

#define KVM_SYNC_CRS    (1UL << 3)

#define KVM_SYNC_ARCH0  (1UL << 4)

#define KVM_SYNC_PFAULT (1UL << 5)

/* definition of registers in kvm_run */

struct kvm_sync_regs {

	__u64 prefix;	/* prefix register */

	__u64 gprs[16];	/* general purpose registers */

	__u32 acrs[16];	/* access registers */

	__u64 crs[16];	/* control registers */

	__u64 todpr;	/* tod programmable register [ARCH0] */

	__u64 cputm;	/* cpu timer [ARCH0] */

	__u64 ckc;	/* clock comparator [ARCH0] */

	__u64 pp;	/* program parameter [ARCH0] */

	__u64 gbea;	/* guest breaking-event address [ARCH0] */

	__u64 pft;	/* pfault token [PFAULT] */

	__u64 pfs;	/* pfault select [PFAULT] */

	__u64 pfc;	/* pfault compare [PFAULT] */

};



#define KVM_REG_S390_TODPR	(KVM_REG_S390 | KVM_REG_SIZE_U32 | 0x1)

arch/s390/kvm/kvm-s390.c

+46 −14
Original line number Diff line number Diff line
@@ -546,7 +546,9 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu) 
	vcpu->run->kvm_valid_regs = KVM_SYNC_PREFIX |

				    KVM_SYNC_GPRS |

				    KVM_SYNC_ACRS |

				    KVM_SYNC_CRS;

				    KVM_SYNC_CRS |

				    KVM_SYNC_ARCH0 |

				    KVM_SYNC_PFAULT;

	return 0;

}
@@ -1296,6 +1298,47 @@ static int __vcpu_run(struct kvm_vcpu *vcpu) 
	return rc;

}



static void sync_regs(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)

{

	vcpu->arch.sie_block->gpsw.mask = kvm_run->psw_mask;

	vcpu->arch.sie_block->gpsw.addr = kvm_run->psw_addr;

	if (kvm_run->kvm_dirty_regs & KVM_SYNC_PREFIX)

		kvm_s390_set_prefix(vcpu, kvm_run->s.regs.prefix);

	if (kvm_run->kvm_dirty_regs & KVM_SYNC_CRS) {

		memcpy(&vcpu->arch.sie_block->gcr, &kvm_run->s.regs.crs, 128);

		kvm_s390_set_prefix(vcpu, kvm_run->s.regs.prefix);

	}

	if (kvm_run->kvm_dirty_regs & KVM_SYNC_ARCH0) {

		vcpu->arch.sie_block->cputm = kvm_run->s.regs.cputm;

		vcpu->arch.sie_block->ckc = kvm_run->s.regs.ckc;

		vcpu->arch.sie_block->todpr = kvm_run->s.regs.todpr;

		vcpu->arch.sie_block->pp = kvm_run->s.regs.pp;

		vcpu->arch.sie_block->gbea = kvm_run->s.regs.gbea;

	}

	if (kvm_run->kvm_dirty_regs & KVM_SYNC_PFAULT) {

		vcpu->arch.pfault_token = kvm_run->s.regs.pft;

		vcpu->arch.pfault_select = kvm_run->s.regs.pfs;

		vcpu->arch.pfault_compare = kvm_run->s.regs.pfc;

	}

	kvm_run->kvm_dirty_regs = 0;

}



static void store_regs(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)

{

	kvm_run->psw_mask = vcpu->arch.sie_block->gpsw.mask;

	kvm_run->psw_addr = vcpu->arch.sie_block->gpsw.addr;

	kvm_run->s.regs.prefix = kvm_s390_get_prefix(vcpu);

	memcpy(&kvm_run->s.regs.crs, &vcpu->arch.sie_block->gcr, 128);

	kvm_run->s.regs.cputm = vcpu->arch.sie_block->cputm;

	kvm_run->s.regs.ckc = vcpu->arch.sie_block->ckc;

	kvm_run->s.regs.todpr = vcpu->arch.sie_block->todpr;

	kvm_run->s.regs.pp = vcpu->arch.sie_block->pp;

	kvm_run->s.regs.gbea = vcpu->arch.sie_block->gbea;

	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;

}



int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)

{

	int rc;
@@ -1317,15 +1360,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
		return -EINVAL;

	}



	vcpu->arch.sie_block->gpsw.mask = kvm_run->psw_mask;

	vcpu->arch.sie_block->gpsw.addr = kvm_run->psw_addr;

	if (kvm_run->kvm_dirty_regs & KVM_SYNC_PREFIX)

		kvm_s390_set_prefix(vcpu, kvm_run->s.regs.prefix);

	if (kvm_run->kvm_dirty_regs & KVM_SYNC_CRS) {

		memcpy(&vcpu->arch.sie_block->gcr, &kvm_run->s.regs.crs, 128);

		kvm_s390_set_prefix(vcpu, kvm_run->s.regs.prefix);

	}

	kvm_run->kvm_dirty_regs = 0;

	sync_regs(vcpu, kvm_run);



	might_fault();

	rc = __vcpu_run(vcpu);
@@ -1355,10 +1390,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
		rc = 0;

	}



	kvm_run->psw_mask     = vcpu->arch.sie_block->gpsw.mask;

	kvm_run->psw_addr     = vcpu->arch.sie_block->gpsw.addr;

	kvm_run->s.regs.prefix = kvm_s390_get_prefix(vcpu);

	memcpy(&kvm_run->s.regs.crs, &vcpu->arch.sie_block->gcr, 128);

	store_regs(vcpu, kvm_run);



	if (vcpu->sigset_active)

		sigprocmask(SIG_SETMASK, &sigsaved, NULL);

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