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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH 06/15] x86/emul: Rework emulator event injection
The emulator needs to gain an understanding of interrupts and exceptions
generated by its actions.
Move hvm_emulate_ctxt.{exn_pending,trap} into struct x86_emulate_ctxt so they
are visible to the emulator. This removes the need for the
inject_{hw,sw}_interrupt() hooks, which are dropped and replaced with
x86_emul_{hw_exception,software_event}() instead.
The shadow pagetable and PV uses of x86_emulate() previously failed with
X86EMUL_UNHANDLEABLE due to the lack of inject_*() hooks, but this behaviour
has subtly changed. Adjust the return value checking to cause a pending event
to fall back into the previous codepath.
No overall functional change.
Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: Jan Beulich <JBeulich@xxxxxxxx>
CC: Paul Durrant <paul.durrant@xxxxxxxxxx>
CC: Tim Deegan <tim@xxxxxxx>
CC: George Dunlap <george.dunlap@xxxxxxxxxxxxx>
CC: Jun Nakajima <jun.nakajima@xxxxxxxxx>
CC: Kevin Tian <kevin.tian@xxxxxxxxx>
CC: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
CC: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
---
tools/tests/x86_emulator/test_x86_emulator.c | 1 +
xen/arch/x86/hvm/emulate.c | 81 ++++------------------------
xen/arch/x86/hvm/hvm.c | 4 +-
xen/arch/x86/hvm/io.c | 4 +-
xen/arch/x86/hvm/vmx/realmode.c | 16 +++---
xen/arch/x86/mm.c | 5 +-
xen/arch/x86/mm/shadow/multi.c | 4 +-
xen/arch/x86/x86_emulate/x86_emulate.c | 12 ++---
xen/arch/x86/x86_emulate/x86_emulate.h | 67 ++++++++++++++++++-----
xen/include/asm-x86/hvm/emulate.h | 3 --
10 files changed, 86 insertions(+), 111 deletions(-)
diff --git a/tools/tests/x86_emulator/test_x86_emulator.c
b/tools/tests/x86_emulator/test_x86_emulator.c
index 948ee8d..146e15e 100644
--- a/tools/tests/x86_emulator/test_x86_emulator.c
+++ b/tools/tests/x86_emulator/test_x86_emulator.c
@@ -1,3 +1,4 @@
+#include <assert.h>
#include <errno.h>
#include <limits.h>
#include <stdbool.h>
diff --git a/xen/arch/x86/hvm/emulate.c b/xen/arch/x86/hvm/emulate.c
index 790e9c1..c0fbde1 100644
--- a/xen/arch/x86/hvm/emulate.c
+++ b/xen/arch/x86/hvm/emulate.c
@@ -568,12 +568,9 @@ static int hvmemul_virtual_to_linear(
return X86EMUL_UNHANDLEABLE;
/* This is a singleton operation: fail it with an exception. */
- hvmemul_ctxt->exn_pending = 1;
- hvmemul_ctxt->trap.vector =
- (seg == x86_seg_ss) ? TRAP_stack_error : TRAP_gp_fault;
- hvmemul_ctxt->trap.type = X86_EVENTTYPE_HW_EXCEPTION;
- hvmemul_ctxt->trap.error_code = 0;
- hvmemul_ctxt->trap.insn_len = 0;
+ x86_emul_hw_exception((seg == x86_seg_ss)
+ ? TRAP_stack_error
+ : TRAP_gp_fault, 0, &hvmemul_ctxt->ctxt);
return X86EMUL_EXCEPTION;
}
@@ -1562,59 +1559,6 @@ int hvmemul_cpuid(
