Re: [Xen-devel] [PATCH] x86/hvm/dmop: Only copy what is needed to/from the guest

2018-02-09 Thread Paul Durrant
> -Original Message- > From: Ross Lagerwall [mailto:ross.lagerw...@citrix.com] > Sent: 09 February 2018 15:49 > To: Paul Durrant ; xen-de...@lists.xen.org > Cc: Jan Beulich ; Andrew Cooper > > Subject: Re: [PATCH]

Re: [Xen-devel] [PATCH] x86/hvm/dmop: Only copy what is needed to/from the guest

2018-02-09 Thread Ross Lagerwall
On 02/09/2018 03:42 PM, Paul Durrant wrote: -Original Message- From: Ross Lagerwall [mailto:ross.lagerw...@citrix.com] Sent: 09 February 2018 15:34 To: xen-de...@lists.xen.org Cc: Ross Lagerwall ; Jan Beulich ; Andrew Cooper

Re: [Xen-devel] [PATCH] x86/hvm/dmop: Only copy what is needed to/from the guest

2018-02-09 Thread Andrew Cooper
On 09/02/18 15:42, Paul Durrant wrote: >> -Original Message- >> From: Ross Lagerwall [mailto:ross.lagerw...@citrix.com] >> Sent: 09 February 2018 15:34 >> To: xen-de...@lists.xen.org >> Cc: Ross Lagerwall ; Jan Beulich >> ; Andrew Cooper

[Xen-devel] [PATCH] x86/hvm/dmop: Only copy what is needed to/from the guest

2018-02-09 Thread Ross Lagerwall
dm_op() fails with -EFAULT if the struct xen_dm_op given by the guest is smaller than Xen's struct xen_dm_op. This is a problem because DMOP is meant to be a stable ABI but it breaks whenever the size of struct xen_dm_op changes. To fix this, change how the copying to and from the guest is done.