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authorPeter Zijlstra <peterz@infradead.org>2022-03-21 12:57:51 +0300
committerPeter Zijlstra <peterz@infradead.org>2022-03-22 23:12:14 +0300
commitb9067cd80fbc5b3ae061e5bde6efd19bbf02f9e2 (patch)
treefdaaed7ef09b95c42def87363f084a4f46b7369f /arch/x86/kvm/emulate.c
parentf6a2c2b2de817078ac5a7e58c10e746165e7825d (diff)
parentfe83f5eae432ccc8e90082d6ed506d5233547473 (diff)
downloadlinux-b9067cd80fbc5b3ae061e5bde6efd19bbf02f9e2.tar.xz
Merge branch 'kvm/kvm-sls-fix'
Sync with the last minute SLS fix to extend it for IBT. Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Diffstat (limited to 'arch/x86/kvm/emulate.c')
-rw-r--r--arch/x86/kvm/emulate.c19
1 files changed, 17 insertions, 2 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 08c4e9c1a382..d98fb36c68ed 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -430,8 +430,23 @@ static int fastop(struct x86_emulate_ctxt *ctxt, fastop_t fop);
FOP_END
/* Special case for SETcc - 1 instruction per cc */
+
+/*
+ * Depending on .config the SETcc functions look like:
+ *
+ * SETcc %al [3 bytes]
+ * RET [1 byte]
+ * INT3 [1 byte; CONFIG_SLS]
+ *
+ * Which gives possible sizes 4 or 5. When rounded up to the
+ * next power-of-two alignment they become 4 or 8.
+ */
+#define SETCC_LENGTH (4 + IS_ENABLED(CONFIG_SLS))
+#define SETCC_ALIGN (4 << IS_ENABLED(CONFIG_SLS))
+static_assert(SETCC_LENGTH <= SETCC_ALIGN);
+
#define FOP_SETCC(op) \
- ".align 4 \n\t" \
+ ".align " __stringify(SETCC_ALIGN) " \n\t" \
".type " #op ", @function \n\t" \
#op ": \n\t" \
ASM_ENDBR \
@@ -1049,7 +1064,7 @@ static int em_bsr_c(struct x86_emulate_ctxt *ctxt)
static __always_inline u8 test_cc(unsigned int condition, unsigned long flags)
{
u8 rc;
- void (*fop)(void) = (void *)em_setcc + 4 * (condition & 0xf);
+ void (*fop)(void) = (void *)em_setcc + SETCC_ALIGN * (condition & 0xf);
flags = (flags & EFLAGS_MASK) | X86_EFLAGS_IF;
asm("push %[flags]; popf; " CALL_NOSPEC