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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH 4/8] x86/vm-event/monitor: turn monitor_write_data.do_write into enum
After trapping a control-register write vm-event and -until- deciding if that
write is to be permitted or not (VM_EVENT_FLAG_DENY) and doing the actual write,
there cannot and should not be another trapped control-register write event.
That is, currently -only one- of the fields of monitor_write_data.do_write can
be true at any given moment and therefore it would be more appropriate to
replace those fields with an enum value.
Signed-off-by: Corneliu ZUZU <czuzu@xxxxxxxxxxxxxxx>
---
xen/arch/x86/hvm/hvm.c | 18 +++++++++++-------
xen/arch/x86/monitor.c | 37 ++++++++++++++++++-------------------
xen/arch/x86/vm_event.c | 25 ++-----------------------
xen/include/asm-x86/domain.h | 20 ++++++++++----------
4 files changed, 41 insertions(+), 59 deletions(-)
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 5481a6e..884ae40 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -2186,8 +2186,9 @@ int hvm_set_cr0(unsigned long value, bool_t may_defer)
* The actual write will occur in arch_monitor_write_data(), if
* permitted.
*/
- v->arch.vm_event->write_data.do_write.cr0 = 1;
- v->arch.vm_event->write_data.cr0 = value;
+ ASSERT(MWS_NOWRITE == v->arch.vm_event->write_data.status);
+ v->arch.vm_event->write_data.status = MWS_CR0;
+ v->arch.vm_event->write_data.value = value;
return X86EMUL_OKAY;
}
@@ -2291,8 +2292,9 @@ int hvm_set_cr3(unsigned long value, bool_t may_defer)
* The actual write will occur in arch_monitor_write_data(), if
* permitted.
*/
- v->arch.vm_event->write_data.do_write.cr3 = 1;
- v->arch.vm_event->write_data.cr3 = value;
+ ASSERT(MWS_NOWRITE == v->arch.vm_event->write_data.status);
+ v->arch.vm_event->write_data.status = MWS_CR3;
+ v->arch.vm_event->write_data.value = value;
return X86EMUL_OKAY;
}
@@ -2374,8 +2376,9 @@ int hvm_set_cr4(unsigned long value, bool_t may_defer)
* The actual write will occur in arch_monitor_write_data(), if
* permitted.
*/
- v->arch.vm_event->write_data.do_write.cr4 = 1;
- v->arch.vm_event->write_data.cr4 = value;
+ ASSERT(MWS_NOWRITE == v->arch.vm_event->write_data.status);
+ v->arch.vm_event->write_data.status = MWS_CR4;
+ v->arch.vm_event->write_data.value = value;
return X86EMUL_OKAY;
}
@@ -3756,7 +3759,8 @@ int hvm_msr_write_intercept(unsigned int msr, uint64_t
msr_content,
* The actual write will occur in arch_monitor_write_data(), if
* permitted.
*/
- v->arch.vm_event->write_data.do_write.msr = 1;
+ ASSERT(MWS_NOWRITE == v->arch.vm_event->write_data.status);
+ v->arch.vm_event->write_data.status = MWS_MSR;
v->arch.vm_event->write_data.msr = msr;
v->arch.vm_event->write_data.value = msr_content;
diff --git a/xen/arch/x86/monitor.c b/xen/arch/x86/monitor.c
index 90e4856..5c8d4da 100644
--- a/xen/arch/x86/monitor.c
+++ b/xen/arch/x86/monitor.c
@@ -53,29 +53,28 @@ void arch_monitor_write_data(struct vcpu *v)
w = &v->arch.vm_event->write_data;
- if ( w->do_write.msr )
- {
- hvm_msr_write_intercept(w->msr, w->value, 0);
- w->do_write.msr = 0;
- }
-
- if ( w->do_write.cr0 )
- {
- hvm_set_cr0(w->cr0, 0);
- w->do_write.cr0 = 0;
- }
+ if ( likely(MWS_NOWRITE == w->status) )
+ return;
- if ( w->do_write.cr4 )
+ switch ( w->status )
{
- hvm_set_cr4(w->cr4, 0);
- w->do_write.cr4 = 0;
+ case MWS_MSR:
+ hvm_msr_write_intercept(w->msr, w->value, 0);
+ break;
+ case MWS_CR0:
+ hvm_set_cr0(w->value, 0);
+ break;
+ case MWS_CR3:
+ hvm_set_cr3(w->value, 0);
+ break;
+ case MWS_CR4:
+ hvm_set_cr4(w->value, 0);
+ break;
+ default:
+ break;
}
- if ( w->do_write.cr3 )
- {
- hvm_set_cr3(w->cr3, 0);
- w->do_write.cr3 = 0;
- }
+ w->status = MWS_NOWRITE;
}
static unsigned long *monitor_bitmap_for_msr(const struct domain *d, u32 *msr)
diff --git a/xen/arch/x86/vm_event.c b/xen/arch/x86/vm_event.c
index 80f84d6..825da48 100644
--- a/xen/arch/x86/vm_event.c
+++ b/xen/arch/x86/vm_event.c
@@ -73,34 +73,13 @@ void vm_event_register_write_resume(struct vcpu *v,
vm_event_response_t *rsp)
{
if ( rsp->flags & VM_EVENT_FLAG_DENY )
{
- struct monitor_write_data *w = &v->arch.vm_event->write_data;
-
- ASSERT(w);
+ ASSERT(v->arch.vm_event);
/* deny flag requires the vCPU to be paused */
if ( !atomic_read(&v->vm_event_pause_count) )
return;
- switch ( rsp->reason )
- {
- case VM_EVENT_REASON_MOV_TO_MSR:
- w->do_write.msr = 0;
- break;
- case VM_EVENT_REASON_WRITE_CTRLREG:
- switch ( rsp->u.write_ctrlreg.index )
- {
- case VM_EVENT_X86_CR0:
- w->do_write.cr0 = 0;
- break;
- case VM_EVENT_X86_CR3:
- w->do_write.cr3 = 0;
- break;
- case VM_EVENT_X86_CR4:
- w->do_write.cr4 = 0;
- break;
- }
- break;
- }
+ v->arch.vm_event->write_data.status = MWS_NOWRITE;
}
}
diff --git a/xen/include/asm-x86/domain.h b/xen/include/asm-x86/domain.h
index 7c27f9e..a22ee6b 100644
--- a/xen/include/asm-x86/domain.h
+++ b/xen/include/asm-x86/domain.h
@@ -259,19 +259,19 @@ struct pv_domain
struct cpuidmasks *cpuidmasks;
};
-struct monitor_write_data {
- struct {
- unsigned int msr : 1;
- unsigned int cr0 : 1;
- unsigned int cr3 : 1;
- unsigned int cr4 : 1;
- } do_write;
+enum monitor_write_status
+{
+ MWS_NOWRITE = 0,
+ MWS_MSR,
+ MWS_CR0,
+ MWS_CR3,
+ MWS_CR4,
+};
+struct monitor_write_data {
+ enum monitor_write_status status;
uint32_t msr;
uint64_t value;
- uint64_t cr0;
- uint64_t cr3;
- uint64_t cr4;
};
struct arch_domain
--
2.5.0
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