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From: Andy Lutomirski <luto@kernel.org>
To: X86 ML <x86@kernel.org>
Cc: KVM list <kvm@vger.kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	xen-devel <Xen-devel@lists.xen.org>,
	Andy Lutomirski <luto@kernel.org>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Arjan van de Ven <arjan@linux.intel.com>
Subject: [PATCH v3 4/5] x86/paravirt: Make "unsafe" MSR accesses unsafe even if PARAVIRT=y
Date: Fri, 11 Mar 2016 11:06:49 -0800	[thread overview]
Message-ID: <0462ae2bb67bf8f59eda24c37937744a20be862e.1457723023.git.luto__422.691790345375$1457723347$gmane$org@kernel.org> (raw)
In-Reply-To: <cover.1457723023.git.luto@kernel.org>
In-Reply-To: <cover.1457723023.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 68297d87e85c..0c99f10874e4 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -151,24 +151,21 @@ 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)
-- 
2.5.0


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  parent reply	other threads:[~2016-03-11 19:06 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <cover.1457723023.git.luto@kernel.org>
2016-03-11 19:06 ` [PATCH v3 1/5] x86/paravirt: Add _safe to the read_msr and write_msr PV hooks Andy Lutomirski
2016-03-11 19:06 ` [PATCH v3 2/5] x86/msr: Carry on after a non-"safe" MSR access fails without !panic_on_oops Andy Lutomirski
2016-03-11 19:06 ` [PATCH v3 3/5] x86/paravirt: Add paravirt_{read, write}_msr Andy Lutomirski
2016-03-11 19:06 ` Andy Lutomirski [this message]
2016-03-11 19:06 ` [PATCH v3 5/5] x86/msr: Set the return value to zero when native_rdmsr_safe fails Andy Lutomirski
     [not found] ` <35f2f107e0d85473a0e66c08f93d571a9c72b7fc.1457723023.git.luto@kernel.org>
2016-03-12 15:31   ` [PATCH v3 2/5] x86/msr: Carry on after a non-"safe" MSR access fails without !panic_on_oops Ingo Molnar
2016-03-12 15:36   ` Ingo Molnar
     [not found]   ` <20160312153615.GB17873@gmail.com>
2016-03-12 17:32     ` Andy Lutomirski
     [not found] ` <c7fb2aafd8a5885e9c333957abef9e29b691098e.1457723023.git.luto@kernel.org>
2016-03-14 14:02   ` [PATCH v3 3/5] x86/paravirt: Add paravirt_{read, write}_msr Paolo Bonzini
     [not found]   ` <56E6C492.5060308@redhat.com>
2016-03-14 16:53     ` Andy Lutomirski
2016-03-14 16:58       ` Linus Torvalds
2016-03-14 17:02         ` Andy Lutomirski
     [not found]         ` <CALCETrWYmJdOeHqjR6-Uyqiyym35DOjFpsB1xhgTHO_JB==EMA@mail.gmail.com>
2016-03-15  8:49           ` Paolo Bonzini
2016-03-15  8:56       ` Paolo Bonzini

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