@@ -2029,6 +2029,8 @@ int xc_monitor_debug_exceptions(xc_interface *xch, domid_t domain_id,
int xc_monitor_cpuid(xc_interface *xch, domid_t domain_id, bool enable);
int xc_monitor_privileged_call(xc_interface *xch, domid_t domain_id,
bool enable);
+int xc_monitor_emul_unhandleable(xc_interface *xch, domid_t domain_id,
+ bool enable);
/**
* This function enables / disables emulation for each REP for a
* REP-compatible instruction.
@@ -216,6 +216,20 @@ int xc_monitor_privileged_call(xc_interface *xch, domid_t domain_id,
return do_domctl(xch, &domctl);
}
+int xc_monitor_emul_unhandleable(xc_interface *xch, domid_t domain_id,
+ bool enable)
+{
+ DECLARE_DOMCTL;
+
+ domctl.cmd = XEN_DOMCTL_monitor_op;
+ domctl.domain = domain_id;
+ domctl.u.monitor_op.op = enable ? XEN_DOMCTL_MONITOR_OP_ENABLE
+ : XEN_DOMCTL_MONITOR_OP_DISABLE;
+ domctl.u.monitor_op.event = XEN_DOMCTL_MONITOR_EVENT_EMUL_UNHANDLEABLE;
+
+ return do_domctl(xch, &domctl);
+}
+
/*
* Local variables:
* mode: C
@@ -14,12 +14,14 @@
#include <xen/sched.h>
#include <xen/paging.h>
#include <xen/trace.h>
+#include <xen/vm_event.h>
#include <asm/event.h>
#include <asm/i387.h>
#include <asm/xstate.h>
#include <asm/hvm/emulate.h>
#include <asm/hvm/hvm.h>
#include <asm/hvm/ioreq.h>
+#include <asm/hvm/monitor.h>
#include <asm/hvm/trace.h>
#include <asm/hvm/support.h>
#include <asm/hvm/svm/svm.h>
@@ -2104,7 +2106,10 @@ void hvm_emulate_one_vm_event(enum emul_kind kind, unsigned int trapnr,
return;
case X86EMUL_UNHANDLEABLE:
hvm_dump_emulation_state(XENLOG_G_DEBUG, "Mem event", &ctx);
- hvm_inject_hw_exception(trapnr, errcode);
+ if ( hvm_monitor_emul_unhandleable() )
+ return;
+ else
+ hvm_inject_hw_exception(trapnr, errcode);
break;
case X86EMUL_EXCEPTION:
hvm_inject_event(&ctx.ctxt.event);
@@ -57,6 +57,23 @@ bool_t hvm_monitor_cr(unsigned int index, unsigned long value, unsigned long old
return 0;
}
+bool hvm_monitor_emul_unhandleable(void)
+{
+ struct vcpu *curr = current;
+
+ /*
+ * Send a vm_event to the monitor to signal that the current
+ * instruction couldn't be emulated.
