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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH 3/4] x86/pv: Drop {compat_, }create_bounce_frame() and use the C version instead
The clobbering of TRAPBOUNCE_flags in .L{compat_}bounce_exception is subsumed
by the logic at the end of pv_create_bounce_frame().
This cleanup removes all callers of asm_domain_crash_synchronous(), which is
therefore dropped as well.
Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: Jan Beulich <JBeulich@xxxxxxxx>
---
xen/arch/x86/traps.c | 23 ------
xen/arch/x86/x86_64/compat/entry.S | 116 ++----------------------------
xen/arch/x86/x86_64/entry.S | 141 ++-----------------------------------
xen/include/xen/sched.h | 7 --
4 files changed, 10 insertions(+), 277 deletions(-)
diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index ece2c13..73a9c7c 100644
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -4195,29 +4195,6 @@ unsigned long do_get_debugreg(int reg)
return -EINVAL;
}
-void asm_domain_crash_synchronous(unsigned long addr)
-{
- /*
- * We need clear AC bit here because in entry.S AC is set
- * by ASM_STAC to temporarily allow accesses to user pages
- * which is prevented by SMAP by default.
- *
- * For some code paths, where this function is called, clac()
- * is not needed, but adding clac() here instead of each place
- * asm_domain_crash_synchronous() is called can reduce the code
- * redundancy, and it is harmless as well.
- */
- clac();
-
- if ( addr == 0 )
- addr = this_cpu(last_extable_addr);
-
- printk("domain_crash_sync called from entry.S: fault at %p %pS\n",
- _p(addr), _p(addr));
-
- __domain_crash_synchronous();
-}
-
/*
* Local variables:
* mode: C
diff --git a/xen/arch/x86/x86_64/compat/entry.S
b/xen/arch/x86/x86_64/compat/entry.S
index 90bda09..1cd4672 100644
--- a/xen/arch/x86/x86_64/compat/entry.S
+++ b/xen/arch/x86/x86_64/compat/entry.S
@@ -51,7 +51,7 @@ compat_test_guest_events:
movl VCPU_event_sel(%rbx),%eax
movw %ax,TRAPBOUNCE_cs(%rdx)
movb $TBF_INTERRUPT,TRAPBOUNCE_flags(%rdx)
- call compat_create_bounce_frame
+ call pv_create_exception_frame
jmp compat_test_all_events
ALIGN
@@ -95,7 +95,7 @@ compat_process_nmi:
/* FALLTHROUGH */
compat_process_trap:
leaq VCPU_trap_bounce(%rbx),%rdx
- call compat_create_bounce_frame
+ call pv_create_exception_frame
jmp compat_test_all_events
/* %rbx: struct vcpu, interrupts disabled */
@@ -181,8 +181,7 @@ ENTRY(compat_post_handle_exception)
testb $TBF_EXCEPTION,TRAPBOUNCE_flags(%rdx)
jz compat_test_all_events
.Lcompat_bounce_exception:
- call compat_create_bounce_frame
- movb $0,TRAPBOUNCE_flags(%rdx)
+ call pv_create_exception_frame
jmp compat_test_all_events
/* See lstar_enter for entry register state. */
@@ -234,115 +233,10 @@ ENTRY(compat_sysenter)