return X86EMUL_OKAY;
}
-static int hvmemul_inject_hw_exception(
- uint8_t vector,
- int32_t error_code,
- struct x86_emulate_ctxt *ctxt)
-{
- struct hvm_emulate_ctxt *hvmemul_ctxt =
- container_of(ctxt, struct hvm_emulate_ctxt, ctxt);
-
- hvmemul_ctxt->exn_pending = 1;
- hvmemul_ctxt->trap.vector = vector;
- hvmemul_ctxt->trap.type = X86_EVENTTYPE_HW_EXCEPTION;
- hvmemul_ctxt->trap.error_code = error_code;
- hvmemul_ctxt->trap.insn_len = 0;
-
- return X86EMUL_OKAY;
-}
-
-static int hvmemul_inject_sw_interrupt(
- enum x86_swint_type type,
- uint8_t vector,
- uint8_t insn_len,
- struct x86_emulate_ctxt *ctxt)
-{
- struct hvm_emulate_ctxt *hvmemul_ctxt =
- container_of(ctxt, struct hvm_emulate_ctxt, ctxt);
-
- switch ( type )
- {
- case x86_swint_icebp:
- hvmemul_ctxt->trap.type = X86_EVENTTYPE_PRI_SW_EXCEPTION;
- break;
-
- case x86_swint_int3:
- case x86_swint_into:
- hvmemul_ctxt->trap.type = X86_EVENTTYPE_SW_EXCEPTION;
- break;
-
- case x86_swint_int:
- hvmemul_ctxt->trap.type = X86_EVENTTYPE_SW_INTERRUPT;
- break;
-
- default:
- return X86EMUL_UNHANDLEABLE;
- }
-
- hvmemul_ctxt->exn_pending = 1;
- hvmemul_ctxt->trap.vector = vector;
- hvmemul_ctxt->trap.error_code = X86_EVENT_NO_EC;
- hvmemul_ctxt->trap.insn_len = insn_len;
-
- return X86EMUL_OKAY;
-}
-
static int hvmemul_get_fpu(
void (*exception_callback)(void *, struct cpu_user_regs *),
void *exception_callback_arg,
@@ -1678,8 +1622,7 @@ static int hvmemul_invlpg(
* hvmemul_virtual_to_linear() raises exceptions for type/limit
* violations, so squash them.
*/
- hvmemul_ctxt->exn_pending = 0;
- hvmemul_ctxt->trap = (struct x86_event){};
+ x86_emul_reset_event(ctxt);
rc = X86EMUL_OKAY;
}
@@ -1696,7 +1639,7 @@ static int hvmemul_vmfunc(
rc = hvm_funcs.altp2m_vcpu_emulate_vmfunc(ctxt->regs);
if ( rc != X86EMUL_OKAY )
- hvmemul_inject_hw_exception(TRAP_invalid_op, 0, ctxt);
+ x86_emul_hw_exception(TRAP_invalid_op, 0, ctxt);
return rc;
}
@@ -1720,8 +1663,6 @@ static const struct x86_emulate_ops hvm_emulate_ops = {
.write_msr = hvmemul_write_msr,
.wbinvd = hvmemul_wbinvd,
.cpuid = hvmemul_cpuid,
- .inject_hw_exception = hvmemul_inject_hw_exception,
- .inject_sw_interrupt = hvmemul_inject_sw_interrupt,
.get_fpu = hvmemul_get_fpu,
.put_fpu = hvmemul_put_fpu,
.invlpg = hvmemul_invlpg,
@@ -1747,8 +1688,6 @@ static const struct x86_emulate_ops
hvm_emulate_ops_no_write = {
.write_msr = hvmemul_write_msr_discard,
.wbinvd = hvmemul_wbinvd_discard,
.cpuid = hvmemul_cpuid,
- .inject_hw_exception = hvmemul_inject_hw_exception,
- .inject_sw_interrupt = hvmemul_inject_sw_interrupt,
.get_fpu = hvmemul_get_fpu,
.put_fpu = hvmemul_put_fpu,
.invlpg = hvmemul_invlpg,
@@ -1867,8 +1806,8 @@ int hvm_emulate_one_mmio(unsigned long mfn, unsigned long
gla)
hvm_dump_emulation_state(XENLOG_G_WARNING "MMCFG", &ctxt);
