Re: [PATCH] x86/vhpet: Fix type size in timer_int_route_valid

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 28/07/2020 09:33, Eslam Elnikety wrote:
> The macro timer_int_route_cap evalutes to a 64 bit value. Extend the
> size of left side of timer_int_route_valid to match.
>
> This bug was discovered and resolved using Coverity Static Analysis
> Security Testing (SAST) by Synopsys, Inc.
>
> Signed-off-by: Eslam Elnikety <elnikety@amazon.com>
> ---
>  xen/arch/x86/hvm/hpet.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/xen/arch/x86/hvm/hpet.c b/xen/arch/x86/hvm/hpet.c
> index ca94e8b453..9afe6e6760 100644
> --- a/xen/arch/x86/hvm/hpet.c
> +++ b/xen/arch/x86/hvm/hpet.c
> @@ -66,7 +66,7 @@
>      MASK_EXTR(timer_config(h, n), HPET_TN_INT_ROUTE_CAP)
>  
>  #define timer_int_route_valid(h, n) \
> -    ((1u << timer_int_route(h, n)) & timer_int_route_cap(h, n))
> +    ((1ULL << timer_int_route(h, n)) & timer_int_route_cap(h, n))
>  
>  static inline uint64_t hpet_read_maincounter(HPETState *h, uint64_t guest_time)
>  {

Does this work?

diff --git a/xen/arch/x86/hvm/hpet.c b/xen/arch/x86/hvm/hpet.c
index ca94e8b453..638f6174de 100644
--- a/xen/arch/x86/hvm/hpet.c
+++ b/xen/arch/x86/hvm/hpet.c
@@ -62,8 +62,7 @@
 
 #define timer_int_route(h, n)    MASK_EXTR(timer_config(h, n),
HPET_TN_ROUTE)
 
-#define timer_int_route_cap(h, n) \
-    MASK_EXTR(timer_config(h, n), HPET_TN_INT_ROUTE_CAP)
+#define timer_int_route_cap(h, n) (h)->hpet.timers[(n)].route
 
 #define timer_int_route_valid(h, n) \
     ((1u << timer_int_route(h, n)) & timer_int_route_cap(h, n))
diff --git a/xen/include/asm-x86/hvm/vpt.h b/xen/include/asm-x86/hvm/vpt.h
index f0e0eaec83..a41fc443cc 100644
--- a/xen/include/asm-x86/hvm/vpt.h
+++ b/xen/include/asm-x86/hvm/vpt.h
@@ -73,7 +73,13 @@ struct hpet_registers {
     uint64_t isr;               /* interrupt status reg */
     uint64_t mc64;              /* main counter */
     struct {                    /* timers */
-        uint64_t config;        /* configuration/cap */
+        union {
+            uint64_t config;    /* configuration/cap */
+            struct {
+                uint32_t _;
+                uint32_t route;
+            };
+        };
         uint64_t cmp;           /* comparator */
         uint64_t fsb;           /* FSB route, not supported now */
     } timers[HPET_TIMER_NUM];