fw/msr_feature_control: add support to set MSR_IA32_FEATURE_CONTROL

OS usually expects BIOS to set certain bits in MSR_IA32_FEATURE_CONTROL
for some features (e.g. VMX and LMCE). QEMU provides a fw_cfg file
"etc/msr_feature_control" to advise bits that should be set in
MSR_IA32_FEATURE_CONTROL. If this file exists, SeaBIOS will set the
advised bits in that MSR.

Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20160622065324.23812-1-haozhong.zhang@intel.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
(cherry picked from commit 20f83d5c7c0f9ae5f775b6701c205349abe003fb)

diff --git a/src/fw/paravirt.c b/src/fw/paravirt.c
index 3fae13a8312fa6677db98fedf49566aa75cac6f0..e8e419ea8235cde1ed899269f201f50532c3b336 100644 (file)
--- a/src/fw/paravirt.c
+++ b/src/fw/paravirt.c
@@ -130,6 +130,15 @@ qemu_preinit(void)
     dprintf(1, "RamSize: 0x%08x [cmos]\n", RamSize);
 }
 
+#define MSR_IA32_FEATURE_CONTROL 0x0000003a
+
+static void msr_feature_control_setup(void)
+{
+    u64 feature_control_bits = romfile_loadint("etc/msr_feature_control", 0);
+    if (feature_control_bits)
+        wrmsr_smp(MSR_IA32_FEATURE_CONTROL, feature_control_bits);
+}
+
 void
 qemu_platform_setup(void)
 {
@@ -148,8 +157,9 @@ qemu_platform_setup(void)
     smm_device_setup();
     smm_setup();
 
-    // Initialize mtrr and smp
+    // Initialize mtrr, msr_feature_control and smp
     mtrr_setup();
+    msr_feature_control_setup();
     smp_setup();
 
     // Create bios tables

diff --git a/src/fw/smp.c b/src/fw/smp.c
index 579acdbd0145e50edaa8c84d7c9c117390dfde2b..6e706e42a4e74f6a01c47538d606b8acd829dc28 100644 (file)
--- a/src/fw/smp.c
+++ b/src/fw/smp.c
@@ -10,7 +10,7 @@
 #include "output.h" // dprintf
 #include "romfile.h" // romfile_loadint
 #include "stacks.h" // yield
-#include "util.h" // smp_setup
+#include "util.h" // smp_setup, msr_feature_control_setup
 #include "x86.h" // wrmsr
 
 #define APIC_ICR_LOW ((u8*)BUILD_APIC_ADDR + 0x300)
@@ -20,20 +20,20 @@
 
 #define APIC_ENABLED 0x0100
 
-static struct { u32 index; u64 val; } smp_mtrr[32];
-static u32 smp_mtrr_count;
+static struct { u32 index; u64 val; } smp_msr[32];
+static u32 smp_msr_count;
 
 void
 wrmsr_smp(u32 index, u64 val)
 {
     wrmsr(index, val);
-    if (smp_mtrr_count >= ARRAY_SIZE(smp_mtrr)) {
+    if (smp_msr_count >= ARRAY_SIZE(smp_msr)) {
         warn_noalloc();
         return;
     }
-    smp_mtrr[smp_mtrr_count].index = index;
-    smp_mtrr[smp_mtrr_count].val = val;
-    smp_mtrr_count++;
+    smp_msr[smp_msr_count].index = index;
+    smp_msr[smp_msr_count].val = val;
+    smp_msr_count++;
 }
 
 u32 MaxCountCPUs;
@@ -58,10 +58,10 @@ handle_smp(void)
     u8 apic_id = ebx>>24;
     dprintf(DEBUG_HDL_smp, "handle_smp: apic_id=%d\n", apic_id);
 
-    // MTRR setup
+    // MTRR and MSR_IA32_FEATURE_CONTROL setup
     int i;
-    for (i=0; i<smp_mtrr_count; i++)
-        wrmsr(smp_mtrr[i].index, smp_mtrr[i].val);
+    for (i=0; i<smp_msr_count; i++)
+        wrmsr(smp_msr[i].index, smp_msr[i].val);
 
     // Set bit on FoundAPICIDs
     FoundAPICIDs[apic_id/32] |= (1 << (apic_id % 32));