ia64/pv_ops: paravirtualized instruction checker.

This patch implements a checker to detect instructions which
should be paravirtualized instead of direct writing raw instruction.
This patch does rough check so that it doesn't fully cover all cases,
but it can detects most cases of paravirtualization breakage of hand
written assembly codes.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>

4 files changed, 316 insertions, 1 deletions

diff --git a/arch/ia64/include/asm/native/pvchk_inst.h b/arch/ia64/include/asm/native/pvchk_inst.h
new file mode 100644
index 000000000000..b8e6eb1090d7
--- /dev/null
+++ b/arch/ia64/include/asm/native/pvchk_inst.h
@@ -0,0 +1,263 @@
+#ifndef _ASM_NATIVE_PVCHK_INST_H
+#define _ASM_NATIVE_PVCHK_INST_H
+
+/******************************************************************************
+ * arch/ia64/include/asm/native/pvchk_inst.h
+ * Checker for paravirtualizations of privileged operations.
+ *
+ * Copyright (C) 2005 Hewlett-Packard Co
+ *      Dan Magenheimer <dan.magenheimer@hp.com>
+ *
+ * Copyright (c) 2008 Isaku Yamahata <yamahata at valinux co jp>
+ *                    VA Linux Systems Japan K.K.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+/**********************************************
+ * Instructions paravirtualized for correctness
+ **********************************************/
+
+/* "fc" and "thash" are privilege-sensitive instructions, meaning they
+ *  may have different semantics depending on whether they are executed
+ *  at PL0 vs PL!=0.  When paravirtualized, these instructions mustn't
+ *  be allowed to execute directly, lest incorrect semantics result.
+ */
+
+#define fc      .error "fc should not be used directly."
+#define thash   .error "thash should not be used directly."
+
+/* Note that "ttag" and "cover" are also privilege-sensitive; "ttag"
+ * is not currently used (though it may be in a long-format VHPT system!)
+ * and the semantics of cover only change if psr.ic is off which is very
+ * rare (and currently non-existent outside of assembly code
+ */
+#define ttag    .error "ttag should not be used directly."
+#define cover   .error "cover should not be used directly."
+
+/* There are also privilege-sensitive registers.  These registers are
+ * readable at any privilege level but only writable at PL0.
+ */
+#define cpuid   .error "cpuid should not be used directly."
+#define pmd     .error "pmd should not be used directly."
+
+/*
+ * mov ar.eflag =
+ * mov = ar.eflag
+ */
+
+/**********************************************
+ * Instructions paravirtualized for performance
+ **********************************************/
+/*
+ * Those instructions include '.' which can't be handled by cpp.
+ * or can't be handled by cpp easily.
+ * They are handled by sed instead of cpp.
+ */
+
+/* for .S
+ * itc.i
+ * itc.d
+ *
+ * bsw.0
+ * bsw.1
+ *
+ * ssm psr.ic | PSR_DEFAULT_BITS
+ * ssm psr.ic
+ * rsm psr.ic
+ * ssm psr.i
+ * rsm psr.i
+ * rsm psr.i | psr.ic
+ * rsm psr.dt
+ * ssm psr.dt
+ *
+ * mov = cr.ifa
+ * mov = cr.itir
+ * mov = cr.isr
+ * mov = cr.iha
+ * mov = cr.ipsr
+ * mov = cr.iim
+ * mov = cr.iip
+ * mov = cr.ivr
+ * mov = psr
+ *
+ * mov cr.ifa =
+ * mov cr.itir =
+ * mov cr.iha =
+ * mov cr.ipsr =
+ * mov cr.ifs =
+ * mov cr.iip =
+ * mov cr.kr =
+ */
+
+/* for intrinsics
+ * ssm psr.i
+ * rsm psr.i
+ * mov = psr
+ * mov = ivr
+ * mov = tpr
+ * mov cr.itm =
+ * mov eoi =
+ * mov rr[] =
+ * mov = rr[]
+ * mov = kr
+ * mov kr =
+ * ptc.ga
+ */
+
+/*************************************************************
+ * define paravirtualized instrcution macros as nop to ingore.
