[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH 2/3] xen/privcmd: Add IOCTL_PRIVCMD_DM_OP
On 09/02/17 16:03, Jan Beulich wrote: >>>> On 09.02.17 at 16:56, <andrew.cooper3@xxxxxxxxxx> wrote: >> On 09/02/17 15:50, Boris Ostrovsky wrote: >>> >>> On 02/09/2017 09:27 AM, Paul Durrant wrote: >>>>> -----Original Message----- >>>>> From: Paul Durrant [mailto:paul.durrant@xxxxxxxxxx] >>>>> Sent: 09 February 2017 14:18 >>>>> To: xen-devel@xxxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx >>>>> Cc: Paul Durrant <Paul.Durrant@xxxxxxxxxx>; Boris Ostrovsky >>>>> <boris.ostrovsky@xxxxxxxxxx>; Juergen Gross <jgross@xxxxxxxx> >>>>> Subject: [PATCH 2/3] xen/privcmd: Add IOCTL_PRIVCMD_DM_OP >>>>> >>>>> Recently a new dm_op[1] hypercall was added to Xen to provide a >>>>> mechanism >>>>> for restricting device emulators (such as QEMU) to a limited set of >>>>> hypervisor operations, and being able to audit those operations in the >>>>> kernel of the domain in which they run. >>>>> >>>>> This patch adds IOCTL_PRIVCMD_DM_OP as gateway for >>>>> __HYPERVISOR_dm_op, >>>>> bouncing the callers buffers through kernel memory to allow the address >>>>> ranges to be audited (and negating the need to bounce through locked >>>>> memory in user-space). >>>> Actually, it strikes me (now that I've posted the patch) that I >>>> should probably just mlock the user buffers rather than bouncing them >>>> through kernel... Anyway, I'd still appreciate review on other >>>> aspects of the patch. >>> >>> Are you suggesting that the caller (user) mlocks the buffers? >> Doesn't libxc already use the hypercall buffer API for each of the buffers? >> >> The kernel oughtn’t to need to do anything special to the user pointers >> it has, other than call access_ok() on them. > And translate 32-bit layout to 64-bit for a compat caller. Ah yes (although that looks to be done suitably in the patch as presented). ~Andrew _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx https://lists.xen.org/xen-devel
|
![]() |
Lists.xenproject.org is hosted with RackSpace, monitoring our |