[Qemu-devel] Physical hard disk drive for win32

[Qemu-devel] Physical hard disk drive for win32

[Kazu]

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Hi,

An attached patch fixes to use raw access to physical hard disk drive for
win32.
It can be used as -hdb \\.\PhysicalDrive0 or -hdb //./PhysicalDrive0.

For example, if the guest OS is Linux, the second partition can be accessed
by /dev/hdb2.

Regards,
Kazu

[-- Attachment #2: qemu-20060922-harddisk.patch --]
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Index: block-raw.c
===================================================================
RCS file: /sources/qemu/qemu/block-raw.c,v
retrieving revision 1.10
diff -u -r1.10 block-raw.c
--- block-raw.c	3 Sep 2006 12:08:37 -0000	1.10
+++ block-raw.c	24 Sep 2006 03:56:44 -0000
@@ -833,6 +833,7 @@
 
 #define FTYPE_FILE 0
 #define FTYPE_CD     1
+#define FTYPE_HARDDISK 2
 
 typedef struct BDRVRawState {
     HANDLE hfile;
@@ -1090,6 +1091,9 @@
     BDRVRawState *s = bs->opaque;
     LARGE_INTEGER l;
     ULARGE_INTEGER available, total, total_free; 
+    DISK_GEOMETRY dg;
+    DWORD count;
+    BOOL status;
 
     switch(s->type) {
     case FTYPE_FILE:
@@ -1102,6 +1106,14 @@
             return -EIO;
         l.QuadPart = total.QuadPart;
         break;
+    case FTYPE_HARDDISK:
+        status = DeviceIoControl(s->hfile, IOCTL_DISK_GET_DRIVE_GEOMETRY,
+                                 NULL, 0, &dg, sizeof(dg), &count, NULL);
+        if (status != FALSE) {
+            l.QuadPart = dg.Cylinders.QuadPart * dg.TracksPerCylinder
+                * dg.SectorsPerTrack * dg.BytesPerSector;
+        }
+        break;
     default:
         return -EIO;
     }
@@ -1201,9 +1213,17 @@
     BDRVRawState *s = bs->opaque;
     UINT type;
     const char *p;
+    char *q;
+    int i;
+    char physical_drive[14];
 
     if (strstart(filename, "\\\\.\\", &p) ||
         strstart(filename, "//./", &p)) {
+        for (i = 0, q = p; i < 13; i++, q++) {
+            physical_drive[i] = tolower(*q);
+        }
+        if (strstart(physical_drive, "physicaldrive", NULL))
+            return FTYPE_HARDDISK;
         snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", p[0]);
         type = GetDriveType(s->drive_path);
         if (type == DRIVE_CDROM)

Re: [Qemu-devel] Physical hard disk drive for win32

[Alexey Eremenko]

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Is it hard to access "raw" hardware under Windows ? like Hard Disk...?

Under Linux it is easy.

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Re: [Qemu-devel] Physical hard disk drive for win32

[Kazu]

Alexey Eremenko wrote:

>Is it hard to access "raw" hardware under Windows ? like Hard Disk...?
>
>Under Linux it is easy.

CVS build cannot access host's physical hard disk drive by -hdb
//./PhysicalDrive0 after AIO was introduced.
So I made a patch to fix it.

Regards,
Kazu

[Qemu-devel] [PATCH] Physical hard disk drive for win32

[Stefan Weil]

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Hi,

raw harddisk access for Windows (//./PhysicalDrive0) gives wrong disk sizes.
You can check this by booting a harddisk with the GRUB bootloader installed
and using GRUB's geometry command.

The current QEMU code uses IOCTL_DISK_GET_DRIVE_GEOMETRY which is marked
as obsolete by MS.

The appended patch gives correct results. Please apply it to CVS.

Stefan

Description of block-raw.patch:

* replace IOCTL_DISK_GET_DRIVE_GEOMETRY by IOCTL_DISK_GET_DRIVE_GEOMETRY_EX



[-- Attachment #2: block-raw.patch --]
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Index: block-raw.c
===================================================================
RCS file: /sources/qemu/qemu/block-raw.c,v
retrieving revision 1.24
diff -u -b -B -r1.24 block-raw.c
--- block-raw.c	21 Sep 2007 06:09:39 -0000	1.24
+++ block-raw.c	19 Oct 2007 19:53:48 -0000
@@ -1174,7 +1174,7 @@
     BDRVRawState *s = bs->opaque;
     LARGE_INTEGER l;
     ULARGE_INTEGER available, total, total_free;
-    DISK_GEOMETRY dg;
+    DISK_GEOMETRY_EX dg;
     DWORD count;
     BOOL status;
 
