ARM: KVM: perform save/restore of PAR

commit 6a077e4ab9cbfbf279fb955bae05b03781c97013 upstream.

Not saving PAR is an unfortunate oversight. If the guest performs
an AT* operation and gets scheduled out before reading the result
of the translation from PAR, it could become corrupted by another
guest or the host.

Saving this register is made slightly more complicated as KVM also
uses it on the permission fault handling path, leading to an ugly
"stash and restore" sequence. Fortunately, this is already a slow
path so we don't really care. Also, Linux doesn't do any AT*
operation, so Linux guests are not impacted by this bug.

  [ Slightly tweaked to use an even register as first operand to ldrd
    and strd operations in interrupts_head.S - Christoffer ]

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/arm/include/asm/kvm_asm.h b/arch/arm/include/asm/kvm_asm.h
index 18d5032..4bb08e3 100644
--- a/arch/arm/include/asm/kvm_asm.h
+++ b/arch/arm/include/asm/kvm_asm.h
@@ -37,16 +37,18 @@
 #define c5_AIFSR	15	/* Auxilary Instrunction Fault Status R */
 #define c6_DFAR		16	/* Data Fault Address Register */
 #define c6_IFAR		17	/* Instruction Fault Address Register */
-#define c9_L2CTLR	18	/* Cortex A15 L2 Control Register */
-#define c10_PRRR	19	/* Primary Region Remap Register */
-#define c10_NMRR	20	/* Normal Memory Remap Register */
-#define c12_VBAR	21	/* Vector Base Address Register */
-#define c13_CID		22	/* Context ID Register */
-#define c13_TID_URW	23	/* Thread ID, User R/W */
-#define c13_TID_URO	24	/* Thread ID, User R/O */
-#define c13_TID_PRIV	25	/* Thread ID, Privileged */
-#define c14_CNTKCTL	26	/* Timer Control Register (PL1) */
-#define NR_CP15_REGS	27	/* Number of regs (incl. invalid) */
+#define c7_PAR		18	/* Physical Address Register */
+#define c7_PAR_high	19	/* PAR top 32 bits */
+#define c9_L2CTLR	20	/* Cortex A15 L2 Control Register */
+#define c10_PRRR	21	/* Primary Region Remap Register */
+#define c10_NMRR	22	/* Normal Memory Remap Register */
+#define c12_VBAR	23	/* Vector Base Address Register */
+#define c13_CID		24	/* Context ID Register */
+#define c13_TID_URW	25	/* Thread ID, User R/W */
+#define c13_TID_URO	26	/* Thread ID, User R/O */
+#define c13_TID_PRIV	27	/* Thread ID, Privileged */
+#define c14_CNTKCTL	28	/* Timer Control Register (PL1) */
+#define NR_CP15_REGS	29	/* Number of regs (incl. invalid) */
 
 #define ARM_EXCEPTION_RESET	  0
 #define ARM_EXCEPTION_UNDEFINED   1