diff mbox series

[RFC,3/6] hw/sd/sdcard: Do not use legal address '0' for INVALID_ADDRESS

Message ID 20200918174117.180057-4-f4bug@amsat.org
State Superseded
Headers show
Series hw/sd/sdcard: Do not attempt to erase out of range addresses | expand

Commit Message

Philippe Mathieu-Daudé Sept. 18, 2020, 5:41 p.m. UTC
As it is legal to WRITE/ERASE the address/block 0,
change the value of this definition to an illegal
address: UINT32_MAX.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>

Same problem I had with the pflash device last year...
This break migration :(
What is the best way to do this?
---
 hw/sd/sd.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Comments

Markus Armbruster Sept. 21, 2020, 8:40 a.m. UTC | #1
Philippe Mathieu-Daudé <f4bug@amsat.org> writes:

> As it is legal to WRITE/ERASE the address/block 0,

> change the value of this definition to an illegal

> address: UINT32_MAX.

>

> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

> ---

> Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>

> Cc: Markus Armbruster <armbru@redhat.com>

>

> Same problem I had with the pflash device last year...

> This break migration :(

> What is the best way to do this?


Remind me: did we solve the problem with pflash, and if yes, how?

> ---

>  hw/sd/sd.c | 6 +++---

>  1 file changed, 3 insertions(+), 3 deletions(-)

>

> diff --git a/hw/sd/sd.c b/hw/sd/sd.c

> index 30ae435d669..4c05152f189 100644

> --- a/hw/sd/sd.c

> +++ b/hw/sd/sd.c

> @@ -53,7 +53,7 @@

>  

>  #define SDSC_MAX_CAPACITY   (2 * GiB)

>  

> -#define INVALID_ADDRESS     0

> +#define INVALID_ADDRESS     UINT32_MAX

>  

>  typedef enum {

>      sd_r0 = 0,    /* no response */

> @@ -666,8 +666,8 @@ static int sd_vmstate_pre_load(void *opaque)

>  

>  static const VMStateDescription sd_vmstate = {

>      .name = "sd-card",

> -    .version_id = 1,

> -    .minimum_version_id = 1,

> +    .version_id = 2,

> +    .minimum_version_id = 2,

>      .pre_load = sd_vmstate_pre_load,

>      .fields = (VMStateField[]) {

>          VMSTATE_UINT32(mode, SDState),
Philippe Mathieu-Daudé Sept. 21, 2020, 10:31 a.m. UTC | #2
+Paolo & Kevin.

On 9/21/20 10:40 AM, Markus Armbruster wrote:
> Philippe Mathieu-Daudé <f4bug@amsat.org> writes:

> 

>> As it is legal to WRITE/ERASE the address/block 0,

>> change the value of this definition to an illegal

>> address: UINT32_MAX.

>>

>> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

>> ---

>> Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>

>> Cc: Markus Armbruster <armbru@redhat.com>

>>

>> Same problem I had with the pflash device last year...

>> This break migration :(

>> What is the best way to do this?

> 

> Remind me: did we solve the problem with pflash, and if yes, how?


No we can't. The best I could do is add a comment and as this
is not fixable. See commit aba53a12bd5: ("hw/block/pflash_cfi01:
Document use of non-CFI compliant command '0x00'").

I now consider the device in maintenance-only
mode and won't add any new features.

I started working on a new implementation, hoping it can be a
drop in replacement. Laszlo still has hope that QEMU pflash
device will support sector locking so firmware developers could
test upgrading fw in VMs.

Back to the SDcard, it might be less critical, so a migration
breaking change might be acceptable. I'm only aware of Paolo
and Kevin using this device for testing. Not sure of its
importance in production.

> 

>> ---

>>  hw/sd/sd.c | 6 +++---

>>  1 file changed, 3 insertions(+), 3 deletions(-)

>>

>> diff --git a/hw/sd/sd.c b/hw/sd/sd.c

>> index 30ae435d669..4c05152f189 100644

>> --- a/hw/sd/sd.c

>> +++ b/hw/sd/sd.c

>> @@ -53,7 +53,7 @@

>>  

>>  #define SDSC_MAX_CAPACITY   (2 * GiB)

>>  

>> -#define INVALID_ADDRESS     0

>> +#define INVALID_ADDRESS     UINT32_MAX

>>  

>>  typedef enum {

>>      sd_r0 = 0,    /* no response */

>> @@ -666,8 +666,8 @@ static int sd_vmstate_pre_load(void *opaque)

>>  

>>  static const VMStateDescription sd_vmstate = {

>>      .name = "sd-card",

>> -    .version_id = 1,

>> -    .minimum_version_id = 1,

>> +    .version_id = 2,

>> +    .minimum_version_id = 2,

>>      .pre_load = sd_vmstate_pre_load,

>>      .fields = (VMStateField[]) {

>>          VMSTATE_UINT32(mode, SDState),

> 

>
Markus Armbruster Sept. 21, 2020, 12:21 p.m. UTC | #3
Philippe Mathieu-Daudé <philmd@redhat.com> writes:

> +Paolo & Kevin.

