From: Aravindh Puthiyaparambil Date: Tue, 31 May 2011 13:03:17 +0000 (+0100) Subject: mem_event: Revert pointless, unrelated, and broken (on i386) change in 23434:ef410f262299 X-Git-Tag: 4.1.1-rc2~4 X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=59909f50de3db6916120fb41be6e679f1a5afd0a;p=people%2Fvhanquez%2Fxen.git mem_event: Revert pointless, unrelated, and broken (on i386) change in 23434:ef410f262299 vcpu_pause() is nestable in the hypervisor, hence checking for already-paused is not required. Signed-off-by: Keir Fraser xen-unstable changeset: 23435:c15f06b99bbe xen-unstable date: Sat May 28 08:33:54 2011 +0100 mem_event: Allow memory access listener to perform single step execution. Add a new memory event that handles single step. This allows the memory access listener to handle instructions that modify data within the execution page. This can be enabled in the listener by doing: xc_set_hvm_param(xch, domain_id, HVM_PARAM_MEMORY_EVENT_SINGLE_STEP, HVMPME_mode_sync) Now the listener can start single stepping by: xc_domain_debug_control(xch, domain_id, XEN_DOMCTL_DEBUG_OP_SINGLE_STEP_ON, vcpu_id) And stop single stepping by: xc_domain_debug_control(xch, domain_id, XEN_DOMCTL_DEBUG_OP_SINGLE_STEP_OFF, vcpu_id) Signed-off-by: Aravindh Puthiyaparambil Acked-by: Tim Deegan xen-unstable changeset: 23434:ef410f262299 xen-unstable date: Fri May 27 18:44:26 2011 +0100 --- diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c index ce3caa4fc..bb086bcb2 100644 --- a/xen/arch/x86/hvm/hvm.c +++ b/xen/arch/x86/hvm/hvm.c @@ -3257,7 +3257,8 @@ long do_hvm_op(unsigned long op, XEN_GUEST_HANDLE(void) arg) rc = -EPERM; break; case HVM_PARAM_MEMORY_EVENT_INT3: - if ( d == current->domain ) + case HVM_PARAM_MEMORY_EVENT_SINGLE_STEP: + if ( d == current->domain ) { rc = -EPERM; break; @@ -3274,6 +3275,7 @@ long do_hvm_op(unsigned long op, XEN_GUEST_HANDLE(void) arg) switch( a.index ) { case HVM_PARAM_MEMORY_EVENT_INT3: + case HVM_PARAM_MEMORY_EVENT_SINGLE_STEP: { domain_pause(d); domain_unpause(d); /* Causes guest to latch new status */ @@ -3885,6 +3887,18 @@ int hvm_memory_event_int3(unsigned long gla) MEM_EVENT_REASON_INT3, gfn, 0, 1, gla); } + +int hvm_memory_event_single_step(unsigned long gla) +{ + uint32_t pfec = PFEC_page_present; + unsigned long gfn; + gfn = paging_gva_to_gfn(current, gla, &pfec); + + return hvm_memory_event_traps(current->domain->arch.hvm_domain + .params[HVM_PARAM_MEMORY_EVENT_SINGLE_STEP], + MEM_EVENT_REASON_SINGLESTEP, + gfn, 0, 1, gla); +} #endif /* __x86_64__ */ /* diff --git a/xen/arch/x86/hvm/vmx/vmcs.c b/xen/arch/x86/hvm/vmx/vmcs.c index 18e705515..e51dcdaf1 100644 --- a/xen/arch/x86/hvm/vmx/vmcs.c +++ b/xen/arch/x86/hvm/vmx/vmcs.c @@ -1083,8 +1083,9 @@ void vmx_do_resume(struct vcpu *v) hvm_asid_flush_vcpu(v); } - debug_state = v->domain->debugger_attached - || v->domain->arch.hvm_domain.params[HVM_PARAM_MEMORY_EVENT_INT3]; + debug_state = v->domain->debugger_attached + || v->domain->arch.hvm_domain.params[HVM_PARAM_MEMORY_EVENT_INT3] + || v->domain->arch.hvm_domain.params[HVM_PARAM_MEMORY_EVENT_SINGLE_STEP]; if ( unlikely(v->arch.hvm_vcpu.debug_state_latch != debug_state) ) { diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c index cd5545b36..ab903a354 100644 --- a/xen/arch/x86/hvm/vmx/vmx.c +++ b/xen/arch/x86/hvm/vmx/vmx.c @@ -2626,8 +2626,12 @@ asmlinkage void vmx_vmexit_handler(struct cpu_user_regs *regs) case EXIT_REASON_MONITOR_TRAP_FLAG: v->arch.hvm_vmx.exec_control &= ~CPU_BASED_MONITOR_TRAP_FLAG; vmx_update_cpu_exec_control(v); - if ( v->domain->debugger_attached && v->arch.hvm_vcpu.single_step ) - domain_pause_for_debugger(); + if ( v->arch.hvm_vcpu.single_step ) { + hvm_memory_event_single_step(regs->eip); + if ( v->domain->debugger_attached ) + domain_pause_for_debugger(); + } + break; case EXIT_REASON_PAUSE_INSTRUCTION: diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h index 46baf2c89..fd79ba203 100644 --- a/xen/include/asm-x86/hvm/hvm.h +++ b/xen/include/asm-x86/hvm/hvm.h @@ -380,6 +380,10 @@ void hvm_memory_event_cr4(unsigned long value, unsigned long old); /* Called for current VCPU on int3: returns -1 if no listener */ int hvm_memory_event_int3(unsigned long gla); + +/* Called for current VCPU on single step: returns -1 if no listener */ +int hvm_memory_event_single_step(unsigned long gla); + #else static inline void hvm_memory_event_cr0(unsigned long value, unsigned long old) { } @@ -389,6 +393,8 @@ static inline void hvm_memory_event_cr4(unsigned long value, unsigned long old) { } static inline int hvm_memory_event_int3(unsigned long gla) { return 0; } +static inline int hvm_memory_event_single_step(unsigned long gla) +{ return 0; } #endif #endif /* __ASM_X86_HVM_HVM_H__ */ diff --git a/xen/include/public/hvm/params.h b/xen/include/public/hvm/params.h index 45b9a6398..1c98277d7 100644 --- a/xen/include/public/hvm/params.h +++ b/xen/include/public/hvm/params.h @@ -126,10 +126,11 @@ /* Enable blocking memory events, async or sync (pause vcpu until response) * onchangeonly indicates messages only on a change of value */ -#define HVM_PARAM_MEMORY_EVENT_CR0 20 -#define HVM_PARAM_MEMORY_EVENT_CR3 21 -#define HVM_PARAM_MEMORY_EVENT_CR4 22 -#define HVM_PARAM_MEMORY_EVENT_INT3 23 +#define HVM_PARAM_MEMORY_EVENT_CR0 20 +#define HVM_PARAM_MEMORY_EVENT_CR3 21 +#define HVM_PARAM_MEMORY_EVENT_CR4 22 +#define HVM_PARAM_MEMORY_EVENT_INT3 23 +#define HVM_PARAM_MEMORY_EVENT_SINGLE_STEP 25 #define HVMPME_MODE_MASK (3 << 0) #define HVMPME_mode_disabled 0 @@ -137,6 +138,6 @@ #define HVMPME_mode_sync 2 #define HVMPME_onchangeonly (1 << 2) -#define HVM_NR_PARAMS 24 +#define HVM_NR_PARAMS 26 #endif /* __XEN_PUBLIC_HVM_PARAMS_H__ */ diff --git a/xen/include/public/mem_event.h b/xen/include/public/mem_event.h index 93c824b86..45c15d3ef 100644 --- a/xen/include/public/mem_event.h +++ b/xen/include/public/mem_event.h @@ -46,6 +46,7 @@ #define MEM_EVENT_REASON_CR3 3 /* CR3 was hit: gfn is CR3 value */ #define MEM_EVENT_REASON_CR4 4 /* CR4 was hit: gfn is CR4 value */ #define MEM_EVENT_REASON_INT3 5 /* int3 was hit: gla/gfn are RIP */ +#define MEM_EVENT_REASON_SINGLESTEP 6 /* single step was invoked: gla/gfn are RIP */ typedef struct mem_event_shared_page { uint32_t port;