+ * and check whether arguments are appropriate.
+ *************************************************************/
+
+/* check whether reg is a regular register */
+.macro is_rreg_in reg
+        .ifc "\reg", "r0"
+                nop 0
+                .exitm
+        .endif
+        ;;
+        mov \reg = r0
+        ;;
+.endm
+#define IS_RREG_IN(reg) is_rreg_in reg ;
+
+#define IS_RREG_OUT(reg)                        \
+        ;;                                      \
+        mov reg = r0                            \
+        ;;
+
+#define IS_RREG_CLOB(reg)       IS_RREG_OUT(reg)
+
+/* check whether pred is a predicate register */
+#define IS_PRED_IN(pred)                        \
+        ;;                                      \
+        (pred)  nop 0                           \
+        ;;
+
+#define IS_PRED_OUT(pred)                       \
+        ;;                                      \
+        cmp.eq pred, p0 = r0, r0                \
+        ;;
+
+#define IS_PRED_CLOB(pred)      IS_PRED_OUT(pred)
+
+
+#define DO_SAVE_MIN(__COVER, SAVE_IFS, EXTRA, WORKAROUND)       \
+        nop 0
+#define MOV_FROM_IFA(reg)                       \
+        IS_RREG_OUT(reg)
+#define MOV_FROM_ITIR(reg)                      \
+        IS_RREG_OUT(reg)
+#define MOV_FROM_ISR(reg)                       \
+        IS_RREG_OUT(reg)
+#define MOV_FROM_IHA(reg)                       \
+        IS_RREG_OUT(reg)
+#define MOV_FROM_IPSR(pred, reg)                \
+        IS_PRED_IN(pred)                        \
+        IS_RREG_OUT(reg)
+#define MOV_FROM_IIM(reg)                       \
+        IS_RREG_OUT(reg)
+#define MOV_FROM_IIP(reg)                       \
+        IS_RREG_OUT(reg)
+#define MOV_FROM_IVR(reg, clob)                 \
+        IS_RREG_OUT(reg)                        \
+        IS_RREG_CLOB(clob)
+#define MOV_FROM_PSR(pred, reg, clob)           \
+        IS_PRED_IN(pred)                        \
+        IS_RREG_OUT(reg)                        \
+        IS_RREG_CLOB(clob)
+#define MOV_TO_IFA(reg, clob)                   \
+        IS_RREG_IN(reg)                         \
+        IS_RREG_CLOB(clob)
+#define MOV_TO_ITIR(pred, reg, clob)            \
+        IS_PRED_IN(pred)                        \
+        IS_RREG_IN(reg)                         \
+        IS_RREG_CLOB(clob)
+#define MOV_TO_IHA(pred, reg, clob)             \
+        IS_PRED_IN(pred)                        \
+        IS_RREG_IN(reg)                         \
+        IS_RREG_CLOB(clob)
+#define MOV_TO_IPSR(pred, reg, clob)            \
+        IS_PRED_IN(pred)                        \
+        IS_RREG_IN(reg)                         \
+        IS_RREG_CLOB(clob)
+#define MOV_TO_IFS(pred, reg, clob)             \
+        IS_PRED_IN(pred)                        \
+        IS_RREG_IN(reg)                         \
+        IS_RREG_CLOB(clob)
+#define MOV_TO_IIP(reg, clob)                   \
+        IS_RREG_IN(reg)                         \
+        IS_RREG_CLOB(clob)
+#define MOV_TO_KR(kr, reg, clob0, clob1)        \
+        IS_RREG_IN(reg)                         \
