2020-08-07 08:40:46

by Jürgen Groß

[permalink] [raw]
Subject: [PATCH v3 2/7] x86/xen: eliminate xen-asm_64.S

With 32-bit pv-guest support removed xen-asm_64.S can be merged with
xen-asm.S

Signed-off-by: Juergen Gross <[email protected]>
---
arch/x86/xen/Makefile | 3 +-
arch/x86/xen/xen-asm.S | 179 +++++++++++++++++++++++++++++++++++
arch/x86/xen/xen-asm_64.S | 192 --------------------------------------
3 files changed, 180 insertions(+), 194 deletions(-)
delete mode 100644 arch/x86/xen/xen-asm_64.S

diff --git a/arch/x86/xen/Makefile b/arch/x86/xen/Makefile
index 084de77a109e..5de137d536cc 100644
--- a/arch/x86/xen/Makefile
+++ b/arch/x86/xen/Makefile
@@ -1,5 +1,5 @@
# SPDX-License-Identifier: GPL-2.0
-OBJECT_FILES_NON_STANDARD_xen-asm_$(BITS).o := y
+OBJECT_FILES_NON_STANDARD_xen-asm.o := y

ifdef CONFIG_FUNCTION_TRACER
# Do not profile debug and lowlevel utilities
@@ -34,7 +34,6 @@ obj-$(CONFIG_XEN_PV) += mmu_pv.o
obj-$(CONFIG_XEN_PV) += irq.o
obj-$(CONFIG_XEN_PV) += multicalls.o
obj-$(CONFIG_XEN_PV) += xen-asm.o
-obj-$(CONFIG_XEN_PV) += xen-asm_$(BITS).o

obj-$(CONFIG_XEN_PVH) += enlighten_pvh.o

diff --git a/arch/x86/xen/xen-asm.S b/arch/x86/xen/xen-asm.S
index c59d077510bf..d1272a63f097 100644
--- a/arch/x86/xen/xen-asm.S
+++ b/arch/x86/xen/xen-asm.S
@@ -6,12 +6,19 @@
* operations here; the indirect forms are better handled in C.
*/

+#include <asm/errno.h>
#include <asm/asm-offsets.h>
#include <asm/percpu.h>
#include <asm/processor-flags.h>
+#include <asm/segment.h>
+#include <asm/thread_info.h>
+#include <asm/asm.h>
#include <asm/frame.h>
#include <asm/asm.h>

+#include <xen/interface/xen.h>
+
+#include <linux/init.h>
#include <linux/linkage.h>

