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Date: Fri, 20 Nov 2020 12:46:26 +0100
From: Juergen Gross <jgross@...e.com>
To: xen-devel@...ts.xenproject.org, x86@...nel.org,
linux-kernel@...r.kernel.org,
virtualization@...ts.linux-foundation.org
Cc: peterz@...radead.org, luto@...nel.org,
Juergen Gross <jgross@...e.com>,
Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
"H. Peter Anvin" <hpa@...or.com>, Deep Shah <sdeep@...are.com>,
"VMware, Inc." <pv-drivers@...are.com>
Subject: [PATCH v2 08/12] x86/paravirt: remove no longer needed 32-bit pvops cruft
PVOP_VCALL4() is only used for Xen PV, while PVOP_CALL4() isn't used
at all. Keep PVOP_CALL4() for 64 bits due to symmetry reasons.
This allows to remove the 32-bit definitions of those macros leading
to a substantial simplification of the paravirt macros, as those were
the only ones needing non-empty "pre" and "post" parameters.
PVOP_CALLEE2() and PVOP_VCALLEE2() are used nowhere, so remove them.
Another no longer needed case is special handling of return types
larger than unsigned long. Replace that with a BUILD_BUG_ON().
DISABLE_INTERRUPTS() is used in 32-bit code only, so it can just be
replaced by cli.
INTERRUPT_RETURN in 32-bit code can be replaced by iret.
GET_CR2_INTO_AX and ENABLE_INTERRUPTS are used nowhere, so they can
be removed.
Signed-off-by: Juergen Gross <jgross@...e.com>
---
arch/x86/entry/entry_32.S | 4 +-
arch/x86/include/asm/irqflags.h | 5 --
arch/x86/include/asm/paravirt.h | 46 +----------
arch/x86/include/asm/paravirt_types.h | 112 ++++++++------------------
arch/x86/kernel/asm-offsets.c | 3 -
arch/x86/kernel/head_64.S | 2 -
6 files changed, 35 insertions(+), 137 deletions(-)
diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index df8c017e6161..765487e57d6e 100644
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -430,7 +430,7 @@
* will soon execute iret and the tracer was already set to
* the irqstate after the IRET:
*/
- DISABLE_INTERRUPTS(CLBR_ANY)
+ cli
lss (%esp), %esp /* switch to espfix segment */
.Lend_\@:
#endif /* CONFIG_X86_ESPFIX32 */
@@ -1077,7 +1077,7 @@ restore_all_switch_stack:
* when returning from IPI handler and when returning from
* scheduler to user-space.
*/
- INTERRUPT_RETURN
+ iret
.section .fixup, "ax"
SYM_CODE_START(asm_iret_error)
diff --git a/arch/x86/include/asm/irqflags.h b/arch/x86/include/asm/irqflags.h
index 144d70ea4393..a0efbcd24b86 100644
--- a/arch/x86/include/asm/irqflags.h
+++ b/arch/x86/include/asm/irqflags.h
@@ -109,9 +109,6 @@ static __always_inline unsigned long arch_local_irq_save(void)
}
#else
-#define ENABLE_INTERRUPTS(x) sti
-#define DISABLE_INTERRUPTS(x) cli
-
#ifdef CONFIG_X86_64
#ifdef CONFIG_DEBUG_ENTRY
#define SAVE_FLAGS(x) pushfq; popq %rax
@@ -119,8 +116,6 @@ static __always_inline unsigned long arch_local_irq_save(void)
#define INTERRUPT_RETURN jmp native_iret
-#else
-#define INTERRUPT_RETURN iret
#endif
#endif /* __ASSEMBLY__ */
diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index 01b3e36462c3..1dd30c95505d 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -692,6 +692,7 @@ extern void default_banner(void);
.if ((~(set)) & mask); pop %reg; .endif
#ifdef CONFIG_X86_64
+#ifdef CONFIG_PARAVIRT_XXL
#define PV_SAVE_REGS(set) \
COND_PUSH(set, CLBR_RAX, rax); \
@@ -717,46 +718,12 @@ extern void default_banner(void);
#define PARA_PATCH(off) ((off) / 8)
#define PARA_SITE(ptype, ops) _PVSITE(ptype, ops, .quad, 8)
#define PARA_INDIRECT(addr) *addr(%rip)
-#else
-#define PV_SAVE_REGS(set) \
- COND_PUSH(set, CLBR_EAX, eax); \
- COND_PUSH(set, CLBR_EDI, edi); \
- COND_PUSH(set, CLBR_ECX, ecx); \
- COND_PUSH(set, CLBR_EDX, edx)
-#define PV_RESTORE_REGS(set) \
- COND_POP(set, CLBR_EDX, edx); \
- COND_POP(set, CLBR_ECX, ecx); \
- COND_POP(set, CLBR_EDI, edi); \
- COND_POP(set, CLBR_EAX, eax)
-
-#define PARA_PATCH(off) ((off) / 4)
-#define PARA_SITE(ptype, ops) _PVSITE(ptype, ops, .long, 4)
-#define PARA_INDIRECT(addr) *%cs:addr
-#endif
-#ifdef CONFIG_PARAVIRT_XXL
#define INTERRUPT_RETURN \
PARA_SITE(PARA_PATCH(PV_CPU_iret), \
ANNOTATE_RETPOLINE_SAFE; \
jmp PARA_INDIRECT(pv_ops+PV_CPU_iret);)
-#define DISABLE_INTERRUPTS(clobbers) \
- PARA_SITE(PARA_PATCH(PV_IRQ_irq_disable), \
- PV_SAVE_REGS(clobbers | CLBR_CALLEE_SAVE); \
- ANNOTATE_RETPOLINE_SAFE; \
- call PARA_INDIRECT(pv_ops+PV_IRQ_irq_disable); \
- PV_RESTORE_REGS(clobbers | CLBR_CALLEE_SAVE);)
-
-#define ENABLE_INTERRUPTS(clobbers) \
- PARA_SITE(PARA_PATCH(PV_IRQ_irq_enable), \
- PV_SAVE_REGS(clobbers | CLBR_CALLEE_SAVE); \
- ANNOTATE_RETPOLINE_SAFE; \
- call PARA_INDIRECT(pv_ops+PV_IRQ_irq_enable); \
- PV_RESTORE_REGS(clobbers | CLBR_CALLEE_SAVE);)
-#endif
-
-#ifdef CONFIG_X86_64
-#ifdef CONFIG_PARAVIRT_XXL
#ifdef CONFIG_DEBUG_ENTRY
#define SAVE_FLAGS(clobbers) \
PARA_SITE(PARA_PATCH(PV_IRQ_save_fl), \
@@ -768,17 +735,6 @@ extern void default_banner(void);
#endif /* CONFIG_PARAVIRT_XXL */
#endif /* CONFIG_X86_64 */
-#ifdef CONFIG_PARAVIRT_XXL
-
-#define GET_CR2_INTO_AX \
- PARA_SITE(PARA_PATCH(PV_MMU_read_cr2), \
- ANNOTATE_RETPOLINE_SAFE; \
- call PARA_INDIRECT(pv_ops+PV_MMU_read_cr2); \
- )
-
-#endif /* CONFIG_PARAVIRT_XXL */
-
-
#endif /* __ASSEMBLY__ */
#else /* CONFIG_PARAVIRT */
# define default_banner x86_init_noop
diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h
index 01af7b944224..b86acbb6449f 100644
--- a/arch/x86/include/asm/paravirt_types.h
+++ b/arch/x86/include/asm/paravirt_types.h
@@ -471,55 +471,34 @@ int paravirt_disable_iospace(void);
})
-#define ____PVOP_CALL(rettype, op, clbr, call_clbr, extra_clbr, \
- pre, post, ...) \
+#define ____PVOP_CALL(rettype, op, clbr, call_clbr, extra_clbr, ...) \
({ \
- rettype __ret; \
PVOP_CALL_ARGS; \
PVOP_TEST_NULL(op); \
- /* This is 32-bit specific, but is okay in 64-bit */ \
- /* since this condition will never hold */ \
- if (sizeof(rettype) > sizeof(unsigned long)) { \
- asm volatile(pre \
- paravirt_alt(PARAVIRT_CALL) \
- post \
- : call_clbr, ASM_CALL_CONSTRAINT \
- : paravirt_type(op), \
- paravirt_clobber(clbr), \
- ##__VA_ARGS__ \
- : "memory", "cc" extra_clbr); \
- __ret = (rettype)((((u64)__edx) << 32) | __eax); \
- } else { \
- asm volatile(pre \
- paravirt_alt(PARAVIRT_CALL) \
- post \
- : call_clbr, ASM_CALL_CONSTRAINT \
- : paravirt_type(op), \
- paravirt_clobber(clbr), \
- ##__VA_ARGS__ \
- : "memory", "cc" extra_clbr); \
- __ret = (rettype)(__eax & PVOP_RETMASK(rettype)); \
- } \
- __ret; \
+ BUILD_BUG_ON(sizeof(rettype) > sizeof(unsigned long)); \
+ asm volatile(paravirt_alt(PARAVIRT_CALL) \
+ : call_clbr, ASM_CALL_CONSTRAINT \
+ : paravirt_type(op), \
+ paravirt_clobber(clbr), \
+ ##__VA_ARGS__ \
+ : "memory", "cc" extra_clbr); \
+ (rettype)(__eax & PVOP_RETMASK(rettype)); \
})
-#define __PVOP_CALL(rettype, op, pre, post, ...) \
+#define __PVOP_CALL(rettype, op, ...) \
____PVOP_CALL(rettype, op, CLBR_ANY, PVOP_CALL_CLOBBERS, \
- EXTRA_CLOBBERS, pre, post, ##__VA_ARGS__)
+ EXTRA_CLOBBERS, ##__VA_ARGS__)
-#define __PVOP_CALLEESAVE(rettype, op, pre, post, ...) \
+#define __PVOP_CALLEESAVE(rettype, op, ...) \
____PVOP_CALL(rettype, op.func, CLBR_RET_REG, \
- PVOP_CALLEE_CLOBBERS, , \
- pre, post, ##__VA_ARGS__)
+ PVOP_CALLEE_CLOBBERS, , ##__VA_ARGS__)
-#define ____PVOP_VCALL(op, clbr, call_clbr, extra_clbr, pre, post, ...) \
+#define ____PVOP_VCALL(op, clbr, call_clbr, extra_clbr, ...) \
({ \
PVOP_VCALL_ARGS; \
PVOP_TEST_NULL(op); \
- asm volatile(pre \
- paravirt_alt(PARAVIRT_CALL) \
- post \
+ asm volatile(paravirt_alt(PARAVIRT_CALL) \
: call_clbr, ASM_CALL_CONSTRAINT \
: paravirt_type(op), \
paravirt_clobber(clbr), \
@@ -527,84 +506,57 @@ int paravirt_disable_iospace(void);
: "memory", "cc" extra_clbr); \
})
-#define __PVOP_VCALL(op, pre, post, ...) \
+#define __PVOP_VCALL(op, ...) \
____PVOP_VCALL(op, CLBR_ANY, PVOP_VCALL_CLOBBERS, \
- VEXTRA_CLOBBERS, \
- pre, post, ##__VA_ARGS__)
+ VEXTRA_CLOBBERS, ##__VA_ARGS__)
-#define __PVOP_VCALLEESAVE(op, pre, post, ...) \
+#define __PVOP_VCALLEESAVE(op, ...) \
____PVOP_VCALL(op.func, CLBR_RET_REG, \
- PVOP_VCALLEE_CLOBBERS, , \
- pre, post, ##__VA_ARGS__)
+ PVOP_VCALLEE_CLOBBERS, , ##__VA_ARGS__)
#define PVOP_CALL0(rettype, op) \
- __PVOP_CALL(rettype, op, "", "")
+ __PVOP_CALL(rettype, op)
#define PVOP_VCALL0(op) \
- __PVOP_VCALL(op, "", "")
+ __PVOP_VCALL(op)
#define PVOP_CALLEE0(rettype, op) \
- __PVOP_CALLEESAVE(rettype, op, "", "")
+ __PVOP_CALLEESAVE(rettype, op)
#define PVOP_VCALLEE0(op) \
- __PVOP_VCALLEESAVE(op, "", "")
+ __PVOP_VCALLEESAVE(op)
#define PVOP_CALL1(rettype, op, arg1) \
- __PVOP_CALL(rettype, op, "", "", PVOP_CALL_ARG1(arg1))
+ __PVOP_CALL(rettype, op, PVOP_CALL_ARG1(arg1))
#define PVOP_VCALL1(op, arg1) \
- __PVOP_VCALL(op, "", "", PVOP_CALL_ARG1(arg1))
+ __PVOP_VCALL(op, PVOP_CALL_ARG1(arg1))
#define PVOP_CALLEE1(rettype, op, arg1) \
- __PVOP_CALLEESAVE(rettype, op, "", "", PVOP_CALL_ARG1(arg1))
+ __PVOP_CALLEESAVE(rettype, op, PVOP_CALL_ARG1(arg1))
#define PVOP_VCALLEE1(op, arg1) \
- __PVOP_VCALLEESAVE(op, "", "", PVOP_CALL_ARG1(arg1))
+ __PVOP_VCALLEESAVE(op, PVOP_CALL_ARG1(arg1))
#define PVOP_CALL2(rettype, op, arg1, arg2) \