+        IS_RREG_CLOB(clob0)                     \
+        IS_RREG_CLOB(clob1)
+#define ITC_I(pred, reg, clob)                  \
+        IS_PRED_IN(pred)                        \
+        IS_RREG_IN(reg)                         \
+        IS_RREG_CLOB(clob)
+#define ITC_D(pred, reg, clob)                  \
+        IS_PRED_IN(pred)                        \
+        IS_RREG_IN(reg)                         \
+        IS_RREG_CLOB(clob)
+#define ITC_I_AND_D(pred_i, pred_d, reg, clob)  \
+        IS_PRED_IN(pred_i)                      \
+        IS_PRED_IN(pred_d)                      \
+        IS_RREG_IN(reg)                         \
+        IS_RREG_CLOB(clob)
+#define THASH(pred, reg0, reg1, clob)           \
+        IS_PRED_IN(pred)                        \
+        IS_RREG_OUT(reg0)                       \
+        IS_RREG_IN(reg1)                        \
+        IS_RREG_CLOB(clob)
+#define SSM_PSR_IC_AND_DEFAULT_BITS_AND_SRLZ_I(clob0, clob1)    \
+        IS_RREG_CLOB(clob0)                                     \
+        IS_RREG_CLOB(clob1)
+#define SSM_PSR_IC_AND_SRLZ_D(clob0, clob1)     \
+        IS_RREG_CLOB(clob0)                     \
+        IS_RREG_CLOB(clob1)
+#define RSM_PSR_IC(clob)                        \
+        IS_RREG_CLOB(clob)
+#define SSM_PSR_I(pred, pred_clob, clob)        \
+        IS_PRED_IN(pred)                        \
+        IS_PRED_CLOB(pred_clob)                 \
+        IS_RREG_CLOB(clob)
+#define RSM_PSR_I(pred, clob0, clob1)           \
+        IS_PRED_IN(pred)                        \
+        IS_RREG_CLOB(clob0)                     \
+        IS_RREG_CLOB(clob1)
+#define RSM_PSR_I_IC(clob0, clob1, clob2)       \
+        IS_RREG_CLOB(clob0)                     \
+        IS_RREG_CLOB(clob1)                     \
+        IS_RREG_CLOB(clob2)
+#define RSM_PSR_DT                              \
+        nop 0
+#define SSM_PSR_DT_AND_SRLZ_I                   \
+        nop 0
+#define BSW_0(clob0, clob1, clob2)              \
+        IS_RREG_CLOB(clob0)                     \
+        IS_RREG_CLOB(clob1)                     \
+        IS_RREG_CLOB(clob2)
+#define BSW_1(clob0, clob1)                     \
+        IS_RREG_CLOB(clob0)                     \
+        IS_RREG_CLOB(clob1)
+#define COVER                                   \
+        nop 0
+#define RFI                                     \
+        br.ret.sptk.many rp /* defining nop causes dependency error */
+
+#endif /* _ASM_NATIVE_PVCHK_INST_H */
diff --git a/arch/ia64/kernel/Makefile b/arch/ia64/kernel/Makefile
index 87fea11aecb7..55e6ca8eebda 100644
--- a/arch/ia64/kernel/Makefile
+++ b/arch/ia64/kernel/Makefile
@@ -112,5 +112,23 @@ clean-files += $(objtree)/include/asm-ia64/nr-irqs.h
 ASM_PARAVIRT_OBJS = ivt.o entry.o
 define paravirtualized_native
 AFLAGS_$(1) += -D__IA64_ASM_PARAVIRTUALIZED_NATIVE
+AFLAGS_pvchk-sed-$(1) += -D__IA64_ASM_PARAVIRTUALIZED_PVCHECK
+extra-y += pvchk-$(1)
 endef
 $(foreach obj,$(ASM_PARAVIRT_OBJS),$(eval $(call paravirtualized_native,$(obj))))
+
+#
+# Checker for paravirtualizations of privileged operations.