@@ -1190,11 +1190,10 @@
         l.QuadPart = total.QuadPart;
         break;
     case FTYPE_HARDDISK:
-        status = DeviceIoControl(s->hfile, IOCTL_DISK_GET_DRIVE_GEOMETRY,
+        status = DeviceIoControl(s->hfile, IOCTL_DISK_GET_DRIVE_GEOMETRY_EX,
                                  NULL, 0, &dg, sizeof(dg), &count, NULL);
-        if (status != FALSE) {
-            l.QuadPart = dg.Cylinders.QuadPart * dg.TracksPerCylinder
-                * dg.SectorsPerTrack * dg.BytesPerSector;
+        if (status != 0) {
+            l = dg.DiskSize;
         }
         break;
     default:

Re: [Qemu-devel] [PATCH] Physical hard disk drive for win32

[Ivan Kalvachev]

2007/10/19, Stefan Weil <weil@mail.berlios.de>:
> Hi,
>
> raw harddisk access for Windows (//./PhysicalDrive0) gives wrong disk sizes.
> You can check this by booting a harddisk with the GRUB bootloader installed
> and using GRUB's geometry command.
>
> The current QEMU code uses IOCTL_DISK_GET_DRIVE_GEOMETRY which is marked
> as obsolete by MS.
>
> The appended patch gives correct results. Please apply it to CVS.
>
> Stefan
>
> Description of block-raw.patch:
>
> * replace IOCTL_DISK_GET_DRIVE_GEOMETRY by IOCTL_DISK_GET_DRIVE_GEOMETRY_EX


According to http://msdn2.microsoft.com/en-us/library/aa365171.aspx
this function requires Win XP or Vista.
Is qemu supported only on these?

Re: [Qemu-devel] [PATCH] Physical hard disk drive for win32

[Stefan Weil]

Ivan Kalvachev schrieb:
> According to http://msdn2.microsoft.com/en-us/library/aa365171.aspx
>
> this function requires Win XP or Vista.
> Is qemu supported only on these?
Good question. The old IOCTL_DISK_GET_DRIVE_GEOMETRY
was also supported for W2K. Will QEMU support W2K as a host
longer than MS does? It would make things easier if we
dropped support for W2K hosts.

If we need host support for W2K, I'll check another method
to get the disk size (reading size of partition 0) and send
a new patch. Please send your feedback in this case.

I hope we don't need W95 or W98 host support!?

Stefan

Re: [Qemu-devel] [PATCH] Physical hard disk drive for win32

[Johannes Schindelin]

Hi,

On Mon, 22 Oct 2007, Stefan Weil wrote:

> Ivan Kalvachev schrieb:
> > According to http://msdn2.microsoft.com/en-us/library/aa365171.aspx
> >
> > this function requires Win XP or Vista.
> > Is qemu supported only on these?
>
> Good question. The old IOCTL_DISK_GET_DRIVE_GEOMETRY was also supported 
> for W2K. Will QEMU support W2K as a host longer than MS does? It would 
> make things easier if we dropped support for W2K hosts.

Do we really want to be as evil as Microsoft and force all users to 
upgrade?

It should not be _that_ hard to stay at least a _little_ backwards 
compatible.

Ciao,
Dscho

Re: [Qemu-devel] [PATCH] Physical hard disk drive for win32

[Shaddy Baddah]

Hi,

Stefan Weil wrote:
> longer than MS does? It would make things easier if we
> dropped support for W2K hosts.
>   
Surely not?!? I've heard of people being off hand about supporting
Win95/98 (and I would agree with that) et al..., but surely W2K support
should be sacrosanct ?!?

Regards,
Shaddy

Re: [Qemu-devel] [PATCH] Physical hard disk drive for win32

[Jamie Lokier]

Shaddy Baddah wrote:
> >longer than MS does? It would make things easier if we
> >dropped support for W2K hosts.
> >  
> Surely not?!? I've heard of people being off hand about supporting
> Win95/98 (and I would agree with that) et al..., but surely W2K support
> should be sacrosanct ?!?