movl $FLAT_COMPAT_USER_SS,UREGS_ss(%rsp)
cmovzl %ecx,%eax
movw %ax,TRAPBOUNCE_cs(%rdx)
- call compat_create_bounce_frame
+ call pv_create_exception_frame
jmp compat_test_all_events
ENTRY(compat_int80_direct_trap)
CR4_PV32_RESTORE
- call compat_create_bounce_frame
+ call pv_create_exception_frame
jmp compat_test_all_events
-
-/* CREATE A BASIC EXCEPTION FRAME ON GUEST OS (RING-1) STACK: */
-/* {[ERRCODE,] EIP, CS, EFLAGS, [ESP, SS]} */
-/* %rdx: trap_bounce, %rbx: struct vcpu */
-/* On return only %rbx and %rdx are guaranteed non-clobbered. */
-compat_create_bounce_frame:
- ASSERT_INTERRUPTS_ENABLED
- mov %fs,%edi
- ASM_STAC
- testb $2,UREGS_cs+8(%rsp)
- jz 1f
- /* Push new frame at registered guest-OS stack base. */
- movl VCPU_kernel_sp(%rbx),%esi
-.Lft1: mov VCPU_kernel_ss(%rbx),%fs
- subl $2*4,%esi
- movl UREGS_rsp+8(%rsp),%eax
-.Lft2: movl %eax,%fs:(%rsi)
- movl UREGS_ss+8(%rsp),%eax
-.Lft3: movl %eax,%fs:4(%rsi)
- jmp 2f
-1: /* In kernel context already: push new frame at existing %rsp. */
- movl UREGS_rsp+8(%rsp),%esi
-.Lft4: mov UREGS_ss+8(%rsp),%fs
-2:
- movq VCPU_domain(%rbx),%r8
- subl $3*4,%esi
- movq VCPU_vcpu_info(%rbx),%rax
- pushq COMPAT_VCPUINFO_upcall_mask(%rax)
- testb $TBF_INTERRUPT,TRAPBOUNCE_flags(%rdx)
- setnz %ch # TBF_INTERRUPT -> set upcall mask
- orb %ch,COMPAT_VCPUINFO_upcall_mask(%rax)
- popq %rax
- shll $16,%eax # Bits 16-23: saved_upcall_mask
- movw UREGS_cs+8(%rsp),%ax # Bits 0-15: CS
-.Lft5: movl %eax,%fs:4(%rsi) # CS / saved_upcall_mask
- shrl $16,%eax
- testb %al,%al # Bits 0-7: saved_upcall_mask
- setz %ch # %ch == !saved_upcall_mask
- movl UREGS_eflags+8(%rsp),%eax
- andl $~(X86_EFLAGS_IF|X86_EFLAGS_IOPL),%eax
- addb %ch,%ch # Bit 9 (EFLAGS.IF)
- orb %ch,%ah # Fold EFLAGS.IF into %eax
- xorl %ecx,%ecx # if ( VM_ASSIST(v->domain,
architectural_iopl) )
- testb $1 << VMASST_TYPE_architectural_iopl,DOMAIN_vm_assist(%r8)
- cmovnzl VCPU_iopl(%rbx),%ecx # Bits 13:12 (EFLAGS.IOPL)
- orl %ecx,%eax # Fold EFLAGS.IOPL into %eax
-.Lft6: movl %eax,%fs:2*4(%rsi) # EFLAGS
- movl UREGS_rip+8(%rsp),%eax
-.Lft7: movl %eax,%fs:(%rsi) # EIP
- testb $TBF_EXCEPTION_ERRCODE,TRAPBOUNCE_flags(%rdx)
- jz 1f
- subl $4,%esi
- movl TRAPBOUNCE_error_code(%rdx),%eax
-.Lft8: movl %eax,%fs:(%rsi) # ERROR CODE
-1:
- ASM_CLAC
- /* Rewrite our stack frame and return to guest-OS mode. */
- /* IA32 Ref. Vol. 3: TF, VM, RF and NT flags are cleared on trap. */
- andl $~(X86_EFLAGS_VM|X86_EFLAGS_RF|\
- X86_EFLAGS_NT|X86_EFLAGS_TF),UREGS_eflags+8(%rsp)
- mov %fs,UREGS_ss+8(%rsp)
- movl %esi,UREGS_rsp+8(%rsp)
-.Lft13: mov %edi,%fs
- movzwl TRAPBOUNCE_cs(%rdx),%eax
- /* Null selectors (0-3) are not allowed. */
- testl $~3,%eax
-UNLIKELY_START(z, compat_bounce_null_selector)
- lea UNLIKELY_DISPATCH_LABEL(compat_bounce_null_selector)(%rip), %rdi
- jmp asm_domain_crash_synchronous /* Does not return */
-__UNLIKELY_END(compat_bounce_null_selector)
- movl %eax,UREGS_cs+8(%rsp)
- movl TRAPBOUNCE_eip(%rdx),%eax
- movl %eax,UREGS_rip+8(%rsp)
- ret
-.section .fixup,"ax"
-.Lfx13:
- xorl %edi,%edi
- jmp .Lft13
-.previous
- _ASM_EXTABLE(.Lft1, dom_crash_sync_extable)
- _ASM_EXTABLE(.Lft2, compat_crash_page_fault)
- _ASM_EXTABLE(.Lft3, compat_crash_page_fault_4)
- _ASM_EXTABLE(.Lft4, dom_crash_sync_extable)
- _ASM_EXTABLE(.Lft5, compat_crash_page_fault_4)
- _ASM_EXTABLE(.Lft6, compat_crash_page_fault_8)
- _ASM_EXTABLE(.Lft7, compat_crash_page_fault)
- _ASM_EXTABLE(.Lft8, compat_crash_page_fault)
- _ASM_EXTABLE(.Lft13, .Lfx13)
-
-compat_crash_page_fault_8:
- addl $4,%esi
-compat_crash_page_fault_4:
- addl $4,%esi
-compat_crash_page_fault:
-.Lft14: mov %edi,%fs
- ASM_CLAC
- movl %esi,%edi
- call show_page_walk
- jmp dom_crash_sync_extable
-.section .fixup,"ax"
-.Lfx14:
- xorl %edi,%edi
- jmp .Lft14
-.previous
- _ASM_EXTABLE(.Lft14, .Lfx14)
diff --git a/xen/arch/x86/x86_64/entry.S b/xen/arch/x86/x86_64/entry.S
index 57952d0..7d59051 100644
--- a/xen/arch/x86/x86_64/entry.S
+++ b/xen/arch/x86/x86_64/entry.S
@@ -28,7 +28,7 @@ ENTRY(switch_to_kernel)
setc %cl
leal (,%rcx,TBF_INTERRUPT),%ecx
movb %cl,TRAPBOUNCE_flags(%rdx)
- call create_bounce_frame
+ call pv_create_exception_frame
andl $~X86_EFLAGS_DF,UREGS_eflags(%rsp)
jmp test_all_events
@@ -131,7 +131,7 @@ test_guest_events:
movq VCPU_event_addr(%rbx),%rax
movq %rax,TRAPBOUNCE_eip(%rdx)
movb $TBF_INTERRUPT,TRAPBOUNCE_flags(%rdx)
- call create_bounce_frame
+ call pv_create_exception_frame
jmp test_all_events
ALIGN
@@ -175,7 +175,7 @@ process_nmi:
/* FALLTHROUGH */
process_trap:
leaq VCPU_trap_bounce(%rbx),%rdx
- call create_bounce_frame
+ call pv_create_exception_frame
jmp test_all_events
ENTRY(sysenter_entry)
@@ -266,7 +266,7 @@ UNLIKELY_END(msi_check)
testb $1,DOMAIN_is_32bit_pv(%rax)
jnz compat_int80_direct_trap
- call create_bounce_frame
+ call pv_create_exception_frame
jmp test_all_events
int80_slow_path:
@@ -281,136 +281,6 @@ int80_slow_path:
subq $2,UREGS_rip(%rsp)
jmp handle_exception_saved
-/* CREATE A BASIC EXCEPTION FRAME ON GUEST OS STACK: */
-/* { RCX, R11, [ERRCODE,] RIP, CS, RFLAGS, RSP, SS } */
-/* %rdx: trap_bounce, %rbx: struct vcpu */
-/* On return only %rbx and %rdx are guaranteed non-clobbered. */
-create_bounce_frame:
- ASSERT_INTERRUPTS_ENABLED
- testb $TF_kernel_mode,VCPU_thread_flags(%rbx)
- jnz 1f
- /* Push new frame at registered guest-OS stack base. */
- pushq %rdx
- movq %rbx,%rdi
- call toggle_guest_mode
- popq %rdx
- movq VCPU_kernel_sp(%rbx),%rsi
- jmp 2f
-1: /* In kernel context already: push new frame at existing %rsp. */
- movq UREGS_rsp+8(%rsp),%rsi
- andb $0xfc,UREGS_cs+8(%rsp) # Indicate kernel context to guest.
