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From: Andy Lutomirski <luto@kernel.org>
To: x86@kernel.org
Cc: Paolo Bonzini <pbonzini@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	KVM list <kvm@vger.kernel.org>,
	Arjan van de Ven <arjan@linux.intel.com>,
	xen-devel <Xen-devel@lists.xen.org>,
	linux-kernel@vger.kernel.org, Andy Lutomirski <luto@kernel.org>
Subject: [PATCH 3/3] x86/paravirt: Make "unsafe" MSR accesses unsafe even if PARAVIRT=y
Date: Wed, 16 Sep 2015 16:33:14 -0700	[thread overview]
Message-ID: <feb46beb7ad7c692f8ede2d68f29a2926bd5bac9.1442445946.git.luto@kernel.org> (raw)
In-Reply-To: <cover.1442445946.git.luto@kernel.org>
In-Reply-To: <cover.1442445946.git.luto@kernel.org>

Enabling CONFIG_PARAVIRT had an unintended side effect: rdmsr turned
into rdmsr_safe and wrmsr turned into wrmsr_safe, even on bare
metal.  Undo that by using the new unsafe paravirt MSR hooks.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
 arch/x86/include/asm/paravirt.h | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index e6569a3b0a37..f61975a3ccfd 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -145,24 +145,21 @@ static inline int paravirt_write_msr_safe(unsigned msr,
 	return PVOP_CALL3(int, pv_cpu_ops.write_msr_safe, msr, low, high);
 }
 
-/* These should all do BUG_ON(_err), but our headers are too tangled. */
 #define rdmsr(msr, val1, val2)			\
 do {						\
-	int _err;				\
-	u64 _l = paravirt_read_msr_safe(msr, &_err);	\
+	u64 _l = paravirt_read_msr(msr);	\
 	val1 = (u32)_l;				\
 	val2 = _l >> 32;			\
 } while (0)
 
 #define wrmsr(msr, val1, val2)			\
 do {						\
-	paravirt_write_msr_safe(msr, val1, val2);	\
+	paravirt_write_msr(msr, val1, val2);	\
 } while (0)
 
 #define rdmsrl(msr, val)			\
 do {						\
-	int _err;				\
-	val = paravirt_read_msr_safe(msr, &_err);	\
+	val = paravirt_read_msr(msr);		\
 } while (0)
 
 static inline void wrmsrl(unsigned msr, u64 val)
-- 
2.4.3


  parent reply	other threads:[~2015-09-16 23:33 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-09-16 23:33 [PATCH 0/3] x86/paravirt: Fix baremetal paravirt MSR ops Andy Lutomirski
2015-09-16 23:33 ` [PATCH 1/3] x86/paravirt: Add _safe to the read_msr and write_msr PV hooks Andy Lutomirski
2015-09-16 23:33 ` [PATCH 2/3] x86/paravirt: Add paravirt_{read,write}_msr Andy Lutomirski
2015-09-16 23:33 ` Andy Lutomirski [this message]
2015-09-17  7:19 ` [PATCH 0/3] x86/paravirt: Fix baremetal paravirt MSR ops Ingo Molnar
2015-09-17  9:31   ` Borislav Petkov
2015-09-17 11:22     ` H. Peter Anvin
2015-09-17 11:39     ` Paolo Bonzini
2015-09-17 15:27       ` Borislav Petkov
2015-09-17 15:32         ` [Xen-devel] " Andrew Cooper
2015-09-17 15:37           ` Borislav Petkov
2015-09-17 15:23   ` Andy Lutomirski
2015-09-17 15:27     ` Arjan van de Ven
2015-09-17 15:29       ` Paolo Bonzini
2015-09-17 15:31         ` Arjan van de Ven
2015-09-17 15:33           ` Paolo Bonzini
2015-09-17 17:30     ` Ingo Molnar
2015-09-17 18:51       ` Andy Lutomirski
2015-09-17  8:58 ` Peter Zijlstra
2015-09-17 11:40   ` Paolo Bonzini
2015-09-17 12:27     ` Peter Zijlstra
2015-09-17 15:17       ` Andy Lutomirski
2015-09-17 15:17         ` Peter Zijlstra
2015-09-17 15:26           ` Andy Lutomirski
2015-09-17 15:29             ` Paolo Bonzini
2015-09-17  9:10 ` [Xen-devel] " Andrew Cooper
2015-09-17 15:11   ` Boris Ostrovsky

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