I would hope so, as I get the impression W2K is the last Windows
version which can be run reliably in a VM, due to the "legitimacy"
checking done by XP and later. :-)

-- Jamie

Re: [Qemu-devel] [PATCH] Physical hard disk drive for win32

[Ivan Kalvachev]

2007/10/22, Stefan Weil <weil@mail.berlios.de>:
> Ivan Kalvachev schrieb:
> > According to http://msdn2.microsoft.com/en-us/library/aa365171.aspx
> >
> > this function requires Win XP or Vista.
> > Is qemu supported only on these?
> Good question. The old IOCTL_DISK_GET_DRIVE_GEOMETRY
> was also supported for W2K. Will QEMU support W2K as a host
> longer than MS does? It would make things easier if we
> dropped support for W2K hosts.
>
> If we need host support for W2K, I'll check another method
> to get the disk size (reading size of partition 0) and send
> a new patch. Please send your feedback in this case.
>
> I hope we don't need W95 or W98 host support!?

Why not. :P

Anyway, calling the old ioctl code if the new one fails, should be
compatible enough. (and the new structure contains the old one, so no
need of having 2 variables).

It would be even better if somebody finds out what the error for not
supported function is (I don't feel like checking 16000 error codes),
but it is not critical.

Re: [Qemu-devel] [PATCH] Physical hard disk drive for win32

[Johannes Schindelin]

Hi,

On Wed, 24 Oct 2007, Ivan Kalvachev wrote:

> 2007/10/22, Stefan Weil <weil@mail.berlios.de>:
> > Ivan Kalvachev schrieb:
> > > According to http://msdn2.microsoft.com/en-us/library/aa365171.aspx
> > >
> > > this function requires Win XP or Vista.
> > > Is qemu supported only on these?
> > Good question. The old IOCTL_DISK_GET_DRIVE_GEOMETRY
> > was also supported for W2K. Will QEMU support W2K as a host
> > longer than MS does? It would make things easier if we
> > dropped support for W2K hosts.
> >
> > If we need host support for W2K, I'll check another method
> > to get the disk size (reading size of partition 0) and send
> > a new patch. Please send your feedback in this case.
> >
> > I hope we don't need W95 or W98 host support!?
> 
> Why not. :P
> 
> Anyway, calling the old ioctl code if the new one fails, should be
> compatible enough. (and the new structure contains the old one, so no
> need of having 2 variables).

It is not just that.  You'll have to guard the new ioctl within #ifdef's 
so that it still compiles on MinGW, even if that version does not define 
the constant.

Staying backwards compatible in this case is so easy, it is not even 
funny.  (And certainly no reason to groan over having to support it.)

Ciao,
Dscho

Re: [Qemu-devel] [PATCH] Physical hard disk drive for win32

[Thiemo Seufer]

Johannes Schindelin wrote:
> Hi,
> 
> On Wed, 24 Oct 2007, Ivan Kalvachev wrote:
> 
> > 2007/10/22, Stefan Weil <weil@mail.berlios.de>:
> > > Ivan Kalvachev schrieb:
> > > > According to http://msdn2.microsoft.com/en-us/library/aa365171.aspx
> > > >
> > > > this function requires Win XP or Vista.
> > > > Is qemu supported only on these?
> > > Good question. The old IOCTL_DISK_GET_DRIVE_GEOMETRY
> > > was also supported for W2K. Will QEMU support W2K as a host
> > > longer than MS does? It would make things easier if we
> > > dropped support for W2K hosts.
> > >
> > > If we need host support for W2K, I'll check another method
> > > to get the disk size (reading size of partition 0) and send
> > > a new patch. Please send your feedback in this case.
> > >
> > > I hope we don't need W95 or W98 host support!?
> > 
> > Why not. :P
> > 
> > Anyway, calling the old ioctl code if the new one fails, should be
> > compatible enough. (and the new structure contains the old one, so no
> > need of having 2 variables).
> 
> It is not just that.  You'll have to guard the new ioctl within #ifdef's 
> so that it still compiles on MinGW, even if that version does not define 
> the constant.
> 
> Staying backwards compatible in this case is so easy, it is not even 
> funny.  (And certainly no reason to groan over having to support it.)

A undirected remark to the general public: If somebody comes up with a
patch for better backward compatibility I'll certainly consider it.


Thiemo
>

Re: [Qemu-devel] [PATCH] Physical hard disk drive for win32

[Johannes Schindelin]

Hi,

On Wed, 24 Oct 2007, Thiemo Seufer wrote:

> Johannes Schindelin wrote:
> 
> > Staying backwards compatible in this case is so easy, it is not even 
> > funny.  (And certainly no reason to groan over having to support it.)
> 
> A undirected remark to the general public: If somebody comes up with a 
> patch for better backward compatibility I'll certainly consider it.

I think I fixed it.  Since I am not your regular Windows user (I only use 
Windows when I have to), I cannot tell if it works, though.

It is here: http://repo.or.cz/w/qemu/dscho.git?a=shortlog;h=diskgeometry

Any testing (especially the physical drive on Windows < XP) would be very 
much appreciated.