-2: andq $~0xf,%rsi # Stack frames are 16-byte aligned.
- movq $HYPERVISOR_VIRT_START+1,%rax
- cmpq %rax,%rsi
- movq $HYPERVISOR_VIRT_END+8*8,%rax
- sbb %ecx,%ecx # In +ve address space? Then okay.
- cmpq %rax,%rsi
- adc %ecx,%ecx # Above Xen private area? Then okay.
-UNLIKELY_START(g, create_bounce_frame_bad_sp)
- lea UNLIKELY_DISPATCH_LABEL(create_bounce_frame_bad_sp)(%rip), %rdi
- jmp asm_domain_crash_synchronous /* Does not return */
-__UNLIKELY_END(create_bounce_frame_bad_sp)
-
-#define STORE_GUEST_STACK(reg, n) \
-0: movq %reg,(n)*8(%rsi); \
- _ASM_EXTABLE(0b, domain_crash_page_fault_ ## n ## x8)
-
- subq $7*8,%rsi
- movq UREGS_ss+8(%rsp),%rax
- ASM_STAC
- movq VCPU_domain(%rbx),%rdi
- STORE_GUEST_STACK(rax,6) # SS
- movq UREGS_rsp+8(%rsp),%rax
- STORE_GUEST_STACK(rax,5) # RSP
- movq VCPU_vcpu_info(%rbx),%rax
- pushq VCPUINFO_upcall_mask(%rax)
- testb $TBF_INTERRUPT,TRAPBOUNCE_flags(%rdx)
- setnz %ch # TBF_INTERRUPT -> set upcall mask
- orb %ch,VCPUINFO_upcall_mask(%rax)
- popq %rax
- shlq $32,%rax # Bits 32-39: saved_upcall_mask
- movw UREGS_cs+8(%rsp),%ax # Bits 0-15: CS
- STORE_GUEST_STACK(rax,3) # CS / saved_upcall_mask
- shrq $32,%rax
- testb $0xFF,%al # Bits 0-7: saved_upcall_mask
- setz %ch # %ch == !saved_upcall_mask
- movl UREGS_eflags+8(%rsp),%eax
- andl $~(X86_EFLAGS_IF|X86_EFLAGS_IOPL),%eax
- addb %ch,%ch # Bit 9 (EFLAGS.IF)
- orb %ch,%ah # Fold EFLAGS.IF into %eax
- xorl %ecx,%ecx # if ( VM_ASSIST(v->domain,
architectural_iopl) )
- testb $1 << VMASST_TYPE_architectural_iopl,DOMAIN_vm_assist(%rdi)
- cmovnzl VCPU_iopl(%rbx),%ecx # Bits 13:12 (EFLAGS.IOPL)
- orl %ecx,%eax # Fold EFLAGS.IOPL into %eax
- STORE_GUEST_STACK(rax,4) # RFLAGS
- movq UREGS_rip+8(%rsp),%rax
- STORE_GUEST_STACK(rax,2) # RIP
- testb $TBF_EXCEPTION_ERRCODE,TRAPBOUNCE_flags(%rdx)
- jz 1f
- subq $8,%rsi
- movl TRAPBOUNCE_error_code(%rdx),%eax
- STORE_GUEST_STACK(rax,2) # ERROR CODE
-1:
- movq UREGS_r11+8(%rsp),%rax
- STORE_GUEST_STACK(rax,1) # R11
- movq UREGS_rcx+8(%rsp),%rax
- STORE_GUEST_STACK(rax,0) # RCX
- ASM_CLAC
-
-#undef STORE_GUEST_STACK
-
- /* Rewrite our stack frame and return to guest-OS mode. */
- /* IA32 Ref. Vol. 3: TF, VM, RF and NT flags are cleared on trap. */
- /* Also clear AC: alignment checks shouldn't trigger in kernel mode. */
- orl $TRAP_syscall,UREGS_entry_vector+8(%rsp)
- andl $~(X86_EFLAGS_AC|X86_EFLAGS_VM|X86_EFLAGS_RF|\
- X86_EFLAGS_NT|X86_EFLAGS_TF),UREGS_eflags+8(%rsp)