>

> On 9/21/20 10:40 AM, Markus Armbruster wrote:

>> Philippe Mathieu-Daudé <f4bug@amsat.org> writes:

>> 

>>> As it is legal to WRITE/ERASE the address/block 0,

>>> change the value of this definition to an illegal

>>> address: UINT32_MAX.

>>>

>>> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

>>> ---

>>> Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>

>>> Cc: Markus Armbruster <armbru@redhat.com>

>>>

>>> Same problem I had with the pflash device last year...

>>> This break migration :(

>>> What is the best way to do this?

>> 

>> Remind me: did we solve the problem with pflash, and if yes, how?

>

> No we can't. The best I could do is add a comment and as this

> is not fixable. See commit aba53a12bd5: ("hw/block/pflash_cfi01:

> Document use of non-CFI compliant command '0x00'").

>

> I now consider the device in maintenance-only

> mode and won't add any new features.

>

> I started working on a new implementation, hoping it can be a

> drop in replacement. Laszlo still has hope that QEMU pflash

> device will support sector locking so firmware developers could

> test upgrading fw in VMs.

>

> Back to the SDcard, it might be less critical, so a migration

> breaking change might be acceptable. I'm only aware of Paolo

> and Kevin using this device for testing. Not sure of its

> importance in production.


Neither am I.

Which machine types include this device by default?

How can a non-default device be added, and to which machine types?

I gather the fix changes device state incompatibly.  Always, or only in
certain states?  I'm asking because if device state remains compatible
most of the time, we might be able use subsection trickery to keep
migration working most of the time.  Has been done before, I think.
Dr. David Alan Gilbert Sept. 21, 2020, 12:24 p.m. UTC | #4
* Markus Armbruster (armbru@redhat.com) wrote:
> Philippe Mathieu-Daudé <philmd@redhat.com> writes:
> 
> > +Paolo & Kevin.
> >
> > On 9/21/20 10:40 AM, Markus Armbruster wrote:
> >> Philippe Mathieu-Daudé <f4bug@amsat.org> writes:
> >> 
> >>> As it is legal to WRITE/ERASE the address/block 0,
> >>> change the value of this definition to an illegal
> >>> address: UINT32_MAX.
> >>>
> >>> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> >>> ---
> >>> Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
> >>> Cc: Markus Armbruster <armbru@redhat.com>
> >>>
> >>> Same problem I had with the pflash device last year...
> >>> This break migration :(
> >>> What is the best way to do this?
> >> 
> >> Remind me: did we solve the problem with pflash, and if yes, how?
> >
> > No we can't. The best I could do is add a comment and as this
> > is not fixable. See commit aba53a12bd5: ("hw/block/pflash_cfi01:
> > Document use of non-CFI compliant command '0x00'").
> >
> > I now consider the device in maintenance-only
> > mode and won't add any new features.
> >
> > I started working on a new implementation, hoping it can be a
> > drop in replacement. Laszlo still has hope that QEMU pflash
> > device will support sector locking so firmware developers could
> > test upgrading fw in VMs.
> >
> > Back to the SDcard, it might be less critical, so a migration
> > breaking change might be acceptable. I'm only aware of Paolo
> > and Kevin using this device for testing. Not sure of its
> > importance in production.
> 
> Neither am I.
> 
> Which machine types include this device by default?

To me it looks like it's some of the ARM boards.

Dave

> How can a non-default device be added, and to which machine types?
> 
> I gather the fix changes device state incompatibly.  Always, or only in
> certain states?  I'm asking because if device state remains compatible
> most of the time, we might be able use subsection trickery to keep
> migration working most of the time.  Has been done before, I think.
Philippe Mathieu-Daudé Sept. 21, 2020, 2:23 p.m. UTC | #5
On 9/21/20 2:24 PM, Dr. David Alan Gilbert wrote:
> * Markus Armbruster (armbru@redhat.com) wrote:

>> Philippe Mathieu-Daudé <philmd@redhat.com> writes:

>>

>>> +Paolo & Kevin.