There is also a compilation bugfix with the current CVS on Windows: the 
tap down script patch left a for() loop without a body.

A question: on some other lists, the preferred way to submit patches is to 
inline them into the mail, but here I saw many attachments and/or weblinks 
to patches.  The easiest way for me would be like I just did: provide 
a link to repo.or.cz.

What is the preferred way on this list?

Ciao,
Dscho

Re: [Qemu-devel] [PATCH] Physical hard disk drive for win32

[Stefan Weil]

Johannes Schindelin schrieb:
> I think I fixed it. Since I am not your regular Windows user (I only use
>
> Windows when I have to), I cannot tell if it works, though.
>
> It is here: http://repo.or.cz/w/qemu/dscho.git?a=shortlog;h=diskgeometry
>
> Any testing (especially the physical drive on Windows < XP) would be very
> much appreciated.
> ...
> Ciao,
> Dscho
With your patch, W2K will still see a wrong disk size.
This is caused by the fact that the size of a modern harddisk
has nothing to do with tracks per cylinder or sectors per track
- it is not simply the product of four values.

You can use a disk to some degree even when some part at
the end is inaccessible, but it is also possible to destroy
it (for example if a partition tool "corrects" the disk
size in the boot sector) or get other kinds of errors.

I prefer a patch which gives correct values for all
Windows versions and will send one as soon as possible.

Even without a patch, the current code in CVS HEAD
still allows compilation using MinGW on any Windows.
QEMU will also run on the same Windows variants as
before. The only thing no longer working on W2K and
older variants is physical hard disk access. I think
this is better than working with a wrong disk size!

Regards,
Stefan

Re: [Qemu-devel] [PATCH] Physical hard disk drive for win32

[Johannes Schindelin]

Hi,

On Wed, 24 Oct 2007, Stefan Weil wrote:

> Johannes Schindelin schrieb:
> > I think I fixed it. Since I am not your regular Windows user (I only 
> > use Windows when I have to), I cannot tell if it works, though.
> >
> > It is here: 
> > http://repo.or.cz/w/qemu/dscho.git?a=shortlog;h=diskgeometry
> >
> > Any testing (especially the physical drive on Windows < XP) would be 
> > very much appreciated. ... Ciao, Dscho
>
> With your patch, W2K will still see a wrong disk size.

Funny.  I thought that since kazu did the original patch, and kazu is a 
Windows user, that it worked at _some_ stage.

Also I have to note that IOCTL_DISK_GET_DRIVE_GEOMETRY is a Windows 2000 
feature, so unfortunately there is really no backwards compatibility to 
Windows 95/98/ME.

> This is caused by the fact that the size of a modern harddisk has 
> nothing to do with tracks per cylinder or sectors per track - it is not 
> simply the product of four values.

Since it obviously worked in one setting, there might be a chance that it 
is fixable.  Could you be a little bit more specific in what is going 
wrong?  I.e. what is the real size, and what are the four values?

> Even without a patch, the current code in CVS HEAD
> still allows compilation using MinGW on any Windows.

Yes, but a setup that was evidently working before was broken.

Ciao,
Dscho

Re: [Qemu-devel] [PATCH] Physical hard disk drive for win32

[Thiemo Seufer]

Johannes Schindelin wrote:
> Hi,
> 
> On Wed, 24 Oct 2007, Thiemo Seufer wrote:
> 
> > Johannes Schindelin wrote:
> > 
> > > Staying backwards compatible in this case is so easy, it is not even 
> > > funny.  (And certainly no reason to groan over having to support it.)
> > 
> > A undirected remark to the general public: If somebody comes up with a 
> > patch for better backward compatibility I'll certainly consider it.
> 
> I think I fixed it.  Since I am not your regular Windows user (I only use 
> Windows when I have to), I cannot tell if it works, though.
> 
> It is here: http://repo.or.cz/w/qemu/dscho.git?a=shortlog;h=diskgeometry
> 
> Any testing (especially the physical drive on Windows < XP) would be very 
> much appreciated.
> 
> There is also a compilation bugfix with the current CVS on Windows: the 
> tap down script patch left a for() loop without a body.
> 
> A question: on some other lists, the preferred way to submit patches is to 
> inline them into the mail, but here I saw many attachments and/or weblinks 
> to patches.  The easiest way for me would be like I just did: provide 
> a link to repo.or.cz.
> 
> What is the preferred way on this list?

I prefer inlined or attached patches, so they get archived and don't
develop a 404 problem over time.


Thiemo