/*
@@ -137,3 +144,175 @@ SYM_FUNC_START(xen_read_cr2_direct)
FRAME_END
ret
SYM_FUNC_END(xen_read_cr2_direct);
+
+.macro xen_pv_trap name
+SYM_CODE_START(xen_\name)
+ pop %rcx
+ pop %r11
+ jmp \name
+SYM_CODE_END(xen_\name)
+_ASM_NOKPROBE(xen_\name)
+.endm
+
+xen_pv_trap asm_exc_divide_error
+xen_pv_trap asm_xenpv_exc_debug
+xen_pv_trap asm_exc_int3
+xen_pv_trap asm_xenpv_exc_nmi
+xen_pv_trap asm_exc_overflow
+xen_pv_trap asm_exc_bounds
+xen_pv_trap asm_exc_invalid_op
+xen_pv_trap asm_exc_device_not_available
+xen_pv_trap asm_exc_double_fault
+xen_pv_trap asm_exc_coproc_segment_overrun
+xen_pv_trap asm_exc_invalid_tss
+xen_pv_trap asm_exc_segment_not_present
+xen_pv_trap asm_exc_stack_segment
+xen_pv_trap asm_exc_general_protection
+xen_pv_trap asm_exc_page_fault
+xen_pv_trap asm_exc_spurious_interrupt_bug
+xen_pv_trap asm_exc_coprocessor_error
+xen_pv_trap asm_exc_alignment_check
+#ifdef CONFIG_X86_MCE
+xen_pv_trap asm_exc_machine_check
+#endif /* CONFIG_X86_MCE */
+xen_pv_trap asm_exc_simd_coprocessor_error
+#ifdef CONFIG_IA32_EMULATION
+xen_pv_trap entry_INT80_compat
+#endif
+xen_pv_trap asm_exc_xen_hypervisor_callback
+
+ __INIT
+SYM_CODE_START(xen_early_idt_handler_array)
+ i = 0
+ .rept NUM_EXCEPTION_VECTORS
+ pop %rcx
+ pop %r11
+ jmp early_idt_handler_array + i*EARLY_IDT_HANDLER_SIZE
+ i = i + 1
+ .fill xen_early_idt_handler_array + i*XEN_EARLY_IDT_HANDLER_SIZE - ., 1, 0xcc
+ .endr
+SYM_CODE_END(xen_early_idt_handler_array)
+ __FINIT
+
+hypercall_iret = hypercall_page + __HYPERVISOR_iret * 32
+/*
+ * Xen64 iret frame:
+ *
+ * ss
+ * rsp
+ * rflags
+ * cs
+ * rip <-- standard iret frame
+ *
+ * flags
+ *
+ * rcx }
+ * r11 }<-- pushed by hypercall page
+ * rsp->rax }
+ */
+SYM_CODE_START(xen_iret)
+ pushq $0
+ jmp hypercall_iret
+SYM_CODE_END(xen_iret)
+
+SYM_CODE_START(xen_sysret64)
+ /*
+ * We're already on the usermode stack at this point, but
+ * still with the kernel gs, so we can easily switch back.
+ *
+ * tss.sp2 is scratch space.
+ */
+ movq %rsp, PER_CPU_VAR(cpu_tss_rw + TSS_sp2)
+ movq PER_CPU_VAR(cpu_current_top_of_stack), %rsp
+
+ pushq $__USER_DS
+ pushq PER_CPU_VAR(cpu_tss_rw + TSS_sp2)
+ pushq %r11
+ pushq $__USER_CS
+ pushq %rcx
+
+ pushq $VGCF_in_syscall
+ jmp hypercall_iret
+SYM_CODE_END(xen_sysret64)
+
+/*
+ * Xen handles syscall callbacks much like ordinary exceptions, which
+ * means we have:
+ * - kernel gs
+ * - kernel rsp
+ * - an iret-like stack frame on the stack (including rcx and r11):
+ * ss
+ * rsp
+ * rflags
+ * cs
+ * rip
+ * r11
+ * rsp->rcx
+ */
+
+/* Normal 64-bit system call target */
+SYM_FUNC_START(xen_syscall_target)
+ popq %rcx
+ popq %r11
+
+ /*
+ * Neither Xen nor the kernel really knows what the old SS and
+ * CS were. The kernel expects __USER_DS and __USER_CS, so
+ * report those values even though Xen will guess its own values.
+ */
+ movq $__USER_DS, 4*8(%rsp)
+ movq $__USER_CS, 1*8(%rsp)
+
+ jmp entry_SYSCALL_64_after_hwframe
+SYM_FUNC_END(xen_syscall_target)
+
+#ifdef CONFIG_IA32_EMULATION
+
+/* 32-bit compat syscall target */
+SYM_FUNC_START(xen_syscall32_target)
+ popq %rcx
+ popq %r11
+
+ /*
+ * Neither Xen nor the kernel really knows what the old SS and
+ * CS were. The kernel expects __USER32_DS and __USER32_CS, so
+ * report those values even though Xen will guess its own values.
+ */
+ movq $__USER32_DS, 4*8(%rsp)
+ movq $__USER32_CS, 1*8(%rsp)
+
+ jmp entry_SYSCALL_compat_after_hwframe
+SYM_FUNC_END(xen_syscall32_target)
+
+/* 32-bit compat sysenter target */
+SYM_FUNC_START(xen_sysenter_target)
+ /*
+ * NB: Xen is polite and clears TF from EFLAGS for us. This means
+ * that we don't need to guard against single step exceptions here.
+ */
+ popq %rcx
+ popq %r11
+
+ /*
+ * Neither Xen nor the kernel really knows what the old SS and
+ * CS were. The kernel expects __USER32_DS and __USER32_CS, so
+ * report those values even though Xen will guess its own values.
+ */
+ movq $__USER32_DS, 4*8(%rsp)
+ movq $__USER32_CS, 1*8(%rsp)
+
+ jmp entry_SYSENTER_compat_after_hwframe
+SYM_FUNC_END(xen_sysenter_target)
+
+#else /* !CONFIG_IA32_EMULATION */
+
+SYM_FUNC_START_ALIAS(xen_syscall32_target)
+SYM_FUNC_START(xen_sysenter_target)
+ lea 16(%rsp), %rsp /* strip %rcx, %r11 */
+ mov $-ENOSYS, %rax
+ pushq $0
+ jmp hypercall_iret
+SYM_FUNC_END(xen_sysenter_target)
+SYM_FUNC_END_ALIAS(xen_syscall32_target)
+
+#endif /* CONFIG_IA32_EMULATION */
diff --git a/arch/x86/xen/xen-asm_64.S b/arch/x86/xen/xen-asm_64.S
deleted file mode 100644
index aab1d99b2b48..000000000000
--- a/arch/x86/xen/xen-asm_64.S
+++ /dev/null
@@ -1,192 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * Asm versions of Xen pv-ops, suitable for direct use.
- *
- * We only bother with direct forms (ie, vcpu in pda) of the
- * operations here; the indirect forms are better handled in C.
- */
-
-#include <asm/errno.h>
-#include <asm/percpu.h>
-#include <asm/processor-flags.h>
-#include <asm/segment.h>
-#include <asm/asm-offsets.h>
-#include <asm/thread_info.h>
-#include <asm/asm.h>
-
-#include <xen/interface/xen.h>
-
-#include <linux/init.h>
-#include <linux/linkage.h>
-
-.macro xen_pv_trap name
-SYM_CODE_START(xen_\name)
- pop %rcx
- pop %r11
- jmp \name
-SYM_CODE_END(xen_\name)
-_ASM_NOKPROBE(xen_\name)
-.endm
-
-xen_pv_trap asm_exc_divide_error
-xen_pv_trap asm_xenpv_exc_debug
-xen_pv_trap asm_exc_int3
-xen_pv_trap asm_xenpv_exc_nmi
-xen_pv_trap asm_exc_overflow
-xen_pv_trap asm_exc_bounds
-xen_pv_trap asm_exc_invalid_op
-xen_pv_trap asm_exc_device_not_available
-xen_pv_trap asm_exc_double_fault
-xen_pv_trap asm_exc_coproc_segment_overrun
-xen_pv_trap asm_exc_invalid_tss
-xen_pv_trap asm_exc_segment_not_present
-xen_pv_trap asm_exc_stack_segment
-xen_pv_trap asm_exc_general_protection
-xen_pv_trap asm_exc_page_fault
-xen_pv_trap asm_exc_spurious_interrupt_bug
-xen_pv_trap asm_exc_coprocessor_error
-xen_pv_trap asm_exc_alignment_check
-#ifdef CONFIG_X86_MCE
-xen_pv_trap asm_exc_machine_check
-#endif /* CONFIG_X86_MCE */
-xen_pv_trap asm_exc_simd_coprocessor_error
-#ifdef CONFIG_IA32_EMULATION
-xen_pv_trap entry_INT80_compat
-#endif
-xen_pv_trap asm_exc_xen_hypervisor_callback
-
- __INIT
-SYM_CODE_START(xen_early_idt_handler_array)
- i = 0
- .rept NUM_EXCEPTION_VECTORS
- pop %rcx
- pop %r11
- jmp early_idt_handler_array + i*EARLY_IDT_HANDLER_SIZE
- i = i + 1
- .fill xen_early_idt_handler_array + i*XEN_EARLY_IDT_HANDLER_SIZE - ., 1, 0xcc
- .endr
-SYM_CODE_END(xen_early_idt_handler_array)
- __FINIT
-
-hypercall_iret = hypercall_page + __HYPERVISOR_iret * 32
-/*
- * Xen64 iret frame:
- *
- * ss
- * rsp
- * rflags
- * cs
- * rip <-- standard iret frame
- *
- * flags
- *
- * rcx }
- * r11 }<-- pushed by hypercall page
- * rsp->rax }
- */
-SYM_CODE_START(xen_iret)
- pushq $0
- jmp hypercall_iret
-SYM_CODE_END(xen_iret)
-
-SYM_CODE_START(xen_sysret64)
- /*
- * We're already on the usermode stack at this point, but
- * still with the kernel gs, so we can easily switch back.
- *
- * tss.sp2 is scratch space.
- */
- movq %rsp, PER_CPU_VAR(cpu_tss_rw + TSS_sp2)
- movq PER_CPU_VAR(cpu_current_top_of_stack), %rsp
-
- pushq $__USER_DS
- pushq PER_CPU_VAR(cpu_tss_rw + TSS_sp2)
- pushq %r11
- pushq $__USER_CS
- pushq %rcx
-
- pushq $VGCF_in_syscall
- jmp hypercall_iret
-SYM_CODE_END(xen_sysret64)
-
-/*
- * Xen handles syscall callbacks much like ordinary exceptions, which
- * means we have:
- * - kernel gs
- * - kernel rsp
- * - an iret-like stack frame on the stack (including rcx and r11):
- * ss
- * rsp
- * rflags
- * cs
- * rip
- * r11
- * rsp->rcx
- */
-
-/* Normal 64-bit system call target */
-SYM_FUNC_START(xen_syscall_target)
- popq %rcx
- popq %r11
-
- /*
- * Neither Xen nor the kernel really knows what the old SS and
- * CS were. The kernel expects __USER_DS and __USER_CS, so
- * report those values even though Xen will guess its own values.
- */
- movq $__USER_DS, 4*8(%rsp)
- movq $__USER_CS, 1*8(%rsp)
-
- jmp entry_SYSCALL_64_after_hwframe
-SYM_FUNC_END(xen_syscall_target)
-
-#ifdef CONFIG_IA32_EMULATION
-
-/* 32-bit compat syscall target */
-SYM_FUNC_START(xen_syscall32_target)
- popq %rcx
- popq %r11
-
- /*
- * Neither Xen nor the kernel really knows what the old SS and
- * CS were. The kernel expects __USER32_DS and __USER32_CS, so
- * report those values even though Xen will guess its own values.
- */
- movq $__USER32_DS, 4*8(%rsp)
- movq $__USER32_CS, 1*8(%rsp)
-
- jmp entry_SYSCALL_compat_after_hwframe
-SYM_FUNC_END(xen_syscall32_target)
-
-/* 32-bit compat sysenter target */
-SYM_FUNC_START(xen_sysenter_target)
- /*
- * NB: Xen is polite and clears TF from EFLAGS for us. This means
- * that we don't need to guard against single step exceptions here.
- */
- popq %rcx
- popq %r11
-
- /*
- * Neither Xen nor the kernel really knows what the old SS and
- * CS were. The kernel expects __USER32_DS and __USER32_CS, so
- * report those values even though Xen will guess its own values.
- */
- movq $__USER32_DS, 4*8(%rsp)
- movq $__USER32_CS, 1*8(%rsp)
-
- jmp entry_SYSENTER_compat_after_hwframe
-SYM_FUNC_END(xen_sysenter_target)
-
-#else /* !CONFIG_IA32_EMULATION */
-
-SYM_FUNC_START_ALIAS(xen_syscall32_target)
-SYM_FUNC_START(xen_sysenter_target)
- lea 16(%rsp), %rsp /* strip %rcx, %r11 */
- mov $-ENOSYS, %rax
- pushq $0
- jmp hypercall_iret
-SYM_FUNC_END(xen_sysenter_target)
-SYM_FUNC_END_ALIAS(xen_syscall32_target)
-
-#endif /* CONFIG_IA32_EMULATION */
--
2.26.2


