Re: [Xen-devel] [PATCH v3 1/2] x86/hvm: Always do SMAP check when updating runstate_guest(v)

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 29.07.14 at 10:13, <feng.wu@xxxxxxxxx> wrote:
>> From: Jan Beulich [mailto:JBeulich@xxxxxxxx]
>> >>> On 08.01.01 at 23:52, <feng.wu@xxxxxxxxx> wrote:
>> > @@ -446,13 +452,22 @@ struct arch_vcpu
>> >
>> >      /* A secondary copy of the vcpu time info. */
>> >      XEN_GUEST_HANDLE(vcpu_time_info_t) time_info_guest;
>> > +
>> > +    /*
>> > +     * The SMAP check policy when updating runstate_guest(v) and the
>> > +     * secondary system time.
>> > +     */
>> > +    smap_check_policy_t smap_check_policy;
>> >  } __cacheline_aligned;
>> 
>> ... and try to find a better place (current padding) in this structure?
> 
> Seems I cannot find a padding place in struct arch_vcpu, neither in struct 
> hvm_vcpu.

Here's the tail of struct arch_vcpu:

    uint64_t xcr0_accum;
    /* This variable determines whether nonlazy extended state has been used,
     * and thus should be saved/restored. */
    bool_t nonlazy_xstate_used;

    struct vmce vmce;

    struct paging_vcpu paging;

    uint32_t gdbsx_vcpu_event;

    /* A secondary copy of the vcpu time info. */
    XEN_GUEST_HANDLE(vcpu_time_info_t) time_info_guest;
} __cacheline_aligned;

Obviously there are gaps after both nonlazy_xstate_used and
gdbsx_vcpu_event.

Jan


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