From: Christian Borntraeger <borntraeger@de.ibm.com>
To: Avi Kivity <avi@redhat.com>
Cc: Alexander Graf <agraf@suse.de>,
virtualization@lists.linux-foundation.org,
Rusty Russell <rusty@rustcorp.com.au>,
Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>,
Carsten Otte <carsteno@de.ibm.com>,
KVM list <kvm@vger.kernel.org>
Subject: Re: [PATCH 1/2] S390: take a full byte as ext_param indicator
Date: Tue, 24 Aug 2010 15:24:16 +0200 [thread overview]
Message-ID: <4C73C800.4020000@de.ibm.com> (raw)
In-Reply-To: <4C73B97E.2060303@redhat.com>
[-- Attachment #1: Type: text/plain, Size: 207 bytes --]
Am 24.08.2010 14:22, schrieb Avi Kivity:
> First of all we need a virtio/s390 specification, like we have a
> virtio/pci spec.
Here is something that I started a year ago but never finished.
Christian
[-- Attachment #2: virtio.txt --]
[-- Type: text/plain, Size: 9520 bytes --]
guest/host interface for s390/virtio devices
KVM_DEVICE_DESCRIPTOR PAGE
0 8 16 24 31
+--------+--------+--------+--------+
0 | type | num_vq | featlen| conflen|
+--------+--------+--------+--------+
1 | status | |
+--------+ +------>+
2 | config | |
+ + |
... |
|
+-----------------------------------------------------+
|
| CONFIG ARRAY
| 0 8 16 24 31
+-------->+--------+--------+--------+--------+
0 | |
+ +
1 | |
+ +
2 | |
+ virtqueue 0 +------>+
3 | | |
+ + |
4 | | |
+ + |
5 | | |
+--------+--------+--------+--------+ |
|///////////////////////////////////+ |
|///////////////////////////////////+ |
+--------+--------+--------+--------+ |
| | |
+ + |
| | |
+ + |
| | |
+ virtqueue num_vq - 1 +------>+
| | |
+ + |
| | |
+ + |
| | |
+--------+--------+--------+--------+ |
num_vq*6 | feature bits (featlen * 2 Bytes) | |
+ +--------+--------+ |
| | | |
+--------+--------+ + |
| config space (conflen Bytes) | |
+ +--------+ |
| | |
+--------+--------+--------+ |
|
|
+-----------------------------------------------------+
|
| VIRTQUEUE
| 0 8 16 24 31
|-------->+--------+--------+--------+--------+
0 | interrupt token ... |
+ +
1 | ... set by guest |
+--------+--------+--------+--------+
2 | virtio ring address |
+ +
3 | ... set by host |
+--------+--------+--------+--------+
4 | number of elems |/////////////////+
+--------+--------+/////////////////+
5 |///////////////////////////////////+
+--------+--------+--------+--------+
COMPLETE KVM_DEVICE_DESCRIPTOR PAGE
0 8 16 24 31
+--------+--------+--------+--------+
0 | type | num_vq | featlen| conflen|
+--------+--------+--------+--------+
1 | status | interrupt token |
+--------+ +
2 | virtqueue 0(set by guest) |
+ +--------+--------+--------+
3 | | virtio ring address |
+--------+ +
4 | virtqueue 0 (set by host) |
+ +--------+--------+--------+
5 | | number of descr |////////|
+--------+--------+--------+////////+
6 |///////////////////////////////////|
+////////+--------+--------+--------+
7 |////////| interrupt token |
+--------+ +
8 | virtqueue 1(set by guest) |
+ +--------+--------+--------+
9 | | virtio ring address |
+--------+ +
10 | virtqueue 1 (set by host) |
+ +--------+--------+--------+
11 | | number of descr |////////|
+--------+--------+--------+////////+
12 |///////////////////////////////////|
+////////+--------+--------+--------+
13 |////////|
+--------+ .....