break;
case X86EMUL_EXCEPTION:
- if ( ctxt.exn_pending )
- hvm_inject_event(&ctxt.trap);
+ if ( ctxt.ctxt.event_pending )
+ hvm_inject_event(&ctxt.ctxt.event);
/* fallthrough */
default:
hvm_emulate_writeback(&ctxt);
@@ -1927,8 +1866,8 @@ void hvm_emulate_one_vm_event(enum emul_kind kind,
unsigned int trapnr,
hvm_inject_hw_exception(trapnr, errcode);
break;
case X86EMUL_EXCEPTION:
- if ( ctx.exn_pending )
- hvm_inject_event(&ctx.trap);
+ if ( ctx.ctxt.event_pending )
+ hvm_inject_event(&ctx.ctxt.event);
break;
}
@@ -2005,8 +1944,6 @@ void hvm_emulate_init_per_insn(
hvmemul_ctxt->insn_buf_bytes = insn_bytes;
memcpy(hvmemul_ctxt->insn_buf, insn_buf, insn_bytes);
}
-
- hvmemul_ctxt->exn_pending = 0;
}
void hvm_emulate_writeback(
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index b950842..ef83100 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -4076,8 +4076,8 @@ void hvm_ud_intercept(struct cpu_user_regs *regs)
hvm_inject_hw_exception(TRAP_invalid_op, X86_EVENT_NO_EC);
break;
case X86EMUL_EXCEPTION:
- if ( ctxt.exn_pending )
- hvm_inject_event(&ctxt.trap);
+ if ( ctxt.ctxt.event_pending )
+ hvm_inject_event(&ctxt.ctxt.event);
/* fall through */
default:
hvm_emulate_writeback(&ctxt);
diff --git a/xen/arch/x86/hvm/io.c b/xen/arch/x86/hvm/io.c
index 1279f68..abb9d51 100644
--- a/xen/arch/x86/hvm/io.c
+++ b/xen/arch/x86/hvm/io.c
@@ -102,8 +102,8 @@ int handle_mmio(void)
hvm_dump_emulation_state(XENLOG_G_WARNING "MMIO", &ctxt);
return 0;
case X86EMUL_EXCEPTION:
- if ( ctxt.exn_pending )
- hvm_inject_event(&ctxt.trap);
+ if ( ctxt.ctxt.event_pending )
+ hvm_inject_event(&ctxt.ctxt.event);
break;
default:
break;
diff --git a/xen/arch/x86/hvm/vmx/realmode.c b/xen/arch/x86/hvm/vmx/realmode.c
index 9002638..dc3ab44 100644
--- a/xen/arch/x86/hvm/vmx/realmode.c
+++ b/xen/arch/x86/hvm/vmx/realmode.c
@@ -122,7 +122,7 @@ void vmx_realmode_emulate_one(struct hvm_emulate_ctxt
*hvmemul_ctxt)
if ( rc == X86EMUL_EXCEPTION )
{
- if ( !hvmemul_ctxt->exn_pending )
+ if ( !hvmemul_ctxt->ctxt.event_pending )
{
unsigned long intr_info;
@@ -133,27 +133,27 @@ void vmx_realmode_emulate_one(struct hvm_emulate_ctxt
*hvmemul_ctxt)
gdprintk(XENLOG_ERR, "Exception pending but no info.\n");
goto fail;
}
- hvmemul_ctxt->trap.vector = (uint8_t)intr_info;
- hvmemul_ctxt->trap.insn_len = 0;
+ hvmemul_ctxt->ctxt.event.vector = (uint8_t)intr_info;
+ hvmemul_ctxt->ctxt.event.insn_len = 0;
}
if ( unlikely(curr->domain->debugger_attached) &&
- ((hvmemul_ctxt->trap.vector == TRAP_debug) ||
- (hvmemul_ctxt->trap.vector == TRAP_int3)) )
+ ((hvmemul_ctxt->ctxt.event.vector == TRAP_debug) ||
+ (hvmemul_ctxt->ctxt.event.vector == TRAP_int3)) )
{
domain_pause_for_debugger();
}
else if ( curr->arch.hvm_vcpu.guest_cr[0] & X86_CR0_PE )
{
