From mboxrd@z Thu Jan  1 00:00:00 1970
From: Avi Kivity <avi@redhat.com>
Subject: Re: [patch 04/12] [PATCH] kvm-s390-ucontrol: export SIE control block
 to user
Date: Thu, 01 Dec 2011 15:25:48 +0200
Message-ID: <4ED7805C.2000609@redhat.com>
References: <20111201125732.085553111@de.ibm.com> <20111201130409.221824848@de.ibm.com>
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Cc: Marcelo Tossati <mtosatti@redhat.com>,
	Christian Borntraeger <borntraeger@de.ibm.com>,
	Heiko Carstens <heiko.carstens@de.ibm.com>,
	Martin Schwidefsky <schwidefsky@de.ibm.com>,
	Cornelia Huck <cornelia.huck@de.ibm.com>,
	KVM <kvm@vger.kernel.org>,
	Joachim von Buttlar <joachim_von_buttlar@de.ibm.com>,
	Jens Freimann <jfrei@de.ibm.com>,
	Constantin Werner <constantin.werner@de.ibm.com>
To: Carsten Otte <cotte@de.ibm.com>
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On 12/01/2011 02:57 PM, Carsten Otte wrote:
> This patch exports the SIE hardware control block to userspace
> via the mapping of the vcpu file descriptor.
>
> Signed-off-by: Carsten Otte <cotte@de.ibm.com>
> ---
> ---
>  arch/s390/include/asm/kvm_host.h |    2 ++
>  virt/kvm/kvm_main.c              |    5 +++++
>  2 files changed, 7 insertions(+)
>
> --- a/arch/s390/include/asm/kvm_host.h
> +++ b/arch/s390/include/asm/kvm_host.h
> @@ -24,6 +24,8 @@
>  /* memory slots that does not exposed to userspace */
>  #define KVM_PRIVATE_MEM_SLOTS 4
>  
> +#define KVM_SIE_PAGE_OFFSET 1
> +

How does userspace get to know what this value is?

Coalesced mmio does this with the return value of
KVM_CAP_COALESCED_MMIO.  You can hardcode it, but in a user visible
header please.

>  struct sca_entry {
>  	atomic_t scn;
>  	__u32	reserved;
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -1656,6 +1656,11 @@ static int kvm_vcpu_fault(struct vm_area
>  	else if (vmf->pgoff == KVM_COALESCED_MMIO_PAGE_OFFSET)
>  		page = virt_to_page(vcpu->kvm->coalesced_mmio_ring);
>  #endif
> +#if defined(CONFIG_S390) && defined(CONFIG_KVM_UCONTROL)
> +	else if ((vmf->pgoff == KVM_SIE_PAGE_OFFSET)
> +		 && (!(vcpu->kvm->arch.gmap)))
> +		page = virt_to_page(vcpu->arch.sie_block);
> +#endif

kvm_arch_vcpu_fault()

-- 
error compiling committee.c: too many arguments to function