linux-kernel - [PATCH 2/3] KVM: x86: handle SMBASE as physical address in RSM

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Message-Id: <1446219386-23937-3-git-send-email-rkrcmar@redhat.com>
Date:	Fri, 30 Oct 2015 16:36:25 +0100
From:	Radim Krčmář <rkrcmar@...hat.com>
To:	linux-kernel@...r.kernel.org
Cc:	kvm@...r.kernel.org, Paolo Bonzini <pbonzini@...hat.com>,
	Laszlo Ersek <lersek@...hat.com>
Subject: [PATCH 2/3] KVM: x86: handle SMBASE as physical address in RSM

GET_SMSTATE depends on real mode to ensure that smbase+offset is treated
as a physical address, which has already caused a bug after shuffling
the code.  Enforce physical addressing.

Signed-off-by: Radim Krčmář <rkrcmar@...hat.com>
---
 arch/x86/kvm/emulate.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 25e16b6f6ffa..59e80e0de865 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -2272,8 +2272,8 @@ static int emulator_has_longmode(struct x86_emulate_ctxt *ctxt)
 #define GET_SMSTATE(type, smbase, offset)				  \
 	({								  \
 	 type __val;							  \
-	 int r = ctxt->ops->read_std(ctxt, smbase + offset, &__val,       \
-				     sizeof(__val), NULL);		  \
+	 int r = ctxt->ops->read_phys(ctxt, smbase + offset, &__val,      \
+				      sizeof(__val));			  \
 	 if (r != X86EMUL_CONTINUE)					  \
 		 return X86EMUL_UNHANDLEABLE;				  \
 	 __val;								  \
@@ -2507,8 +2507,7 @@ static int em_rsm(struct x86_emulate_ctxt *ctxt)
 
 	/*
 	 * Get back to real mode, to prepare a safe state in which to load
-	 * CR0/CR3/CR4/EFER.  Also this will ensure that addresses passed
-	 * to read_std/write_std are not virtual.
+	 * CR0/CR3/CR4/EFER.
 	 *
 	 * CR4.PCIDE must be zero, because it is a 64-bit mode only feature.
 	 */
-- 
2.5.3

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