From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Xen-devel <xen-devel@lists.xen.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Subject: [PATCH v2 6/7] x86/alt: Drop explicit padding of origin sites
Date: Mon, 26 Feb 2018 11:35:03 +0000 [thread overview]
Message-ID: <1519644904-11349-7-git-send-email-andrew.cooper3@citrix.com> (raw)
In-Reply-To: <1519644904-11349-1-git-send-email-andrew.cooper3@citrix.com>
Now that the alternatives infrastructure can calculate the required padding
automatically, there is no need to hard code it.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
---
xen/arch/x86/x86_64/compat/entry.S | 2 +-
xen/arch/x86/x86_64/entry.S | 2 +-
xen/include/asm-x86/nops.h | 7 -------
xen/include/asm-x86/spec_ctrl_asm.h | 19 ++++++++-----------
4 files changed, 10 insertions(+), 20 deletions(-)
diff --git a/xen/arch/x86/x86_64/compat/entry.S b/xen/arch/x86/x86_64/compat/entry.S
index 8aba269..f650610 100644
--- a/xen/arch/x86/x86_64/compat/entry.S
+++ b/xen/arch/x86/x86_64/compat/entry.S
@@ -134,7 +134,7 @@ ENTRY(compat_restore_all_guest)
jne 1b
2:
.endm
- ALTERNATIVE_2 ".skip 45, 0x90", \
+ ALTERNATIVE_2 "", \
alt_cr4_pv32, X86_FEATURE_XEN_SMEP, \
alt_cr4_pv32, X86_FEATURE_XEN_SMAP
diff --git a/xen/arch/x86/x86_64/entry.S b/xen/arch/x86/x86_64/entry.S
index e939f20..cc94333 100644
--- a/xen/arch/x86/x86_64/entry.S
+++ b/xen/arch/x86/x86_64/entry.S
@@ -564,7 +564,7 @@ handle_exception_saved:
testb $X86_EFLAGS_IF>>8,UREGS_eflags+1(%rsp)
jz exception_with_ints_disabled
- ALTERNATIVE_2 "jmp .Lcr4_pv32_done; .skip 2, 0x90", \
+ ALTERNATIVE_2 "jmp .Lcr4_pv32_done", \
__stringify(mov VCPU_domain(%rbx), %rax), X86_FEATURE_XEN_SMEP, \
__stringify(mov VCPU_domain(%rbx), %rax), X86_FEATURE_XEN_SMAP
diff --git a/xen/include/asm-x86/nops.h b/xen/include/asm-x86/nops.h
index 61319cc..1a46b97 100644
--- a/xen/include/asm-x86/nops.h
+++ b/xen/include/asm-x86/nops.h
@@ -65,13 +65,6 @@
#define ASM_NOP8 _ASM_MK_NOP(P6_NOP8)
#define ASM_NOP9 _ASM_MK_NOP(P6_NOP9)
-#define ASM_NOP17 ASM_NOP8; ASM_NOP7; ASM_NOP2
-#define ASM_NOP21 ASM_NOP8; ASM_NOP8; ASM_NOP5
-#define ASM_NOP24 ASM_NOP8; ASM_NOP8; ASM_NOP8
-#define ASM_NOP29 ASM_NOP8; ASM_NOP8; ASM_NOP8; ASM_NOP5
-#define ASM_NOP32 ASM_NOP8; ASM_NOP8; ASM_NOP8; ASM_NOP8
-#define ASM_NOP40 ASM_NOP8; ASM_NOP8; ASM_NOP8; ASM_NOP8; ASM_NOP8
-
#define ASM_NOP_MAX 9
#endif /* __X86_ASM_NOPS_H__ */
diff --git a/xen/include/asm-x86/spec_ctrl_asm.h b/xen/include/asm-x86/spec_ctrl_asm.h
index 1f2b6f3..1623fc0 100644
--- a/xen/include/asm-x86/spec_ctrl_asm.h
+++ b/xen/include/asm-x86/spec_ctrl_asm.h
@@ -216,9 +216,8 @@
/* Use after a VMEXIT from an HVM guest. */
#define SPEC_CTRL_ENTRY_FROM_VMEXIT \
- ALTERNATIVE __stringify(ASM_NOP40), \
- DO_OVERWRITE_RSB, X86_FEATURE_RSB_VMEXIT; \
- ALTERNATIVE_2 __stringify(ASM_NOP32), \
+ ALTERNATIVE "", DO_OVERWRITE_RSB, X86_FEATURE_RSB_VMEXIT; \
+ ALTERNATIVE_2 "", \
__stringify(DO_SPEC_CTRL_ENTRY_FROM_VMEXIT \
ibrs_val=SPEC_CTRL_IBRS), \