? |///////////////////////////////////|
+////////+--------+--------+--------+
? |////////| feature bits |
+--------+ (size multiple +--------+
| of 2 bytes) | |
+--------+--------+--------+ +
| config space (size of any length) |
+ +++++++++++++++++++
| |
+--------+--------+
Host->Guest notification:
-------------------------
via external interrupt with
- real storage 0x86-0x87 : 0x2603 --> host interrupt
- real storage 0x84: 0xd --> VIRTIO_SUBCODE_64
- real storage 0x11B8-0x11bf: the interrupt token (is a pointer to a struct virtqueue -> set by guest)
- real storage 0x83:
0: normal interrupt
1: config change
Guest->Host notification:
-------------------------
via diagnose call:
diag 2,4,0x500\n"
The calling convention is similar to the
* s390 ABI, so we use R2-R6 for parameters 1-5. In addition we use R1
* as hypercall number and R7 as parameter 6. The return value is
* written to R2. We use the diagnose instru
hypercall numbers are
#define KVM_S390_VIRTIO_NOTIFY 0
#define KVM_S390_VIRTIO_RESET 1
#define KVM_S390_VIRTIO_SET_STATUS 2
Virtio Ring: (3Pages)
---------------------
0 8 16 24 31
+--------+--------+--------+--------+\
0 | Desriptor 0: | \
+ guest physical address + \
1 | | \
+--------+--------+--------+--------+ one descriptor
2 | Descriptor 0: Length | /
+--------+--------+--------+--------+ /
3 | D0: Flags | D0: Next | /
+--------+--------+--------+--------+/
| |
...
| |
+--------+--------+--------+--------+
0 | Descriptor num -1 |
+ - guest physical address 64bit +
1 | - Length 32bit |
+ - flags 16 bit +
2 | - next 16 bit |
+ +
3 | |
+--------+--------+--------+--------+
|///////////////////////////////////|
...
|///////////////////////////////////|
+--------+--------+--------+--------+
4096 | avail_flags | avail_idx |
+--------+--------+--------+--------+
4097 | available 0 | available 1 |
+--------+--------+--------+--------+
| |
...
| |
+--------+--------+--------+--------+
| available num-2 | available num-1 |
+--------+--------+--------+--------+
|///////////////////////////////////|
...
|///////////////////////////////////|
+--------+--------+--------+--------+
8192 | used_flags | used_idx |
+--------+--------+--------+--------+
| used_elem_id 0 |
+--------+--------+--------+--------+
| used_elem_len 0 |
+--------+--------+--------+--------+
| |
...
| |
+--------+--------+--------+--------+
| used_elem_id num-1 |
+--------+--------+--------+--------+
| used_elem_len num-1 |
+--------+--------+--------+--------+
next prev parent reply other threads:[~2010-08-24 13:24 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-23 21:31 [PATCH 1/2] S390: take a full byte as ext_param indicator Alexander Graf
2010-08-23 21:31 ` [PATCH 2/2] S390: Add virtio hotplug add support Alexander Graf
2010-08-24 7:13 ` Christian Borntraeger
2010-08-24 7:13 ` Christian Borntraeger
2010-08-23 21:31 ` Alexander Graf
2010-08-24 7:03 ` [PATCH 1/2] S390: take a full byte as ext_param indicator Christian Borntraeger
2010-08-24 12:06 ` Alexander Graf
2010-08-24 12:14 ` Christian Borntraeger
2010-08-24 12:22 ` Avi Kivity
2010-08-24 12:25 ` Alexander Graf
2010-08-24 12:25 ` Alexander Graf
2010-08-24 12:30 ` Avi Kivity
2010-08-24 12:30 ` Avi Kivity
2010-08-24 12:32 ` Alexander Graf
2010-08-24 12:35 ` Avi Kivity
2010-08-24 12:35 ` Avi Kivity
2010-08-24 12:32 ` Alexander Graf
2010-08-24 13:24 ` Christian Borntraeger [this message]
2010-08-24 13:24 ` Christian Borntraeger
2010-08-24 12:22 ` Avi Kivity
2010-08-24 12:14 ` Christian Borntraeger
2010-08-24 12:06 ` Alexander Graf
2010-08-24 7:03 ` Christian Borntraeger
-- strict thread matches above, loose matches on Subject: below --
2010-08-23 21:31 Alexander Graf
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4C73C800.4020000@de.ibm.com \
--to=borntraeger@de.ibm.com \
--cc=agraf@suse.de \
--cc=avi@redhat.com \
--cc=carsteno@de.ibm.com \
--cc=ehrhardt@linux.vnet.ibm.com \
--cc=kvm@vger.kernel.org \
--cc=rusty@rustcorp.com.au \
--cc=virtualization@lists.linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.