+#
+quiet_cmd_pv_check_sed = PVCHK   $@
+define cmd_pv_check_sed
+        sed -f $(srctree)/arch/$(SRCARCH)/scripts/pvcheck.sed $< > $@
+endef
+
+$(obj)/pvchk-sed-%.s: $(src)/%.S $(srctree)/arch/$(SRCARCH)/scripts/pvcheck.sed FORCE
+        $(call if_changed_dep,as_s_S)
+$(obj)/pvchk-%.s: $(obj)/pvchk-sed-%.s FORCE
+        $(call if_changed,pv_check_sed)
+$(obj)/pvchk-%.o: $(obj)/pvchk-%.s FORCE
+        $(call if_changed,as_o_S)
+.PRECIOUS: $(obj)/pvchk-sed-%.s $(obj)/pvchk-%.s $(obj)/pvchk-%.o
diff --git a/arch/ia64/kernel/paravirt_inst.h b/arch/ia64/kernel/paravirt_inst.h
index 5cad6fb2ed19..64d6d810c64b 100644
--- a/arch/ia64/kernel/paravirt_inst.h
+++ b/arch/ia64/kernel/paravirt_inst.h
@@ -20,7 +20,9 @@
  *
  */
 
-#ifdef __IA64_ASM_PARAVIRTUALIZED_XEN
+#ifdef __IA64_ASM_PARAVIRTUALIZED_PVCHECK
+#include <asm/native/pvchk_inst.h>
+#elif defined(__IA64_ASM_PARAVIRTUALIZED_XEN)
 #include <asm/xen/inst.h>
 #include <asm/xen/minstate.h>
 #else
diff --git a/arch/ia64/scripts/pvcheck.sed b/arch/ia64/scripts/pvcheck.sed
new file mode 100644
index 000000000000..ba66ac2e4c60
--- /dev/null
+++ b/arch/ia64/scripts/pvcheck.sed
@@ -0,0 +1,32 @@
+#
+# Checker for paravirtualizations of privileged operations.
+#
+s/ssm.*psr\.ic.*/.warning \"ssm psr.ic should not be used directly\"/g
+s/rsm.*psr\.ic.*/.warning \"rsm psr.ic should not be used directly\"/g
+s/ssm.*psr\.i.*/.warning \"ssm psr.i should not be used directly\"/g
+s/rsm.*psr\.i.*/.warning \"rsm psr.i should not be used directly\"/g
+s/ssm.*psr\.dt.*/.warning \"ssm psr.dt should not be used directly\"/g
+s/rsm.*psr\.dt.*/.warning \"rsm psr.dt should not be used directly\"/g
+s/mov.*=.*cr\.ifa/.warning \"cr.ifa should not used directly\"/g
+s/mov.*=.*cr\.itir/.warning \"cr.itir should not used directly\"/g
+s/mov.*=.*cr\.isr/.warning \"cr.isr should not used directly\"/g
+s/mov.*=.*cr\.iha/.warning \"cr.iha should not used directly\"/g
+s/mov.*=.*cr\.ipsr/.warning \"cr.ipsr should not used directly\"/g
+s/mov.*=.*cr\.iim/.warning \"cr.iim should not used directly\"/g
+s/mov.*=.*cr\.iip/.warning \"cr.iip should not used directly\"/g
+s/mov.*=.*cr\.ivr/.warning \"cr.ivr should not used directly\"/g
+s/mov.*=[^\.]*psr/.warning \"psr should not used directly\"/g   # avoid ar.fpsr
+s/mov.*=.*ar\.eflags/.warning \"ar.eflags should not used directly\"/g
+s/mov.*cr\.ifa.*=.*/.warning \"cr.ifa should not used directly\"/g
+s/mov.*cr\.itir.*=.*/.warning \"cr.itir should not used directly\"/g
+s/mov.*cr\.iha.*=.*/.warning \"cr.iha should not used directly\"/g
+s/mov.*cr\.ipsr.*=.*/.warning \"cr.ipsr should not used directly\"/g
+s/mov.*cr\.ifs.*=.*/.warning \"cr.ifs should not used directly\"/g
+s/mov.*cr\.iip.*=.*/.warning \"cr.iip should not used directly\"/g
+s/mov.*cr\.kr.*=.*/.warning \"cr.kr should not used directly\"/g
+s/mov.*ar\.eflags.*=.*/.warning \"ar.eflags should not used directly\"/g
+s/itc\.i.*/.warning \"itc.i should not be used directly.\"/g
+s/itc\.d.*/.warning \"itc.d should not be used directly.\"/g
+s/bsw\.0/.warning \"bsw.0 should not be used directly.\"/g
+s/bsw\.1/.warning \"bsw.1 should not be used directly.\"/g
+s/ptc\.ga.*/.warning \"ptc.ga should not be used directly.\"/g