[PATCH v2 12/16] KVM: Move vcpu_load to arch-specific kvm_arch_vcpu_ioctl_get_fpu

[David Hildenbrand]

On 29.11.2017 17:41, Christoffer Dall wrote:
> Move vcpu_load() and vcpu_put() into the architecture specific
> implementations of kvm_arch_vcpu_ioctl_get_fpu().
> 
> Signed-off-by: Christoffer Dall <christoffer.dall at linaro.org>
> ---
>  arch/s390/kvm/kvm-s390.c | 4 ++++
>  arch/x86/kvm/x86.c       | 7 +++++--
>  virt/kvm/kvm_main.c      | 2 --
>  3 files changed, 9 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index 4bf80b5..88dcb89 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -2765,6 +2765,8 @@ int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
>  
>  int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
>  {
> +	vcpu_load(vcpu);
> +
>  	/* make sure we have the latest values */
>  	save_fpu_regs();
>  	if (MACHINE_HAS_VX)
> @@ -2773,6 +2775,8 @@ int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
>  	else
>  		memcpy(fpu->fprs, vcpu->run->s.regs.fprs, sizeof(fpu->fprs));
>  	fpu->fpc = vcpu->run->s.regs.fpc;
> +
> +	vcpu_put(vcpu);

This is one example where we need the vcpu_put/load.

>  	return 0;
>  }
>  
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index a074b0bd..8b54567 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -7679,9 +7679,11 @@ int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
>  
>  int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
>  {
> -	struct fxregs_state *fxsave =
> -			&vcpu->arch.guest_fpu.state.fxsave;
> +	struct fxregs_state *fxsave;
>  
> +	vcpu_load(vcpu);
> +
> +	fxsave = &vcpu->arch.guest_fpu.state.fxsave;
>  	memcpy(fpu->fpr, fxsave->st_space, 128);
>  	fpu->fcw = fxsave->cwd;
>  	fpu->fsw = fxsave->swd;
> @@ -7691,6 +7693,7 @@ int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
>  	fpu->last_dp = fxsave->rdp;
>  	memcpy(fpu->xmm, fxsave->xmm_space, sizeof fxsave->xmm_space);
>  
> +	vcpu_put(vcpu);
>  	return 0;
>  }
>  
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index c688eb7..73ad70a 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -2673,9 +2673,7 @@ static long kvm_vcpu_ioctl(struct file *filp,
>  		r = -ENOMEM;
>  		if (!fpu)
>  			goto out;
> -		vcpu_load(vcpu);
>  		r = kvm_arch_vcpu_ioctl_get_fpu(vcpu, fpu);
> -		vcpu_put(vcpu);
>  		if (r)
>  			goto out;
>  		r = -EFAULT;
> 

Reviewed-by: David Hildenbrand <david at redhat.com>

-- 

Thanks,

David / dhildenb