Re: [Xen-devel] [PATCH v4 3/7] x86/HVM: introduce "curr" into hvmemul_rep_{mov, sto}s()

["Durrant, Paul" <pdurrant@xxxxxxxxxxxx>]

> -----Original Message-----
> From: Xen-devel <xen-devel-bounces@xxxxxxxxxxxxxxxxxxxx> On Behalf Of Jan
> Beulich
> Sent: 31 January 2020 16:43
> To: xen-devel@xxxxxxxxxxxxxxxxxxxx
> Cc: George Dunlap <George.Dunlap@xxxxxxxxxxxxx>; Andrew Cooper
> <andrew.cooper3@xxxxxxxxxx>; Roger Pau Monné <roger.pau@xxxxxxxxxx>; Wei
> Liu <wl@xxxxxxx>; Paul Durrant <paul@xxxxxxx>
> Subject: [Xen-devel] [PATCH v4 3/7] x86/HVM: introduce "curr" into
> hvmemul_rep_{mov, sto}s()
> 
> There are a number of uses of "current" already, and more may appear
> down the road. Latch into a local variable.
> 
> At this occasion also drop stray casts from code getting touched anyway.
> 
> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

Reviewed-by: Paul Durrant <pdurrant@xxxxxxxxxx>

...with one suggestion:

> ---
> v4: New.
> 
> --- a/xen/arch/x86/hvm/emulate.c
> +++ b/xen/arch/x86/hvm/emulate.c
> @@ -1747,7 +1747,8 @@ static int hvmemul_rep_movs(
>  {
>      struct hvm_emulate_ctxt *hvmemul_ctxt =
>          container_of(ctxt, struct hvm_emulate_ctxt, ctxt);
> -    struct hvm_vcpu_io *vio = &current->arch.hvm.hvm_io;
> +    struct vcpu *curr = current;
> +    struct hvm_vcpu_io *vio = &curr->arch.hvm.hvm_io;
>      unsigned long saddr, daddr, bytes;
>      paddr_t sgpa, dgpa;
>      uint32_t pfec = PFEC_page_present;
> @@ -1807,8 +1808,8 @@ static int hvmemul_rep_movs(
>      }
> 
>      /* Check for MMIO ops */
> -    (void) get_gfn_query_unlocked(current->domain, sgpa >> PAGE_SHIFT,
> &sp2mt);
> -    (void) get_gfn_query_unlocked(current->domain, dgpa >> PAGE_SHIFT,
> &dp2mt);
> +    get_gfn_query_unlocked(curr->domain, sgpa >> PAGE_SHIFT, &sp2mt);
> +    get_gfn_query_unlocked(curr->domain, dgpa >> PAGE_SHIFT, &dp2mt);

Since we have more than one 'curr->domain', I think it would be nice to a 
latched 'currd' domain pointer too.

  Paul

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel