* [PATCH] FPU LWP 4/8: clean up FPU context restore function
@ 2011-05-03 20:17 Wei Huang
0 siblings, 0 replies; only message in thread
From: Wei Huang @ 2011-05-03 20:17 UTC (permalink / raw)
To: 'xen-devel@lists.xensource.com', Keir Fraser, Jan Beulich
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FPU: clean up FPU context restore function
This patch cleans up context restore function. It renames the function
name to vcpu_restore_fpu(). It also extracts FPU restore code (frstor,
fxrstor, xrstor) out into seperate functions. vcpu_restor_fpu() will
dispatch to these functions depending on CPU's capability.
Signed-off-by: Wei Huang <wei.huang2@amd.com>
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# HG changeset patch
# User Wei Huang <wei.huang2@amd.com>
# Date 1304448326 18000
# Node ID 63208cfe3c558cebc5149fc569702785f6d8e73b
# Parent 0d71902c5b8fb8e6deadccf7ef7c39e05105267a
FPU: clean up FPU context restore function
This patch cleans up context restore function. It renames the function name to vcpu_restore_fpu(). It also extracts FPU restore code (frstor, fxrstor, xrstor) out into seperate functions. vcpu_restor_fpu() will dispatch to these functions depending on CPU's capability.
Signed-off-by: Wei Huang <wei.huang2@amd.com>
diff -r 0d71902c5b8f -r 63208cfe3c55 xen/arch/x86/hvm/svm/svm.c
--- a/xen/arch/x86/hvm/svm/svm.c Tue May 03 13:43:13 2011 -0500
+++ b/xen/arch/x86/hvm/svm/svm.c Tue May 03 13:45:26 2011 -0500
@@ -348,7 +348,7 @@
{
struct vmcb_struct *vmcb = v->arch.hvm_svm.vmcb;
- setup_fpu(v);
+ vcpu_restore_fpu(v);
vmcb_set_exception_intercepts(
vmcb, vmcb_get_exception_intercepts(vmcb) & ~(1U << TRAP_no_device));
}
diff -r 0d71902c5b8f -r 63208cfe3c55 xen/arch/x86/hvm/vmx/vmx.c
--- a/xen/arch/x86/hvm/vmx/vmx.c Tue May 03 13:43:13 2011 -0500
+++ b/xen/arch/x86/hvm/vmx/vmx.c Tue May 03 13:45:26 2011 -0500
@@ -612,7 +612,7 @@
static void vmx_fpu_enter(struct vcpu *v)
{
- setup_fpu(v);
+ vcpu_restore_fpu(v);
v->arch.hvm_vmx.exception_bitmap &= ~(1u << TRAP_no_device);
vmx_update_exception_bitmap(v);
v->arch.hvm_vmx.host_cr0 &= ~X86_CR0_TS;
diff -r 0d71902c5b8f -r 63208cfe3c55 xen/arch/x86/i387.c
--- a/xen/arch/x86/i387.c Tue May 03 13:43:13 2011 -0500
+++ b/xen/arch/x86/i387.c Tue May 03 13:45:26 2011 -0500
@@ -17,56 +17,37 @@
#include <asm/xstate.h>
#include <asm/asm_defns.h>
-static void load_mxcsr(unsigned long val)
+#define MXCSR_DEFAULT 0x1f80
+static void fpu_init(void)
{
- val &= 0xffbf;
- asm volatile ( "ldmxcsr %0" : : "m" (val) );
+ unsigned long val;
+
+ asm volatile ( "fninit" );
+ if ( cpu_has_xmm )
+ {
+ /* load default value into MXCSR control/status register */
+ val = MXCSR_DEFAULT;
+ asm volatile ( "ldmxcsr %0" : : "m" (val) );
+ }
}
-static void init_fpu(void);
-static void restore_fpu(struct vcpu *v);
-
-void setup_fpu(struct vcpu *v)
+/*******************************/
+/* FPU Restore Functions */
+/*******************************/
+/* Restore x87 extended state */
+static inline void fpu_xrstor(struct vcpu *v)
{
- ASSERT(!is_idle_vcpu(v));
-
- /* Avoid recursion. */
- clts();
-
- if ( v->fpu_dirtied )
- return;
-
- if ( xsave_enabled(v) )
- {
- /*
- * XCR0 normally represents what guest OS set. In case of Xen itself,
- * we set all supported feature mask before doing save/restore.
- */
- set_xcr0(v->arch.xcr0_accum);
- xrstor(v);
- set_xcr0(v->arch.xcr0);
- }
- else if ( v->fpu_initialised )
- {
- restore_fpu(v);
- }
- else
- {
- init_fpu();
- }
-
- v->fpu_initialised = 1;
- v->fpu_dirtied = 1;
+ /*
+ * XCR0 normally represents what guest OS set. In case of Xen itself,
+ * we set all supported feature mask before doing save/restore.
+ */
+ set_xcr0(v->arch.xcr0_accum);
+ xrstor(v);
+ set_xcr0(v->arch.xcr0);
}
-static void init_fpu(void)
-{
- asm volatile ( "fninit" );
- if ( cpu_has_xmm )
- load_mxcsr(0x1f80);
-}
-
-static void restore_fpu(struct vcpu *v)
+/* Restor x87 FPU, MMX, SSE and SSE2 state */
+static inline void fpu_fxrstor(struct vcpu *v)
{
const char *fpu_ctxt = v->arch.fpu_ctxt;
@@ -75,41 +56,42 @@
* possibility, which may occur if the block was passed to us by control
* tools, by silently clearing the block.
*/
- if ( cpu_has_fxsr )
- {
- asm volatile (
+ asm volatile (
#ifdef __i386__
- "1: fxrstor %0 \n"
+ "1: fxrstor %0 \n"
#else /* __x86_64__ */
- /* See above for why the operands/constraints are this way. */
- "1: " REX64_PREFIX "fxrstor (%2)\n"
+ /* See above for why the operands/constraints are this way. */
+ "1: " REX64_PREFIX "fxrstor (%2)\n"
#endif
- ".section .fixup,\"ax\" \n"
- "2: push %%"__OP"ax \n"
- " push %%"__OP"cx \n"
- " push %%"__OP"di \n"
- " lea %0,%%"__OP"di \n"
- " mov %1,%%ecx \n"
- " xor %%eax,%%eax \n"
- " rep ; stosl \n"
- " pop %%"__OP"di \n"
- " pop %%"__OP"cx \n"
- " pop %%"__OP"ax \n"
- " jmp 1b \n"
- ".previous \n"
- _ASM_EXTABLE(1b, 2b)
- :
- : "m" (*fpu_ctxt),
- "i" (sizeof(v->arch.xsave_area->fpu_sse)/4)
+ ".section .fixup,\"ax\" \n"
+ "2: push %%"__OP"ax \n"
+ " push %%"__OP"cx \n"
+ " push %%"__OP"di \n"
+ " lea %0,%%"__OP"di \n"
+ " mov %1,%%ecx \n"
+ " xor %%eax,%%eax \n"
+ " rep ; stosl \n"
+ " pop %%"__OP"di \n"
+ " pop %%"__OP"cx \n"
+ " pop %%"__OP"ax \n"
+ " jmp 1b \n"
+ ".previous \n"
+ _ASM_EXTABLE(1b, 2b)
+ :
+ : "m" (*fpu_ctxt),
+ "i" (sizeof(v->arch.xsave_area->fpu_sse)/4)
#ifdef __x86_64__
- ,"cdaSDb" (fpu_ctxt)
+ ,"cdaSDb" (fpu_ctxt)
#endif
- );
- }
- else
- {
- asm volatile ( "frstor %0" : : "m" (*fpu_ctxt) );
- }
+ );
+}
+
+/* Restore x87 extended state */
+static inline void fpu_frstor(struct vcpu *v)
+{
+ const char *fpu_ctxt = v->arch.fpu_ctxt;
+
+ asm volatile ( "frstor %0" : : "m" (*fpu_ctxt) );
}
/*******************************/
@@ -178,6 +160,35 @@
/*******************************/
/* VCPU FPU Functions */
/*******************************/
+/*
+ * Restore FPU state when #NM is triggered.
+ */
+void vcpu_restore_fpu(struct vcpu *v)
+{
+ ASSERT(!is_idle_vcpu(v));
+
+ /* Avoid recursion. */
+ clts();
+
+ if ( v->fpu_dirtied )
+ return;
+
+ if ( xsave_enabled(v) )
+ fpu_xrstor(v);
+ else if ( v->fpu_initialised )
+ {
+ if ( cpu_has_fxsr )
+ fpu_fxrstor(v);
+ else
+ fpu_frstor(v);
+ }
+ else
+ fpu_init();
+
+ v->fpu_initialised = 1;
+ v->fpu_dirtied = 1;
+}
+
/*
* On each context switch, save the necessary FPU info of VCPU being switch
* out. It dispatches saving operation based on CPU's capability.
diff -r 0d71902c5b8f -r 63208cfe3c55 xen/arch/x86/traps.c
--- a/xen/arch/x86/traps.c Tue May 03 13:43:13 2011 -0500
+++ b/xen/arch/x86/traps.c Tue May 03 13:45:26 2011 -0500
@@ -3198,7 +3198,7 @@
BUG_ON(!guest_mode(regs));
- setup_fpu(curr);
+ vcpu_restore_fpu(curr);
if ( curr->arch.pv_vcpu.ctrlreg[0] & X86_CR0_TS )
{
diff -r 0d71902c5b8f -r 63208cfe3c55 xen/include/asm-x86/i387.h
--- a/xen/include/asm-x86/i387.h Tue May 03 13:43:13 2011 -0500
+++ b/xen/include/asm-x86/i387.h Tue May 03 13:45:26 2011 -0500
@@ -14,7 +14,7 @@
#include <xen/types.h>
#include <xen/percpu.h>
-void setup_fpu(struct vcpu *v);
+void vcpu_restore_fpu(struct vcpu *v);
void vcpu_save_fpu(struct vcpu *v);
int vcpu_init_fpu(struct vcpu *v);
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2011-05-03 20:17 [PATCH] FPU LWP 4/8: clean up FPU context restore function Wei Huang
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