From c7195afd321d43c695e2c58e967e07cec0ae0ace Mon Sep 17 00:00:00 2001 From: Eduardo Habkost Date: Mon, 26 Feb 2018 04:33:16 -0500 Subject: [PATCH] target-i386: xsave: Calculate enabled components only once Instead of checking both env->features and ena_mask at two different places in the CPUID code, initialize ena_mask based on the features that are enabled for the CPU, and then clear unsupported bits based on kvm_arch_get_supported_cpuid(). The results should be exactly the same, but it will make it easier to move the mask calculation elsewhare, and reuse x86_cpu_filter_features() for the kvm_arch_get_supported_cpuid() check. Backports commit 4928cd6de6b4211a79f98c8dc39115be1e815c2b from qemu --- qemu/target-i386/cpu.c | 30 ++++++++++++++++++------------ 1 file changed, 18 insertions(+), 12 deletions(-) diff --git a/qemu/target-i386/cpu.c b/qemu/target-i386/cpu.c index e1b9c4ad..19d95b09 100644 --- a/qemu/target-i386/cpu.c +++ b/qemu/target-i386/cpu.c @@ -2528,21 +2528,28 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count, break; } - //if (kvm_enabled()) { - // Unicorn: commented out - //ena_mask = kvm_arch_get_supported_cpuid(s, 0xd, 0, R_EDX); - //ena_mask <<= 32; - //ena_mask |= kvm_arch_get_supported_cpuid(s, 0xd, 0, R_EAX); - //} else { - ena_mask = -1; - //} + ena_mask = (XSTATE_FP_MASK | XSTATE_SSE_MASK); + for (i = 2; i < ARRAY_SIZE(x86_ext_save_areas); i++) { + const ExtSaveArea *esa = &x86_ext_save_areas[i]; + if (env->features[esa->feature] & esa->bits) { + ena_mask |= (1ULL << i); + } + } + + /* Unicorn: commented out + if (kvm_enabled()) { + KVMState *s = cs->kvm_state; + uint64_t kvm_mask = kvm_arch_get_supported_cpuid(s, 0xd, 0, R_EDX); + kvm_mask <<= 32; + kvm_mask |= kvm_arch_get_supported_cpuid(s, 0xd, 0, R_EAX); + ena_mask &= kvm_mask; + } */ if (count == 0) { *ecx = 0x240; for (i = 2; i < ARRAY_SIZE(x86_ext_save_areas); i++) { const ExtSaveArea *esa = &x86_ext_save_areas[i]; - if ((env->features[esa->feature] & esa->bits) - && ((ena_mask >> i) & 1) != 0) { + if ((ena_mask >> i) & 1) { if (i < 32) { *eax |= 1u << i; } else { @@ -2557,8 +2564,7 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count, *eax = env->features[FEAT_XSAVE]; } else if (count < ARRAY_SIZE(x86_ext_save_areas)) { const ExtSaveArea *esa = &x86_ext_save_areas[count]; - if ((env->features[esa->feature] & esa->bits) - && ((ena_mask >> count) & 1) != 0) { + if ((ena_mask >> count) & 1) { *eax = esa->size; *ebx = esa->offset; }