Re: [PATCH] virtio_console: Stop doing DMA on the stack

2016-09-09 Thread Ingo Molnar
* Michael S. Tsirkin wrote: > On Thu, Sep 08, 2016 at 08:49:43AM +0200, Ingo Molnar wrote: > > > > * Amit Shah wrote: > > > > > On (Tue) 30 Aug 2016 [08:04:15], Andy Lutomirski wrote: > > > > virtio_console uses a small DMA buffer for control requests. Move > > > > that buffer into heap memo

Re: [PATCH] virtio_console: Stop doing DMA on the stack

2016-09-09 Thread Michael S. Tsirkin
On Thu, Sep 08, 2016 at 08:49:43AM +0200, Ingo Molnar wrote: > > * Amit Shah wrote: > > > On (Tue) 30 Aug 2016 [08:04:15], Andy Lutomirski wrote: > > > virtio_console uses a small DMA buffer for control requests. Move > > > that buffer into heap memory. > > > > > > Doing virtio DMA on the stac

Re: [PATCH] virtio_console: Stop doing DMA on the stack

2016-09-07 Thread Ingo Molnar
* Amit Shah wrote: > On (Tue) 30 Aug 2016 [08:04:15], Andy Lutomirski wrote: > > virtio_console uses a small DMA buffer for control requests. Move > > that buffer into heap memory. > > > > Doing virtio DMA on the stack is normally okay on non-DMA-API virtio > > systems (which is currently most

Re: [PATCH] virtio_console: Stop doing DMA on the stack

2016-09-06 Thread Amit Shah
On (Tue) 30 Aug 2016 [08:04:15], Andy Lutomirski wrote: > virtio_console uses a small DMA buffer for control requests. Move > that buffer into heap memory. > > Doing virtio DMA on the stack is normally okay on non-DMA-API virtio > systems (which is currently most of them), but it breaks completel

[PATCH] virtio_console: Stop doing DMA on the stack

2016-08-30 Thread Andy Lutomirski
virtio_console uses a small DMA buffer for control requests. Move that buffer into heap memory. Doing virtio DMA on the stack is normally okay on non-DMA-API virtio systems (which is currently most of them), but it breaks completely if the stack is virtually mapped. Tested by typing both directi