[kvm-unit-tests PATCH v2 03/14] x86: Use X86_PROPERTY_MAX_VIRT_ADDR in is_canonical()

[Sean Christopherson <seanjc@google.com>]

Use X86_PROPERTY_MAX_VIRT_ADDR in is_canonical() instead of open coding a
*very* rough equivalent.  Default to a maximum virtual address width of
48 bits instead of 64 bits to better match real x86 CPUs (and Intel and
AMD architectures).

Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 lib/x86/processor.h | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/lib/x86/processor.h b/lib/x86/processor.h
index e6bd964f..10391cc0 100644
--- a/lib/x86/processor.h
+++ b/lib/x86/processor.h
@@ -1022,9 +1022,14 @@ static inline void write_pkru(u32 pkru)
 
 static inline bool is_canonical(u64 addr)
 {
-	int va_width = (raw_cpuid(0x80000008, 0).a & 0xff00) >> 8;
-	int shift_amt = 64 - va_width;
+	int va_width, shift_amt;
 
+	if (this_cpu_has_p(X86_PROPERTY_MAX_VIRT_ADDR))
+		va_width = this_cpu_property(X86_PROPERTY_MAX_VIRT_ADDR);
+	else
+		va_width = 48;
+
+	shift_amt = 64 - va_width;
 	return (s64)(addr << shift_amt) >> shift_amt == addr;
 }
 
-- 
2.50.0.rc0.642.g800a2b2222-goog