[Qemu-devel] [PULL 0/2] VFIO endian updates

[Qemu-devel] [PULL 0/2] VFIO endian updates

[Alex Williamson]

The following changes since commit 07e2863d0271ac6c05206d8ce9e4f4c39b25d3ea:

  exec.c: fix setting 1-byte-long watchpoints (2014-09-19 17:42:16 +0100)

are available in the git repository at:

  git://github.com/awilliam/qemu-vfio.git tags/vfio-pci-for-qemu-20140923.0

for you to fetch changes up to 75bd0c7253f384e868b638db5c6350796cf584f7:

  vfio: make rom read endian sensitive (2014-09-22 15:27:43 -0600)

----------------------------------------------------------------
Endian updates to re-fix cross endian host and guest and
enable the same for ROM loading (Alexey)

----------------------------------------------------------------
Alexey Kardashevskiy (1):
      Revert "vfio: Make BARs native endian"

Nikunj A Dadhania (1):
      vfio: make rom read endian sensitive

 hw/misc/vfio.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

[Qemu-devel] [PULL 1/2] Revert "vfio: Make BARs native endian"

[Alex Williamson]

From: Alexey Kardashevskiy <aik@ozlabs.ru>

This reverts commit c40708176a6b52b73bec14796b7c71b882ceb102.

The resulting code wrongly assumed target and host endianness are
the same which is not always the case for PPC64.

[aw: or potentially any host supporting VFIO and TCG]

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---
 hw/misc/vfio.c |   41 ++++++++++-------------------------------
 1 file changed, 10 insertions(+), 31 deletions(-)

diff --git a/hw/misc/vfio.c b/hw/misc/vfio.c
index 40dcaa6..22ebcbd 100644
--- a/hw/misc/vfio.c
+++ b/hw/misc/vfio.c
@@ -1098,10 +1098,10 @@ static void vfio_bar_write(void *opaque, hwaddr addr,
         buf.byte = data;
         break;
     case 2:
-        buf.word = data;
+        buf.word = cpu_to_le16(data);
         break;
     case 4:
-        buf.dword = data;
+        buf.dword = cpu_to_le32(data);
         break;
     default:
         hw_error("vfio: unsupported write size, %d bytes", size);
@@ -1158,10 +1158,10 @@ static uint64_t vfio_bar_read(void *opaque,
         data = buf.byte;
         break;
     case 2:
-        data = buf.word;
+        data = le16_to_cpu(buf.word);
         break;
     case 4:
-        data = buf.dword;
+        data = le32_to_cpu(buf.dword);
         break;
     default:
         hw_error("vfio: unsupported read size, %d bytes", size);
@@ -1188,7 +1188,7 @@ static uint64_t vfio_bar_read(void *opaque,
 static const MemoryRegionOps vfio_bar_ops = {
     .read = vfio_bar_read,
     .write = vfio_bar_write,
-    .endianness = DEVICE_NATIVE_ENDIAN,
+    .endianness = DEVICE_LITTLE_ENDIAN,
 };
 
 static void vfio_pci_load_rom(VFIODevice *vdev)
@@ -1250,42 +1250,21 @@ static void vfio_pci_load_rom(VFIODevice *vdev)
 static uint64_t vfio_rom_read(void *opaque, hwaddr addr, unsigned size)
 {
     VFIODevice *vdev = opaque;
-    union {
-        uint8_t byte;
-        uint16_t word;
-        uint32_t dword;
-        uint64_t qword;
-    } buf;
-    uint64_t data = 0;
+    uint64_t val = ((uint64_t)1 << (size * 8)) - 1;
 
     /* Load the ROM lazily when the guest tries to read it */
     if (unlikely(!vdev->rom && !vdev->rom_read_failed)) {
         vfio_pci_load_rom(vdev);
     }
 
-    memcpy(&buf, vdev->rom + addr,
+    memcpy(&val, vdev->rom + addr,
            (addr < vdev->rom_size) ? MIN(size, vdev->rom_size - addr) : 0);
 
-    switch (size) {
-    case 1:
-        data = buf.byte;
-        break;
-    case 2:
-        data = buf.word;
-        break;
-    case 4:
-        data = buf.dword;
-        break;
-    default:
-        hw_error("vfio: unsupported read size, %d bytes", size);
-        break;
-    }
-
     DPRINTF("%s(%04x:%02x:%02x.%x, 0x%"HWADDR_PRIx", 0x%x) = 0x%"PRIx64"\n",
             __func__, vdev->host.domain, vdev->host.bus, vdev->host.slot,
-            vdev->host.function, addr, size, data);
+            vdev->host.function, addr, size, val);
 
-    return data;
+    return val;
 }
 
 static void vfio_rom_write(void *opaque, hwaddr addr,
@@ -1296,7 +1275,7 @@ static void vfio_rom_write(void *opaque, hwaddr addr,
 static const MemoryRegionOps vfio_rom_ops = {
     .read = vfio_rom_read,
     .write = vfio_rom_write,
-    .endianness = DEVICE_NATIVE_ENDIAN,
+    .endianness = DEVICE_LITTLE_ENDIAN,
 };
 
 static bool vfio_blacklist_opt_rom(VFIODevice *vdev)

Re: [Qemu-devel] [PULL 1/2] Revert "vfio: Make BARs native endian"

