Re: [Xen-devel] [PATCH v1 1/2] x86/vvmx: check vmcs address in vmread/vmwrite

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 01.03.17 at 15:22, <sergey.dyasli@xxxxxxxxxx> wrote:
> On Wed, 2017-03-01 at 07:04 -0700, Jan Beulich wrote:
>> > > > On 01.03.17 at 14:44, <sergey.dyasli@xxxxxxxxxx> wrote:
>> > Additionally, it would be painful to return the correct error value
>> > all the way back to nvmx_handle_vmptrld().
>> 
>> Surely that's at best relevant in the other patch. Here you're in
>> virtual_vmcs_vmwrite_safe(), which already knows how to
>> communicate back an error indicator.
> 
> How checking the return value of virtual_vmcs_enter() is different
> from checking nv_vvmcxaddr?

Checking the address is just one step. As the other patch shows,
checking the ID is necessary too. Over time more such checks may
be found necessary. Checking what hardware hands us is a single
check, and is always going to be sufficient no matter what new
features get added to hardware.

Jan


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel