The MSR (33H) controls support for #AC exception for split locked accesses. When bit 29 of the MSR (33H) is set, the processor causes an #AC exception to be issued instead of suppressing LOCK on bus (during split lock access).
Signed-off-by: Jingqi Liu <jingqi....@intel.com> --- target/i386/cpu.h | 2 ++ target/i386/kvm.c | 13 +++++++++++++ target/i386/machine.c | 20 ++++++++++++++++++++ 3 files changed, 35 insertions(+) diff --git a/target/i386/cpu.h b/target/i386/cpu.h index 8eaefee..9728552 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -348,6 +348,7 @@ typedef enum X86Seg { #define MSR_IA32_APICBASE_ENABLE (1<<11) #define MSR_IA32_APICBASE_EXTD (1 << 10) #define MSR_IA32_APICBASE_BASE (0xfffffU<<12) +#define MSR_SPLIT_LOCK_CTRL 0x00000033 #define MSR_IA32_FEATURE_CONTROL 0x0000003a #define MSR_TSC_ADJUST 0x0000003b #define MSR_IA32_SPEC_CTRL 0x48 @@ -1209,6 +1210,7 @@ typedef struct CPUX86State { uint32_t pkru; uint64_t spec_ctrl; + uint64_t split_lock_ctrl; uint64_t virt_ssbd; /* End of state preserved by INIT (dummy marker). */ diff --git a/target/i386/kvm.c b/target/i386/kvm.c index 032f0ad..043ca9b 100644 --- a/target/i386/kvm.c +++ b/target/i386/kvm.c @@ -92,6 +92,7 @@ static bool has_msr_hv_frequencies; static bool has_msr_hv_reenlightenment; static bool has_msr_xss; static bool has_msr_spec_ctrl; +static bool has_msr_split_lock_ctrl; static bool has_msr_virt_ssbd; static bool has_msr_smi_count; @@ -1272,6 +1273,9 @@ static int kvm_get_supported_msrs(KVMState *s) case MSR_IA32_SPEC_CTRL: has_msr_spec_ctrl = true; break; + case MSR_SPLIT_LOCK_CTRL: + has_msr_split_lock_ctrl = true; + break; case MSR_VIRT_SSBD: has_msr_virt_ssbd = true; break; @@ -1786,6 +1790,9 @@ static int kvm_put_msrs(X86CPU *cpu, int level) if (has_msr_spec_ctrl) { kvm_msr_entry_add(cpu, MSR_IA32_SPEC_CTRL, env->spec_ctrl); } + if (has_msr_split_lock_ctrl) { + kvm_msr_entry_add(cpu, MSR_SPLIT_LOCK_CTRL, env->split_lock_ctrl); + } if (has_msr_virt_ssbd) { kvm_msr_entry_add(cpu, MSR_VIRT_SSBD, env->virt_ssbd); } @@ -2169,6 +2176,9 @@ static int kvm_get_msrs(X86CPU *cpu) if (has_msr_spec_ctrl) { kvm_msr_entry_add(cpu, MSR_IA32_SPEC_CTRL, 0); } + if (has_msr_split_lock_ctrl) { + kvm_msr_entry_add(cpu, MSR_SPLIT_LOCK_CTRL, 0); + } if (has_msr_virt_ssbd) { kvm_msr_entry_add(cpu, MSR_VIRT_SSBD, 0); } @@ -2551,6 +2561,9 @@ static int kvm_get_msrs(X86CPU *cpu) case MSR_IA32_SPEC_CTRL: env->spec_ctrl = msrs[i].data; break; + case MSR_SPLIT_LOCK_CTRL: + env->split_lock_ctrl = msrs[i].data; + break; case MSR_VIRT_SSBD: env->virt_ssbd = msrs[i].data; break; diff --git a/target/i386/machine.c b/target/i386/machine.c index 4d98d36..c82dc0d 100644 --- a/target/i386/machine.c +++ b/target/i386/machine.c @@ -935,6 +935,25 @@ static const VMStateDescription vmstate_msr_virt_ssbd = { } }; +static bool split_lock_ctrl_needed(void *opaque) +{ + X86CPU *cpu = opaque; + CPUX86State *env = &cpu->env; + + return env->split_lock_ctrl != 0; +} + +static const VMStateDescription vmstate_split_lock_ctrl = { + .name = "cpu/split_lock_ctrl", + .version_id = 1, + .minimum_version_id = 1, + .needed = split_lock_ctrl_needed, + .fields = (VMStateField[]){ + VMSTATE_UINT64(env.split_lock_ctrl, X86CPU), + VMSTATE_END_OF_LIST() + } +}; + VMStateDescription vmstate_x86_cpu = { .name = "cpu", .version_id = 12, @@ -1059,6 +1078,7 @@ VMStateDescription vmstate_x86_cpu = { &vmstate_mcg_ext_ctl, &vmstate_msr_intel_pt, &vmstate_msr_virt_ssbd, + &vmstate_split_lock_ctrl, NULL } }; -- 1.8.3.1