X86_FEATURE_XEN_IBRS_SET, \
@@ -228,9 +227,8 @@
/* Use after an entry from PV context (syscall/sysenter/int80/int82/etc). */
#define SPEC_CTRL_ENTRY_FROM_PV \
- ALTERNATIVE __stringify(ASM_NOP40), \
- DO_OVERWRITE_RSB, X86_FEATURE_RSB_NATIVE; \
- ALTERNATIVE_2 __stringify(ASM_NOP21), \
+ ALTERNATIVE "", DO_OVERWRITE_RSB, X86_FEATURE_RSB_NATIVE; \
+ ALTERNATIVE_2 "", \
__stringify(DO_SPEC_CTRL_ENTRY maybexen=0 \
ibrs_val=SPEC_CTRL_IBRS), \
X86_FEATURE_XEN_IBRS_SET, \
@@ -239,9 +237,8 @@
/* Use in interrupt/exception context. May interrupt Xen or PV context. */
#define SPEC_CTRL_ENTRY_FROM_INTR \
- ALTERNATIVE __stringify(ASM_NOP40), \
- DO_OVERWRITE_RSB, X86_FEATURE_RSB_NATIVE; \
- ALTERNATIVE_2 __stringify(ASM_NOP29), \
+ ALTERNATIVE "", DO_OVERWRITE_RSB, X86_FEATURE_RSB_NATIVE; \
+ ALTERNATIVE_2 "", \
__stringify(DO_SPEC_CTRL_ENTRY maybexen=1 \
ibrs_val=SPEC_CTRL_IBRS), \
X86_FEATURE_XEN_IBRS_SET, \
@@ -250,13 +247,13 @@
/* Use when exiting to Xen context. */
#define SPEC_CTRL_EXIT_TO_XEN \
- ALTERNATIVE_2 __stringify(ASM_NOP17), \
+ ALTERNATIVE_2 "", \
DO_SPEC_CTRL_EXIT_TO_XEN, X86_FEATURE_XEN_IBRS_SET, \
DO_SPEC_CTRL_EXIT_TO_XEN, X86_FEATURE_XEN_IBRS_CLEAR
/* Use when exiting to guest context. */
#define SPEC_CTRL_EXIT_TO_GUEST \
- ALTERNATIVE_2 __stringify(ASM_NOP24), \
+ ALTERNATIVE_2 "", \
DO_SPEC_CTRL_EXIT_TO_GUEST, X86_FEATURE_XEN_IBRS_SET, \
DO_SPEC_CTRL_EXIT_TO_GUEST, X86_FEATURE_XEN_IBRS_CLEAR
--
2.1.4
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next prev parent reply other threads:[~2018-02-26 11:35 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-26 11:34 [PATCH RESEND v2 0/7] x86/alternatives: Support for automatic padding calculations Andrew Cooper
2018-02-26 11:34 ` [PATCH v2 1/7] x86/alt: Drop unused alternative infrastructure Andrew Cooper
2018-02-26 11:34 ` [PATCH v2 2/7] x86/alt: Clean up struct alt_instr and its users Andrew Cooper
2018-02-26 11:35 ` [PATCH v2 3/7] x86/alt: Clean up the assembly used to generate alternatives Andrew Cooper
2018-02-26 14:09 ` Roger Pau Monné
2018-02-28 15:59 ` Jan Beulich
2018-03-01 12:44 ` Wei Liu
2018-02-26 11:35 ` [PATCH v2 4/7] x86/asm: Remove opencoded uses of altinstruction_entry Andrew Cooper
2018-02-26 11:35 ` [PATCH v2 5/7] x86/alt: Support for automatic padding calculations Andrew Cooper
2018-02-28 16:16 ` Jan Beulich
2018-02-28 17:26 ` Andrew Cooper
2018-03-01 7:26 ` Jan Beulich
2018-02-26 11:35 ` Andrew Cooper [this message]
2018-02-26 11:35 ` [PATCH v2 7/7] x86/build: Use new .nop directive when available Andrew Cooper
2018-02-26 12:31 ` Roger Pau Monné
2018-02-26 13:08 ` Andrew Cooper
2018-02-26 14:27 ` Roger Pau Monné
2018-02-28 16:22 ` Jan Beulich
2018-02-28 17:45 ` Andrew Cooper
2018-03-01 7:28 ` Jan Beulich
2018-03-01 10:36 ` Roger Pau Monné
2018-03-01 10:54 ` Jan Beulich
2018-03-01 16:58 ` Andrew Cooper
2018-03-02 7:10 ` Jan Beulich
2018-03-02 19:34 ` Andrew Cooper
2018-03-05 8:33 ` Jan Beulich
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