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authorIngo Molnar <mingo@kernel.org>2019-11-25 11:09:27 +0300
committerIngo Molnar <mingo@kernel.org>2019-11-25 11:09:27 +0300
commitceb9e77324fa661b1001a0ae66f061b5fcb4e4e6 (patch)
treedce8c1a21347cd12b44ed56af4aafc2a58c9ec08 /tools/arch
parentc494cd6469ab0f4bdd663d1a2d396b0ec2f42103 (diff)
parent004e8dce9c5595697951f7cd0e9f66b35c92265e (diff)
downloadlinux-ceb9e77324fa661b1001a0ae66f061b5fcb4e4e6.tar.xz
Merge branch 'x86/core' into perf/core, to resolve conflicts and to pick up completed topic tree
Conflicts: tools/perf/check-headers.sh Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'tools/arch')
-rw-r--r--tools/arch/x86/include/asm/emulate_prefix.h14
-rw-r--r--tools/arch/x86/include/asm/insn.h6
-rw-r--r--tools/arch/x86/lib/insn.c34
3 files changed, 54 insertions, 0 deletions
diff --git a/tools/arch/x86/include/asm/emulate_prefix.h b/tools/arch/x86/include/asm/emulate_prefix.h
new file mode 100644
index 000000000000..70f5b98a5286
--- /dev/null
+++ b/tools/arch/x86/include/asm/emulate_prefix.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_EMULATE_PREFIX_H
+#define _ASM_X86_EMULATE_PREFIX_H
+
+/*
+ * Virt escape sequences to trigger instruction emulation;
+ * ideally these would decode to 'whole' instruction and not destroy
+ * the instruction stream; sadly this is not true for the 'kvm' one :/
+ */
+
+#define __XEN_EMULATE_PREFIX 0x0f,0x0b,0x78,0x65,0x6e /* ud2 ; .ascii "xen" */
+#define __KVM_EMULATE_PREFIX 0x0f,0x0b,0x6b,0x76,0x6d /* ud2 ; .ascii "kvm" */
+
+#endif
diff --git a/tools/arch/x86/include/asm/insn.h b/tools/arch/x86/include/asm/insn.h
index 37a4c390750b..568854b14d0a 100644
--- a/tools/arch/x86/include/asm/insn.h
+++ b/tools/arch/x86/include/asm/insn.h
@@ -45,6 +45,7 @@ struct insn {
struct insn_field immediate2; /* for 64bit imm or seg16 */
};
+ int emulate_prefix_size;
insn_attr_t attr;
unsigned char opnd_bytes;
unsigned char addr_bytes;
@@ -128,6 +129,11 @@ static inline int insn_is_evex(struct insn *insn)
return (insn->vex_prefix.nbytes == 4);
}
+static inline int insn_has_emulate_prefix(struct insn *insn)
+{
+ return !!insn->emulate_prefix_size;
+}
+
/* Ensure this instruction is decoded completely */
static inline int insn_complete(struct insn *insn)
{
diff --git a/tools/arch/x86/lib/insn.c b/tools/arch/x86/lib/insn.c
index 79e048f1d902..0151dfc6da61 100644
--- a/tools/arch/x86/lib/insn.c
+++ b/tools/arch/x86/lib/insn.c
@@ -13,6 +13,8 @@
#include "../include/asm/inat.h"
#include "../include/asm/insn.h"
+#include "../include/asm/emulate_prefix.h"
+
/* Verify next sizeof(t) bytes can be on the same instruction */
#define validate_next(t, insn, n) \
((insn)->next_byte + sizeof(t) + n <= (insn)->end_kaddr)
@@ -58,6 +60,36 @@ void insn_init(struct insn *insn, const void *kaddr, int buf_len, int x86_64)
insn->addr_bytes = 4;
}
+static const insn_byte_t xen_prefix[] = { __XEN_EMULATE_PREFIX };
+static const insn_byte_t kvm_prefix[] = { __KVM_EMULATE_PREFIX };
+
+static int __insn_get_emulate_prefix(struct insn *insn,
+ const insn_byte_t *prefix, size_t len)
+{
+ size_t i;
+
+ for (i = 0; i < len; i++) {
+ if (peek_nbyte_next(insn_byte_t, insn, i) != prefix[i])
+ goto err_out;
+ }
+
+ insn->emulate_prefix_size = len;
+ insn->next_byte += len;
+
+ return 1;
+
+err_out:
+ return 0;
+}
+
+static void insn_get_emulate_prefix(struct insn *insn)
+{
+ if (__insn_get_emulate_prefix(insn, xen_prefix, sizeof(xen_prefix)))
+ return;
+
+ __insn_get_emulate_prefix(insn, kvm_prefix, sizeof(kvm_prefix));
+}
+
/**
* insn_get_prefixes - scan x86 instruction prefix bytes
* @insn: &struct insn containing instruction
@@ -76,6 +108,8 @@ void insn_get_prefixes(struct insn *insn)
if (prefixes->got)
return;
+ insn_get_emulate_prefix(insn);
+
nb = 0;
lb = 0;
b = peek_next(insn_byte_t, insn);