- __PVOP_CALL(rettype, op, "", "", PVOP_CALL_ARG1(arg1), \
- PVOP_CALL_ARG2(arg2))
+ __PVOP_CALL(rettype, op, PVOP_CALL_ARG1(arg1), PVOP_CALL_ARG2(arg2))
#define PVOP_VCALL2(op, arg1, arg2) \
- __PVOP_VCALL(op, "", "", PVOP_CALL_ARG1(arg1), \
- PVOP_CALL_ARG2(arg2))
-
-#define PVOP_CALLEE2(rettype, op, arg1, arg2) \
- __PVOP_CALLEESAVE(rettype, op, "", "", PVOP_CALL_ARG1(arg1), \
- PVOP_CALL_ARG2(arg2))
-#define PVOP_VCALLEE2(op, arg1, arg2) \
- __PVOP_VCALLEESAVE(op, "", "", PVOP_CALL_ARG1(arg1), \
- PVOP_CALL_ARG2(arg2))
-
+ __PVOP_VCALL(op, PVOP_CALL_ARG1(arg1), PVOP_CALL_ARG2(arg2))
#define PVOP_CALL3(rettype, op, arg1, arg2, arg3) \
- __PVOP_CALL(rettype, op, "", "", PVOP_CALL_ARG1(arg1), \
+ __PVOP_CALL(rettype, op, PVOP_CALL_ARG1(arg1), \
PVOP_CALL_ARG2(arg2), PVOP_CALL_ARG3(arg3))
#define PVOP_VCALL3(op, arg1, arg2, arg3) \
- __PVOP_VCALL(op, "", "", PVOP_CALL_ARG1(arg1), \
+ __PVOP_VCALL(op, PVOP_CALL_ARG1(arg1), \
PVOP_CALL_ARG2(arg2), PVOP_CALL_ARG3(arg3))
-/* This is the only difference in x86_64. We can make it much simpler */
-#ifdef CONFIG_X86_32
#define PVOP_CALL4(rettype, op, arg1, arg2, arg3, arg4) \
__PVOP_CALL(rettype, op, \
- "push %[_arg4];", "lea 4(%%esp),%%esp;", \
- PVOP_CALL_ARG1(arg1), PVOP_CALL_ARG2(arg2), \
- PVOP_CALL_ARG3(arg3), [_arg4] "mr" ((u32)(arg4)))
-#define PVOP_VCALL4(op, arg1, arg2, arg3, arg4) \
- __PVOP_VCALL(op, \
- "push %[_arg4];", "lea 4(%%esp),%%esp;", \
- "0" ((u32)(arg1)), "1" ((u32)(arg2)), \
- "2" ((u32)(arg3)), [_arg4] "mr" ((u32)(arg4)))
-#else
-#define PVOP_CALL4(rettype, op, arg1, arg2, arg3, arg4) \
- __PVOP_CALL(rettype, op, "", "", \
PVOP_CALL_ARG1(arg1), PVOP_CALL_ARG2(arg2), \
PVOP_CALL_ARG3(arg3), PVOP_CALL_ARG4(arg4))
#define PVOP_VCALL4(op, arg1, arg2, arg3, arg4) \
- __PVOP_VCALL(op, "", "", \
- PVOP_CALL_ARG1(arg1), PVOP_CALL_ARG2(arg2), \
+ __PVOP_VCALL(op, PVOP_CALL_ARG1(arg1), PVOP_CALL_ARG2(arg2), \
PVOP_CALL_ARG3(arg3), PVOP_CALL_ARG4(arg4))
-#endif
/* Lazy mode for batching updates / context switch */
enum paravirt_lazy_mode {
diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c
index 70b7154f4bdd..736508004b30 100644
--- a/arch/x86/kernel/asm-offsets.c
+++ b/arch/x86/kernel/asm-offsets.c
@@ -63,10 +63,7 @@ static void __used common(void)
#ifdef CONFIG_PARAVIRT_XXL
BLANK();
- OFFSET(PV_IRQ_irq_disable, paravirt_patch_template, irq.irq_disable);
- OFFSET(PV_IRQ_irq_enable, paravirt_patch_template, irq.irq_enable);
OFFSET(PV_CPU_iret, paravirt_patch_template, cpu.iret);
- OFFSET(PV_MMU_read_cr2, paravirt_patch_template, mmu.read_cr2);
#endif
#ifdef CONFIG_XEN
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index 3c417734790f..ccb3a16ae6d0 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -29,10 +29,8 @@
#ifdef CONFIG_PARAVIRT_XXL
#include <asm/asm-offsets.h>
#include <asm/paravirt.h>
-#define GET_CR2_INTO(reg) GET_CR2_INTO_AX ; _ASM_MOV %_ASM_AX, reg
#else
#define INTERRUPT_RETURN iretq
-#define GET_CR2_INTO(reg) _ASM_MOV %cr2, reg
#endif
/*
--
2.26.2
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