stos/amd64: cpu: Save KPCR in IA32_GS_BASE

Signed-off-by: Chloe M. <chloe@mensia.org>
2026-06-24 05:49:59 +00:00
parent 5beb6f1d62
commit 9b1f4dde43
2 changed files with 26 additions and 0 deletions
@@ -13,6 +13,7 @@
 #include <ke/knot.h>
 #include <machine/cpuid.h>
 #include <machine/idt.h>
+#include <machine/msr.h>
 #include <stdef.h>

 #define DTRACE(Fmt, ...) \
@@ -132,6 +133,9 @@ HalKpcrP1Init(KPCR *Kpcr)
        : "r" ((UQUAD)IRQL_PASSIVE)
        : "memory"
    );
+
+    /* Save the current KPCR */
+    MdWrmsr(IA32_GS_BASE, (UPTR)Kpcr);
 }

 VOID
@@ -152,3 +156,19 @@ HalKpcrP2Init(KPCR *Kpcr)
        );
    }
 }
+
+KPCR *
+HalKpcrCurrent(VOID)
+{
+    KPCR *Kpcr;
+
+    Kpcr = (KPCR *)MdRdmsr(IA32_GS_BASE);
+    if (Kpcr == NULL) {
+        KeKnot(
+            KNOT_UNBOUND_RSRC,
+            "current kpcr is NULL\n"
+        );
+    }
+
+    return Kpcr;
+}