[Qemu-devel] [PATCH] MTRR support on x86, part 2

[Carl-Daniel Hailfinger]

Load and save MTRR state together with machine state.

Add support for the MTRRcap MSR which is used by the latest Bochs BIOS
and some operating systems.

Fix a typo in ext2_feature_name.

With this patch, MTRR emulation should be good enough to not trigger any
sanity checks in well behaved BIOS/kernel code.
Some corner cases for BIOS/firmware usage remain to be implemented, but
that can be deferred to another patch.
Also, MTRR accesses on hardware not supporting MTRRs should cause #GP.
That can be enforced by another patch as well.

Signed-off-by: Carl-Daniel Hailfinger <address@hidden>

Index: target-i386/helper.c
===================================================================
--- target-i386/helper.c        (Revision 6461)
+++ target-i386/helper.c        (Arbeitskopie)
@@ -55,7 +55,7 @@
     };
     static const char *ext2_feature_name[] = {
        "fpu", "vme", "de", "pse", "tsc", "msr", "pae", "mce",
-       "cx8" /* AMD CMPXCHG8B */, "apic", NULL, "syscall", "mttr", "pge", 
"mca", "cmov",
+       "cx8" /* AMD CMPXCHG8B */, "apic", NULL, "syscall", "mtrr", "pge", 
"mca", "cmov",
        "pat", "pse36", NULL, NULL /* Linux mp */, "nx" /* Intel xd */, NULL, 
"mmxext", "mmx",
        "fxsr", "fxsr_opt" /* AMD ffxsr */, "pdpe1gb" /* AMD Page1GB */, 
"rdtscp", NULL, "lm" /* Intel 64 */, "3dnowext", "3dnow",
     };
Index: target-i386/machine.c
===================================================================
--- target-i386/machine.c       (Revision 6461)
+++ target-i386/machine.c       (Arbeitskopie)
@@ -134,6 +134,15 @@
     qemu_put_be16s(f, &env->intercept_dr_write);
     qemu_put_be32s(f, &env->intercept_exceptions);
     qemu_put_8s(f, &env->v_tpr);
+
+    /* MTRRs */
+    for(i = 0; i < 11; i++)
+        qemu_put_be64s(f, &env->mtrr_fixed[i]);
+    qemu_put_be64s(f, &env->mtrr_deftype);
+    for(i = 0; i < 8; i++) {
+        qemu_put_be64s(f, &env->mtrr_var[i].base);
+        qemu_put_be64s(f, &env->mtrr_var[i].mask);
+    }
 }
 
 #ifdef USE_X86LDOUBLE
@@ -169,7 +178,7 @@
     int32_t a20_mask;
 
     if (version_id != 3 && version_id != 4 && version_id != 5
-        && version_id != 6 && version_id != 7)
+        && version_id != 6 && version_id != 7 && version_id != 8)
         return -EINVAL;
     for(i = 0; i < CPU_NB_REGS; i++)
         qemu_get_betls(f, &env->regs[i]);
@@ -302,6 +311,18 @@
         qemu_get_be32s(f, &env->intercept_exceptions);
         qemu_get_8s(f, &env->v_tpr);
     }
+
+    if (version_id >= 8) {
+        /* MTRRs */
+        for(i = 0; i < 11; i++)
+            qemu_get_be64s(f, &env->mtrr_fixed[i]);
+        qemu_get_be64s(f, &env->mtrr_deftype);
+        for(i = 0; i < 8; i++) {
+            qemu_get_be64s(f, &env->mtrr_var[i].base);
+            qemu_get_be64s(f, &env->mtrr_var[i].mask);
+        }
+    }
+
     /* XXX: ensure compatiblity for halted bit ? */
     /* XXX: compute redundant hflags bits */
     env->hflags = hflags;
Index: target-i386/cpu.h
===================================================================
--- target-i386/cpu.h   (Revision 6461)
+++ target-i386/cpu.h   (Arbeitskopie)
@@ -251,6 +251,11 @@
 #define MSR_IA32_APICBASE_ENABLE        (1<<11)
 #define MSR_IA32_APICBASE_BASE          (0xfffff<<12)
 
+#define MSR_MTRRcap                    0xfe
+#define MSR_MTRRcap_VCNT               8
+#define MSR_MTRRcap_FIXRANGE_SUPPORT   (1 << 8)
+#define MSR_MTRRcap_WC_SUPPORTED       (1 << 10)
+
 #define MSR_IA32_SYSENTER_CS            0x174
 #define MSR_IA32_SYSENTER_ESP           0x175
 #define MSR_IA32_SYSENTER_EIP           0x176
Index: target-i386/op_helper.c
===================================================================
--- target-i386/op_helper.c     (Revision 6461)
+++ target-i386/op_helper.c     (Arbeitskopie)
@@ -3215,6 +3215,13 @@
     case MSR_MTRRdefType:
         val = env->mtrr_deftype;
         break;
+    case MSR_MTRRcap:
+        if (env->cpuid_features & CPUID_MTRR)
+            val = MSR_MTRRcap_VCNT | MSR_MTRRcap_FIXRANGE_SUPPORT | 
MSR_MTRRcap_WC_SUPPORTED;
+        else
+            /* XXX: exception ? */
+            val = 0;
+        break;
     default:
         /* XXX: exception ? */
         val = 0;


-- 
http://www.hailfinger.org/