gdprintk(XENLOG_ERR, "Exception %02x in protected mode.\n",
- hvmemul_ctxt->trap.vector);
+ hvmemul_ctxt->ctxt.event.vector);
goto fail;
}
else
{
realmode_deliver_exception(
- hvmemul_ctxt->trap.vector,
- hvmemul_ctxt->trap.insn_len,
+ hvmemul_ctxt->ctxt.event.vector,
+ hvmemul_ctxt->ctxt.event.insn_len,
hvmemul_ctxt);
}
}
diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 9901f6f..66ecdab 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -5377,7 +5377,7 @@ int ptwr_do_page_fault(struct vcpu *v, unsigned long addr,
page_unlock(page);
put_page(page);
- if ( rc == X86EMUL_UNHANDLEABLE )
+ if ( rc == X86EMUL_UNHANDLEABLE || ptwr_ctxt.ctxt.event_pending )
goto bail;
perfc_incr(ptwr_emulations);
@@ -5501,7 +5501,8 @@ int mmio_ro_do_page_fault(struct vcpu *v, unsigned long
addr,
else
rc = x86_emulate(&ctxt, &mmio_ro_emulate_ops);
- return rc != X86EMUL_UNHANDLEABLE ? EXCRET_fault_fixed : 0;
+ return ((rc != X86EMUL_UNHANDLEABLE && !ctxt.event_pending)
+ ? EXCRET_fault_fixed : 0);
}
void *alloc_xen_pagetable(void)
diff --git a/xen/arch/x86/mm/shadow/multi.c b/xen/arch/x86/mm/shadow/multi.c
index d70b1c6..84cb6b6 100644
--- a/xen/arch/x86/mm/shadow/multi.c
+++ b/xen/arch/x86/mm/shadow/multi.c
@@ -3378,7 +3378,7 @@ static int sh_page_fault(struct vcpu *v,
* would be a good unshadow hint. If we *do* decide to unshadow-on-fault
* then it must be 'failable': we cannot require the unshadow to succeed.
*/
- if ( r == X86EMUL_UNHANDLEABLE )
+ if ( r == X86EMUL_UNHANDLEABLE || emul_ctxt.ctxt.event_pending )
{
perfc_incr(shadow_fault_emulate_failed);
#if SHADOW_OPTIMIZATIONS & SHOPT_FAST_EMULATION
@@ -3433,7 +3433,7 @@ static int sh_page_fault(struct vcpu *v,
shadow_continue_emulation(&emul_ctxt, regs);
v->arch.paging.last_write_was_pt = 0;
r = x86_emulate(&emul_ctxt.ctxt, emul_ops);
- if ( r == X86EMUL_OKAY )
+ if ( r == X86EMUL_OKAY && !emul_ctxt.ctxt.event_pending )
{
emulation_count++;
if ( v->arch.paging.last_write_was_pt )
diff --git a/xen/arch/x86/x86_emulate/x86_emulate.c
b/xen/arch/x86/x86_emulate/x86_emulate.c
index f8271b3..768a436 100644
--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -680,9 +680,8 @@ static inline int mkec(uint8_t e, int32_t ec, ...)
#define generate_exception_if(p, e, ec...) \
({ if ( (p) ) { \
- fail_if(ops->inject_hw_exception == NULL); \
- rc = ops->inject_hw_exception(e, mkec(e, ##ec, 0), ctxt) \
- ? : X86EMUL_EXCEPTION; \
+ x86_emul_hw_exception(e, mkec(e, ##ec, 0), ctxt); \
+ rc = X86EMUL_EXCEPTION; \
goto done; \
} \
})
@@ -1604,9 +1603,6 @@ static int inject_swint(enum x86_swint_type type,
{
int rc, error_code, fault_type = EXC_GP;
- fail_if(ops->inject_sw_interrupt == NULL);
- fail_if(ops->inject_hw_exception == NULL);
-
/*
* Without hardware support, injecting software interrupts/exceptions is
* problematic.