>>>

>>> On 9/21/20 10:40 AM, Markus Armbruster wrote:

>>>> Philippe Mathieu-Daudé <f4bug@amsat.org> writes:

>>>>

>>>>> As it is legal to WRITE/ERASE the address/block 0,

>>>>> change the value of this definition to an illegal

>>>>> address: UINT32_MAX.

>>>>>

>>>>> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

>>>>> ---

>>>>> Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>

>>>>> Cc: Markus Armbruster <armbru@redhat.com>

>>>>>

>>>>> Same problem I had with the pflash device last year...

>>>>> This break migration :(

>>>>> What is the best way to do this?

>>>>

>>>> Remind me: did we solve the problem with pflash, and if yes, how?

>>>

>>> No we can't. The best I could do is add a comment and as this

>>> is not fixable. See commit aba53a12bd5: ("hw/block/pflash_cfi01:

>>> Document use of non-CFI compliant command '0x00'").

>>>

>>> I now consider the device in maintenance-only

>>> mode and won't add any new features.

>>>

>>> I started working on a new implementation, hoping it can be a

>>> drop in replacement. Laszlo still has hope that QEMU pflash

>>> device will support sector locking so firmware developers could

>>> test upgrading fw in VMs.

>>>

>>> Back to the SDcard, it might be less critical, so a migration

>>> breaking change might be acceptable. I'm only aware of Paolo

>>> and Kevin using this device for testing. Not sure of its

>>> importance in production.

>>

>> Neither am I.

>>

>> Which machine types include this device by default?

> 

> To me it looks like it's some of the ARM boards.


My worry is TYPE_PCI_SDHCI ("sdhci-pci"):

    k->vendor_id = PCI_VENDOR_ID_REDHAT;
    k->device_id = PCI_DEVICE_ID_REDHAT_SDHCI;
    k->class_id = PCI_CLASS_SYSTEM_SDHCI;

config SDHCI_PCI
    bool
    default y if PCI_DEVICES

> 

> Dave

> 

>> How can a non-default device be added, and to which machine types?

>>

>> I gather the fix changes device state incompatibly.  Always, or only in

>> certain states?  I'm asking because if device state remains compatible

>> most of the time, we might be able use subsection trickery to keep

>> migration working most of the time.  Has been done before, I think.
Markus Armbruster Sept. 21, 2020, 3:08 p.m. UTC | #6
Philippe Mathieu-Daudé <philmd@redhat.com> writes:

> On 9/21/20 2:24 PM, Dr. David Alan Gilbert wrote:
>> * Markus Armbruster (armbru@redhat.com) wrote:
>>> Philippe Mathieu-Daudé <philmd@redhat.com> writes:
>>>
>>>> +Paolo & Kevin.
>>>>
>>>> On 9/21/20 10:40 AM, Markus Armbruster wrote:
>>>>> Philippe Mathieu-Daudé <f4bug@amsat.org> writes:
>>>>>
>>>>>> As it is legal to WRITE/ERASE the address/block 0,
>>>>>> change the value of this definition to an illegal
>>>>>> address: UINT32_MAX.
>>>>>>
>>>>>> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
>>>>>> ---
>>>>>> Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
>>>>>> Cc: Markus Armbruster <armbru@redhat.com>
>>>>>>
>>>>>> Same problem I had with the pflash device last year...
>>>>>> This break migration :(
>>>>>> What is the best way to do this?
>>>>>
>>>>> Remind me: did we solve the problem with pflash, and if yes, how?
>>>>
>>>> No we can't. The best I could do is add a comment and as this
>>>> is not fixable. See commit aba53a12bd5: ("hw/block/pflash_cfi01:
>>>> Document use of non-CFI compliant command '0x00'").
>>>>
>>>> I now consider the device in maintenance-only
>>>> mode and won't add any new features.
>>>>
>>>> I started working on a new implementation, hoping it can be a
>>>> drop in replacement. Laszlo still has hope that QEMU pflash
>>>> device will support sector locking so firmware developers could
>>>> test upgrading fw in VMs.
>>>>
>>>> Back to the SDcard, it might be less critical, so a migration
>>>> breaking change might be acceptable. I'm only aware of Paolo
>>>> and Kevin using this device for testing. Not sure of its
>>>> importance in production.
>>>
>>> Neither am I.
>>>
>>> Which machine types include this device by default?
>> 
>> To me it looks like it's some of the ARM boards.
>
> My worry is TYPE_PCI_SDHCI ("sdhci-pci"):
>
>     k->vendor_id = PCI_VENDOR_ID_REDHAT;
>     k->device_id = PCI_DEVICE_ID_REDHAT_SDHCI;
>     k->class_id = PCI_CLASS_SYSTEM_SDHCI;
>
> config SDHCI_PCI
>     bool
>     default y if PCI_DEVICES

Ah, now I remember.  Not the first time I wished it wouldn't exist...

