x86/boot: Support the watchdog on newer AMD systems

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 25
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@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: 131892e0dcc1265b621c2b7d844cb9e7c3a4404f
master date: 2024-03-19 18:29:37 +0000

diff --git a/xen/arch/x86/nmi.c b/xen/arch/x86/nmi.c
index dd31034ac8d7d184e4913ef988227e2e34462498..c7c51614a619e1159e71c94995c7274a1320e15f 100644 (file)
--- a/xen/arch/x86/nmi.c
+++ b/xen/arch/x86/nmi.c
@@ -386,15 +386,12 @@ 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: