Hypercall detection is failing with xen_hypercall_intel() chosen even on
an AMD processor. Looking at the disassembly, the call to
xen_get_vendor() was removed.
The check for boot_cpu_has(X86_FEATURE_CPUID) was used as a proxy for
the x86_vendor having been set. When
CONFIG_X86_REQUIRED_FEATURE_CPUID=y (the default value), DCE eliminates
the call to xen_get_vendor(). An uninitialized value 0 means
X86_VENDOR_INTEL, so the Intel function is always returned.
Remove the if and always call xen_get_vendor() to avoid this issue.
Fixes: 3d37d9396eb3 ("x86/cpufeatures: Add {REQUIRED,DISABLED} feature configs")
Suggested-by: Juergen Gross <jgr...@suse.com>
Signed-off-by: Jason Andryuk <jason.andr...@amd.com>
---
I think the Fixes is correct in that it default enables requiring the
feature. There were a lot of other changes to how headers were
generated as well.
---
arch/x86/xen/enlighten.c | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 43dcd8c7badc..6a5cae915eb1 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -100,10 +100,6 @@ noinstr void *__xen_hypercall_setfunc(void)
void (*func)(void);
/*
- * Xen is supported only on CPUs with CPUID, so testing for
- * X86_FEATURE_CPUID is a test for early_cpu_init() having been
- * run.
- *
* Note that __xen_hypercall_setfunc() is noinstr only due to a nasty
* dependency chain: it is being called via the xen_hypercall static
* call when running as a PVH or HVM guest. Hypercalls need to be
@@ -115,8 +111,7 @@ noinstr void *__xen_hypercall_setfunc(void)
*/
instrumentation_begin();
- if (!boot_cpu_has(X86_FEATURE_CPUID))
- xen_get_vendor();
+ xen_get_vendor();
if ((boot_cpu_data.x86_vendor == X86_VENDOR_AMD ||
boot_cpu_data.x86_vendor == X86_VENDOR_HYGON))
--
2.34.1
