From 6fd8e67dd83437118cf46a4a9c224142004c3d51 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Mon, 18 Jan 2016 14:46:34 +0100 Subject: [PATCH] KVM: s390: sync of fp registers via kvm_run As we already store the floating point registers in the vector save area in floating point register format when we don't have MACHINE_HAS_VX, we can directly expose them to user space using a new sync flag. The floating point registers will be valid when KVM_SYNC_FPRS is set. The fpc will also be valid when KVM_SYNC_FPRS is set. Either KVM_SYNC_FPRS or KVM_SYNC_VRS will be enabled, never both. Let's also change two positions where we access vrs, making the code easier to read and one comment superfluous. Suggested-by: Christian Borntraeger Signed-off-by: David Hildenbrand Signed-off-by: Christian Borntraeger --- arch/s390/include/uapi/asm/kvm.h | 8 ++++++-- arch/s390/kvm/kvm-s390.c | 12 +++++++----- 2 files changed, 13 insertions(+), 7 deletions(-) diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h index fe84bd5..347fe5a 100644 --- a/arch/s390/include/uapi/asm/kvm.h +++ b/arch/s390/include/uapi/asm/kvm.h @@ -154,6 +154,7 @@ struct kvm_guest_debug_arch { #define KVM_SYNC_PFAULT (1UL << 5) #define KVM_SYNC_VRS (1UL << 6) #define KVM_SYNC_RICCB (1UL << 7) +#define KVM_SYNC_FPRS (1UL << 8) /* definition of registers in kvm_run */ struct kvm_sync_regs { __u64 prefix; /* prefix register */ @@ -168,9 +169,12 @@ struct kvm_sync_regs { __u64 pft; /* pfault token [PFAULT] */ __u64 pfs; /* pfault select [PFAULT] */ __u64 pfc; /* pfault compare [PFAULT] */ - __u64 vrs[32][2]; /* vector registers */ + union { + __u64 vrs[32][2]; /* vector registers (KVM_SYNC_VRS) */ + __u64 fprs[16]; /* fp registers (KVM_SYNC_FPRS) */ + }; __u8 reserved[512]; /* for future vector expansion */ - __u32 fpc; /* only valid with vector registers */ + __u32 fpc; /* valid on KVM_SYNC_VRS or KVM_SYNC_FPRS */ __u8 padding[52]; /* riccb needs to be 64byte aligned */ __u8 riccb[64]; /* runtime instrumentation controls block */ }; diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 8fcdf98..2270fe4 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -1419,6 +1419,8 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu) */ if (MACHINE_HAS_VX) vcpu->run->kvm_valid_regs |= KVM_SYNC_VRS; + else + vcpu->run->kvm_valid_regs |= KVM_SYNC_FPRS; if (kvm_is_ucontrol(vcpu->kvm)) return __kvm_ucontrol_vcpu_init(vcpu); @@ -1433,10 +1435,10 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) vcpu->arch.host_fpregs.fpc = current->thread.fpu.fpc; vcpu->arch.host_fpregs.regs = current->thread.fpu.regs; - /* Depending on MACHINE_HAS_VX, data stored to vrs either - * has vector register or floating point register format. - */ - current->thread.fpu.regs = vcpu->run->s.regs.vrs; + 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 */ @@ -2389,7 +2391,7 @@ int kvm_s390_store_status_unloaded(struct kvm_vcpu *vcpu, unsigned long gpa) fprs, 128); } else { rc = write_guest_abs(vcpu, gpa + __LC_FPREGS_SAVE_AREA, - vcpu->run->s.regs.vrs, 128); + vcpu->run->s.regs.fprs, 128); } rc |= write_guest_abs(vcpu, gpa + __LC_GPREGS_SAVE_AREA, vcpu->run->s.regs.gprs, 128); -- 2.7.4