>>> How can a non-default device be added, and to which machine types?
>>>
>>> I gather the fix changes device state incompatibly.  Always, or only in
>>> certain states?

I think we need to answer this question.

>>>                  I'm asking because if device state remains compatible
>>> most of the time, we might be able use subsection trickery to keep
>>> migration working most of the time.  Has been done before, I think.
Paolo Bonzini Sept. 21, 2020, 7:23 p.m. UTC | #7
I think we can just bite the bullet and bump the version number. Just like
not all boards are created equal in terms of migration compatibility,
neither are all devices.

Unfortunately pflash is among those that need some care, but we have much
more leeway with sdhci-pci.

Paolo

Il lun 21 set 2020, 17:08 Markus Armbruster <armbru@redhat.com> ha scritto:

> Philippe Mathieu-Daudé <philmd@redhat.com> writes:
>
> > On 9/21/20 2:24 PM, Dr. David Alan Gilbert wrote:
> >> * Markus Armbruster (armbru@redhat.com) wrote:
> >>> Philippe Mathieu-Daudé <philmd@redhat.com> writes:
> >>>
> >>>> +Paolo & Kevin.
> >>>>
> >>>> On 9/21/20 10:40 AM, Markus Armbruster wrote:
> >>>>> Philippe Mathieu-Daudé <f4bug@amsat.org> writes:
> >>>>>
> >>>>>> As it is legal to WRITE/ERASE the address/block 0,
> >>>>>> change the value of this definition to an illegal
> >>>>>> address: UINT32_MAX.
> >>>>>>
> >>>>>> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> >>>>>> ---
> >>>>>> Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
> >>>>>> Cc: Markus Armbruster <armbru@redhat.com>
> >>>>>>
> >>>>>> Same problem I had with the pflash device last year...
> >>>>>> This break migration :(
> >>>>>> What is the best way to do this?
> >>>>>
> >>>>> Remind me: did we solve the problem with pflash, and if yes, how?
> >>>>
> >>>> No we can't. The best I could do is add a comment and as this
> >>>> is not fixable. See commit aba53a12bd5: ("hw/block/pflash_cfi01:
> >>>> Document use of non-CFI compliant command '0x00'").
> >>>>
> >>>> I now consider the device in maintenance-only
> >>>> mode and won't add any new features.
> >>>>
> >>>> I started working on a new implementation, hoping it can be a
> >>>> drop in replacement. Laszlo still has hope that QEMU pflash
> >>>> device will support sector locking so firmware developers could
> >>>> test upgrading fw in VMs.
> >>>>
> >>>> Back to the SDcard, it might be less critical, so a migration
> >>>> breaking change might be acceptable. I'm only aware of Paolo
> >>>> and Kevin using this device for testing. Not sure of its
> >>>> importance in production.
> >>>
> >>> Neither am I.
> >>>
> >>> Which machine types include this device by default?
> >>
> >> To me it looks like it's some of the ARM boards.
> >
> > My worry is TYPE_PCI_SDHCI ("sdhci-pci"):
> >
> >     k->vendor_id = PCI_VENDOR_ID_REDHAT;
> >     k->device_id = PCI_DEVICE_ID_REDHAT_SDHCI;
> >     k->class_id = PCI_CLASS_SYSTEM_SDHCI;
> >
> > config SDHCI_PCI
> >     bool
> >     default y if PCI_DEVICES
>
> Ah, now I remember.  Not the first time I wished it wouldn't exist...
>
> >>> How can a non-default device be added, and to which machine types?
> >>>
> >>> I gather the fix changes device state incompatibly.  Always, or only in
> >>> certain states?
>
> I think we need to answer this question.
>
> >>>                  I'm asking because if device state remains compatible
> >>> most of the time, we might be able use subsection trickery to keep
> >>> migration working most of the time.  Has been done before, I think.
>
>
<div dir="auto">I think we can just bite the bullet and bump the version number. Just like not all boards are created equal in terms of migration compatibility, neither are all devices.<div dir="auto"><br></div><div dir="auto">Unfortunately pflash is among those that need some care, but we have much more leeway with sdhci-pci.</div><div dir="auto"><br></div><div dir="auto">Paolo</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">Il lun 21 set 2020, 17:08 Markus Armbruster &lt;<a href="mailto:armbru@redhat.com">armbru@redhat.com</a>&gt; ha scritto:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Philippe Mathieu-Daudé &lt;<a href="mailto:philmd@redhat.com" target="_blank" rel="noreferrer">philmd@redhat.com</a>&gt; writes:<br>
<br>
&gt; On 9/21/20 2:24 PM, Dr. David Alan Gilbert wrote:<br>
&gt;&gt; * Markus Armbruster (<a href="mailto:armbru@redhat.com" target="_blank" rel="noreferrer">armbru@redhat.com</a>) wrote:<br>
&gt;&gt;&gt; Philippe Mathieu-Daudé &lt;<a href="mailto:philmd@redhat.com" target="_blank" rel="noreferrer">philmd@redhat.com</a>&gt; writes:<br>
&gt;&gt;&gt;<br>
&gt;&gt;&gt;&gt; +Paolo &amp; Kevin.<br>
&gt;&gt;&gt;&gt;<br>
&gt;&gt;&gt;&gt; On 9/21/20 10:40 AM, Markus Armbruster wrote:<br>
&gt;&gt;&gt;&gt;&gt; Philippe Mathieu-Daudé &lt;<a href="mailto:f4bug@amsat.org" target="_blank" rel="noreferrer">f4bug@amsat.org</a>&gt; writes:<br>
&gt;&gt;&gt;&gt;&gt;<br>
&gt;&gt;&gt;&gt;&gt;&gt; As it is legal to WRITE/ERASE the address/block 0,<br>
&gt;&gt;&gt;&gt;&gt;&gt; change the value of this definition to an illegal<br>
&gt;&gt;&gt;&gt;&gt;&gt; address: UINT32_MAX.<br>
&gt;&gt;&gt;&gt;&gt;&gt;<br>
&gt;&gt;&gt;&gt;&gt;&gt; Signed-off-by: Philippe Mathieu-Daudé &lt;<a href="mailto:f4bug@amsat.org" target="_blank" rel="noreferrer">f4bug@amsat.org</a>&gt;<br>
&gt;&gt;&gt;&gt;&gt;&gt; ---<br>
&gt;&gt;&gt;&gt;&gt;&gt; Cc: Dr. David Alan Gilbert &lt;<a href="mailto:dgilbert@redhat.com" target="_blank" rel="noreferrer">dgilbert@redhat.com</a>&gt;<br>
&gt;&gt;&gt;&gt;&gt;&gt; Cc: Markus Armbruster &lt;<a href="mailto:armbru@redhat.com" target="_blank" rel="noreferrer">armbru@redhat.com</a>&gt;<br>
&gt;&gt;&gt;&gt;&gt;&gt;<br>
&gt;&gt;&gt;&gt;&gt;&gt; Same problem I had with the pflash device last year...<br>
&gt;&gt;&gt;&gt;&gt;&gt; This break migration :(<br>
&gt;&gt;&gt;&gt;&gt;&gt; What is the best way to do this?<br>
&gt;&gt;&gt;&gt;&gt;<br>
&gt;&gt;&gt;&gt;&gt; Remind me: did we solve the problem with pflash, and if yes, how?<br>
&gt;&gt;&gt;&gt;<br>
&gt;&gt;&gt;&gt; No we can&#39;t. The best I could do is add a comment and as this<br>
&gt;&gt;&gt;&gt; is not fixable. See commit aba53a12bd5: (&quot;hw/block/pflash_cfi01:<br>
&gt;&gt;&gt;&gt; Document use of non-CFI compliant command &#39;0x00&#39;&quot;).<br>
&gt;&gt;&gt;&gt;<br>
&gt;&gt;&gt;&gt; I now consider the device in maintenance-only<br>
&gt;&gt;&gt;&gt; mode and won&#39;t add any new features.<br>
&gt;&gt;&gt;&gt;<br>
&gt;&gt;&gt;&gt; I started working on a new implementation, hoping it can be a<br>
&gt;&gt;&gt;&gt; drop in replacement. Laszlo still has hope that QEMU pflash<br>
&gt;&gt;&gt;&gt; device will support sector locking so firmware developers could<br>
&gt;&gt;&gt;&gt; test upgrading fw in VMs.<br>
&gt;&gt;&gt;&gt;<br>
&gt;&gt;&gt;&gt; Back to the SDcard, it might be less critical, so a migration<br>
&gt;&gt;&gt;&gt; breaking change might be acceptable. I&#39;m only aware of Paolo<br>
&gt;&gt;&gt;&gt; and Kevin using this device for testing. Not sure of its<br>
&gt;&gt;&gt;&gt; importance in production.<br>
&gt;&gt;&gt;<br>
&gt;&gt;&gt; Neither am I.<br>
&gt;&gt;&gt;<br>
&gt;&gt;&gt; Which machine types include this device by default?<br>
&gt;&gt; <br>
&gt;&gt; To me it looks like it&#39;s some of the ARM boards.<br>
&gt;<br>
&gt; My worry is TYPE_PCI_SDHCI (&quot;sdhci-pci&quot;):<br>
&gt;<br>
&gt;     k-&gt;vendor_id = PCI_VENDOR_ID_REDHAT;<br>
&gt;     k-&gt;device_id = PCI_DEVICE_ID_REDHAT_SDHCI;<br>
&gt;     k-&gt;class_id = PCI_CLASS_SYSTEM_SDHCI;<br>
&gt;<br>
&gt; config SDHCI_PCI<br>
&gt;     bool<br>
&gt;     default y if PCI_DEVICES<br>
<br>
Ah, now I remember.  Not the first time I wished it wouldn&#39;t exist...<br>
<br>
&gt;&gt;&gt; How can a non-default device be added, and to which machine types?<br>
&gt;&gt;&gt;<br>
&gt;&gt;&gt; I gather the fix changes device state incompatibly.  Always, or only in<br>
&gt;&gt;&gt; certain states?<br>
<br>
I think we need to answer this question.<br>
<br>
&gt;&gt;&gt;                  I&#39;m asking because if device state remains compatible<br>
&gt;&gt;&gt; most of the time, we might be able use subsection trickery to keep<br>
&gt;&gt;&gt; migration working most of the time.  Has been done before, I think.<br>
<br>
</blockquote></div>
Kevin O'Connor Sept. 21, 2020, 11:53 p.m. UTC | #8
On Mon, Sep 21, 2020 at 12:31:21PM +0200, Philippe Mathieu-Daudé wrote:
> Back to the SDcard, it might be less critical, so a migration

