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From: Lara Lazier <laramglazier@gmail.com>
To: kvm@vger.kernel.org
Cc: pbonzini@redhat.com, Lara Lazier <laramglazier@gmail.com>
Subject: [PATCH kvm-unit-tests] x86: Added LA57 support to is_canonical
Date: Fri, 13 Aug 2021 13:18:33 +0200	[thread overview]
Message-ID: <20210813111833.42377-1-laramglazier@gmail.com> (raw)

In case LA57 is enabled, the function is_canonical would need to
check if the address is correctly sign-extended from bit 57 (instead of 48)
to bit 63.

Signed-off-by: Lara Lazier <laramglazier@gmail.com>
---
 lib/x86/processor.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/x86/processor.h b/lib/x86/processor.h
index a08ea1f..3b43fc4 100644
--- a/lib/x86/processor.h
+++ b/lib/x86/processor.h
@@ -640,7 +640,10 @@ static inline void write_pkru(u32 pkru)
 
 static inline bool is_canonical(u64 addr)
 {
-	return (s64)(addr << 16) >> 16 == addr;
+	int va_width = (raw_cpuid(0x80000008, 0).a & 0xff00) >> 8;
+	int shift_amt = 64 - va_width;
+
+	return (s64)(addr << shift_amt) >> shift_amt == addr;
 }
 
 static inline void clear_bit(int bit, u8 *addr)
-- 
2.25.1


             reply	other threads:[~2021-08-13 11:18 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-13 11:18 Lara Lazier [this message]
2021-08-13 11:29 ` [PATCH kvm-unit-tests] x86: Added LA57 support to is_canonical Paolo Bonzini

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