- movq $FLAT_KERNEL_SS,UREGS_ss+8(%rsp)
- movq %rsi,UREGS_rsp+8(%rsp)
- movq $FLAT_KERNEL_CS,UREGS_cs+8(%rsp)
- movq TRAPBOUNCE_eip(%rdx),%rax
- testq %rax,%rax
-UNLIKELY_START(z, create_bounce_frame_bad_bounce_ip)
- lea
UNLIKELY_DISPATCH_LABEL(create_bounce_frame_bad_bounce_ip)(%rip), %rdi
- jmp asm_domain_crash_synchronous /* Does not return */
-__UNLIKELY_END(create_bounce_frame_bad_bounce_ip)
- movq %rax,UREGS_rip+8(%rsp)
- ret
-
- .pushsection .fixup, "ax", @progbits
- # Numeric tags below represent the intended overall %rsi adjustment.
-domain_crash_page_fault_6x8:
- addq $8,%rsi
-domain_crash_page_fault_5x8:
- addq $8,%rsi
-domain_crash_page_fault_4x8:
- addq $8,%rsi
-domain_crash_page_fault_3x8:
- addq $8,%rsi
-domain_crash_page_fault_2x8:
- addq $8,%rsi
-domain_crash_page_fault_1x8:
- addq $8,%rsi
-domain_crash_page_fault_0x8:
- ASM_CLAC
- movq %rsi,%rdi
- call show_page_walk
-ENTRY(dom_crash_sync_extable)
- ASM_CLAC
- # Get out of the guest-save area of the stack.
- GET_STACK_END(ax)
- leaq STACK_CPUINFO_FIELD(guest_cpu_user_regs)(%rax),%rsp
- # create_bounce_frame() temporarily clobbers CS.RPL. Fix up.
- __GET_CURRENT(ax)
- movq VCPU_domain(%rax),%rax
- testb $1,DOMAIN_is_32bit_pv(%rax)
- setz %al
- leal (%rax,%rax,2),%eax
- orb %al,UREGS_cs(%rsp)
- xorl %edi,%edi
- jmp asm_domain_crash_synchronous /* Does not return */
- .popsection
-
ENTRY(common_interrupt)
SAVE_ALL CLAC
CR4_PV32_RESTORE
@@ -506,8 +376,7 @@ handle_exception_saved:
testb $TBF_EXCEPTION,TRAPBOUNCE_flags(%rdx)
jz test_all_events
.Lbounce_exception:
- call create_bounce_frame
- movb $0,TRAPBOUNCE_flags(%rdx)
+ call pv_create_exception_frame
jmp test_all_events
/* No special register assumptions. */
diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h
index 1127ca9..a0ef63a 100644
--- a/xen/include/xen/sched.h
+++ b/xen/include/xen/sched.h
@@ -632,13 +632,6 @@ void noreturn __domain_crash_synchronous(void);
__domain_crash_synchronous(); \
} while (0)
-/*
- * Called from assembly code, with an optional address to help indicate why
- * the crash occured. If addr is 0, look up address from last extable
- * redirection.
- */
-void noreturn asm_domain_crash_synchronous(unsigned long addr);
-
#define set_current_state(_s) do { current->state = (_s); } while (0)
void scheduler_init(void);
int sched_init_vcpu(struct vcpu *v, unsigned int processor);
--
2.1.4
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