Changeset 93830 in vbox

Timestamp:

Feb 17, 2022 4:56:18 PM (3 years ago)

Author:

vboxsync

Message:

VMM/CPUM: Add some helpers for NEM to activate the hyper or guest debug state respectively without loading the host's DRx registers which doesn't work from ring-3 anyway, bugref:9044

Location:

trunk

Files:

• include/VBox/vmm/cpum.h (modified) (1 diff)
• src/VBox/VMM/VMMR3/CPUM.cpp (modified) (1 diff)

trunk/include/VBox/vmm/cpum.h

@@ -2726 +2726 @@
 /** Pointer to CPUMR3DbGetEntryByName. */
 typedef DECLCALLBACKPTR(PCCPUMDBENTRY, PFNCPUMDBGETENTRYBYNAME, (const char *pszName));
+
+VMMR3_INT_DECL(void)    CPUMR3NemActivateGuestDebugState(PVMCPUCC pVCpu);
+VMMR3_INT_DECL(void)    CPUMR3NemActivateHyperDebugState(PVMCPUCC pVCpu);
 /** @} */
 #endif /* IN_RING3 */

trunk/src/VBox/VMM/VMMR3/CPUM.cpp

@@ -4448 +4448 @@
 }
 
+
+/**
+ * Marks the guest debug state as active.
+ *
+ * @returns nothing.
+ * @param   pVCpu       The cross context virtual CPU structure.
+ *
+ * @note This is used solely by NEM (hence the name) to set the correct flags here
+ *       without loading the host's DRx registers, which is not possible from ring-3 anyway.
+ *       The specific NEM backends have to make sure to load the correct values.
+ */
+VMMR3_INT_DECL(void) CPUMR3NemActivateGuestDebugState(PVMCPUCC pVCpu)
+{
+    ASMAtomicAndU32(&pVCpu->cpum.s.fUseFlags, ~CPUM_USED_DEBUG_REGS_HYPER);
+    ASMAtomicOrU32(&pVCpu->cpum.s.fUseFlags, CPUM_USED_DEBUG_REGS_GUEST);
+}
+
+
+/**
+ * Marks the hyper debug state as active.
+ *
+ * @returns nothing.
+ * @param   pVCpu       The cross context virtual CPU structure.
+ *
+ * @note This is used solely by NEM (hence the name) to set the correct flags here
+ *       without loading the host's DRx registers, which is not possible from ring-3 anyway.
+ *       The specific NEM backends have to make sure to load the correct values.
+ */
+VMMR3_INT_DECL(void) CPUMR3NemActivateHyperDebugState(PVMCPUCC pVCpu)
+{
+    /*
+     * Make sure the hypervisor values are up to date.
+     */
+    CPUMRecalcHyperDRx(pVCpu, UINT8_MAX /* no loading, please */);
+
+    ASMAtomicAndU32(&pVCpu->cpum.s.fUseFlags, ~CPUM_USED_DEBUG_REGS_GUEST);
+    ASMAtomicOrU32(&pVCpu->cpum.s.fUseFlags, CPUM_USED_DEBUG_REGS_HYPER);
+}