CR4.CET bit (bit 23) is as master enable for CET. Check and adjust CR4.CET bit based on CET CPUIDs.
Tested-by: Farrah Chen <[email protected]> Signed-off-by: Zhao Liu <[email protected]> --- Changes Since v3: - Reorder CR4_RESERVED_MASK. --- target/i386/cpu.h | 9 +++++++-- target/i386/helper.c | 12 ++++++++++++ 2 files changed, 19 insertions(+), 2 deletions(-) diff --git a/target/i386/cpu.h b/target/i386/cpu.h index bfc38830e29e..f4cb1dc49b71 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -257,6 +257,7 @@ typedef enum X86Seg { #define CR4_SMEP_MASK (1U << 20) #define CR4_SMAP_MASK (1U << 21) #define CR4_PKE_MASK (1U << 22) +#define CR4_CET_MASK (1U << 23) #define CR4_PKS_MASK (1U << 24) #define CR4_LAM_SUP_MASK (1U << 28) @@ -273,8 +274,8 @@ 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_LAM_SUP_MASK | CR4_FRED_MASK)) + | CR4_SMEP_MASK | CR4_SMAP_MASK | CR4_PKE_MASK | CR4_CET_MASK \ + | CR4_PKS_MASK | CR4_LAM_SUP_MASK | CR4_FRED_MASK)) #define DR6_BD (1 << 13) #define DR6_BS (1 << 14) @@ -2951,6 +2952,10 @@ static inline uint64_t cr4_reserved_bits(CPUX86State *env) if (!(env->features[FEAT_7_1_EAX] & CPUID_7_1_EAX_FRED)) { reserved_bits |= CR4_FRED_MASK; } + if (!(env->features[FEAT_7_0_ECX] & CPUID_7_0_ECX_CET_SHSTK) && + !(env->features[FEAT_7_0_EDX] & CPUID_7_0_EDX_CET_IBT)) { + reserved_bits |= CR4_CET_MASK; + } return reserved_bits; } diff --git a/target/i386/helper.c b/target/i386/helper.c index 72b2e195a31e..3f179c6c11f8 100644 --- a/target/i386/helper.c +++ b/target/i386/helper.c @@ -232,6 +232,18 @@ void cpu_x86_update_cr4(CPUX86State *env, uint32_t new_cr4) new_cr4 &= ~CR4_LAM_SUP_MASK; } + /* + * In fact, "CR4.CET can be set only if CR0.WP is set, and it must be + * clear before CR0.WP can be cleared". However, here we only check + * CR4.CET based on the supported CPUID CET bit, without checking the + * dependency on CR4.WP - the latter need to be determined by the + * underlying accelerators. + */ + if (!(env->features[FEAT_7_0_ECX] & CPUID_7_0_ECX_CET_SHSTK) && + !(env->features[FEAT_7_0_EDX] & CPUID_7_0_EDX_CET_IBT)) { + new_cr4 &= ~CR4_CET_MASK; + } + env->cr[4] = new_cr4; env->hflags = hflags; -- 2.34.1
