On 04/10/2023 09:42, Andrii Chepurnyi wrote:
Hello,
Hi,
On 10/3/23 16:49, Julien Grall wrote:
Hi,
On 03/10/2023 14:19, Andrii Chepurnyi wrote:
For read operations, there's a potential issue when the data field
of the ioreq struct is partially updated in the response. To address
this, zero data field during read operations. This modification
serves as a safeguard against implementations that may inadvertently
partially update the data field in response to read requests.
For instance, consider an 8-bit read operation. In such cases, QEMU,
returns the same content of the data field with only 8 bits of
updated data.
Do you have a pointer to the code?
First of all, using the term "user-space" with respect to this problem
was a mistake from my side.
In general, my use case is to run u-boot with virtio-blk inside the
guest domain.
I.e. setup configuration(hardware renesas gen3 kingfisher board): Dom0,
DomD ( QEMU as backend) and running u-boot in DomA with virtio-blk.
The problem appeared inside the u-boot code :
I was asking a pointer to the code in the Device Emulator (QEMU in your
case). I am confident the code is correct in U-boot, because when using
'w0', the unused bits are meant to be set to zero (per the Arm Arm). But
I am curious to know why QEMU is not doing it.
Cheers,
--
Julien Grall