2020-08-09 02:07:49

by Boris Ostrovsky

[permalink] [raw]
Subject: Re: [PATCH v3 2/7] x86/xen: eliminate xen-asm_64.S

On 8/7/20 4:38 AM, Juergen Gross wrote:
> With 32-bit pv-guest support removed xen-asm_64.S can be merged with
> xen-asm.S
>
> Signed-off-by: Juergen Gross <[email protected]>


Reviewed-by: Boris Ostrovsky <[email protected]>


except for


> diff --git a/arch/x86/xen/xen-asm.S b/arch/x86/xen/xen-asm.S
> index c59d077510bf..d1272a63f097 100644
> --- a/arch/x86/xen/xen-asm.S
> +++ b/arch/x86/xen/xen-asm.S
> @@ -6,12 +6,19 @@
> * operations here; the indirect forms are better handled in C.
> */
>
> +#include <asm/errno.h>
> #include <asm/asm-offsets.h>
> #include <asm/percpu.h>
> #include <asm/processor-flags.h>
> +#include <asm/segment.h>
> +#include <asm/thread_info.h>
> +#include <asm/asm.h>
> #include <asm/frame.h>
> #include <asm/asm.h>


asm/asm.h included twice now.



2020-08-10 04:40:45

by Jürgen Groß

[permalink] [raw]
Subject: Re: [PATCH v3 2/7] x86/xen: eliminate xen-asm_64.S

On 09.08.20 04:04, Boris Ostrovsky wrote:
> On 8/7/20 4:38 AM, Juergen Gross wrote:
>> With 32-bit pv-guest support removed xen-asm_64.S can be merged with
>> xen-asm.S
>>
>> Signed-off-by: Juergen Gross <[email protected]>
>
>
> Reviewed-by: Boris Ostrovsky <[email protected]>
>
>
> except for
>
>
>> diff --git a/arch/x86/xen/xen-asm.S b/arch/x86/xen/xen-asm.S
>> index c59d077510bf..d1272a63f097 100644
>> --- a/arch/x86/xen/xen-asm.S
>> +++ b/arch/x86/xen/xen-asm.S
>> @@ -6,12 +6,19 @@
>> * operations here; the indirect forms are better handled in C.
>> */
>>
>> +#include <asm/errno.h>
>> #include <asm/asm-offsets.h>
>> #include <asm/percpu.h>
>> #include <asm/processor-flags.h>
>> +#include <asm/segment.h>
>> +#include <asm/thread_info.h>
>> +#include <asm/asm.h>
>> #include <asm/frame.h>
>> #include <asm/asm.h>
>
>
> asm/asm.h included twice now.

Right, will drop that.


Juergen