[David Gibson]

[-- Attachment #1: Type: text/plain, Size: 744 bytes --]

On Tue, Sep 23, 2014 at 11:14:50AM -0600, Alex Williamson wrote:
> From: Alexey Kardashevskiy <aik@ozlabs.ru>
> 
> This reverts commit c40708176a6b52b73bec14796b7c71b882ceb102.
> 
> The resulting code wrongly assumed target and host endianness are
> the same which is not always the case for PPC64.
> 
> [aw: or potentially any host supporting VFIO and TCG]
> 
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

[-- Attachment #2: Type: application/pgp-signature, Size: 819 bytes --]

[Qemu-devel] [PULL 2/2] vfio: make rom read endian sensitive

[Alex Williamson]

From: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>

All memory regions used by VFIO are LITTLE_ENDIAN and they
already take care of endiannes when accessing real device BARs
except ROM - it was broken on BE hosts.

This fixes endiannes for ROM BARs the same way as it is done
for other BARs.

This has been tested on PPC64 BE/LE host/guest in all possible
combinations including TCG.

Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
[aik: added commit log]
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---
 hw/misc/vfio.c |   27 ++++++++++++++++++++++++---
 1 file changed, 24 insertions(+), 3 deletions(-)

diff --git a/hw/misc/vfio.c b/hw/misc/vfio.c
index 22ebcbd..d66f3d2 100644
--- a/hw/misc/vfio.c
+++ b/hw/misc/vfio.c
@@ -1250,7 +1250,13 @@ static void vfio_pci_load_rom(VFIODevice *vdev)
 static uint64_t vfio_rom_read(void *opaque, hwaddr addr, unsigned size)
 {
     VFIODevice *vdev = opaque;
-    uint64_t val = ((uint64_t)1 << (size * 8)) - 1;
+    union {
+        uint8_t byte;
+        uint16_t word;
+        uint32_t dword;
+        uint64_t qword;
+    } val;
+    uint64_t data = 0;
 
     /* Load the ROM lazily when the guest tries to read it */
     if (unlikely(!vdev->rom && !vdev->rom_read_failed)) {
@@ -1260,11 +1266,26 @@ static uint64_t vfio_rom_read(void *opaque, hwaddr addr, unsigned size)
     memcpy(&val, vdev->rom + addr,
            (addr < vdev->rom_size) ? MIN(size, vdev->rom_size - addr) : 0);
 
+    switch (size) {
+    case 1:
+        data = val.byte;
+        break;
+    case 2:
+        data = le16_to_cpu(val.word);
+        break;
+    case 4:
+        data = le32_to_cpu(val.dword);
+        break;
+    default:
+        hw_error("vfio: unsupported read size, %d bytes\n", size);
+        break;
+    }
+
     DPRINTF("%s(%04x:%02x:%02x.%x, 0x%"HWADDR_PRIx", 0x%x) = 0x%"PRIx64"\n",
             __func__, vdev->host.domain, vdev->host.bus, vdev->host.slot,
-            vdev->host.function, addr, size, val);
+            vdev->host.function, addr, size, data);
 
-    return val;
+    return data;
 }
 
 static void vfio_rom_write(void *opaque, hwaddr addr,

Re: [Qemu-devel] [PULL 2/2] vfio: make rom read endian sensitive

[David Gibson]

[-- Attachment #1: Type: text/plain, Size: 952 bytes --]

On Tue, Sep 23, 2014 at 11:14:57AM -0600, Alex Williamson wrote:
> From: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
> 
> All memory regions used by VFIO are LITTLE_ENDIAN and they
> already take care of endiannes when accessing real device BARs
> except ROM - it was broken on BE hosts.
> 
> This fixes endiannes for ROM BARs the same way as it is done
> for other BARs.
> 
> This has been tested on PPC64 BE/LE host/guest in all possible
> combinations including TCG.
> 
> Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
> [aik: added commit log]
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

[-- Attachment #2: Type: application/pgp-signature, Size: 819 bytes --]

Re: [Qemu-devel] [PULL 0/2] VFIO endian updates

[Peter Maydell]

On 23 September 2014 10:14, Alex Williamson <alex.williamson@redhat.com> wrote:
> The following changes since commit 07e2863d0271ac6c05206d8ce9e4f4c39b25d3ea:
>
>   exec.c: fix setting 1-byte-long watchpoints (2014-09-19 17:42:16 +0100)
>
> are available in the git repository at:
>
>   git://github.com/awilliam/qemu-vfio.git tags/vfio-pci-for-qemu-20140923.0
>
> for you to fetch changes up to 75bd0c7253f384e868b638db5c6350796cf584f7:
>
>   vfio: make rom read endian sensitive (2014-09-22 15:27:43 -0600)
>
> ----------------------------------------------------------------
> Endian updates to re-fix cross endian host and guest and
> enable the same for ROM loading (Alexey)
>
> ----------------------------------------------------------------
> Alexey Kardashevskiy (1):
>       Revert "vfio: Make BARs native endian"
>
> Nikunj A Dadhania (1):
>       vfio: make rom read endian sensitive
>
>  hw/misc/vfio.c | 24 ++++++++++++------------
>  1 file changed, 12 insertions(+), 12 deletions(-)

Applied, thanks.

-- PMM