> breaking change might be acceptable. I'm only aware of Paolo

> and Kevin using this device for testing. Not sure of its

> importance in production.


FWIW, I only use the sdcard for testing (and only use sdhci-pci).  I
don't know if others use it in production, however.

Cheers,
-Kevin
Markus Armbruster Sept. 22, 2020, 2:48 p.m. UTC | #9
Paolo Bonzini <pbonzini@redhat.com> writes:

> I think we can just bite the bullet and bump the version number. Just like
> not all boards are created equal in terms of migration compatibility,
> neither are all devices.
>
> Unfortunately pflash is among those that need some care, but we have much
> more leeway with sdhci-pci.

No objection.
Philippe Mathieu-Daudé Oct. 15, 2020, 6:27 a.m. UTC | #10
On 9/22/20 4:48 PM, Markus Armbruster wrote:
> Paolo Bonzini <pbonzini@redhat.com> writes:

> 

>> I think we can just bite the bullet and bump the version number. Just like

>> not all boards are created equal in terms of migration compatibility,

>> neither are all devices.


Great. I'll add that to the commit description.

>>

>> Unfortunately pflash is among those that need some care, but we have much

>> more leeway with sdhci-pci.

> 

> No objection.

>
diff mbox series

Patch

diff --git a/hw/sd/sd.c b/hw/sd/sd.c
index 30ae435d669..4c05152f189 100644
--- a/hw/sd/sd.c
+++ b/hw/sd/sd.c
@@ -53,7 +53,7 @@ 
 
 #define SDSC_MAX_CAPACITY   (2 * GiB)
 
-#define INVALID_ADDRESS     0
+#define INVALID_ADDRESS     UINT32_MAX
 
 typedef enum {
     sd_r0 = 0,    /* no response */
@@ -666,8 +666,8 @@  static int sd_vmstate_pre_load(void *opaque)
 
 static const VMStateDescription sd_vmstate = {
     .name = "sd-card",
-    .version_id = 1,
-    .minimum_version_id = 1,
+    .version_id = 2,
+    .minimum_version_id = 2,
     .pre_load = sd_vmstate_pre_load,
     .fields = (VMStateField[]) {
         VMSTATE_UINT32(mode, SDState),