This is slightly more efficient than loading 64-bit quantities.
Signed-off-by: Jan Beulich <jbeul...@suse.com>
Reviewed-by: Andrew Cooper <andrew.coop...@citrix.com>
--- a/xen/include/asm-x86/asm_defns.h
+++ b/xen/include/asm-x86/asm_defns.h
@@ -313,6 +313,13 @@ static always_inline void stac(void)
987:
.endm
+#define LOAD_ONE_REG(reg, compat) \
+.if !(compat); \
+ movq UREGS_r##reg(%rsp),%r##reg; \
+.else; \
+ movl UREGS_r##reg(%rsp),%e##reg; \
+.endif
+
/*
* Reload registers not preserved by C code from frame.
*
@@ -326,16 +333,14 @@ static always_inline void stac(void)
movq UREGS_r10(%rsp),%r10
movq UREGS_r9(%rsp),%r9
movq UREGS_r8(%rsp),%r8
-.if \ax
- movq UREGS_rax(%rsp),%rax
.endif
-.elseif \ax
- movl UREGS_rax(%rsp),%eax
+.if \ax
+ LOAD_ONE_REG(ax, \compat)
.endif
- movq UREGS_rcx(%rsp),%rcx
- movq UREGS_rdx(%rsp),%rdx
- movq UREGS_rsi(%rsp),%rsi
- movq UREGS_rdi(%rsp),%rdi
+ LOAD_ONE_REG(cx, \compat)
+ LOAD_ONE_REG(dx, \compat)
+ LOAD_ONE_REG(si, \compat)
+ LOAD_ONE_REG(di, \compat)
.endm
/*
@@ -372,8 +377,9 @@ static always_inline void stac(void)
.subsection 0
#endif
.endif
-987: movq UREGS_rbp(%rsp),%rbp
- movq UREGS_rbx(%rsp),%rbx
+987:
+ LOAD_ONE_REG(bp, \compat)
+ LOAD_ONE_REG(bx, \compat)
subq $-(UREGS_error_code-UREGS_r15+\adj), %rsp
.endm
x86: use 32-bit loads for 32-bit PV guest state reload
This is slightly more efficient than loading 64-bit quantities.
Signed-off-by: Jan Beulich <jbeul...@suse.com>
Reviewed-by: Andrew Cooper <andrew.coop...@citrix.com>
--- a/xen/include/asm-x86/asm_defns.h
+++ b/xen/include/asm-x86/asm_defns.h
@@ -313,6 +313,13 @@ static always_inline void stac(void)
987:
.endm
+#define LOAD_ONE_REG(reg, compat) \
+.if !(compat); \
+ movq UREGS_r##reg(%rsp),%r##reg; \
+.else; \
+ movl UREGS_r##reg(%rsp),%e##reg; \
+.endif
+
/*
* Reload registers not preserved by C code from frame.
*
@@ -326,16 +333,14 @@ static always_inline void stac(void)
movq UREGS_r10(%rsp),%r10
movq UREGS_r9(%rsp),%r9
movq UREGS_r8(%rsp),%r8
-.if \ax
- movq UREGS_rax(%rsp),%rax
.endif
-.elseif \ax
- movl UREGS_rax(%rsp),%eax
+.if \ax
+ LOAD_ONE_REG(ax, \compat)
.endif
- movq UREGS_rcx(%rsp),%rcx
- movq UREGS_rdx(%rsp),%rdx
- movq UREGS_rsi(%rsp),%rsi
- movq UREGS_rdi(%rsp),%rdi
+ LOAD_ONE_REG(cx, \compat)
+ LOAD_ONE_REG(dx, \compat)
+ LOAD_ONE_REG(si, \compat)
+ LOAD_ONE_REG(di, \compat)
.endm
/*
@@ -372,8 +377,9 @@ static always_inline void stac(void)
.subsection 0
#endif
.endif
-987: movq UREGS_rbp(%rsp),%rbp
- movq UREGS_rbx(%rsp),%rbx
+987:
+ LOAD_ONE_REG(bp, \compat)
+ LOAD_ONE_REG(bx, \compat)
subq $-(UREGS_error_code-UREGS_r15+\adj), %rsp
.endm
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