@@ -1703,7 +1699,8 @@ static int inject_swint(enum x86_swint_type type,
ctxt->regs->eip += insn_len;
}
- rc = ops->inject_sw_interrupt(type, vector, insn_len, ctxt);
+ x86_emul_software_event(type, vector, insn_len, ctxt);
+ rc = X86EMUL_OKAY;
done:
return rc;
@@ -1912,6 +1909,7 @@ x86_decode(
/* Initialise output state in x86_emulate_ctxt */
ctxt->opcode = ~0u;
ctxt->retire.byte = 0;
+ x86_emul_reset_event(ctxt);
op_bytes = def_op_bytes = ad_bytes = def_ad_bytes = ctxt->addr_size/8;
if ( op_bytes == 8 )
diff --git a/xen/arch/x86/x86_emulate/x86_emulate.h
b/xen/arch/x86/x86_emulate/x86_emulate.h
index 9df083e..ddcd93c 100644
--- a/xen/arch/x86/x86_emulate/x86_emulate.h
+++ b/xen/arch/x86/x86_emulate/x86_emulate.h
@@ -388,19 +388,6 @@ struct x86_emulate_ops
unsigned int *edx,
struct x86_emulate_ctxt *ctxt);
- /* inject_hw_exception */
- int (*inject_hw_exception)(
- uint8_t vector,
- int32_t error_code,
- struct x86_emulate_ctxt *ctxt);
-
- /* inject_sw_interrupt */
- int (*inject_sw_interrupt)(
- enum x86_swint_type type,
- uint8_t vector,
- uint8_t insn_len,
- struct x86_emulate_ctxt *ctxt);
-
/*
* get_fpu: Load emulated environment's FPU state onto processor.
* @exn_callback: On any FPU or SIMD exception, pass control to
@@ -473,6 +460,9 @@ struct x86_emulate_ctxt
} flags;
uint8_t byte;
} retire;
+
+ bool event_pending;
+ struct x86_event event;
};
/*
@@ -594,4 +584,55 @@ void x86_emulate_free_state(struct x86_emulate_state
*state);
#endif
+#ifndef ASSERT
+#define ASSERT assert
+#endif
+
+static inline void x86_emul_hw_exception(
+ unsigned int vector, unsigned int error_code, struct x86_emulate_ctxt
*ctxt)
+{
+ ASSERT(!ctxt->event_pending);
+
+ ctxt->event.vector = vector;
+ ctxt->event.type = X86_EVENTTYPE_HW_EXCEPTION;
+ ctxt->event.error_code = error_code;
+
+ ctxt->event_pending = true;
+}
+
+static inline void x86_emul_software_event(
+ enum x86_swint_type type, uint8_t vector, uint8_t insn_len,
+ struct x86_emulate_ctxt *ctxt)
+{
+ ASSERT(!ctxt->event_pending);
+
+ switch ( type )
+ {
+ case x86_swint_icebp:
+ ctxt->event.type = X86_EVENTTYPE_PRI_SW_EXCEPTION;
+ break;
+
+ case x86_swint_int3:
+ case x86_swint_into:
+ ctxt->event.type = X86_EVENTTYPE_SW_EXCEPTION;
+ break;
+
+ case x86_swint_int:
+ ctxt->event.type = X86_EVENTTYPE_SW_INTERRUPT;
+ break;
+ }
+
+ ctxt->event.vector = vector;
+ ctxt->event.error_code = X86_EVENT_NO_EC;
+ ctxt->event.insn_len = insn_len;
+
+ ctxt->event_pending = true;
+}
+
+static inline void x86_emul_reset_event(struct x86_emulate_ctxt *ctxt)
+{
+ ctxt->event_pending = false;
+ ctxt->event = (struct x86_event){};
+}
+
#endif /* __X86_EMULATE_H__ */
diff --git a/xen/include/asm-x86/hvm/emulate.h
b/xen/include/asm-x86/hvm/emulate.h
index 3b7ec33..d64d834 100644
--- a/xen/include/asm-x86/hvm/emulate.h
+++ b/xen/include/asm-x86/hvm/emulate.h
@@ -29,9 +29,6 @@ struct hvm_emulate_ctxt {
unsigned long seg_reg_accessed;
unsigned long seg_reg_dirty;
- bool_t exn_pending;
- struct x86_event trap;
-
uint32_t intr_shadow;
bool_t set_context;
--
2.1.4
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