[PATCH v3 2/6] target/i386: mark CR4.FRED not reserved

Xin Li
2023-11-09T07:50:23Z

The CR4.FRED bit, i.e., CR4[32], is no longer a reserved bit when FRED
is exposed to guests, otherwise it is still a reserved bit.

Tested-by: Shan Kang <shan.kang@intel.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
---
target/i386/cpu.h | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index 5faf00551d..e210957cba 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -262,6 +262,12 @@ typedef enum X86Seg {
#define CR4_PKE_MASK (1U << 22)
#define CR4_PKS_MASK (1U << 24)

+#ifdef TARGET_X86_64
+#define CR4_FRED_MASK (1ULL << 32)
+#else
+#define CR4_FRED_MASK 0
+#endif
+
#define CR4_RESERVED_MASK \
(~(target_ulong)(CR4_VME_MASK | CR4_PVI_MASK | CR4_TSD_MASK \
| CR4_DE_MASK | CR4_PSE_MASK | CR4_PAE_MASK \
@@ -269,7 +275,8 @@ typedef enum X86Seg {
| CR4_OSFXSR_MASK | CR4_OSXMMEXCPT_MASK | CR4_UMIP_MASK \
| CR4_LA57_MASK \
| CR4_FSGSBASE_MASK | CR4_PCIDE_MASK | CR4_OSXSAVE_MASK \
- | CR4_SMEP_MASK | CR4_SMAP_MASK | CR4_PKE_MASK | CR4_PKS_MASK))
+ | CR4_SMEP_MASK | CR4_SMAP_MASK | CR4_PKE_MASK | CR4_PKS_MASK \
+ | CR4_FRED_MASK))

#define DR6_BD (1 << 13)
#define DR6_BS (1 << 14)
@@ -2520,6 +2527,9 @@ static inline uint64_t cr4_reserved_bits(CPUX86State *env)
if (!(env->features[FEAT_7_0_ECX] & CPUID_7_0_ECX_PKS)) {
reserved_bits |= CR4_PKS_MASK;
}
+ if (!(env->features[FEAT_7_1_EAX] & CPUID_7_1_EAX_FRED)) {
+ reserved_bits |= CR4_FRED_MASK;
+ }
return reserved_bits;
}

--
2.42.0