@@ -57,6 +57,13 @@
#define X86_TRAP_DEBUG 1
#define X86_TRAP_INT3 3
+/* From xen/include/asm-x86/x86-defns.h */
+#define X86_CR4_PGE 0x00000080 /* enable global pages */
+
+#ifndef ARRAY_SIZE
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+#endif
+
typedef struct vm_event {
domid_t domain_id;
xenevtchn_handle *xce_handle;
@@ -314,6 +321,24 @@ static void get_request(vm_event_t *vm_event, vm_event_request_t *req)
}
/*
+ * X86 control register names
+ */
+static const char* get_x86_ctrl_reg_name(uint32_t index)
+{
+ static const char* names[] = {
+ [VM_EVENT_X86_CR0] = "CR0",
+ [VM_EVENT_X86_CR3] = "CR3",
+ [VM_EVENT_X86_CR4] = "CR4",
+ [VM_EVENT_X86_XCR0] = "XCR0",
+ };
+
+ if ( index > ARRAY_SIZE(names) || names[index] == NULL )
+ return "";
+
+ return names[index];
+}
+
+/*
* Note that this function is not thread safe.
*/
static void put_response(vm_event_t *vm_event, vm_event_response_t *rsp)
@@ -337,7 +362,7 @@ void usage(char* progname)
{
fprintf(stderr, "Usage: %s [-m] <domain_id> write|exec", progname);
#if defined(__i386__) || defined(__x86_64__)
- fprintf(stderr, "|breakpoint|altp2m_write|altp2m_exec|debug|cpuid|desc_access");
+ fprintf(stderr, "|breakpoint|altp2m_write|altp2m_exec|debug|cpuid|desc_access|write_ctrlreg_cr4");
#elif defined(__arm__) || defined(__aarch64__)
fprintf(stderr, "|privcall");
#endif
@@ -369,6 +394,7 @@ int main(int argc, char *argv[])
int debug = 0;
int cpuid = 0;
int desc_access = 0;
+ int write_ctrlreg_cr4 = 1;
uint16_t altp2m_view_id = 0;
char* progname = argv[0];
@@ -439,6 +465,10 @@ int main(int argc, char *argv[])
{
desc_access = 1;
}
+ else if ( !strcmp(argv[0], "write_ctrlreg_cr4") )
+ {
+ write_ctrlreg_cr4 = 1;
+ }
#elif defined(__arm__) || defined(__aarch64__)
else if ( !strcmp(argv[0], "privcall") )
{
@@ -596,6 +626,18 @@ int main(int argc, char *argv[])
}
}
+ if ( write_ctrlreg_cr4 )
+ {
+ /* Mask the CR4.PGE bit so no events will be generated for global TLB flushes. */
+ rc = xc_monitor_write_ctrlreg(xch, domain_id, VM_EVENT_X86_CR4, 1, 1,
+ X86_CR4_PGE, 1);
+ if ( rc < 0 )
+ {
+ ERROR("Error %d setting write control register trapping with vm_event\n", rc);
+ goto exit;
+ }
+ }
+
/* Wait for access */
for (;;)
{
@@ -806,6 +848,15 @@ int main(int argc, char *argv[])
req.u.desc_access.is_write);
rsp.flags |= VM_EVENT_FLAG_EMULATE;
break;
+ case VM_EVENT_REASON_WRITE_CTRLREG:
+ printf("Control register written: rip=%016"PRIx64", vcpu %d: "
+ "reg=%s, old_value=%016"PRIx64", new_value=%016"PRIx64"\n",
+ req.data.regs.x86.rip,
+ req.vcpu_id,
+ get_x86_ctrl_reg_name(req.u.write_ctrlreg.index),
+ req.u.write_ctrlreg.old_value,
+ req.u.write_ctrlreg.new_value);
+ break;
default:
fprintf(stderr, "UNKNOWN REASON CODE %d\n", req.reason);
}
Add test for write_ctrlreg event handling. Signed-off-by: Petre Pircalabu <ppircalabu@bitdefender.com> --- tools/tests/xen-access/xen-access.c | 53 ++++++++++++++++++++++++++++++++++++- 1 file changed, 52 insertions(+), 1 deletion(-)