+ */
+ vm_event_request_t req = {
+ .reason = VM_EVENT_REASON_EMUL_UNHANDLEABLE,
+ .vcpu_id = curr->vcpu_id,
+ };
+
+ return curr->domain->arch.monitor.emul_unhandleable_enabled &&
+ monitor_traps(curr, true, &req) == 1;
+}
+
void hvm_monitor_msr(unsigned int msr, uint64_t value)
{
struct vcpu *curr = current;
@@ -283,6 +283,18 @@ int arch_monitor_domctl_event(struct domain *d,
break;
}
+ case XEN_DOMCTL_MONITOR_EVENT_EMUL_UNHANDLEABLE:
+ {
+ bool old_status = ad->monitor.emul_unhandleable_enabled;
+ if ( unlikely(old_status == requested_status) )
+ return -EEXIST;
+
+ domain_pause(d);
+ ad->monitor.emul_unhandleable_enabled = requested_status;
+ domain_unpause(d);
+ break;
+ }
+
default:
/*
* Should not be reached unless arch_monitor_get_capabilities() is
@@ -405,6 +405,7 @@ struct arch_domain
unsigned int debug_exception_sync : 1;
unsigned int cpuid_enabled : 1;
unsigned int descriptor_access_enabled : 1;
+ unsigned int emul_unhandleable_enabled : 1;
struct monitor_msr_bitmap *msr_bitmap;
uint64_t write_ctrlreg_mask[4];
} monitor;
@@ -47,6 +47,7 @@ int hvm_monitor_cpuid(unsigned long insn_length, unsigned int leaf,
unsigned int subleaf);
void hvm_monitor_interrupt(unsigned int vector, unsigned int type,
unsigned int err, uint64_t cr2);
+bool hvm_monitor_emul_unhandleable(void);
#endif /* __ASM_X86_HVM_MONITOR_H__ */
@@ -77,7 +77,8 @@ static inline uint32_t arch_monitor_get_capabilities(struct domain *d)
(1U << XEN_DOMCTL_MONITOR_EVENT_GUEST_REQUEST) |
(1U << XEN_DOMCTL_MONITOR_EVENT_DEBUG_EXCEPTION) |
(1U << XEN_DOMCTL_MONITOR_EVENT_CPUID) |
- (1U << XEN_DOMCTL_MONITOR_EVENT_INTERRUPT);
+ (1U << XEN_DOMCTL_MONITOR_EVENT_INTERRUPT) |
+ (1U << XEN_DOMCTL_MONITOR_EVENT_EMUL_UNHANDLEABLE);
/* Since we know this is on VMX, we can just call the hvm func */
if ( hvm_is_singlestep_supported() )
@@ -1083,6 +1083,7 @@ DEFINE_XEN_GUEST_HANDLE(xen_domctl_psr_cmt_op_t);
#define XEN_DOMCTL_MONITOR_EVENT_PRIVILEGED_CALL 7
#define XEN_DOMCTL_MONITOR_EVENT_INTERRUPT 8
#define XEN_DOMCTL_MONITOR_EVENT_DESC_ACCESS 9
+#define XEN_DOMCTL_MONITOR_EVENT_EMUL_UNHANDLEABLE 10
struct xen_domctl_monitor_op {
uint32_t op; /* XEN_DOMCTL_MONITOR_OP_* */
@@ -148,6 +148,8 @@
#define VM_EVENT_REASON_INTERRUPT 12
/* A descriptor table register was accessed. */
#define VM_EVENT_REASON_DESCRIPTOR_ACCESS 13
+/* Current instruction couldn't be emulated */
+#define VM_EVENT_REASON_EMUL_UNHANDLEABLE 14
/* Supported values for the vm_event_write_ctrlreg index. */
#define VM_EVENT_X86_CR0 0
If case of a vm_event with the emulate_flags set, if the instruction cannot be emulated, the monitor should be notified instead of directly injecting a hw exception. This behavior can be used to re-execute an instruction not supported by the emulator using the real processor (e.g. altp2m) instead of just crashing. Signed-off-by: Petre Pircalabu <ppircalabu@bitdefender.com> --- Changed since v1: * Removed the emulation kind check when calling hvm_inject_hw_exception Changed since v2: * Removed a file added by mistake Changed since v3: * Removed extra stray line * Added the _enabled suffix to the emul_unhandleable monitor option Changed since v4 * Fixed return expression of hvm_monitor_emul_unhandleable handle monitor_traps failures. * Removed stray parantheses. --- tools/libxc/include/xenctrl.h | 2 ++ tools/libxc/xc_monitor.c | 14 ++++++++++++++ xen/arch/x86/hvm/emulate.c | 7 ++++++- xen/arch/x86/hvm/monitor.c | 17 +++++++++++++++++ xen/arch/x86/monitor.c | 12 ++++++++++++ xen/include/asm-x86/domain.h | 1 + xen/include/asm-x86/hvm/monitor.h | 1 + xen/include/asm-x86/monitor.h | 3 ++- xen/include/public/domctl.h | 1 + xen/include/public/vm_event.h | 2 ++ 10 files changed, 58 insertions(+), 2 deletions(-)