Am 23.12.2019 um 18:51 hat Alexander Popov geschrieben: > The commit a718978ed58a from July 2015 introduced the assertion which > implies that the size of successful DMA transfers handled in ide_dma_cb() > should be multiple of 512 (the size of a sector). But guest systems can > initiate DMA transfers that don't fit this requirement. > > For fixing that let's check the number of bytes prepared for the transfer > by the prepare_buf() handler. The code in ide_dma_cb() must behave > according to the Programming Interface for Bus Master IDE Controller > (Revision 1.0 5/16/94): > 1. If PRDs specified a smaller size than the IDE transfer > size, then the Interrupt and Active bits in the Controller > status register are not set (Error Condition). > 2. If the size of the physical memory regions was equal to > the IDE device transfer size, the Interrupt bit in the > Controller status register is set to 1, Active bit is set to 0. > 3. If PRDs specified a larger size than the IDE transfer size, > the Interrupt and Active bits in the Controller status register > are both set to 1. > > Signed-off-by: Alexander Popov <alex.po...@linux.com>
Reviewed-by: Kevin Wolf <kw...@redhat.com>
