[PATCH 2/2] x86/boot: Support the watchdog on newer AMD systems

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

The MSRs used by setup_k7_watchdog() are architectural in 64bit.  The Unit
Select (0x76, cycles not in halt state) isn't, but it hasn't changed in 23
years, making this a trend likely to continue.

Drop the family check.  If the Unit Select does happen to change meaning in
the future, check_nmi_watchdog() will still notice the watchdog not operating
as expected.

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: Jan Beulich <JBeulich@xxxxxxxx>
CC: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
 xen/arch/x86/nmi.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/xen/arch/x86/nmi.c b/xen/arch/x86/nmi.c
index 33f77a92047f..f6329cb0270e 100644
--- a/xen/arch/x86/nmi.c
+++ b/xen/arch/x86/nmi.c
@@ -387,15 +387,12 @@ void setup_apic_nmi_watchdog(void)
     if ( nmi_watchdog == NMI_NONE )
         return;
 
-    switch (boot_cpu_data.x86_vendor) {
+    switch ( boot_cpu_data.x86_vendor )
+    {
     case X86_VENDOR_AMD:
-        switch (boot_cpu_data.x86) {
-        case 6:
-        case 0xf ... 0x19:
-            setup_k7_watchdog();
-            break;
-        }
+        setup_k7_watchdog();
         break;
+
     case X86_VENDOR_INTEL:
         switch (boot_cpu_data.x86) {
         case 6:
-- 
2.30.2