hvm/svm: implement CPUID events

At this moment the CPUID events for the AMD architecture are not
forwarded to the monitor layer.

This patch adds the CPUID event to the common capabilities and then
forwards the event to the monitor layer.

Signed-off-by: Alexandru Isaila <aisaila@bitdefender.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: Tamas K Lengyel <tamas@tklengyel.com>

xen/arch/x86/hvm/svm/svm.c

@@ -1806,19 +1806,15 @@ static void svm_fpu_dirty_intercept(void)
         vmcb_set_cr0(vmcb, vmcb_get_cr0(vmcb) & ~X86_CR0_TS);
 }
 
-static void svm_vmexit_do_cpuid(struct cpu_user_regs *regs)
+static int svm_vmexit_do_cpuid(struct cpu_user_regs *regs, unsigned int inst_len)
 {
     struct vcpu *curr = current;
-    unsigned int inst_len;
     struct cpuid_leaf res;
 
-    if ( (inst_len = __get_instruction_length(curr, INSTR_CPUID)) == 0 )
-        return;
-
     if ( hvm_check_cpuid_faulting(curr) )
     {
         hvm_inject_hw_exception(TRAP_gp_fault, 0);
-        return;
+        return 1; /* Don't advance the guest IP! */
     }
 
     guest_cpuid(curr, regs->eax, regs->ecx, &res);
@@ -1829,7 +1825,7 @@ static void svm_vmexit_do_cpuid(struct cpu_user_regs *regs)
     regs->rcx = res.c;
     regs->rdx = res.d;
 
-    __update_guest_eip(regs, inst_len);
+    return hvm_monitor_cpuid(inst_len, regs->eax, regs->ecx);
 }
 
 static void svm_vmexit_do_cr_access(
@@ -2775,9 +2771,22 @@ void svm_vmexit_handler(struct cpu_user_regs *regs)
     }
 
     case VMEXIT_CPUID:
-        svm_vmexit_do_cpuid(regs);
-        break;
+    {
+        unsigned int inst_len = __get_instruction_length(v, INSTR_CPUID);
+        int rc = 0;
 
+        if ( inst_len == 0 )
+            break;
+
+        rc = svm_vmexit_do_cpuid(regs, inst_len);
+
+        if ( rc < 0 )
+            goto unexpected_exit_type;
+        if ( !rc )
+            __update_guest_eip(regs, inst_len); /* Safe: CPUID */
+
+        break;
+    }
     case VMEXIT_HLT:
         svm_vmexit_do_hlt(vmcb, regs);
         break;

xen/include/asm-x86/monitor.h

@@ -81,12 +81,12 @@ static inline uint32_t arch_monitor_get_capabilities(struct domain *d)
                     (1U << XEN_DOMCTL_MONITOR_EVENT_SOFTWARE_BREAKPOINT) |
                     (1U << XEN_DOMCTL_MONITOR_EVENT_MOV_TO_MSR) |
                     (1U << XEN_DOMCTL_MONITOR_EVENT_INTERRUPT) |
+                    (1U << XEN_DOMCTL_MONITOR_EVENT_CPUID) |
                     (1U << XEN_DOMCTL_MONITOR_EVENT_WRITE_CTRLREG));
 
     if ( cpu_has_vmx )
     {
         capabilities |= ((1U << XEN_DOMCTL_MONITOR_EVENT_DEBUG_EXCEPTION) |
-                         (1U << XEN_DOMCTL_MONITOR_EVENT_CPUID) |
                          (1U << XEN_DOMCTL_MONITOR_EVENT_EMUL_UNIMPLEMENTED));
 
         /* Since we know this is on VMX, we can just call the hvm func */