From: Laurent Dufour <ldufour@linux.vnet.ibm.com>
To: Alexander Graf <agraf@suse.de>
Cc: Gleb Natapov <gleb@kernel.org>,
Paolo Bonzini <pbonzini@redhat.com>,
Paul Mackerras <paulus@samba.org>,
Ben Herrenschmidt <benh@kernel.crashing.org>,
linuxppc-dev@lists.ozlabs.org, kvm-ppc <kvm-ppc@vger.kernel.org>,
"kvm@vger.kernel.org mailing list" <kvm@vger.kernel.org>
Subject: Re: [PATCH] PPC: KVM: Introduce hypervisor call H_GET_TCE
Date: Tue, 25 Feb 2014 16:00:52 +0000 [thread overview]
Message-ID: <530CBE34.4000004@linux.vnet.ibm.com> (raw)
In-Reply-To: <75FB1EEB-910A-49A9-A4CC-0A2E5403C54C@suse.de>
On 21/02/2014 16:57, Alexander Graf wrote:
>
> On 21.02.2014, at 16:31, Laurent Dufour <ldufour@linux.vnet.ibm.com> wrote:
>
>> This fix introduces the H_GET_TCE hypervisor call which is basically the
>> reverse of H_PUT_TCE, as defined in the Power Architecture Platform
>> Requirements (PAPR).
>>
>> The hcall H_GET_TCE is required by the kdump kernel which is calling it to
>> retrieve the TCE set up by the panicing kernel.
>>
>> Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
>
> Thanks, applied to kvm-ppc-queue. Btw, why exactly are we using struct page pointers and alloc_page rather than __get_free_page() and simple page start pointers?
FWIW, I'm not so familiar with that part of code, it seems that this is
due to the page fault handler (kvm_spapr_tce_fault) which is part of the
mmap file operation handlers associated to the fd returned by
kvm_vm_ioctl_create_spapr_tce. Underlying vma's operation requires the
page fault handler to return a struct page value in the vm_fault structure.
Cheers,
Laurent.
WARNING: multiple messages have this Message-ID (diff)
From: Laurent Dufour <ldufour@linux.vnet.ibm.com>
To: Alexander Graf <agraf@suse.de>
Cc: "kvm@vger.kernel.org mailing list" <kvm@vger.kernel.org>,
Gleb Natapov <gleb@kernel.org>, kvm-ppc <kvm-ppc@vger.kernel.org>,
Paul Mackerras <paulus@samba.org>,
Paolo Bonzini <pbonzini@redhat.com>,
linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH] PPC: KVM: Introduce hypervisor call H_GET_TCE
Date: Tue, 25 Feb 2014 17:00:52 +0100 [thread overview]
Message-ID: <530CBE34.4000004@linux.vnet.ibm.com> (raw)
In-Reply-To: <75FB1EEB-910A-49A9-A4CC-0A2E5403C54C@suse.de>
On 21/02/2014 16:57, Alexander Graf wrote:
>
> On 21.02.2014, at 16:31, Laurent Dufour <ldufour@linux.vnet.ibm.com> wrote:
>
>> This fix introduces the H_GET_TCE hypervisor call which is basically the
>> reverse of H_PUT_TCE, as defined in the Power Architecture Platform
>> Requirements (PAPR).
>>
>> The hcall H_GET_TCE is required by the kdump kernel which is calling it to
>> retrieve the TCE set up by the panicing kernel.
>>
>> Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
>
> Thanks, applied to kvm-ppc-queue. Btw, why exactly are we using struct page pointers and alloc_page rather than __get_free_page() and simple page start pointers?
FWIW, I'm not so familiar with that part of code, it seems that this is
due to the page fault handler (kvm_spapr_tce_fault) which is part of the
mmap file operation handlers associated to the fd returned by
kvm_vm_ioctl_create_spapr_tce. Underlying vma's operation requires the
page fault handler to return a struct page value in the vm_fault structure.
Cheers,
Laurent.
WARNING: multiple messages have this Message-ID (diff)
From: Laurent Dufour <ldufour@linux.vnet.ibm.com>
To: Alexander Graf <agraf@suse.de>
Cc: Gleb Natapov <gleb@kernel.org>,
Paolo Bonzini <pbonzini@redhat.com>,
Paul Mackerras <paulus@samba.org>,
Ben Herrenschmidt <benh@kernel.crashing.org>,
linuxppc-dev@lists.ozlabs.org, kvm-ppc <kvm-ppc@vger.kernel.org>,
"kvm@vger.kernel.org mailing list" <kvm@vger.kernel.org>
Subject: Re: [PATCH] PPC: KVM: Introduce hypervisor call H_GET_TCE
Date: Tue, 25 Feb 2014 17:00:52 +0100 [thread overview]
Message-ID: <530CBE34.4000004@linux.vnet.ibm.com> (raw)
In-Reply-To: <75FB1EEB-910A-49A9-A4CC-0A2E5403C54C@suse.de>
On 21/02/2014 16:57, Alexander Graf wrote:
>
> On 21.02.2014, at 16:31, Laurent Dufour <ldufour@linux.vnet.ibm.com> wrote:
>
>> This fix introduces the H_GET_TCE hypervisor call which is basically the
>> reverse of H_PUT_TCE, as defined in the Power Architecture Platform
>> Requirements (PAPR).
>>
>> The hcall H_GET_TCE is required by the kdump kernel which is calling it to
>> retrieve the TCE set up by the panicing kernel.
>>
>> Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
>
> Thanks, applied to kvm-ppc-queue. Btw, why exactly are we using struct page pointers and alloc_page rather than __get_free_page() and simple page start pointers?
FWIW, I'm not so familiar with that part of code, it seems that this is
due to the page fault handler (kvm_spapr_tce_fault) which is part of the
mmap file operation handlers associated to the fd returned by
kvm_vm_ioctl_create_spapr_tce. Underlying vma's operation requires the
page fault handler to return a struct page value in the vm_fault structure.
Cheers,
Laurent.
next prev parent reply other threads:[~2014-02-25 16:00 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-21 15:31 [PATCH] PPC: KVM: Introduce hypervisor call H_GET_TCE Laurent Dufour
2014-02-21 15:31 ` Laurent Dufour
2014-02-21 15:31 ` Laurent Dufour
2014-02-21 15:57 ` Alexander Graf
2014-02-21 15:57 ` Alexander Graf
2014-02-21 15:57 ` Alexander Graf
2014-02-25 16:00 ` Laurent Dufour [this message]
2014-02-25 16:00 ` Laurent Dufour
2014-02-25 16:00 ` Laurent Dufour
2014-02-21 19:23 ` Benjamin Herrenschmidt
2014-02-21 19:23 ` Benjamin Herrenschmidt
2014-02-21 19:23 ` Benjamin Herrenschmidt
2014-02-22 0:28 ` Alexey Kardashevskiy
2014-02-22 0:28 ` Alexey Kardashevskiy
2014-02-22 0:48 ` Alexey Kardashevskiy
2014-02-22 0:48 ` Alexey Kardashevskiy
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