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

From: Radim KrÄmÃÅ
Date: Fri Oct 30 2015 - 11:38:01 EST


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 KrÄmÃÅ <rkrcmar@xxxxxxxxxx>
---
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

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/